diff --git a/racket/src/configure b/racket/src/configure
index fe2c906383..164fe5ca1c 100755
--- a/racket/src/configure
+++ b/racket/src/configure
@@ -838,7 +838,8 @@ LDFLAGS
 LIBS
 CPPFLAGS
 CPP'
-ac_subdirs_all='foreign/libffi '
+ac_subdirs_all='foreign/libffi
+rktio '
 
 # Initialize some variables set by options.
 ac_init_help=
@@ -7150,6 +7151,9 @@ else
 fi
 makefiles="$makefiles foreign/Makefile"
 
+subdirs="$subdirs rktio"
+
+
 # Remove any --enable or --disable arguments from `ac_configure_args':
 new_configure_args=
 fixup_prev=
diff --git a/racket/src/racket/configure.ac b/racket/src/racket/configure.ac
index d62a42ad3d..0fe411d03e 100644
--- a/racket/src/racket/configure.ac
+++ b/racket/src/racket/configure.ac
@@ -1,7 +1,7 @@
 
 #################################################################
 # This is the source for the `configure' script, to be compiled #
-# by autoconf (use make-configure in this directory).           #
+# by autoconf (use `make-configure` in this directory).         #
 #################################################################
 
 # Remember:
@@ -1938,6 +1938,8 @@ else
 fi
 makefiles="$makefiles foreign/Makefile"
 
+AC_CONFIG_SUBDIRS( rktio )
+
 # Remove any --enable or --disable arguments from `ac_configure_args':
 new_configure_args=
 fixup_prev=
diff --git a/racket/src/racket/make-configure b/racket/src/racket/make-configure
index c593b1c144..99aede84ae 100755
--- a/racket/src/racket/make-configure
+++ b/racket/src/racket/make-configure
@@ -10,6 +10,11 @@ if [ -e "$tgt" ]; then
 fi
 autoconf "$src" | racket "$0" > "$tgt"
 chmod +x "$tgt"
+src="../rktio/configure.ac"
+tgt="../rktio/configure"
+echo "Creating $tgt from $src"
+autoconf "$src" > "$tgt"
+chmod +x "$tgt"
 exit 0
 |#
 #lang racket/base
diff --git a/racket/src/rktio/Makefile.in b/racket/src/rktio/Makefile.in
new file mode 100644
index 0000000000..846e7f5fb6
--- /dev/null
+++ b/racket/src/rktio/Makefile.in
@@ -0,0 +1,21 @@
+
+srcdir = @srcdir@
+
+CC = @CC@
+CFLAGS = @CFLAGS@ @CPPFLAGS@
+
+RKTIO_HEADERS = $(srcdir)/rktio.h $(srcdir)/rktio_private.h rktio_config.h
+
+all: rktio_filesystem.o rktio_read_write.o rktio_poll_set.o rktio_error.o
+
+rktio_filesystem.o: $(srcdir)/rktio_filesystem.c $(RKTIO_HEADERS)
+	$(CC) $(CFLAGS) -I$(srcdir) -I. -o rktio_filesystem.o -c $(srcdir)/rktio_filesystem.c
+
+rktio_read_write.o: $(srcdir)/rktio_read_write.c $(RKTIO_HEADERS)
+	$(CC) $(CFLAGS) -I$(srcdir) -I. -o rktio_read_write.o -c $(srcdir)/rktio_read_write.c
+
+rktio_poll_set.o: $(srcdir)/rktio_poll_set.c $(RKTIO_HEADERS)
+	$(CC) $(CFLAGS) -I$(srcdir) -I. -o rktio_poll_set.o -c $(srcdir)/rktio_poll_set.c
+
+rktio_error.o: $(srcdir)/rktio_error.c $(RKTIO_HEADERS)
+	$(CC) $(CFLAGS) -I$(srcdir) -I. -o rktio_error.o -c $(srcdir)/rktio_error.c
diff --git a/racket/src/rktio/configure b/racket/src/rktio/configure
new file mode 100755
index 0000000000..e4231d8330
--- /dev/null
+++ b/racket/src/rktio/configure
@@ -0,0 +1,5110 @@
+#! /bin/sh
+# Guess values for system-dependent variables and create Makefiles.
+# Generated by GNU Autoconf 2.69.
+#
+#
+# Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
+#
+#
+# This configure script is free software; the Free Software Foundation
+# gives unlimited permission to copy, distribute and modify it.
+## -------------------- ##
+## M4sh Initialization. ##
+## -------------------- ##
+
+# Be more Bourne compatible
+DUALCASE=1; export DUALCASE # for MKS sh
+if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then :
+  emulate sh
+  NULLCMD=:
+  # Pre-4.2 versions of Zsh do word splitting on ${1+"$@"}, which
+  # is contrary to our usage.  Disable this feature.
+  alias -g '${1+"$@"}'='"$@"'
+  setopt NO_GLOB_SUBST
+else
+  case `(set -o) 2>/dev/null` in #(
+  *posix*) :
+    set -o posix ;; #(
+  *) :
+     ;;
+esac
+fi
+
+
+as_nl='
+'
+export as_nl
+# Printing a long string crashes Solaris 7 /usr/bin/printf.
+as_echo='\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'
+as_echo=$as_echo$as_echo$as_echo$as_echo$as_echo
+as_echo=$as_echo$as_echo$as_echo$as_echo$as_echo$as_echo
+# Prefer a ksh shell builtin over an external printf program on Solaris,
+# but without wasting forks for bash or zsh.
+if test -z "$BASH_VERSION$ZSH_VERSION" \
+    && (test "X`print -r -- $as_echo`" = "X$as_echo") 2>/dev/null; then
+  as_echo='print -r --'
+  as_echo_n='print -rn --'
+elif (test "X`printf %s $as_echo`" = "X$as_echo") 2>/dev/null; then
+  as_echo='printf %s\n'
+  as_echo_n='printf %s'
+else
+  if test "X`(/usr/ucb/echo -n -n $as_echo) 2>/dev/null`" = "X-n $as_echo"; then
+    as_echo_body='eval /usr/ucb/echo -n "$1$as_nl"'
+    as_echo_n='/usr/ucb/echo -n'
+  else
+    as_echo_body='eval expr "X$1" : "X\\(.*\\)"'
+    as_echo_n_body='eval
+      arg=$1;
+      case $arg in #(
+      *"$as_nl"*)
+	expr "X$arg" : "X\\(.*\\)$as_nl";
+	arg=`expr "X$arg" : ".*$as_nl\\(.*\\)"`;;
+      esac;
+      expr "X$arg" : "X\\(.*\\)" | tr -d "$as_nl"
+    '
+    export as_echo_n_body
+    as_echo_n='sh -c $as_echo_n_body as_echo'
+  fi
+  export as_echo_body
+  as_echo='sh -c $as_echo_body as_echo'
+fi
+
+# The user is always right.
+if test "${PATH_SEPARATOR+set}" != set; then
+  PATH_SEPARATOR=:
+  (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 && {
+    (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 ||
+      PATH_SEPARATOR=';'
+  }
+fi
+
+
+# IFS
+# We need space, tab and new line, in precisely that order.  Quoting is
+# there to prevent editors from complaining about space-tab.
+# (If _AS_PATH_WALK were called with IFS unset, it would disable word
+# splitting by setting IFS to empty value.)
+IFS=" ""	$as_nl"
+
+# Find who we are.  Look in the path if we contain no directory separator.
+as_myself=
+case $0 in #((
+  *[\\/]* ) as_myself=$0 ;;
+  *) as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    test -r "$as_dir/$0" && as_myself=$as_dir/$0 && break
+  done
+IFS=$as_save_IFS
+
+     ;;
+esac
+# We did not find ourselves, most probably we were run as `sh COMMAND'
+# in which case we are not to be found in the path.
+if test "x$as_myself" = x; then
+  as_myself=$0
+fi
+if test ! -f "$as_myself"; then
+  $as_echo "$as_myself: error: cannot find myself; rerun with an absolute file name" >&2
+  exit 1
+fi
+
+# Unset variables that we do not need and which cause bugs (e.g. in
+# pre-3.0 UWIN ksh).  But do not cause bugs in bash 2.01; the "|| exit 1"
+# suppresses any "Segmentation fault" message there.  '((' could
+# trigger a bug in pdksh 5.2.14.
+for as_var in BASH_ENV ENV MAIL MAILPATH
+do eval test x\${$as_var+set} = xset \
+  && ( (unset $as_var) || exit 1) >/dev/null 2>&1 && unset $as_var || :
+done
+PS1='$ '
+PS2='> '
+PS4='+ '
+
+# NLS nuisances.
+LC_ALL=C
+export LC_ALL
+LANGUAGE=C
+export LANGUAGE
+
+# CDPATH.
+(unset CDPATH) >/dev/null 2>&1 && unset CDPATH
+
+# Use a proper internal environment variable to ensure we don't fall
+  # into an infinite loop, continuously re-executing ourselves.
+  if test x"${_as_can_reexec}" != xno && test "x$CONFIG_SHELL" != x; then
+    _as_can_reexec=no; export _as_can_reexec;
+    # We cannot yet assume a decent shell, so we have to provide a
+# neutralization value for shells without unset; and this also
+# works around shells that cannot unset nonexistent variables.
+# Preserve -v and -x to the replacement shell.
+BASH_ENV=/dev/null
+ENV=/dev/null
+(unset BASH_ENV) >/dev/null 2>&1 && unset BASH_ENV ENV
+case $- in # ((((
+  *v*x* | *x*v* ) as_opts=-vx ;;
+  *v* ) as_opts=-v ;;
+  *x* ) as_opts=-x ;;
+  * ) as_opts= ;;
+esac
+exec $CONFIG_SHELL $as_opts "$as_myself" ${1+"$@"}
+# Admittedly, this is quite paranoid, since all the known shells bail
+# out after a failed `exec'.
+$as_echo "$0: could not re-execute with $CONFIG_SHELL" >&2
+as_fn_exit 255
+  fi
+  # We don't want this to propagate to other subprocesses.
+          { _as_can_reexec=; unset _as_can_reexec;}
+if test "x$CONFIG_SHELL" = x; then
+  as_bourne_compatible="if test -n \"\${ZSH_VERSION+set}\" && (emulate sh) >/dev/null 2>&1; then :
+  emulate sh
+  NULLCMD=:
+  # Pre-4.2 versions of Zsh do word splitting on \${1+\"\$@\"}, which
+  # is contrary to our usage.  Disable this feature.
+  alias -g '\${1+\"\$@\"}'='\"\$@\"'
+  setopt NO_GLOB_SUBST
+else
+  case \`(set -o) 2>/dev/null\` in #(
+  *posix*) :
+    set -o posix ;; #(
+  *) :
+     ;;
+esac
+fi
+"
+  as_required="as_fn_return () { (exit \$1); }
+as_fn_success () { as_fn_return 0; }
+as_fn_failure () { as_fn_return 1; }
+as_fn_ret_success () { return 0; }
+as_fn_ret_failure () { return 1; }
+
+exitcode=0
+as_fn_success || { exitcode=1; echo as_fn_success failed.; }
+as_fn_failure && { exitcode=1; echo as_fn_failure succeeded.; }
+as_fn_ret_success || { exitcode=1; echo as_fn_ret_success failed.; }
+as_fn_ret_failure && { exitcode=1; echo as_fn_ret_failure succeeded.; }
+if ( set x; as_fn_ret_success y && test x = \"\$1\" ); then :
+
+else
+  exitcode=1; echo positional parameters were not saved.
+fi
+test x\$exitcode = x0 || exit 1
+test -x / || exit 1"
+  as_suggested="  as_lineno_1=";as_suggested=$as_suggested$LINENO;as_suggested=$as_suggested" as_lineno_1a=\$LINENO
+  as_lineno_2=";as_suggested=$as_suggested$LINENO;as_suggested=$as_suggested" as_lineno_2a=\$LINENO
+  eval 'test \"x\$as_lineno_1'\$as_run'\" != \"x\$as_lineno_2'\$as_run'\" &&
+  test \"x\`expr \$as_lineno_1'\$as_run' + 1\`\" = \"x\$as_lineno_2'\$as_run'\"' || exit 1
+test \$(( 1 + 1 )) = 2 || exit 1"
+  if (eval "$as_required") 2>/dev/null; then :
+  as_have_required=yes
+else
+  as_have_required=no
+fi
+  if test x$as_have_required = xyes && (eval "$as_suggested") 2>/dev/null; then :
+
+else
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+as_found=false
+for as_dir in /bin$PATH_SEPARATOR/usr/bin$PATH_SEPARATOR$PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+  as_found=:
+  case $as_dir in #(
+	 /*)
+	   for as_base in sh bash ksh sh5; do
+	     # Try only shells that exist, to save several forks.
+	     as_shell=$as_dir/$as_base
+	     if { test -f "$as_shell" || test -f "$as_shell.exe"; } &&
+		    { $as_echo "$as_bourne_compatible""$as_required" | as_run=a "$as_shell"; } 2>/dev/null; then :
+  CONFIG_SHELL=$as_shell as_have_required=yes
+		   if { $as_echo "$as_bourne_compatible""$as_suggested" | as_run=a "$as_shell"; } 2>/dev/null; then :
+  break 2
+fi
+fi
+	   done;;
+       esac
+  as_found=false
+done
+$as_found || { if { test -f "$SHELL" || test -f "$SHELL.exe"; } &&
+	      { $as_echo "$as_bourne_compatible""$as_required" | as_run=a "$SHELL"; } 2>/dev/null; then :
+  CONFIG_SHELL=$SHELL as_have_required=yes
+fi; }
+IFS=$as_save_IFS
+
+
+      if test "x$CONFIG_SHELL" != x; then :
+  export CONFIG_SHELL
+             # We cannot yet assume a decent shell, so we have to provide a
+# neutralization value for shells without unset; and this also
+# works around shells that cannot unset nonexistent variables.
+# Preserve -v and -x to the replacement shell.
+BASH_ENV=/dev/null
+ENV=/dev/null
+(unset BASH_ENV) >/dev/null 2>&1 && unset BASH_ENV ENV
+case $- in # ((((
+  *v*x* | *x*v* ) as_opts=-vx ;;
+  *v* ) as_opts=-v ;;
+  *x* ) as_opts=-x ;;
+  * ) as_opts= ;;
+esac
+exec $CONFIG_SHELL $as_opts "$as_myself" ${1+"$@"}
+# Admittedly, this is quite paranoid, since all the known shells bail
+# out after a failed `exec'.
+$as_echo "$0: could not re-execute with $CONFIG_SHELL" >&2
+exit 255
+fi
+
+    if test x$as_have_required = xno; then :
+  $as_echo "$0: This script requires a shell more modern than all"
+  $as_echo "$0: the shells that I found on your system."
+  if test x${ZSH_VERSION+set} = xset ; then
+    $as_echo "$0: In particular, zsh $ZSH_VERSION has bugs and should"
+    $as_echo "$0: be upgraded to zsh 4.3.4 or later."
+  else
+    $as_echo "$0: Please tell bug-autoconf@gnu.org about your system,
+$0: including any error possibly output before this
+$0: message. Then install a modern shell, or manually run
+$0: the script under such a shell if you do have one."
+  fi
+  exit 1
+fi
+fi
+fi
+SHELL=${CONFIG_SHELL-/bin/sh}
+export SHELL
+# Unset more variables known to interfere with behavior of common tools.
+CLICOLOR_FORCE= GREP_OPTIONS=
+unset CLICOLOR_FORCE GREP_OPTIONS
+
+## --------------------- ##
+## M4sh Shell Functions. ##
+## --------------------- ##
+# as_fn_unset VAR
+# ---------------
+# Portably unset VAR.
+as_fn_unset ()
+{
+  { eval $1=; unset $1;}
+}
+as_unset=as_fn_unset
+
+# as_fn_set_status STATUS
+# -----------------------
+# Set $? to STATUS, without forking.
+as_fn_set_status ()
+{
+  return $1
+} # as_fn_set_status
+
+# as_fn_exit STATUS
+# -----------------
+# Exit the shell with STATUS, even in a "trap 0" or "set -e" context.
+as_fn_exit ()
+{
+  set +e
+  as_fn_set_status $1
+  exit $1
+} # as_fn_exit
+
+# as_fn_mkdir_p
+# -------------
+# Create "$as_dir" as a directory, including parents if necessary.
+as_fn_mkdir_p ()
+{
+
+  case $as_dir in #(
+  -*) as_dir=./$as_dir;;
+  esac
+  test -d "$as_dir" || eval $as_mkdir_p || {
+    as_dirs=
+    while :; do
+      case $as_dir in #(
+      *\'*) as_qdir=`$as_echo "$as_dir" | sed "s/'/'\\\\\\\\''/g"`;; #'(
+      *) as_qdir=$as_dir;;
+      esac
+      as_dirs="'$as_qdir' $as_dirs"
+      as_dir=`$as_dirname -- "$as_dir" ||
+$as_expr X"$as_dir" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
+	 X"$as_dir" : 'X\(//\)[^/]' \| \
+	 X"$as_dir" : 'X\(//\)$' \| \
+	 X"$as_dir" : 'X\(/\)' \| . 2>/dev/null ||
+$as_echo X"$as_dir" |
+    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)[^/].*/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\).*/{
+	    s//\1/
+	    q
+	  }
+	  s/.*/./; q'`
+      test -d "$as_dir" && break
+    done
+    test -z "$as_dirs" || eval "mkdir $as_dirs"
+  } || test -d "$as_dir" || as_fn_error $? "cannot create directory $as_dir"
+
+
+} # as_fn_mkdir_p
+
+# as_fn_executable_p FILE
+# -----------------------
+# Test if FILE is an executable regular file.
+as_fn_executable_p ()
+{
+  test -f "$1" && test -x "$1"
+} # as_fn_executable_p
+# as_fn_append VAR VALUE
+# ----------------------
+# Append the text in VALUE to the end of the definition contained in VAR. Take
+# advantage of any shell optimizations that allow amortized linear growth over
+# repeated appends, instead of the typical quadratic growth present in naive
+# implementations.
+if (eval "as_var=1; as_var+=2; test x\$as_var = x12") 2>/dev/null; then :
+  eval 'as_fn_append ()
+  {
+    eval $1+=\$2
+  }'
+else
+  as_fn_append ()
+  {
+    eval $1=\$$1\$2
+  }
+fi # as_fn_append
+
+# as_fn_arith ARG...
+# ------------------
+# Perform arithmetic evaluation on the ARGs, and store the result in the
+# global $as_val. Take advantage of shells that can avoid forks. The arguments
+# must be portable across $(()) and expr.
+if (eval "test \$(( 1 + 1 )) = 2") 2>/dev/null; then :
+  eval 'as_fn_arith ()
+  {
+    as_val=$(( $* ))
+  }'
+else
+  as_fn_arith ()
+  {
+    as_val=`expr "$@" || test $? -eq 1`
+  }
+fi # as_fn_arith
+
+
+# as_fn_error STATUS ERROR [LINENO LOG_FD]
+# ----------------------------------------
+# Output "`basename $0`: error: ERROR" to stderr. If LINENO and LOG_FD are
+# provided, also output the error to LOG_FD, referencing LINENO. Then exit the
+# script with STATUS, using 1 if that was 0.
+as_fn_error ()
+{
+  as_status=$1; test $as_status -eq 0 && as_status=1
+  if test "$4"; then
+    as_lineno=${as_lineno-"$3"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+    $as_echo "$as_me:${as_lineno-$LINENO}: error: $2" >&$4
+  fi
+  $as_echo "$as_me: error: $2" >&2
+  as_fn_exit $as_status
+} # as_fn_error
+
+if expr a : '\(a\)' >/dev/null 2>&1 &&
+   test "X`expr 00001 : '.*\(...\)'`" = X001; then
+  as_expr=expr
+else
+  as_expr=false
+fi
+
+if (basename -- /) >/dev/null 2>&1 && test "X`basename -- / 2>&1`" = "X/"; then
+  as_basename=basename
+else
+  as_basename=false
+fi
+
+if (as_dir=`dirname -- /` && test "X$as_dir" = X/) >/dev/null 2>&1; then
+  as_dirname=dirname
+else
+  as_dirname=false
+fi
+
+as_me=`$as_basename -- "$0" ||
+$as_expr X/"$0" : '.*/\([^/][^/]*\)/*$' \| \
+	 X"$0" : 'X\(//\)$' \| \
+	 X"$0" : 'X\(/\)' \| . 2>/dev/null ||
+$as_echo X/"$0" |
+    sed '/^.*\/\([^/][^/]*\)\/*$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\/\(\/\/\)$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\/\(\/\).*/{
+	    s//\1/
+	    q
+	  }
+	  s/.*/./; q'`
+
+# Avoid depending upon Character Ranges.
+as_cr_letters='abcdefghijklmnopqrstuvwxyz'
+as_cr_LETTERS='ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+as_cr_Letters=$as_cr_letters$as_cr_LETTERS
+as_cr_digits='0123456789'
+as_cr_alnum=$as_cr_Letters$as_cr_digits
+
+
+  as_lineno_1=$LINENO as_lineno_1a=$LINENO
+  as_lineno_2=$LINENO as_lineno_2a=$LINENO
+  eval 'test "x$as_lineno_1'$as_run'" != "x$as_lineno_2'$as_run'" &&
+  test "x`expr $as_lineno_1'$as_run' + 1`" = "x$as_lineno_2'$as_run'"' || {
+  # Blame Lee E. McMahon (1931-1989) for sed's syntax.  :-)
+  sed -n '
+    p
+    /[$]LINENO/=
+  ' <$as_myself |
+    sed '
+      s/[$]LINENO.*/&-/
+      t lineno
+      b
+      :lineno
+      N
+      :loop
+      s/[$]LINENO\([^'$as_cr_alnum'_].*\n\)\(.*\)/\2\1\2/
+      t loop
+      s/-\n.*//
+    ' >$as_me.lineno &&
+  chmod +x "$as_me.lineno" ||
+    { $as_echo "$as_me: error: cannot create $as_me.lineno; rerun with a POSIX shell" >&2; as_fn_exit 1; }
+
+  # If we had to re-execute with $CONFIG_SHELL, we're ensured to have
+  # already done that, so ensure we don't try to do so again and fall
+  # in an infinite loop.  This has already happened in practice.
+  _as_can_reexec=no; export _as_can_reexec
+  # Don't try to exec as it changes $[0], causing all sort of problems
+  # (the dirname of $[0] is not the place where we might find the
+  # original and so on.  Autoconf is especially sensitive to this).
+  . "./$as_me.lineno"
+  # Exit status is that of the last command.
+  exit
+}
+
+ECHO_C= ECHO_N= ECHO_T=
+case `echo -n x` in #(((((
+-n*)
+  case `echo 'xy\c'` in
+  *c*) ECHO_T='	';;	# ECHO_T is single tab character.
+  xy)  ECHO_C='\c';;
+  *)   echo `echo ksh88 bug on AIX 6.1` > /dev/null
+       ECHO_T='	';;
+  esac;;
+*)
+  ECHO_N='-n';;
+esac
+
+rm -f conf$$ conf$$.exe conf$$.file
+if test -d conf$$.dir; then
+  rm -f conf$$.dir/conf$$.file
+else
+  rm -f conf$$.dir
+  mkdir conf$$.dir 2>/dev/null
+fi
+if (echo >conf$$.file) 2>/dev/null; then
+  if ln -s conf$$.file conf$$ 2>/dev/null; then
+    as_ln_s='ln -s'
+    # ... but there are two gotchas:
+    # 1) On MSYS, both `ln -s file dir' and `ln file dir' fail.
+    # 2) DJGPP < 2.04 has no symlinks; `ln -s' creates a wrapper executable.
+    # In both cases, we have to default to `cp -pR'.
+    ln -s conf$$.file conf$$.dir 2>/dev/null && test ! -f conf$$.exe ||
+      as_ln_s='cp -pR'
+  elif ln conf$$.file conf$$ 2>/dev/null; then
+    as_ln_s=ln
+  else
+    as_ln_s='cp -pR'
+  fi
+else
+  as_ln_s='cp -pR'
+fi
+rm -f conf$$ conf$$.exe conf$$.dir/conf$$.file conf$$.file
+rmdir conf$$.dir 2>/dev/null
+
+if mkdir -p . 2>/dev/null; then
+  as_mkdir_p='mkdir -p "$as_dir"'
+else
+  test -d ./-p && rmdir ./-p
+  as_mkdir_p=false
+fi
+
+as_test_x='test -x'
+as_executable_p=as_fn_executable_p
+
+# Sed expression to map a string onto a valid CPP name.
+as_tr_cpp="eval sed 'y%*$as_cr_letters%P$as_cr_LETTERS%;s%[^_$as_cr_alnum]%_%g'"
+
+# Sed expression to map a string onto a valid variable name.
+as_tr_sh="eval sed 'y%*+%pp%;s%[^_$as_cr_alnum]%_%g'"
+
+
+test -n "$DJDIR" || exec 7<&0 </dev/null
+exec 6>&1
+
+# Name of the host.
+# hostname on some systems (SVR3.2, old GNU/Linux) returns a bogus exit status,
+# so uname gets run too.
+ac_hostname=`(hostname || uname -n) 2>/dev/null | sed 1q`
+
+#
+# Initializations.
+#
+ac_default_prefix=/usr/local
+ac_clean_files=
+ac_config_libobj_dir=.
+LIBOBJS=
+cross_compiling=no
+subdirs=
+MFLAGS=
+MAKEFLAGS=
+
+# Identity of this package.
+PACKAGE_NAME=
+PACKAGE_TARNAME=
+PACKAGE_VERSION=
+PACKAGE_STRING=
+PACKAGE_BUGREPORT=
+PACKAGE_URL=
+
+ac_unique_file="rktio.h"
+# Factoring default headers for most tests.
+ac_includes_default="\
+#include <stdio.h>
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
+#endif
+#ifdef STDC_HEADERS
+# include <stdlib.h>
+# include <stddef.h>
+#else
+# ifdef HAVE_STDLIB_H
+#  include <stdlib.h>
+# endif
+#endif
+#ifdef HAVE_STRING_H
+# if !defined STDC_HEADERS && defined HAVE_MEMORY_H
+#  include <memory.h>
+# endif
+# include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif
+#ifdef HAVE_INTTYPES_H
+# include <inttypes.h>
+#endif
+#ifdef HAVE_STDINT_H
+# include <stdint.h>
+#endif
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif"
+
+ac_subst_vars='LTLIBOBJS
+LIBOBJS
+EGREP
+GREP
+CPP
+OBJEXT
+EXEEXT
+ac_ct_CC
+CPPFLAGS
+LDFLAGS
+CFLAGS
+CC
+target_os
+target_vendor
+target_cpu
+target
+host_os
+host_vendor
+host_cpu
+host
+build_os
+build_vendor
+build_cpu
+build
+target_alias
+host_alias
+build_alias
+LIBS
+ECHO_T
+ECHO_N
+ECHO_C
+DEFS
+mandir
+localedir
+libdir
+psdir
+pdfdir
+dvidir
+htmldir
+infodir
+docdir
+oldincludedir
+includedir
+localstatedir
+sharedstatedir
+sysconfdir
+datadir
+datarootdir
+libexecdir
+sbindir
+bindir
+program_transform_name
+prefix
+exec_prefix
+PACKAGE_URL
+PACKAGE_BUGREPORT
+PACKAGE_STRING
+PACKAGE_VERSION
+PACKAGE_TARNAME
+PACKAGE_NAME
+PATH_SEPARATOR
+SHELL'
+ac_subst_files=''
+ac_user_opts='
+enable_option_checking
+'
+      ac_precious_vars='build_alias
+host_alias
+target_alias
+CC
+CFLAGS
+LDFLAGS
+LIBS
+CPPFLAGS
+CPP'
+
+
+# Initialize some variables set by options.
+ac_init_help=
+ac_init_version=false
+ac_unrecognized_opts=
+ac_unrecognized_sep=
+# The variables have the same names as the options, with
+# dashes changed to underlines.
+cache_file=/dev/null
+exec_prefix=NONE
+no_create=
+no_recursion=
+prefix=NONE
+program_prefix=NONE
+program_suffix=NONE
+program_transform_name=s,x,x,
+silent=
+site=
+srcdir=
+verbose=
+x_includes=NONE
+x_libraries=NONE
+
+# Installation directory options.
+# These are left unexpanded so users can "make install exec_prefix=/foo"
+# and all the variables that are supposed to be based on exec_prefix
+# by default will actually change.
+# Use braces instead of parens because sh, perl, etc. also accept them.
+# (The list follows the same order as the GNU Coding Standards.)
+bindir='${exec_prefix}/bin'
+sbindir='${exec_prefix}/sbin'
+libexecdir='${exec_prefix}/libexec'
+datarootdir='${prefix}/share'
+datadir='${datarootdir}'
+sysconfdir='${prefix}/etc'
+sharedstatedir='${prefix}/com'
+localstatedir='${prefix}/var'
+includedir='${prefix}/include'
+oldincludedir='/usr/include'
+docdir='${datarootdir}/doc/${PACKAGE}'
+infodir='${datarootdir}/info'
+htmldir='${docdir}'
+dvidir='${docdir}'
+pdfdir='${docdir}'
+psdir='${docdir}'
+libdir='${exec_prefix}/lib'
+localedir='${datarootdir}/locale'
+mandir='${datarootdir}/man'
+
+ac_prev=
+ac_dashdash=
+for ac_option
+do
+  # If the previous option needs an argument, assign it.
+  if test -n "$ac_prev"; then
+    eval $ac_prev=\$ac_option
+    ac_prev=
+    continue
+  fi
+
+  case $ac_option in
+  *=?*) ac_optarg=`expr "X$ac_option" : '[^=]*=\(.*\)'` ;;
+  *=)   ac_optarg= ;;
+  *)    ac_optarg=yes ;;
+  esac
+
+  # Accept the important Cygnus configure options, so we can diagnose typos.
+
+  case $ac_dashdash$ac_option in
+  --)
+    ac_dashdash=yes ;;
+
+  -bindir | --bindir | --bindi | --bind | --bin | --bi)
+    ac_prev=bindir ;;
+  -bindir=* | --bindir=* | --bindi=* | --bind=* | --bin=* | --bi=*)
+    bindir=$ac_optarg ;;
+
+  -build | --build | --buil | --bui | --bu)
+    ac_prev=build_alias ;;
+  -build=* | --build=* | --buil=* | --bui=* | --bu=*)
+    build_alias=$ac_optarg ;;
+
+  -cache-file | --cache-file | --cache-fil | --cache-fi \
+  | --cache-f | --cache- | --cache | --cach | --cac | --ca | --c)
+    ac_prev=cache_file ;;
+  -cache-file=* | --cache-file=* | --cache-fil=* | --cache-fi=* \
+  | --cache-f=* | --cache-=* | --cache=* | --cach=* | --cac=* | --ca=* | --c=*)
+    cache_file=$ac_optarg ;;
+
+  --config-cache | -C)
+    cache_file=config.cache ;;
+
+  -datadir | --datadir | --datadi | --datad)
+    ac_prev=datadir ;;
+  -datadir=* | --datadir=* | --datadi=* | --datad=*)
+    datadir=$ac_optarg ;;
+
+  -datarootdir | --datarootdir | --datarootdi | --datarootd | --dataroot \
+  | --dataroo | --dataro | --datar)
+    ac_prev=datarootdir ;;
+  -datarootdir=* | --datarootdir=* | --datarootdi=* | --datarootd=* \
+  | --dataroot=* | --dataroo=* | --dataro=* | --datar=*)
+    datarootdir=$ac_optarg ;;
+
+  -disable-* | --disable-*)
+    ac_useropt=`expr "x$ac_option" : 'x-*disable-\(.*\)'`
+    # Reject names that are not valid shell variable names.
+    expr "x$ac_useropt" : ".*[^-+._$as_cr_alnum]" >/dev/null &&
+      as_fn_error $? "invalid feature name: $ac_useropt"
+    ac_useropt_orig=$ac_useropt
+    ac_useropt=`$as_echo "$ac_useropt" | sed 's/[-+.]/_/g'`
+    case $ac_user_opts in
+      *"
+"enable_$ac_useropt"
+"*) ;;
+      *) ac_unrecognized_opts="$ac_unrecognized_opts$ac_unrecognized_sep--disable-$ac_useropt_orig"
+	 ac_unrecognized_sep=', ';;
+    esac
+    eval enable_$ac_useropt=no ;;
+
+  -docdir | --docdir | --docdi | --doc | --do)
+    ac_prev=docdir ;;
+  -docdir=* | --docdir=* | --docdi=* | --doc=* | --do=*)
+    docdir=$ac_optarg ;;
+
+  -dvidir | --dvidir | --dvidi | --dvid | --dvi | --dv)
+    ac_prev=dvidir ;;
+  -dvidir=* | --dvidir=* | --dvidi=* | --dvid=* | --dvi=* | --dv=*)
+    dvidir=$ac_optarg ;;
+
+  -enable-* | --enable-*)
+    ac_useropt=`expr "x$ac_option" : 'x-*enable-\([^=]*\)'`
+    # Reject names that are not valid shell variable names.
+    expr "x$ac_useropt" : ".*[^-+._$as_cr_alnum]" >/dev/null &&
+      as_fn_error $? "invalid feature name: $ac_useropt"
+    ac_useropt_orig=$ac_useropt
+    ac_useropt=`$as_echo "$ac_useropt" | sed 's/[-+.]/_/g'`
+    case $ac_user_opts in
+      *"
+"enable_$ac_useropt"
+"*) ;;
+      *) ac_unrecognized_opts="$ac_unrecognized_opts$ac_unrecognized_sep--enable-$ac_useropt_orig"
+	 ac_unrecognized_sep=', ';;
+    esac
+    eval enable_$ac_useropt=\$ac_optarg ;;
+
+  -exec-prefix | --exec_prefix | --exec-prefix | --exec-prefi \
+  | --exec-pref | --exec-pre | --exec-pr | --exec-p | --exec- \
+  | --exec | --exe | --ex)
+    ac_prev=exec_prefix ;;
+  -exec-prefix=* | --exec_prefix=* | --exec-prefix=* | --exec-prefi=* \
+  | --exec-pref=* | --exec-pre=* | --exec-pr=* | --exec-p=* | --exec-=* \
+  | --exec=* | --exe=* | --ex=*)
+    exec_prefix=$ac_optarg ;;
+
+  -gas | --gas | --ga | --g)
+    # Obsolete; use --with-gas.
+    with_gas=yes ;;
+
+  -help | --help | --hel | --he | -h)
+    ac_init_help=long ;;
+  -help=r* | --help=r* | --hel=r* | --he=r* | -hr*)
+    ac_init_help=recursive ;;
+  -help=s* | --help=s* | --hel=s* | --he=s* | -hs*)
+    ac_init_help=short ;;
+
+  -host | --host | --hos | --ho)
+    ac_prev=host_alias ;;
+  -host=* | --host=* | --hos=* | --ho=*)
+    host_alias=$ac_optarg ;;
+
+  -htmldir | --htmldir | --htmldi | --htmld | --html | --htm | --ht)
+    ac_prev=htmldir ;;
+  -htmldir=* | --htmldir=* | --htmldi=* | --htmld=* | --html=* | --htm=* \
+  | --ht=*)
+    htmldir=$ac_optarg ;;
+
+  -includedir | --includedir | --includedi | --included | --include \
+  | --includ | --inclu | --incl | --inc)
+    ac_prev=includedir ;;
+  -includedir=* | --includedir=* | --includedi=* | --included=* | --include=* \
+  | --includ=* | --inclu=* | --incl=* | --inc=*)
+    includedir=$ac_optarg ;;
+
+  -infodir | --infodir | --infodi | --infod | --info | --inf)
+    ac_prev=infodir ;;
+  -infodir=* | --infodir=* | --infodi=* | --infod=* | --info=* | --inf=*)
+    infodir=$ac_optarg ;;
+
+  -libdir | --libdir | --libdi | --libd)
+    ac_prev=libdir ;;
+  -libdir=* | --libdir=* | --libdi=* | --libd=*)
+    libdir=$ac_optarg ;;
+
+  -libexecdir | --libexecdir | --libexecdi | --libexecd | --libexec \
+  | --libexe | --libex | --libe)
+    ac_prev=libexecdir ;;
+  -libexecdir=* | --libexecdir=* | --libexecdi=* | --libexecd=* | --libexec=* \
+  | --libexe=* | --libex=* | --libe=*)
+    libexecdir=$ac_optarg ;;
+
+  -localedir | --localedir | --localedi | --localed | --locale)
+    ac_prev=localedir ;;
+  -localedir=* | --localedir=* | --localedi=* | --localed=* | --locale=*)
+    localedir=$ac_optarg ;;
+
+  -localstatedir | --localstatedir | --localstatedi | --localstated \
+  | --localstate | --localstat | --localsta | --localst | --locals)
+    ac_prev=localstatedir ;;
+  -localstatedir=* | --localstatedir=* | --localstatedi=* | --localstated=* \
+  | --localstate=* | --localstat=* | --localsta=* | --localst=* | --locals=*)
+    localstatedir=$ac_optarg ;;
+
+  -mandir | --mandir | --mandi | --mand | --man | --ma | --m)
+    ac_prev=mandir ;;
+  -mandir=* | --mandir=* | --mandi=* | --mand=* | --man=* | --ma=* | --m=*)
+    mandir=$ac_optarg ;;
+
+  -nfp | --nfp | --nf)
+    # Obsolete; use --without-fp.
+    with_fp=no ;;
+
+  -no-create | --no-create | --no-creat | --no-crea | --no-cre \
+  | --no-cr | --no-c | -n)
+    no_create=yes ;;
+
+  -no-recursion | --no-recursion | --no-recursio | --no-recursi \
+  | --no-recurs | --no-recur | --no-recu | --no-rec | --no-re | --no-r)
+    no_recursion=yes ;;
+
+  -oldincludedir | --oldincludedir | --oldincludedi | --oldincluded \
+  | --oldinclude | --oldinclud | --oldinclu | --oldincl | --oldinc \
+  | --oldin | --oldi | --old | --ol | --o)
+    ac_prev=oldincludedir ;;
+  -oldincludedir=* | --oldincludedir=* | --oldincludedi=* | --oldincluded=* \
+  | --oldinclude=* | --oldinclud=* | --oldinclu=* | --oldincl=* | --oldinc=* \
+  | --oldin=* | --oldi=* | --old=* | --ol=* | --o=*)
+    oldincludedir=$ac_optarg ;;
+
+  -prefix | --prefix | --prefi | --pref | --pre | --pr | --p)
+    ac_prev=prefix ;;
+  -prefix=* | --prefix=* | --prefi=* | --pref=* | --pre=* | --pr=* | --p=*)
+    prefix=$ac_optarg ;;
+
+  -program-prefix | --program-prefix | --program-prefi | --program-pref \
+  | --program-pre | --program-pr | --program-p)
+    ac_prev=program_prefix ;;
+  -program-prefix=* | --program-prefix=* | --program-prefi=* \
+  | --program-pref=* | --program-pre=* | --program-pr=* | --program-p=*)
+    program_prefix=$ac_optarg ;;
+
+  -program-suffix | --program-suffix | --program-suffi | --program-suff \
+  | --program-suf | --program-su | --program-s)
+    ac_prev=program_suffix ;;
+  -program-suffix=* | --program-suffix=* | --program-suffi=* \
+  | --program-suff=* | --program-suf=* | --program-su=* | --program-s=*)
+    program_suffix=$ac_optarg ;;
+
+  -program-transform-name | --program-transform-name \
+  | --program-transform-nam | --program-transform-na \
+  | --program-transform-n | --program-transform- \
+  | --program-transform | --program-transfor \
+  | --program-transfo | --program-transf \
+  | --program-trans | --program-tran \
+  | --progr-tra | --program-tr | --program-t)
+    ac_prev=program_transform_name ;;
+  -program-transform-name=* | --program-transform-name=* \
+  | --program-transform-nam=* | --program-transform-na=* \
+  | --program-transform-n=* | --program-transform-=* \
+  | --program-transform=* | --program-transfor=* \
+  | --program-transfo=* | --program-transf=* \
+  | --program-trans=* | --program-tran=* \
+  | --progr-tra=* | --program-tr=* | --program-t=*)
+    program_transform_name=$ac_optarg ;;
+
+  -pdfdir | --pdfdir | --pdfdi | --pdfd | --pdf | --pd)
+    ac_prev=pdfdir ;;
+  -pdfdir=* | --pdfdir=* | --pdfdi=* | --pdfd=* | --pdf=* | --pd=*)
+    pdfdir=$ac_optarg ;;
+
+  -psdir | --psdir | --psdi | --psd | --ps)
+    ac_prev=psdir ;;
+  -psdir=* | --psdir=* | --psdi=* | --psd=* | --ps=*)
+    psdir=$ac_optarg ;;
+
+  -q | -quiet | --quiet | --quie | --qui | --qu | --q \
+  | -silent | --silent | --silen | --sile | --sil)
+    silent=yes ;;
+
+  -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
+    ac_prev=sbindir ;;
+  -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
+  | --sbi=* | --sb=*)
+    sbindir=$ac_optarg ;;
+
+  -sharedstatedir | --sharedstatedir | --sharedstatedi \
+  | --sharedstated | --sharedstate | --sharedstat | --sharedsta \
+  | --sharedst | --shareds | --shared | --share | --shar \
+  | --sha | --sh)
+    ac_prev=sharedstatedir ;;
+  -sharedstatedir=* | --sharedstatedir=* | --sharedstatedi=* \
+  | --sharedstated=* | --sharedstate=* | --sharedstat=* | --sharedsta=* \
+  | --sharedst=* | --shareds=* | --shared=* | --share=* | --shar=* \
+  | --sha=* | --sh=*)
+    sharedstatedir=$ac_optarg ;;
+
+  -site | --site | --sit)
+    ac_prev=site ;;
+  -site=* | --site=* | --sit=*)
+    site=$ac_optarg ;;
+
+  -srcdir | --srcdir | --srcdi | --srcd | --src | --sr)
+    ac_prev=srcdir ;;
+  -srcdir=* | --srcdir=* | --srcdi=* | --srcd=* | --src=* | --sr=*)
+    srcdir=$ac_optarg ;;
+
+  -sysconfdir | --sysconfdir | --sysconfdi | --sysconfd | --sysconf \
+  | --syscon | --sysco | --sysc | --sys | --sy)
+    ac_prev=sysconfdir ;;
+  -sysconfdir=* | --sysconfdir=* | --sysconfdi=* | --sysconfd=* | --sysconf=* \
+  | --syscon=* | --sysco=* | --sysc=* | --sys=* | --sy=*)
+    sysconfdir=$ac_optarg ;;
+
+  -target | --target | --targe | --targ | --tar | --ta | --t)
+    ac_prev=target_alias ;;
+  -target=* | --target=* | --targe=* | --targ=* | --tar=* | --ta=* | --t=*)
+    target_alias=$ac_optarg ;;
+
+  -v | -verbose | --verbose | --verbos | --verbo | --verb)
+    verbose=yes ;;
+
+  -version | --version | --versio | --versi | --vers | -V)
+    ac_init_version=: ;;
+
+  -with-* | --with-*)
+    ac_useropt=`expr "x$ac_option" : 'x-*with-\([^=]*\)'`
+    # Reject names that are not valid shell variable names.
+    expr "x$ac_useropt" : ".*[^-+._$as_cr_alnum]" >/dev/null &&
+      as_fn_error $? "invalid package name: $ac_useropt"
+    ac_useropt_orig=$ac_useropt
+    ac_useropt=`$as_echo "$ac_useropt" | sed 's/[-+.]/_/g'`
+    case $ac_user_opts in
+      *"
+"with_$ac_useropt"
+"*) ;;
+      *) ac_unrecognized_opts="$ac_unrecognized_opts$ac_unrecognized_sep--with-$ac_useropt_orig"
+	 ac_unrecognized_sep=', ';;
+    esac
+    eval with_$ac_useropt=\$ac_optarg ;;
+
+  -without-* | --without-*)
+    ac_useropt=`expr "x$ac_option" : 'x-*without-\(.*\)'`
+    # Reject names that are not valid shell variable names.
+    expr "x$ac_useropt" : ".*[^-+._$as_cr_alnum]" >/dev/null &&
+      as_fn_error $? "invalid package name: $ac_useropt"
+    ac_useropt_orig=$ac_useropt
+    ac_useropt=`$as_echo "$ac_useropt" | sed 's/[-+.]/_/g'`
+    case $ac_user_opts in
+      *"
+"with_$ac_useropt"
+"*) ;;
+      *) ac_unrecognized_opts="$ac_unrecognized_opts$ac_unrecognized_sep--without-$ac_useropt_orig"
+	 ac_unrecognized_sep=', ';;
+    esac
+    eval with_$ac_useropt=no ;;
+
+  --x)
+    # Obsolete; use --with-x.
+    with_x=yes ;;
+
+  -x-includes | --x-includes | --x-include | --x-includ | --x-inclu \
+  | --x-incl | --x-inc | --x-in | --x-i)
+    ac_prev=x_includes ;;
+  -x-includes=* | --x-includes=* | --x-include=* | --x-includ=* | --x-inclu=* \
+  | --x-incl=* | --x-inc=* | --x-in=* | --x-i=*)
+    x_includes=$ac_optarg ;;
+
+  -x-libraries | --x-libraries | --x-librarie | --x-librari \
+  | --x-librar | --x-libra | --x-libr | --x-lib | --x-li | --x-l)
+    ac_prev=x_libraries ;;
+  -x-libraries=* | --x-libraries=* | --x-librarie=* | --x-librari=* \
+  | --x-librar=* | --x-libra=* | --x-libr=* | --x-lib=* | --x-li=* | --x-l=*)
+    x_libraries=$ac_optarg ;;
+
+  -*) as_fn_error $? "unrecognized option: \`$ac_option'
+Try \`$0 --help' for more information"
+    ;;
+
+  *=*)
+    ac_envvar=`expr "x$ac_option" : 'x\([^=]*\)='`
+    # Reject names that are not valid shell variable names.
+    case $ac_envvar in #(
+      '' | [0-9]* | *[!_$as_cr_alnum]* )
+      as_fn_error $? "invalid variable name: \`$ac_envvar'" ;;
+    esac
+    eval $ac_envvar=\$ac_optarg
+    export $ac_envvar ;;
+
+  *)
+    # FIXME: should be removed in autoconf 3.0.
+    $as_echo "$as_me: WARNING: you should use --build, --host, --target" >&2
+    expr "x$ac_option" : ".*[^-._$as_cr_alnum]" >/dev/null &&
+      $as_echo "$as_me: WARNING: invalid host type: $ac_option" >&2
+    : "${build_alias=$ac_option} ${host_alias=$ac_option} ${target_alias=$ac_option}"
+    ;;
+
+  esac
+done
+
+if test -n "$ac_prev"; then
+  ac_option=--`echo $ac_prev | sed 's/_/-/g'`
+  as_fn_error $? "missing argument to $ac_option"
+fi
+
+if test -n "$ac_unrecognized_opts"; then
+  case $enable_option_checking in
+    no) ;;
+    fatal) as_fn_error $? "unrecognized options: $ac_unrecognized_opts" ;;
+    *)     $as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2 ;;
+  esac
+fi
+
+# Check all directory arguments for consistency.
+for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
+		datadir sysconfdir sharedstatedir localstatedir includedir \
+		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
+		libdir localedir mandir
+do
+  eval ac_val=\$$ac_var
+  # Remove trailing slashes.
+  case $ac_val in
+    */ )
+      ac_val=`expr "X$ac_val" : 'X\(.*[^/]\)' \| "X$ac_val" : 'X\(.*\)'`
+      eval $ac_var=\$ac_val;;
+  esac
+  # Be sure to have absolute directory names.
+  case $ac_val in
+    [\\/$]* | ?:[\\/]* )  continue;;
+    NONE | '' ) case $ac_var in *prefix ) continue;; esac;;
+  esac
+  as_fn_error $? "expected an absolute directory name for --$ac_var: $ac_val"
+done
+
+# There might be people who depend on the old broken behavior: `$host'
+# used to hold the argument of --host etc.
+# FIXME: To remove some day.
+build=$build_alias
+host=$host_alias
+target=$target_alias
+
+# FIXME: To remove some day.
+if test "x$host_alias" != x; then
+  if test "x$build_alias" = x; then
+    cross_compiling=maybe
+  elif test "x$build_alias" != "x$host_alias"; then
+    cross_compiling=yes
+  fi
+fi
+
+ac_tool_prefix=
+test -n "$host_alias" && ac_tool_prefix=$host_alias-
+
+test "$silent" = yes && exec 6>/dev/null
+
+
+ac_pwd=`pwd` && test -n "$ac_pwd" &&
+ac_ls_di=`ls -di .` &&
+ac_pwd_ls_di=`cd "$ac_pwd" && ls -di .` ||
+  as_fn_error $? "working directory cannot be determined"
+test "X$ac_ls_di" = "X$ac_pwd_ls_di" ||
+  as_fn_error $? "pwd does not report name of working directory"
+
+
+# Find the source files, if location was not specified.
+if test -z "$srcdir"; then
+  ac_srcdir_defaulted=yes
+  # Try the directory containing this script, then the parent directory.
+  ac_confdir=`$as_dirname -- "$as_myself" ||
+$as_expr X"$as_myself" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
+	 X"$as_myself" : 'X\(//\)[^/]' \| \
+	 X"$as_myself" : 'X\(//\)$' \| \
+	 X"$as_myself" : 'X\(/\)' \| . 2>/dev/null ||
+$as_echo X"$as_myself" |
+    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)[^/].*/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\).*/{
+	    s//\1/
+	    q
+	  }
+	  s/.*/./; q'`
+  srcdir=$ac_confdir
+  if test ! -r "$srcdir/$ac_unique_file"; then
+    srcdir=..
+  fi
+else
+  ac_srcdir_defaulted=no
+fi
+if test ! -r "$srcdir/$ac_unique_file"; then
+  test "$ac_srcdir_defaulted" = yes && srcdir="$ac_confdir or .."
+  as_fn_error $? "cannot find sources ($ac_unique_file) in $srcdir"
+fi
+ac_msg="sources are in $srcdir, but \`cd $srcdir' does not work"
+ac_abs_confdir=`(
+	cd "$srcdir" && test -r "./$ac_unique_file" || as_fn_error $? "$ac_msg"
+	pwd)`
+# When building in place, set srcdir=.
+if test "$ac_abs_confdir" = "$ac_pwd"; then
+  srcdir=.
+fi
+# Remove unnecessary trailing slashes from srcdir.
+# Double slashes in file names in object file debugging info
+# mess up M-x gdb in Emacs.
+case $srcdir in
+*/) srcdir=`expr "X$srcdir" : 'X\(.*[^/]\)' \| "X$srcdir" : 'X\(.*\)'`;;
+esac
+for ac_var in $ac_precious_vars; do
+  eval ac_env_${ac_var}_set=\${${ac_var}+set}
+  eval ac_env_${ac_var}_value=\$${ac_var}
+  eval ac_cv_env_${ac_var}_set=\${${ac_var}+set}
+  eval ac_cv_env_${ac_var}_value=\$${ac_var}
+done
+
+#
+# Report the --help message.
+#
+if test "$ac_init_help" = "long"; then
+  # Omit some internal or obsolete options to make the list less imposing.
+  # This message is too long to be a string in the A/UX 3.1 sh.
+  cat <<_ACEOF
+\`configure' configures this package to adapt to many kinds of systems.
+
+Usage: $0 [OPTION]... [VAR=VALUE]...
+
+To assign environment variables (e.g., CC, CFLAGS...), specify them as
+VAR=VALUE.  See below for descriptions of some of the useful variables.
+
+Defaults for the options are specified in brackets.
+
+Configuration:
+  -h, --help              display this help and exit
+      --help=short        display options specific to this package
+      --help=recursive    display the short help of all the included packages
+  -V, --version           display version information and exit
+  -q, --quiet, --silent   do not print \`checking ...' messages
+      --cache-file=FILE   cache test results in FILE [disabled]
+  -C, --config-cache      alias for \`--cache-file=config.cache'
+  -n, --no-create         do not create output files
+      --srcdir=DIR        find the sources in DIR [configure dir or \`..']
+
+Installation directories:
+  --prefix=PREFIX         install architecture-independent files in PREFIX
+                          [$ac_default_prefix]
+  --exec-prefix=EPREFIX   install architecture-dependent files in EPREFIX
+                          [PREFIX]
+
+By default, \`make install' will install all the files in
+\`$ac_default_prefix/bin', \`$ac_default_prefix/lib' etc.  You can specify
+an installation prefix other than \`$ac_default_prefix' using \`--prefix',
+for instance \`--prefix=\$HOME'.
+
+For better control, use the options below.
+
+Fine tuning of the installation directories:
+  --bindir=DIR            user executables [EPREFIX/bin]
+  --sbindir=DIR           system admin executables [EPREFIX/sbin]
+  --libexecdir=DIR        program executables [EPREFIX/libexec]
+  --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
+  --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
+  --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
+  --libdir=DIR            object code libraries [EPREFIX/lib]
+  --includedir=DIR        C header files [PREFIX/include]
+  --oldincludedir=DIR     C header files for non-gcc [/usr/include]
+  --datarootdir=DIR       read-only arch.-independent data root [PREFIX/share]
+  --datadir=DIR           read-only architecture-independent data [DATAROOTDIR]
+  --infodir=DIR           info documentation [DATAROOTDIR/info]
+  --localedir=DIR         locale-dependent data [DATAROOTDIR/locale]
+  --mandir=DIR            man documentation [DATAROOTDIR/man]
+  --docdir=DIR            documentation root [DATAROOTDIR/doc/PACKAGE]
+  --htmldir=DIR           html documentation [DOCDIR]
+  --dvidir=DIR            dvi documentation [DOCDIR]
+  --pdfdir=DIR            pdf documentation [DOCDIR]
+  --psdir=DIR             ps documentation [DOCDIR]
+_ACEOF
+
+  cat <<\_ACEOF
+
+System types:
+  --build=BUILD     configure for building on BUILD [guessed]
+  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
+  --target=TARGET   configure for building compilers for TARGET [HOST]
+_ACEOF
+fi
+
+if test -n "$ac_init_help"; then
+
+  cat <<\_ACEOF
+
+Some influential environment variables:
+  CC          C compiler command
+  CFLAGS      C compiler flags
+  LDFLAGS     linker flags, e.g. -L<lib dir> if you have libraries in a
+              nonstandard directory <lib dir>
+  LIBS        libraries to pass to the linker, e.g. -l<library>
+  CPPFLAGS    (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
+              you have headers in a nonstandard directory <include dir>
+  CPP         C preprocessor
+
+Use these variables to override the choices made by `configure' or to help
+it to find libraries and programs with nonstandard names/locations.
+
+Report bugs to the package provider.
+_ACEOF
+ac_status=$?
+fi
+
+if test "$ac_init_help" = "recursive"; then
+  # If there are subdirs, report their specific --help.
+  for ac_dir in : $ac_subdirs_all; do test "x$ac_dir" = x: && continue
+    test -d "$ac_dir" ||
+      { cd "$srcdir" && ac_pwd=`pwd` && srcdir=. && test -d "$ac_dir"; } ||
+      continue
+    ac_builddir=.
+
+case "$ac_dir" in
+.) ac_dir_suffix= ac_top_builddir_sub=. ac_top_build_prefix= ;;
+*)
+  ac_dir_suffix=/`$as_echo "$ac_dir" | sed 's|^\.[\\/]||'`
+  # A ".." for each directory in $ac_dir_suffix.
+  ac_top_builddir_sub=`$as_echo "$ac_dir_suffix" | sed 's|/[^\\/]*|/..|g;s|/||'`
+  case $ac_top_builddir_sub in
+  "") ac_top_builddir_sub=. ac_top_build_prefix= ;;
+  *)  ac_top_build_prefix=$ac_top_builddir_sub/ ;;
+  esac ;;
+esac
+ac_abs_top_builddir=$ac_pwd
+ac_abs_builddir=$ac_pwd$ac_dir_suffix
+# for backward compatibility:
+ac_top_builddir=$ac_top_build_prefix
+
+case $srcdir in
+  .)  # We are building in place.
+    ac_srcdir=.
+    ac_top_srcdir=$ac_top_builddir_sub
+    ac_abs_top_srcdir=$ac_pwd ;;
+  [\\/]* | ?:[\\/]* )  # Absolute name.
+    ac_srcdir=$srcdir$ac_dir_suffix;
+    ac_top_srcdir=$srcdir
+    ac_abs_top_srcdir=$srcdir ;;
+  *) # Relative name.
+    ac_srcdir=$ac_top_build_prefix$srcdir$ac_dir_suffix
+    ac_top_srcdir=$ac_top_build_prefix$srcdir
+    ac_abs_top_srcdir=$ac_pwd/$srcdir ;;
+esac
+ac_abs_srcdir=$ac_abs_top_srcdir$ac_dir_suffix
+
+    cd "$ac_dir" || { ac_status=$?; continue; }
+    # Check for guested configure.
+    if test -f "$ac_srcdir/configure.gnu"; then
+      echo &&
+      $SHELL "$ac_srcdir/configure.gnu" --help=recursive
+    elif test -f "$ac_srcdir/configure"; then
+      echo &&
+      $SHELL "$ac_srcdir/configure" --help=recursive
+    else
+      $as_echo "$as_me: WARNING: no configuration information is in $ac_dir" >&2
+    fi || ac_status=$?
+    cd "$ac_pwd" || { ac_status=$?; break; }
+  done
+fi
+
+test -n "$ac_init_help" && exit $ac_status
+if $ac_init_version; then
+  cat <<\_ACEOF
+configure
+generated by GNU Autoconf 2.69
+
+Copyright (C) 2012 Free Software Foundation, Inc.
+This configure script is free software; the Free Software Foundation
+gives unlimited permission to copy, distribute and modify it.
+_ACEOF
+  exit
+fi
+
+## ------------------------ ##
+## Autoconf initialization. ##
+## ------------------------ ##
+
+# ac_fn_c_try_compile LINENO
+# --------------------------
+# Try to compile conftest.$ac_ext, and return whether this succeeded.
+ac_fn_c_try_compile ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  rm -f conftest.$ac_objext
+  if { { ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_compile") 2>conftest.err
+  ac_status=$?
+  if test -s conftest.err; then
+    grep -v '^ *+' conftest.err >conftest.er1
+    cat conftest.er1 >&5
+    mv -f conftest.er1 conftest.err
+  fi
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } && {
+	 test -z "$ac_c_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest.$ac_objext; then :
+  ac_retval=0
+else
+  $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_retval=1
+fi
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+  as_fn_set_status $ac_retval
+
+} # ac_fn_c_try_compile
+
+# ac_fn_c_try_link LINENO
+# -----------------------
+# Try to link conftest.$ac_ext, and return whether this succeeded.
+ac_fn_c_try_link ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  rm -f conftest.$ac_objext conftest$ac_exeext
+  if { { ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_link") 2>conftest.err
+  ac_status=$?
+  if test -s conftest.err; then
+    grep -v '^ *+' conftest.err >conftest.er1
+    cat conftest.er1 >&5
+    mv -f conftest.er1 conftest.err
+  fi
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } && {
+	 test -z "$ac_c_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest$ac_exeext && {
+	 test "$cross_compiling" = yes ||
+	 test -x conftest$ac_exeext
+       }; then :
+  ac_retval=0
+else
+  $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_retval=1
+fi
+  # Delete the IPA/IPO (Inter Procedural Analysis/Optimization) information
+  # created by the PGI compiler (conftest_ipa8_conftest.oo), as it would
+  # interfere with the next link command; also delete a directory that is
+  # left behind by Apple's compiler.  We do this before executing the actions.
+  rm -rf conftest.dSYM conftest_ipa8_conftest.oo
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+  as_fn_set_status $ac_retval
+
+} # ac_fn_c_try_link
+
+# ac_fn_c_check_type LINENO TYPE VAR INCLUDES
+# -------------------------------------------
+# Tests whether TYPE exists after having included INCLUDES, setting cache
+# variable VAR accordingly.
+ac_fn_c_check_type ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $2" >&5
+$as_echo_n "checking for $2... " >&6; }
+if eval \${$3+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  eval "$3=no"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main ()
+{
+if (sizeof ($2))
+	 return 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main ()
+{
+if (sizeof (($2)))
+	    return 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+else
+  eval "$3=yes"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+eval ac_res=\$$3
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+
+} # ac_fn_c_check_type
+
+# ac_fn_c_try_cpp LINENO
+# ----------------------
+# Try to preprocess conftest.$ac_ext, and return whether this succeeded.
+ac_fn_c_try_cpp ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  if { { ac_try="$ac_cpp conftest.$ac_ext"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_cpp conftest.$ac_ext") 2>conftest.err
+  ac_status=$?
+  if test -s conftest.err; then
+    grep -v '^ *+' conftest.err >conftest.er1
+    cat conftest.er1 >&5
+    mv -f conftest.er1 conftest.err
+  fi
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } > conftest.i && {
+	 test -z "$ac_c_preproc_warn_flag$ac_c_werror_flag" ||
+	 test ! -s conftest.err
+       }; then :
+  ac_retval=0
+else
+  $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+    ac_retval=1
+fi
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+  as_fn_set_status $ac_retval
+
+} # ac_fn_c_try_cpp
+
+# ac_fn_c_try_run LINENO
+# ----------------------
+# Try to link conftest.$ac_ext, and return whether this succeeded. Assumes
+# that executables *can* be run.
+ac_fn_c_try_run ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  if { { ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_link") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } && { ac_try='./conftest$ac_exeext'
+  { { case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }; then :
+  ac_retval=0
+else
+  $as_echo "$as_me: program exited with status $ac_status" >&5
+       $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+       ac_retval=$ac_status
+fi
+  rm -rf conftest.dSYM conftest_ipa8_conftest.oo
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+  as_fn_set_status $ac_retval
+
+} # ac_fn_c_try_run
+
+# ac_fn_c_check_header_compile LINENO HEADER VAR INCLUDES
+# -------------------------------------------------------
+# Tests whether HEADER exists and can be compiled using the include files in
+# INCLUDES, setting the cache variable VAR accordingly.
+ac_fn_c_check_header_compile ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $2" >&5
+$as_echo_n "checking for $2... " >&6; }
+if eval \${$3+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+#include <$2>
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  eval "$3=yes"
+else
+  eval "$3=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+eval ac_res=\$$3
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+
+} # ac_fn_c_check_header_compile
+
+# ac_fn_c_check_header_mongrel LINENO HEADER VAR INCLUDES
+# -------------------------------------------------------
+# Tests whether HEADER exists, giving a warning if it cannot be compiled using
+# the include files in INCLUDES and setting the cache variable VAR
+# accordingly.
+ac_fn_c_check_header_mongrel ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  if eval \${$3+:} false; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $2" >&5
+$as_echo_n "checking for $2... " >&6; }
+if eval \${$3+:} false; then :
+  $as_echo_n "(cached) " >&6
+fi
+eval ac_res=\$$3
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+else
+  # Is the header compilable?
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking $2 usability" >&5
+$as_echo_n "checking $2 usability... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+#include <$2>
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_header_compiler=yes
+else
+  ac_header_compiler=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_header_compiler" >&5
+$as_echo "$ac_header_compiler" >&6; }
+
+# Is the header present?
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking $2 presence" >&5
+$as_echo_n "checking $2 presence... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <$2>
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"; then :
+  ac_header_preproc=yes
+else
+  ac_header_preproc=no
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_header_preproc" >&5
+$as_echo "$ac_header_preproc" >&6; }
+
+# So?  What about this header?
+case $ac_header_compiler:$ac_header_preproc:$ac_c_preproc_warn_flag in #((
+  yes:no: )
+    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: accepted by the compiler, rejected by the preprocessor!" >&5
+$as_echo "$as_me: WARNING: $2: accepted by the compiler, rejected by the preprocessor!" >&2;}
+    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: proceeding with the compiler's result" >&5
+$as_echo "$as_me: WARNING: $2: proceeding with the compiler's result" >&2;}
+    ;;
+  no:yes:* )
+    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: present but cannot be compiled" >&5
+$as_echo "$as_me: WARNING: $2: present but cannot be compiled" >&2;}
+    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2:     check for missing prerequisite headers?" >&5
+$as_echo "$as_me: WARNING: $2:     check for missing prerequisite headers?" >&2;}
+    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: see the Autoconf documentation" >&5
+$as_echo "$as_me: WARNING: $2: see the Autoconf documentation" >&2;}
+    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2:     section \"Present But Cannot Be Compiled\"" >&5
+$as_echo "$as_me: WARNING: $2:     section \"Present But Cannot Be Compiled\"" >&2;}
+    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: proceeding with the compiler's result" >&5
+$as_echo "$as_me: WARNING: $2: proceeding with the compiler's result" >&2;}
+    ;;
+esac
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $2" >&5
+$as_echo_n "checking for $2... " >&6; }
+if eval \${$3+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  eval "$3=\$ac_header_compiler"
+fi
+eval ac_res=\$$3
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+fi
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+
+} # ac_fn_c_check_header_mongrel
+cat >config.log <<_ACEOF
+This file contains any messages produced by compilers while
+running configure, to aid debugging if configure makes a mistake.
+
+It was created by $as_me, which was
+generated by GNU Autoconf 2.69.  Invocation command line was
+
+  $ $0 $@
+
+_ACEOF
+exec 5>>config.log
+{
+cat <<_ASUNAME
+## --------- ##
+## Platform. ##
+## --------- ##
+
+hostname = `(hostname || uname -n) 2>/dev/null | sed 1q`
+uname -m = `(uname -m) 2>/dev/null || echo unknown`
+uname -r = `(uname -r) 2>/dev/null || echo unknown`
+uname -s = `(uname -s) 2>/dev/null || echo unknown`
+uname -v = `(uname -v) 2>/dev/null || echo unknown`
+
+/usr/bin/uname -p = `(/usr/bin/uname -p) 2>/dev/null || echo unknown`
+/bin/uname -X     = `(/bin/uname -X) 2>/dev/null     || echo unknown`
+
+/bin/arch              = `(/bin/arch) 2>/dev/null              || echo unknown`
+/usr/bin/arch -k       = `(/usr/bin/arch -k) 2>/dev/null       || echo unknown`
+/usr/convex/getsysinfo = `(/usr/convex/getsysinfo) 2>/dev/null || echo unknown`
+/usr/bin/hostinfo      = `(/usr/bin/hostinfo) 2>/dev/null      || echo unknown`
+/bin/machine           = `(/bin/machine) 2>/dev/null           || echo unknown`
+/usr/bin/oslevel       = `(/usr/bin/oslevel) 2>/dev/null       || echo unknown`
+/bin/universe          = `(/bin/universe) 2>/dev/null          || echo unknown`
+
+_ASUNAME
+
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    $as_echo "PATH: $as_dir"
+  done
+IFS=$as_save_IFS
+
+} >&5
+
+cat >&5 <<_ACEOF
+
+
+## ----------- ##
+## Core tests. ##
+## ----------- ##
+
+_ACEOF
+
+
+# Keep a trace of the command line.
+# Strip out --no-create and --no-recursion so they do not pile up.
+# Strip out --silent because we don't want to record it for future runs.
+# Also quote any args containing shell meta-characters.
+# Make two passes to allow for proper duplicate-argument suppression.
+ac_configure_args=
+ac_configure_args0=
+ac_configure_args1=
+ac_must_keep_next=false
+for ac_pass in 1 2
+do
+  for ac_arg
+  do
+    case $ac_arg in
+    -no-create | --no-c* | -n | -no-recursion | --no-r*) continue ;;
+    -q | -quiet | --quiet | --quie | --qui | --qu | --q \
+    | -silent | --silent | --silen | --sile | --sil)
+      continue ;;
+    *\'*)
+      ac_arg=`$as_echo "$ac_arg" | sed "s/'/'\\\\\\\\''/g"` ;;
+    esac
+    case $ac_pass in
+    1) as_fn_append ac_configure_args0 " '$ac_arg'" ;;
+    2)
+      as_fn_append ac_configure_args1 " '$ac_arg'"
+      if test $ac_must_keep_next = true; then
+	ac_must_keep_next=false # Got value, back to normal.
+      else
+	case $ac_arg in
+	  *=* | --config-cache | -C | -disable-* | --disable-* \
+	  | -enable-* | --enable-* | -gas | --g* | -nfp | --nf* \
+	  | -q | -quiet | --q* | -silent | --sil* | -v | -verb* \
+	  | -with-* | --with-* | -without-* | --without-* | --x)
+	    case "$ac_configure_args0 " in
+	      "$ac_configure_args1"*" '$ac_arg' "* ) continue ;;
+	    esac
+	    ;;
+	  -* ) ac_must_keep_next=true ;;
+	esac
+      fi
+      as_fn_append ac_configure_args " '$ac_arg'"
+      ;;
+    esac
+  done
+done
+{ ac_configure_args0=; unset ac_configure_args0;}
+{ ac_configure_args1=; unset ac_configure_args1;}
+
+# When interrupted or exit'd, cleanup temporary files, and complete
+# config.log.  We remove comments because anyway the quotes in there
+# would cause problems or look ugly.
+# WARNING: Use '\'' to represent an apostrophe within the trap.
+# WARNING: Do not start the trap code with a newline, due to a FreeBSD 4.0 bug.
+trap 'exit_status=$?
+  # Save into config.log some information that might help in debugging.
+  {
+    echo
+
+    $as_echo "## ---------------- ##
+## Cache variables. ##
+## ---------------- ##"
+    echo
+    # The following way of writing the cache mishandles newlines in values,
+(
+  for ac_var in `(set) 2>&1 | sed -n '\''s/^\([a-zA-Z_][a-zA-Z0-9_]*\)=.*/\1/p'\''`; do
+    eval ac_val=\$$ac_var
+    case $ac_val in #(
+    *${as_nl}*)
+      case $ac_var in #(
+      *_cv_*) { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cache variable $ac_var contains a newline" >&5
+$as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
+      esac
+      case $ac_var in #(
+      _ | IFS | as_nl) ;; #(
+      BASH_ARGV | BASH_SOURCE) eval $ac_var= ;; #(
+      *) { eval $ac_var=; unset $ac_var;} ;;
+      esac ;;
+    esac
+  done
+  (set) 2>&1 |
+    case $as_nl`(ac_space='\'' '\''; set) 2>&1` in #(
+    *${as_nl}ac_space=\ *)
+      sed -n \
+	"s/'\''/'\''\\\\'\'''\''/g;
+	  s/^\\([_$as_cr_alnum]*_cv_[_$as_cr_alnum]*\\)=\\(.*\\)/\\1='\''\\2'\''/p"
+      ;; #(
+    *)
+      sed -n "/^[_$as_cr_alnum]*_cv_[_$as_cr_alnum]*=/p"
+      ;;
+    esac |
+    sort
+)
+    echo
+
+    $as_echo "## ----------------- ##
+## Output variables. ##
+## ----------------- ##"
+    echo
+    for ac_var in $ac_subst_vars
+    do
+      eval ac_val=\$$ac_var
+      case $ac_val in
+      *\'\''*) ac_val=`$as_echo "$ac_val" | sed "s/'\''/'\''\\\\\\\\'\'''\''/g"`;;
+      esac
+      $as_echo "$ac_var='\''$ac_val'\''"
+    done | sort
+    echo
+
+    if test -n "$ac_subst_files"; then
+      $as_echo "## ------------------- ##
+## File substitutions. ##
+## ------------------- ##"
+      echo
+      for ac_var in $ac_subst_files
+      do
+	eval ac_val=\$$ac_var
+	case $ac_val in
+	*\'\''*) ac_val=`$as_echo "$ac_val" | sed "s/'\''/'\''\\\\\\\\'\'''\''/g"`;;
+	esac
+	$as_echo "$ac_var='\''$ac_val'\''"
+      done | sort
+      echo
+    fi
+
+    if test -s confdefs.h; then
+      $as_echo "## ----------- ##
+## confdefs.h. ##
+## ----------- ##"
+      echo
+      cat confdefs.h
+      echo
+    fi
+    test "$ac_signal" != 0 &&
+      $as_echo "$as_me: caught signal $ac_signal"
+    $as_echo "$as_me: exit $exit_status"
+  } >&5
+  rm -f core *.core core.conftest.* &&
+    rm -f -r conftest* confdefs* conf$$* $ac_clean_files &&
+    exit $exit_status
+' 0
+for ac_signal in 1 2 13 15; do
+  trap 'ac_signal='$ac_signal'; as_fn_exit 1' $ac_signal
+done
+ac_signal=0
+
+# confdefs.h avoids OS command line length limits that DEFS can exceed.
+rm -f -r conftest* confdefs.h
+
+$as_echo "/* confdefs.h */" > confdefs.h
+
+# Predefined preprocessor variables.
+
+cat >>confdefs.h <<_ACEOF
+#define PACKAGE_NAME "$PACKAGE_NAME"
+_ACEOF
+
+cat >>confdefs.h <<_ACEOF
+#define PACKAGE_TARNAME "$PACKAGE_TARNAME"
+_ACEOF
+
+cat >>confdefs.h <<_ACEOF
+#define PACKAGE_VERSION "$PACKAGE_VERSION"
+_ACEOF
+
+cat >>confdefs.h <<_ACEOF
+#define PACKAGE_STRING "$PACKAGE_STRING"
+_ACEOF
+
+cat >>confdefs.h <<_ACEOF
+#define PACKAGE_BUGREPORT "$PACKAGE_BUGREPORT"
+_ACEOF
+
+cat >>confdefs.h <<_ACEOF
+#define PACKAGE_URL "$PACKAGE_URL"
+_ACEOF
+
+
+# Let the site file select an alternate cache file if it wants to.
+# Prefer an explicitly selected file to automatically selected ones.
+ac_site_file1=NONE
+ac_site_file2=NONE
+if test -n "$CONFIG_SITE"; then
+  # We do not want a PATH search for config.site.
+  case $CONFIG_SITE in #((
+    -*)  ac_site_file1=./$CONFIG_SITE;;
+    */*) ac_site_file1=$CONFIG_SITE;;
+    *)   ac_site_file1=./$CONFIG_SITE;;
+  esac
+elif test "x$prefix" != xNONE; then
+  ac_site_file1=$prefix/share/config.site
+  ac_site_file2=$prefix/etc/config.site
+else
+  ac_site_file1=$ac_default_prefix/share/config.site
+  ac_site_file2=$ac_default_prefix/etc/config.site
+fi
+for ac_site_file in "$ac_site_file1" "$ac_site_file2"
+do
+  test "x$ac_site_file" = xNONE && continue
+  if test /dev/null != "$ac_site_file" && test -r "$ac_site_file"; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: loading site script $ac_site_file" >&5
+$as_echo "$as_me: loading site script $ac_site_file" >&6;}
+    sed 's/^/| /' "$ac_site_file" >&5
+    . "$ac_site_file" \
+      || { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "failed to load site script $ac_site_file
+See \`config.log' for more details" "$LINENO" 5; }
+  fi
+done
+
+if test -r "$cache_file"; then
+  # Some versions of bash will fail to source /dev/null (special files
+  # actually), so we avoid doing that.  DJGPP emulates it as a regular file.
+  if test /dev/null != "$cache_file" && test -f "$cache_file"; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: loading cache $cache_file" >&5
+$as_echo "$as_me: loading cache $cache_file" >&6;}
+    case $cache_file in
+      [\\/]* | ?:[\\/]* ) . "$cache_file";;
+      *)                      . "./$cache_file";;
+    esac
+  fi
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: creating cache $cache_file" >&5
+$as_echo "$as_me: creating cache $cache_file" >&6;}
+  >$cache_file
+fi
+
+# Check that the precious variables saved in the cache have kept the same
+# value.
+ac_cache_corrupted=false
+for ac_var in $ac_precious_vars; do
+  eval ac_old_set=\$ac_cv_env_${ac_var}_set
+  eval ac_new_set=\$ac_env_${ac_var}_set
+  eval ac_old_val=\$ac_cv_env_${ac_var}_value
+  eval ac_new_val=\$ac_env_${ac_var}_value
+  case $ac_old_set,$ac_new_set in
+    set,)
+      { $as_echo "$as_me:${as_lineno-$LINENO}: error: \`$ac_var' was set to \`$ac_old_val' in the previous run" >&5
+$as_echo "$as_me: error: \`$ac_var' was set to \`$ac_old_val' in the previous run" >&2;}
+      ac_cache_corrupted=: ;;
+    ,set)
+      { $as_echo "$as_me:${as_lineno-$LINENO}: error: \`$ac_var' was not set in the previous run" >&5
+$as_echo "$as_me: error: \`$ac_var' was not set in the previous run" >&2;}
+      ac_cache_corrupted=: ;;
+    ,);;
+    *)
+      if test "x$ac_old_val" != "x$ac_new_val"; then
+	# differences in whitespace do not lead to failure.
+	ac_old_val_w=`echo x $ac_old_val`
+	ac_new_val_w=`echo x $ac_new_val`
+	if test "$ac_old_val_w" != "$ac_new_val_w"; then
+	  { $as_echo "$as_me:${as_lineno-$LINENO}: error: \`$ac_var' has changed since the previous run:" >&5
+$as_echo "$as_me: error: \`$ac_var' has changed since the previous run:" >&2;}
+	  ac_cache_corrupted=:
+	else
+	  { $as_echo "$as_me:${as_lineno-$LINENO}: warning: ignoring whitespace changes in \`$ac_var' since the previous run:" >&5
+$as_echo "$as_me: warning: ignoring whitespace changes in \`$ac_var' since the previous run:" >&2;}
+	  eval $ac_var=\$ac_old_val
+	fi
+	{ $as_echo "$as_me:${as_lineno-$LINENO}:   former value:  \`$ac_old_val'" >&5
+$as_echo "$as_me:   former value:  \`$ac_old_val'" >&2;}
+	{ $as_echo "$as_me:${as_lineno-$LINENO}:   current value: \`$ac_new_val'" >&5
+$as_echo "$as_me:   current value: \`$ac_new_val'" >&2;}
+      fi;;
+  esac
+  # Pass precious variables to config.status.
+  if test "$ac_new_set" = set; then
+    case $ac_new_val in
+    *\'*) ac_arg=$ac_var=`$as_echo "$ac_new_val" | sed "s/'/'\\\\\\\\''/g"` ;;
+    *) ac_arg=$ac_var=$ac_new_val ;;
+    esac
+    case " $ac_configure_args " in
+      *" '$ac_arg' "*) ;; # Avoid dups.  Use of quotes ensures accuracy.
+      *) as_fn_append ac_configure_args " '$ac_arg'" ;;
+    esac
+  fi
+done
+if $ac_cache_corrupted; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+  { $as_echo "$as_me:${as_lineno-$LINENO}: error: changes in the environment can compromise the build" >&5
+$as_echo "$as_me: error: changes in the environment can compromise the build" >&2;}
+  as_fn_error $? "run \`make distclean' and/or \`rm $cache_file' and start over" "$LINENO" 5
+fi
+## -------------------- ##
+## Main body of script. ##
+## -------------------- ##
+
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+ac_config_headers="$ac_config_headers rktio_config.h"
+
+
+ac_aux_dir=
+for ac_dir in ../lt "$srcdir"/../lt; do
+  if test -f "$ac_dir/install-sh"; then
+    ac_aux_dir=$ac_dir
+    ac_install_sh="$ac_aux_dir/install-sh -c"
+    break
+  elif test -f "$ac_dir/install.sh"; then
+    ac_aux_dir=$ac_dir
+    ac_install_sh="$ac_aux_dir/install.sh -c"
+    break
+  elif test -f "$ac_dir/shtool"; then
+    ac_aux_dir=$ac_dir
+    ac_install_sh="$ac_aux_dir/shtool install -c"
+    break
+  fi
+done
+if test -z "$ac_aux_dir"; then
+  as_fn_error $? "cannot find install-sh, install.sh, or shtool in ../lt \"$srcdir\"/../lt" "$LINENO" 5
+fi
+
+# These three variables are undocumented and unsupported,
+# and are intended to be withdrawn in a future Autoconf release.
+# They can cause serious problems if a builder's source tree is in a directory
+# whose full name contains unusual characters.
+ac_config_guess="$SHELL $ac_aux_dir/config.guess"  # Please don't use this var.
+ac_config_sub="$SHELL $ac_aux_dir/config.sub"  # Please don't use this var.
+ac_configure="$SHELL $ac_aux_dir/configure"  # Please don't use this var.
+
+
+# Make sure we can run config.sub.
+$SHELL "$ac_aux_dir/config.sub" sun4 >/dev/null 2>&1 ||
+  as_fn_error $? "cannot run $SHELL $ac_aux_dir/config.sub" "$LINENO" 5
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking build system type" >&5
+$as_echo_n "checking build system type... " >&6; }
+if ${ac_cv_build+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_build_alias=$build_alias
+test "x$ac_build_alias" = x &&
+  ac_build_alias=`$SHELL "$ac_aux_dir/config.guess"`
+test "x$ac_build_alias" = x &&
+  as_fn_error $? "cannot guess build type; you must specify one" "$LINENO" 5
+ac_cv_build=`$SHELL "$ac_aux_dir/config.sub" $ac_build_alias` ||
+  as_fn_error $? "$SHELL $ac_aux_dir/config.sub $ac_build_alias failed" "$LINENO" 5
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_build" >&5
+$as_echo "$ac_cv_build" >&6; }
+case $ac_cv_build in
+*-*-*) ;;
+*) as_fn_error $? "invalid value of canonical build" "$LINENO" 5;;
+esac
+build=$ac_cv_build
+ac_save_IFS=$IFS; IFS='-'
+set x $ac_cv_build
+shift
+build_cpu=$1
+build_vendor=$2
+shift; shift
+# Remember, the first character of IFS is used to create $*,
+# except with old shells:
+build_os=$*
+IFS=$ac_save_IFS
+case $build_os in *\ *) build_os=`echo "$build_os" | sed 's/ /-/g'`;; esac
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking host system type" >&5
+$as_echo_n "checking host system type... " >&6; }
+if ${ac_cv_host+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "x$host_alias" = x; then
+  ac_cv_host=$ac_cv_build
+else
+  ac_cv_host=`$SHELL "$ac_aux_dir/config.sub" $host_alias` ||
+    as_fn_error $? "$SHELL $ac_aux_dir/config.sub $host_alias failed" "$LINENO" 5
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_host" >&5
+$as_echo "$ac_cv_host" >&6; }
+case $ac_cv_host in
+*-*-*) ;;
+*) as_fn_error $? "invalid value of canonical host" "$LINENO" 5;;
+esac
+host=$ac_cv_host
+ac_save_IFS=$IFS; IFS='-'
+set x $ac_cv_host
+shift
+host_cpu=$1
+host_vendor=$2
+shift; shift
+# Remember, the first character of IFS is used to create $*,
+# except with old shells:
+host_os=$*
+IFS=$ac_save_IFS
+case $host_os in *\ *) host_os=`echo "$host_os" | sed 's/ /-/g'`;; esac
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking target system type" >&5
+$as_echo_n "checking target system type... " >&6; }
+if ${ac_cv_target+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "x$target_alias" = x; then
+  ac_cv_target=$ac_cv_host
+else
+  ac_cv_target=`$SHELL "$ac_aux_dir/config.sub" $target_alias` ||
+    as_fn_error $? "$SHELL $ac_aux_dir/config.sub $target_alias failed" "$LINENO" 5
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_target" >&5
+$as_echo "$ac_cv_target" >&6; }
+case $ac_cv_target in
+*-*-*) ;;
+*) as_fn_error $? "invalid value of canonical target" "$LINENO" 5;;
+esac
+target=$ac_cv_target
+ac_save_IFS=$IFS; IFS='-'
+set x $ac_cv_target
+shift
+target_cpu=$1
+target_vendor=$2
+shift; shift
+# Remember, the first character of IFS is used to create $*,
+# except with old shells:
+target_os=$*
+IFS=$ac_save_IFS
+case $target_os in *\ *) target_os=`echo "$target_os" | sed 's/ /-/g'`;; esac
+
+
+# The aliases save the names the user supplied, while $host etc.
+# will get canonicalized.
+test -n "$target_alias" &&
+  test "$program_prefix$program_suffix$program_transform_name" = \
+    NONENONEs,x,x, &&
+  program_prefix=${target_alias}-
+
+
+###### Autoconfigure #######
+
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}gcc", so it can be a program name with args.
+set dummy ${ac_tool_prefix}gcc; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_CC+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$CC"; then
+  ac_cv_prog_CC="$CC" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_CC="${ac_tool_prefix}gcc"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+CC=$ac_cv_prog_CC
+if test -n "$CC"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
+$as_echo "$CC" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_prog_CC"; then
+  ac_ct_CC=$CC
+  # Extract the first word of "gcc", so it can be a program name with args.
+set dummy gcc; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_ac_ct_CC+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$ac_ct_CC"; then
+  ac_cv_prog_ac_ct_CC="$ac_ct_CC" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_ac_ct_CC="gcc"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+ac_ct_CC=$ac_cv_prog_ac_ct_CC
+if test -n "$ac_ct_CC"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CC" >&5
+$as_echo "$ac_ct_CC" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+  if test "x$ac_ct_CC" = x; then
+    CC=""
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    CC=$ac_ct_CC
+  fi
+else
+  CC="$ac_cv_prog_CC"
+fi
+
+if test -z "$CC"; then
+          if test -n "$ac_tool_prefix"; then
+    # Extract the first word of "${ac_tool_prefix}cc", so it can be a program name with args.
+set dummy ${ac_tool_prefix}cc; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_CC+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$CC"; then
+  ac_cv_prog_CC="$CC" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_CC="${ac_tool_prefix}cc"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+CC=$ac_cv_prog_CC
+if test -n "$CC"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
+$as_echo "$CC" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+  fi
+fi
+if test -z "$CC"; then
+  # Extract the first word of "cc", so it can be a program name with args.
+set dummy cc; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_CC+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$CC"; then
+  ac_cv_prog_CC="$CC" # Let the user override the test.
+else
+  ac_prog_rejected=no
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    if test "$as_dir/$ac_word$ac_exec_ext" = "/usr/ucb/cc"; then
+       ac_prog_rejected=yes
+       continue
+     fi
+    ac_cv_prog_CC="cc"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+if test $ac_prog_rejected = yes; then
+  # We found a bogon in the path, so make sure we never use it.
+  set dummy $ac_cv_prog_CC
+  shift
+  if test $# != 0; then
+    # We chose a different compiler from the bogus one.
+    # However, it has the same basename, so the bogon will be chosen
+    # first if we set CC to just the basename; use the full file name.
+    shift
+    ac_cv_prog_CC="$as_dir/$ac_word${1+' '}$@"
+  fi
+fi
+fi
+fi
+CC=$ac_cv_prog_CC
+if test -n "$CC"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
+$as_echo "$CC" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+fi
+if test -z "$CC"; then
+  if test -n "$ac_tool_prefix"; then
+  for ac_prog in cl.exe
+  do
+    # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
+set dummy $ac_tool_prefix$ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_CC+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$CC"; then
+  ac_cv_prog_CC="$CC" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_CC="$ac_tool_prefix$ac_prog"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+CC=$ac_cv_prog_CC
+if test -n "$CC"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $CC" >&5
+$as_echo "$CC" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+    test -n "$CC" && break
+  done
+fi
+if test -z "$CC"; then
+  ac_ct_CC=$CC
+  for ac_prog in cl.exe
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_ac_ct_CC+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$ac_ct_CC"; then
+  ac_cv_prog_ac_ct_CC="$ac_ct_CC" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_ac_ct_CC="$ac_prog"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+ac_ct_CC=$ac_cv_prog_ac_ct_CC
+if test -n "$ac_ct_CC"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CC" >&5
+$as_echo "$ac_ct_CC" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+  test -n "$ac_ct_CC" && break
+done
+
+  if test "x$ac_ct_CC" = x; then
+    CC=""
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    CC=$ac_ct_CC
+  fi
+fi
+
+fi
+
+
+test -z "$CC" && { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "no acceptable C compiler found in \$PATH
+See \`config.log' for more details" "$LINENO" 5; }
+
+# Provide some information about the compiler.
+$as_echo "$as_me:${as_lineno-$LINENO}: checking for C compiler version" >&5
+set X $ac_compile
+ac_compiler=$2
+for ac_option in --version -v -V -qversion; do
+  { { ac_try="$ac_compiler $ac_option >&5"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_compiler $ac_option >&5") 2>conftest.err
+  ac_status=$?
+  if test -s conftest.err; then
+    sed '10a\
+... rest of stderr output deleted ...
+         10q' conftest.err >conftest.er1
+    cat conftest.er1 >&5
+  fi
+  rm -f conftest.er1 conftest.err
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+done
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+ac_clean_files_save=$ac_clean_files
+ac_clean_files="$ac_clean_files a.out a.out.dSYM a.exe b.out"
+# Try to create an executable without -o first, disregard a.out.
+# It will help us diagnose broken compilers, and finding out an intuition
+# of exeext.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the C compiler works" >&5
+$as_echo_n "checking whether the C compiler works... " >&6; }
+ac_link_default=`$as_echo "$ac_link" | sed 's/ -o *conftest[^ ]*//'`
+
+# The possible output files:
+ac_files="a.out conftest.exe conftest a.exe a_out.exe b.out conftest.*"
+
+ac_rmfiles=
+for ac_file in $ac_files
+do
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.dSYM | *.o | *.obj ) ;;
+    * ) ac_rmfiles="$ac_rmfiles $ac_file";;
+  esac
+done
+rm -f $ac_rmfiles
+
+if { { ac_try="$ac_link_default"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_link_default") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then :
+  # Autoconf-2.13 could set the ac_cv_exeext variable to `no'.
+# So ignore a value of `no', otherwise this would lead to `EXEEXT = no'
+# in a Makefile.  We should not override ac_cv_exeext if it was cached,
+# so that the user can short-circuit this test for compilers unknown to
+# Autoconf.
+for ac_file in $ac_files ''
+do
+  test -f "$ac_file" || continue
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.dSYM | *.o | *.obj )
+	;;
+    [ab].out )
+	# We found the default executable, but exeext='' is most
+	# certainly right.
+	break;;
+    *.* )
+	if test "${ac_cv_exeext+set}" = set && test "$ac_cv_exeext" != no;
+	then :; else
+	   ac_cv_exeext=`expr "$ac_file" : '[^.]*\(\..*\)'`
+	fi
+	# We set ac_cv_exeext here because the later test for it is not
+	# safe: cross compilers may not add the suffix if given an `-o'
+	# argument, so we may need to know it at that point already.
+	# Even if this section looks crufty: it has the advantage of
+	# actually working.
+	break;;
+    * )
+	break;;
+  esac
+done
+test "$ac_cv_exeext" = no && ac_cv_exeext=
+
+else
+  ac_file=''
+fi
+if test -z "$ac_file"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+$as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+{ { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error 77 "C compiler cannot create executables
+See \`config.log' for more details" "$LINENO" 5; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for C compiler default output file name" >&5
+$as_echo_n "checking for C compiler default output file name... " >&6; }
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_file" >&5
+$as_echo "$ac_file" >&6; }
+ac_exeext=$ac_cv_exeext
+
+rm -f -r a.out a.out.dSYM a.exe conftest$ac_cv_exeext b.out
+ac_clean_files=$ac_clean_files_save
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for suffix of executables" >&5
+$as_echo_n "checking for suffix of executables... " >&6; }
+if { { ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_link") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then :
+  # If both `conftest.exe' and `conftest' are `present' (well, observable)
+# catch `conftest.exe'.  For instance with Cygwin, `ls conftest' will
+# work properly (i.e., refer to `conftest.exe'), while it won't with
+# `rm'.
+for ac_file in conftest.exe conftest conftest.*; do
+  test -f "$ac_file" || continue
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.dSYM | *.o | *.obj ) ;;
+    *.* ) ac_cv_exeext=`expr "$ac_file" : '[^.]*\(\..*\)'`
+	  break;;
+    * ) break;;
+  esac
+done
+else
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot compute suffix of executables: cannot compile and link
+See \`config.log' for more details" "$LINENO" 5; }
+fi
+rm -f conftest conftest$ac_cv_exeext
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_exeext" >&5
+$as_echo "$ac_cv_exeext" >&6; }
+
+rm -f conftest.$ac_ext
+EXEEXT=$ac_cv_exeext
+ac_exeext=$EXEEXT
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdio.h>
+int
+main ()
+{
+FILE *f = fopen ("conftest.out", "w");
+ return ferror (f) || fclose (f) != 0;
+
+  ;
+  return 0;
+}
+_ACEOF
+ac_clean_files="$ac_clean_files conftest.out"
+# Check that the compiler produces executables we can run.  If not, either
+# the compiler is broken, or we cross compile.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are cross compiling" >&5
+$as_echo_n "checking whether we are cross compiling... " >&6; }
+if test "$cross_compiling" != yes; then
+  { { ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_link") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+  if { ac_try='./conftest$ac_cv_exeext'
+  { { case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }; then
+    cross_compiling=no
+  else
+    if test "$cross_compiling" = maybe; then
+	cross_compiling=yes
+    else
+	{ { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot run C compiled programs.
+If you meant to cross compile, use \`--host'.
+See \`config.log' for more details" "$LINENO" 5; }
+    fi
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $cross_compiling" >&5
+$as_echo "$cross_compiling" >&6; }
+
+rm -f conftest.$ac_ext conftest$ac_cv_exeext conftest.out
+ac_clean_files=$ac_clean_files_save
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for suffix of object files" >&5
+$as_echo_n "checking for suffix of object files... " >&6; }
+if ${ac_cv_objext+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.o conftest.obj
+if { { ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_compile") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then :
+  for ac_file in conftest.o conftest.obj conftest.*; do
+  test -f "$ac_file" || continue;
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.dSYM ) ;;
+    *) ac_cv_objext=`expr "$ac_file" : '.*\.\(.*\)'`
+       break;;
+  esac
+done
+else
+  $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+{ { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot compute suffix of object files: cannot compile
+See \`config.log' for more details" "$LINENO" 5; }
+fi
+rm -f conftest.$ac_cv_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_objext" >&5
+$as_echo "$ac_cv_objext" >&6; }
+OBJEXT=$ac_cv_objext
+ac_objext=$OBJEXT
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are using the GNU C compiler" >&5
+$as_echo_n "checking whether we are using the GNU C compiler... " >&6; }
+if ${ac_cv_c_compiler_gnu+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+#ifndef __GNUC__
+       choke me
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_compiler_gnu=yes
+else
+  ac_compiler_gnu=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_cv_c_compiler_gnu=$ac_compiler_gnu
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_compiler_gnu" >&5
+$as_echo "$ac_cv_c_compiler_gnu" >&6; }
+if test $ac_compiler_gnu = yes; then
+  GCC=yes
+else
+  GCC=
+fi
+ac_test_CFLAGS=${CFLAGS+set}
+ac_save_CFLAGS=$CFLAGS
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC accepts -g" >&5
+$as_echo_n "checking whether $CC accepts -g... " >&6; }
+if ${ac_cv_prog_cc_g+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_save_c_werror_flag=$ac_c_werror_flag
+   ac_c_werror_flag=yes
+   ac_cv_prog_cc_g=no
+   CFLAGS="-g"
+   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_prog_cc_g=yes
+else
+  CFLAGS=""
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+else
+  ac_c_werror_flag=$ac_save_c_werror_flag
+	 CFLAGS="-g"
+	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_prog_cc_g=yes
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+   ac_c_werror_flag=$ac_save_c_werror_flag
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_g" >&5
+$as_echo "$ac_cv_prog_cc_g" >&6; }
+if test "$ac_test_CFLAGS" = set; then
+  CFLAGS=$ac_save_CFLAGS
+elif test $ac_cv_prog_cc_g = yes; then
+  if test "$GCC" = yes; then
+    CFLAGS="-g -O2"
+  else
+    CFLAGS="-g"
+  fi
+else
+  if test "$GCC" = yes; then
+    CFLAGS="-O2"
+  else
+    CFLAGS=
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $CC option to accept ISO C89" >&5
+$as_echo_n "checking for $CC option to accept ISO C89... " >&6; }
+if ${ac_cv_prog_cc_c89+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_cv_prog_cc_c89=no
+ac_save_CC=$CC
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdarg.h>
+#include <stdio.h>
+struct stat;
+/* Most of the following tests are stolen from RCS 5.7's src/conf.sh.  */
+struct buf { int x; };
+FILE * (*rcsopen) (struct buf *, struct stat *, int);
+static char *e (p, i)
+     char **p;
+     int i;
+{
+  return p[i];
+}
+static char *f (char * (*g) (char **, int), char **p, ...)
+{
+  char *s;
+  va_list v;
+  va_start (v,p);
+  s = g (p, va_arg (v,int));
+  va_end (v);
+  return s;
+}
+
+/* OSF 4.0 Compaq cc is some sort of almost-ANSI by default.  It has
+   function prototypes and stuff, but not '\xHH' hex character constants.
+   These don't provoke an error unfortunately, instead are silently treated
+   as 'x'.  The following induces an error, until -std is added to get
+   proper ANSI mode.  Curiously '\x00'!='x' always comes out true, for an
+   array size at least.  It's necessary to write '\x00'==0 to get something
+   that's true only with -std.  */
+int osf4_cc_array ['\x00' == 0 ? 1 : -1];
+
+/* IBM C 6 for AIX is almost-ANSI by default, but it replaces macro parameters
+   inside strings and character constants.  */
+#define FOO(x) 'x'
+int xlc6_cc_array[FOO(a) == 'x' ? 1 : -1];
+
+int test (int i, double x);
+struct s1 {int (*f) (int a);};
+struct s2 {int (*f) (double a);};
+int pairnames (int, char **, FILE *(*)(struct buf *, struct stat *, int), int, int);
+int argc;
+char **argv;
+int
+main ()
+{
+return f (e, argv, 0) != argv[0]  ||  f (e, argv, 1) != argv[1];
+  ;
+  return 0;
+}
+_ACEOF
+for ac_arg in '' -qlanglvl=extc89 -qlanglvl=ansi -std \
+	-Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"
+do
+  CC="$ac_save_CC $ac_arg"
+  if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_prog_cc_c89=$ac_arg
+fi
+rm -f core conftest.err conftest.$ac_objext
+  test "x$ac_cv_prog_cc_c89" != "xno" && break
+done
+rm -f conftest.$ac_ext
+CC=$ac_save_CC
+
+fi
+# AC_CACHE_VAL
+case "x$ac_cv_prog_cc_c89" in
+  x)
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
+$as_echo "none needed" >&6; } ;;
+  xno)
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
+$as_echo "unsupported" >&6; } ;;
+  *)
+    CC="$CC $ac_cv_prog_cc_c89"
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_c89" >&5
+$as_echo "$ac_cv_prog_cc_c89" >&6; } ;;
+esac
+if test "x$ac_cv_prog_cc_c89" != xno; then :
+
+fi
+
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for dlopen in -ldl" >&5
+$as_echo_n "checking for dlopen in -ldl... " >&6; }
+if ${ac_cv_lib_dl_dlopen+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-ldl  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char dlopen ();
+int
+main ()
+{
+return dlopen ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_dl_dlopen=yes
+else
+  ac_cv_lib_dl_dlopen=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_dl_dlopen" >&5
+$as_echo "$ac_cv_lib_dl_dlopen" >&6; }
+if test "x$ac_cv_lib_dl_dlopen" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBDL 1
+_ACEOF
+
+  LIBS="-ldl $LIBS"
+
+fi
+
+
+############## platform tests ################
+
+case "$host_os" in
+  *)
+    ;;
+esac
+
+############## C flags ################
+
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking how to run the C preprocessor" >&5
+$as_echo_n "checking how to run the C preprocessor... " >&6; }
+# On Suns, sometimes $CPP names a directory.
+if test -n "$CPP" && test -d "$CPP"; then
+  CPP=
+fi
+if test -z "$CPP"; then
+  if ${ac_cv_prog_CPP+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+      # Double quotes because CPP needs to be expanded
+    for CPP in "$CC -E" "$CC -E -traditional-cpp" "/lib/cpp"
+    do
+      ac_preproc_ok=false
+for ac_c_preproc_warn_flag in '' yes
+do
+  # Use a header file that comes with gcc, so configuring glibc
+  # with a fresh cross-compiler works.
+  # Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
+  # <limits.h> exists even on freestanding compilers.
+  # On the NeXT, cc -E runs the code through the compiler's parser,
+  # not just through cpp. "Syntax error" is here to catch this case.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+		     Syntax error
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"; then :
+
+else
+  # Broken: fails on valid input.
+continue
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+
+  # OK, works on sane cases.  Now check whether nonexistent headers
+  # can be detected and how.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <ac_nonexistent.h>
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"; then :
+  # Broken: success on invalid input.
+continue
+else
+  # Passes both tests.
+ac_preproc_ok=:
+break
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+
+done
+# Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
+rm -f conftest.i conftest.err conftest.$ac_ext
+if $ac_preproc_ok; then :
+  break
+fi
+
+    done
+    ac_cv_prog_CPP=$CPP
+
+fi
+  CPP=$ac_cv_prog_CPP
+else
+  ac_cv_prog_CPP=$CPP
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $CPP" >&5
+$as_echo "$CPP" >&6; }
+ac_preproc_ok=false
+for ac_c_preproc_warn_flag in '' yes
+do
+  # Use a header file that comes with gcc, so configuring glibc
+  # with a fresh cross-compiler works.
+  # Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
+  # <limits.h> exists even on freestanding compilers.
+  # On the NeXT, cc -E runs the code through the compiler's parser,
+  # not just through cpp. "Syntax error" is here to catch this case.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+		     Syntax error
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"; then :
+
+else
+  # Broken: fails on valid input.
+continue
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+
+  # OK, works on sane cases.  Now check whether nonexistent headers
+  # can be detected and how.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <ac_nonexistent.h>
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"; then :
+  # Broken: success on invalid input.
+continue
+else
+  # Passes both tests.
+ac_preproc_ok=:
+break
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+
+done
+# Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
+rm -f conftest.i conftest.err conftest.$ac_ext
+if $ac_preproc_ok; then :
+
+else
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "C preprocessor \"$CPP\" fails sanity check
+See \`config.log' for more details" "$LINENO" 5; }
+fi
+
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for grep that handles long lines and -e" >&5
+$as_echo_n "checking for grep that handles long lines and -e... " >&6; }
+if ${ac_cv_path_GREP+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -z "$GREP"; then
+  ac_path_GREP_found=false
+  # Loop through the user's path and test for each of PROGNAME-LIST
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH$PATH_SEPARATOR/usr/xpg4/bin
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_prog in grep ggrep; do
+    for ac_exec_ext in '' $ac_executable_extensions; do
+      ac_path_GREP="$as_dir/$ac_prog$ac_exec_ext"
+      as_fn_executable_p "$ac_path_GREP" || continue
+# Check for GNU ac_path_GREP and select it if it is found.
+  # Check for GNU $ac_path_GREP
+case `"$ac_path_GREP" --version 2>&1` in
+*GNU*)
+  ac_cv_path_GREP="$ac_path_GREP" ac_path_GREP_found=:;;
+*)
+  ac_count=0
+  $as_echo_n 0123456789 >"conftest.in"
+  while :
+  do
+    cat "conftest.in" "conftest.in" >"conftest.tmp"
+    mv "conftest.tmp" "conftest.in"
+    cp "conftest.in" "conftest.nl"
+    $as_echo 'GREP' >> "conftest.nl"
+    "$ac_path_GREP" -e 'GREP$' -e '-(cannot match)-' < "conftest.nl" >"conftest.out" 2>/dev/null || break
+    diff "conftest.out" "conftest.nl" >/dev/null 2>&1 || break
+    as_fn_arith $ac_count + 1 && ac_count=$as_val
+    if test $ac_count -gt ${ac_path_GREP_max-0}; then
+      # Best one so far, save it but keep looking for a better one
+      ac_cv_path_GREP="$ac_path_GREP"
+      ac_path_GREP_max=$ac_count
+    fi
+    # 10*(2^10) chars as input seems more than enough
+    test $ac_count -gt 10 && break
+  done
+  rm -f conftest.in conftest.tmp conftest.nl conftest.out;;
+esac
+
+      $ac_path_GREP_found && break 3
+    done
+  done
+  done
+IFS=$as_save_IFS
+  if test -z "$ac_cv_path_GREP"; then
+    as_fn_error $? "no acceptable grep could be found in $PATH$PATH_SEPARATOR/usr/xpg4/bin" "$LINENO" 5
+  fi
+else
+  ac_cv_path_GREP=$GREP
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_path_GREP" >&5
+$as_echo "$ac_cv_path_GREP" >&6; }
+ GREP="$ac_cv_path_GREP"
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for egrep" >&5
+$as_echo_n "checking for egrep... " >&6; }
+if ${ac_cv_path_EGREP+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if echo a | $GREP -E '(a|b)' >/dev/null 2>&1
+   then ac_cv_path_EGREP="$GREP -E"
+   else
+     if test -z "$EGREP"; then
+  ac_path_EGREP_found=false
+  # Loop through the user's path and test for each of PROGNAME-LIST
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH$PATH_SEPARATOR/usr/xpg4/bin
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_prog in egrep; do
+    for ac_exec_ext in '' $ac_executable_extensions; do
+      ac_path_EGREP="$as_dir/$ac_prog$ac_exec_ext"
+      as_fn_executable_p "$ac_path_EGREP" || continue
+# Check for GNU ac_path_EGREP and select it if it is found.
+  # Check for GNU $ac_path_EGREP
+case `"$ac_path_EGREP" --version 2>&1` in
+*GNU*)
+  ac_cv_path_EGREP="$ac_path_EGREP" ac_path_EGREP_found=:;;
+*)
+  ac_count=0
+  $as_echo_n 0123456789 >"conftest.in"
+  while :
+  do
+    cat "conftest.in" "conftest.in" >"conftest.tmp"
+    mv "conftest.tmp" "conftest.in"
+    cp "conftest.in" "conftest.nl"
+    $as_echo 'EGREP' >> "conftest.nl"
+    "$ac_path_EGREP" 'EGREP$' < "conftest.nl" >"conftest.out" 2>/dev/null || break
+    diff "conftest.out" "conftest.nl" >/dev/null 2>&1 || break
+    as_fn_arith $ac_count + 1 && ac_count=$as_val
+    if test $ac_count -gt ${ac_path_EGREP_max-0}; then
+      # Best one so far, save it but keep looking for a better one
+      ac_cv_path_EGREP="$ac_path_EGREP"
+      ac_path_EGREP_max=$ac_count
+    fi
+    # 10*(2^10) chars as input seems more than enough
+    test $ac_count -gt 10 && break
+  done
+  rm -f conftest.in conftest.tmp conftest.nl conftest.out;;
+esac
+
+      $ac_path_EGREP_found && break 3
+    done
+  done
+  done
+IFS=$as_save_IFS
+  if test -z "$ac_cv_path_EGREP"; then
+    as_fn_error $? "no acceptable egrep could be found in $PATH$PATH_SEPARATOR/usr/xpg4/bin" "$LINENO" 5
+  fi
+else
+  ac_cv_path_EGREP=$EGREP
+fi
+
+   fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_path_EGREP" >&5
+$as_echo "$ac_cv_path_EGREP" >&6; }
+ EGREP="$ac_cv_path_EGREP"
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for ANSI C header files" >&5
+$as_echo_n "checking for ANSI C header files... " >&6; }
+if ${ac_cv_header_stdc+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <float.h>
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_header_stdc=yes
+else
+  ac_cv_header_stdc=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+if test $ac_cv_header_stdc = yes; then
+  # SunOS 4.x string.h does not declare mem*, contrary to ANSI.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <string.h>
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "memchr" >/dev/null 2>&1; then :
+
+else
+  ac_cv_header_stdc=no
+fi
+rm -f conftest*
+
+fi
+
+if test $ac_cv_header_stdc = yes; then
+  # ISC 2.0.2 stdlib.h does not declare free, contrary to ANSI.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdlib.h>
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "free" >/dev/null 2>&1; then :
+
+else
+  ac_cv_header_stdc=no
+fi
+rm -f conftest*
+
+fi
+
+if test $ac_cv_header_stdc = yes; then
+  # /bin/cc in Irix-4.0.5 gets non-ANSI ctype macros unless using -ansi.
+  if test "$cross_compiling" = yes; then :
+  :
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <ctype.h>
+#include <stdlib.h>
+#if ((' ' & 0x0FF) == 0x020)
+# define ISLOWER(c) ('a' <= (c) && (c) <= 'z')
+# define TOUPPER(c) (ISLOWER(c) ? 'A' + ((c) - 'a') : (c))
+#else
+# define ISLOWER(c) \
+		   (('a' <= (c) && (c) <= 'i') \
+		     || ('j' <= (c) && (c) <= 'r') \
+		     || ('s' <= (c) && (c) <= 'z'))
+# define TOUPPER(c) (ISLOWER(c) ? ((c) | 0x40) : (c))
+#endif
+
+#define XOR(e, f) (((e) && !(f)) || (!(e) && (f)))
+int
+main ()
+{
+  int i;
+  for (i = 0; i < 256; i++)
+    if (XOR (islower (i), ISLOWER (i))
+	|| toupper (i) != TOUPPER (i))
+      return 2;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+
+else
+  ac_cv_header_stdc=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_header_stdc" >&5
+$as_echo "$ac_cv_header_stdc" >&6; }
+if test $ac_cv_header_stdc = yes; then
+
+$as_echo "#define STDC_HEADERS 1" >>confdefs.h
+
+fi
+
+# On IRIX 5.3, sys/types and inttypes.h are conflicting.
+for ac_header in sys/types.h sys/stat.h stdlib.h string.h memory.h strings.h \
+		  inttypes.h stdint.h unistd.h
+do :
+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
+ac_fn_c_check_header_compile "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default
+"
+if eval test \"x\$"$as_ac_Header"\" = x"yes"; then :
+  cat >>confdefs.h <<_ACEOF
+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+
+done
+
+
+
+  ac_fn_c_check_type "$LINENO" "intptr_t" "ac_cv_type_intptr_t" "$ac_includes_default"
+if test "x$ac_cv_type_intptr_t" = xyes; then :
+
+$as_echo "#define HAVE_INTPTR_T 1" >>confdefs.h
+
+else
+  for ac_type in 'int' 'long int' 'long long int'; do
+       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_includes_default
+int
+main ()
+{
+static int test_array [1 - 2 * !(sizeof (void *) <= sizeof ($ac_type))];
+test_array [0] = 0;
+return test_array [0];
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+cat >>confdefs.h <<_ACEOF
+#define intptr_t $ac_type
+_ACEOF
+
+	  ac_type=
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+       test -z "$ac_type" && break
+     done
+fi
+
+
+
+  ac_fn_c_check_type "$LINENO" "uintptr_t" "ac_cv_type_uintptr_t" "$ac_includes_default"
+if test "x$ac_cv_type_uintptr_t" = xyes; then :
+
+$as_echo "#define HAVE_UINTPTR_T 1" >>confdefs.h
+
+else
+  for ac_type in 'unsigned int' 'unsigned long int' \
+	'unsigned long long int'; do
+       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_includes_default
+int
+main ()
+{
+static int test_array [1 - 2 * !(sizeof (void *) <= sizeof ($ac_type))];
+test_array [0] = 0;
+return test_array [0];
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+cat >>confdefs.h <<_ACEOF
+#define uintptr_t $ac_type
+_ACEOF
+
+	  ac_type=
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+       test -z "$ac_type" && break
+     done
+fi
+
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for getaddrinfo" >&5
+$as_echo_n "checking for getaddrinfo... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+int
+main ()
+{
+getaddrinfo(0, 0, 0, 0);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+
+$as_echo "#define HAVE_GETADDRINFO 1" >>confdefs.h
+
+   have_getaddrinfo=yes
+else
+  have_getaddrinfo=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $have_getaddrinfo" >&5
+$as_echo "$have_getaddrinfo" >&6; }
+
+iconv_lib_flag=""
+if test "${skip_iconv_check}" = "no" ; then
+ if test "${enable_iconv}" = "yes" ; then
+  ac_fn_c_check_header_mongrel "$LINENO" "iconv.h" "ac_cv_header_iconv_h" "$ac_includes_default"
+if test "x$ac_cv_header_iconv_h" = xyes; then :
+  enable_iconv=yes
+else
+  enable_iconv=no
+fi
+
+
+  if test "${enable_iconv}" = "yes" ; then
+    # Does it all work, now?
+    if test "$cross_compiling" = yes; then :
+  enable_iconv=yes
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+   #include <iconv.h>
+   #include <langinfo.h>
+    int main() {
+     iconv_open("UTF-8", "UTF-8");
+      return 0;
+    }
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  enable_iconv=yes
+else
+  enable_iconv=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+    if test "${enable_iconv}" = "no" ; then
+      # Try adding -liconv ?
+      #  We did not use AC_CHECK_LIB because iconv is sometimes macro-renamed
+      ORIG_LIBS="$LIBS"
+      LIBS="$LIBS -liconv"
+      if test "$cross_compiling" = yes; then :
+  enable_iconv=yes
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+     #include <iconv.h>
+     #include <langinfo.h>
+      int main() {
+     iconv_open("UTF-8", "UTF-8");
+      return 0;
+      }
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  enable_iconv=yes
+else
+  enable_iconv=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+      if test "${enable_iconv}" = "no" ; then
+        LIBS="$ORIG_LIBS"
+      else
+        iconv_lib_flag=" -liconv"
+      fi
+    fi
+  fi
+ fi
+  msg="iconv is usable"
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking $msg" >&5
+$as_echo_n "checking $msg... " >&6; }
+ iconv_usage_result="$enable_iconv$iconv_lib_flag"
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $iconv_usage_result" >&5
+$as_echo "$iconv_usage_result" >&6; }
+ if test "${enable_iconv}" = "no" ; then
+  CFLAGS="$CFLAGS -DRKTIO_NO_ICONV"
+ fi
+fi
+
+ msg="for mbsrtowcs"
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking $msg" >&5
+$as_echo_n "checking $msg... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+   #include <wchar.h>
+   #include <strings.h>
+   int main() {
+     mbstate_t state;
+     char *src = "X";
+     bzero(&state, sizeof(mbstate_t));
+     mbsrtowcs(0, &src, 0, &state);
+     return 0;
+   }
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  mbsrtowcs=yes
+else
+  mbsrtowcs=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+if test "$mbsrtowcs" = "no" ; then
+  CFLAGS="$CFLAGS -DNO_MBTOWC_FUNCTIONS"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $mbsrtowcs" >&5
+$as_echo "$mbsrtowcs" >&6; }
+
+if test "${try_poll_syscall}" = "yes" ; then
+   msg="for poll"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking $msg" >&5
+$as_echo_n "checking $msg... " >&6; }
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+     #include <poll.h>
+     int main() {
+      struct pollfd pfd;
+      int r;
+      pfd.fd = 0;
+      pfd.events = POLLIN;
+      r = poll(&pfd, 1, 0);
+      return 0;
+     }
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  use_poll=yes
+else
+  use_poll=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $use_poll" >&5
+$as_echo "$use_poll" >&6; }
+  if test "${use_poll}" = "yes" ; then
+
+$as_echo "#define HAVE_POLL_SYSCALL 1" >>confdefs.h
+
+  fi
+fi
+
+if test "${try_epoll_syscall}" = "yes" ; then
+   msg="for epoll"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking $msg" >&5
+$as_echo_n "checking $msg... " >&6; }
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+    #include <sys/epoll.h>
+    int main() {
+      int fd;
+      struct epoll_event ev;
+      fd = epoll_create(5);
+      ev.events = EPOLLIN | EPOLLONESHOT;
+      epoll_ctl(fd, EPOLL_CTL_ADD, 0, &ev);
+      return 0;
+    }
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  use_epoll=yes
+else
+  use_epoll=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $use_epoll" >&5
+$as_echo "$use_epoll" >&6; }
+  if test "${use_epoll}" = "yes" ; then
+
+$as_echo "#define HAVE_EPOLL_SYSCALL 1" >>confdefs.h
+
+  fi
+fi
+
+if test "${try_inotify_syscall}" = "yes" ; then
+   msg="for inotify"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking $msg" >&5
+$as_echo_n "checking $msg... " >&6; }
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+    #include <sys/inotify.h>
+    int main() {
+      int fd;
+      int wd;
+      fd = inotify_init();
+      wd = inotify_add_watch(fd, "/tmp",
+                             (IN_CREATE | IN_DELETE | IN_DELETE_SELF
+                              | IN_MODIFY | IN_MOVE_SELF | IN_MOVED_TO));
+      return 0;
+    }
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  use_inotify=yes
+else
+  use_inotify=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $use_inotify" >&5
+$as_echo "$use_inotify" >&6; }
+  if test "${use_inotify}" = "yes" ; then
+
+$as_echo "#define HAVE_INOTIFY_SYSCALL 1" >>confdefs.h
+
+  fi
+fi
+
+if test "${try_kqueue_syscall}" = "yes" ; then
+   msg="for kqueue"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking $msg" >&5
+$as_echo_n "checking $msg... " >&6; }
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+     #include <sys/types.h>
+     #include <sys/event.h>
+     #include <sys/time.h>
+     int main() {
+        int kq;
+        struct kevent kev;
+        struct timespec timeout = {0, 0};
+        kq = kqueue();
+        EV_SET(&kev, 0, EVFILT_READ, EV_ADD, 0, 0, NULL);
+        kevent(kq, &kev, 1, NULL, 0, &timeout);
+        return 0;
+     }
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  use_kqueue=yes
+else
+  use_kqueue=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $use_kqueue" >&5
+$as_echo "$use_kqueue" >&6; }
+  if test "${use_kqueue}" = "yes" ; then
+
+$as_echo "#define HAVE_KQUEUE_SYSCALL 1" >>confdefs.h
+
+  fi
+fi
+
+LFS_CFLAGS=`getconf LFS_CFLAGS 2> /dev/null`
+if test "${LFS_CFLAGS}" != "" && test "${LFS_CFLAGS}" != "undefined"; then
+  echo "Large-file support: ${LFS_CFLAGS}"
+  CFLAGS="${CFLAGS} ${LFS_CFLAGS}"
+fi
+
+############## final output ################
+
+
+
+
+
+makefiles="Makefile"
+
+ac_config_files="$ac_config_files $makefiles"
+
+cat >confcache <<\_ACEOF
+# This file is a shell script that caches the results of configure
+# tests run on this system so they can be shared between configure
+# scripts and configure runs, see configure's option --config-cache.
+# It is not useful on other systems.  If it contains results you don't
+# want to keep, you may remove or edit it.
+#
+# config.status only pays attention to the cache file if you give it
+# the --recheck option to rerun configure.
+#
+# `ac_cv_env_foo' variables (set or unset) will be overridden when
+# loading this file, other *unset* `ac_cv_foo' will be assigned the
+# following values.
+
+_ACEOF
+
+# The following way of writing the cache mishandles newlines in values,
+# but we know of no workaround that is simple, portable, and efficient.
+# So, we kill variables containing newlines.
+# Ultrix sh set writes to stderr and can't be redirected directly,
+# and sets the high bit in the cache file unless we assign to the vars.
+(
+  for ac_var in `(set) 2>&1 | sed -n 's/^\([a-zA-Z_][a-zA-Z0-9_]*\)=.*/\1/p'`; do
+    eval ac_val=\$$ac_var
+    case $ac_val in #(
+    *${as_nl}*)
+      case $ac_var in #(
+      *_cv_*) { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cache variable $ac_var contains a newline" >&5
+$as_echo "$as_me: WARNING: cache variable $ac_var contains a newline" >&2;} ;;
+      esac
+      case $ac_var in #(
+      _ | IFS | as_nl) ;; #(
+      BASH_ARGV | BASH_SOURCE) eval $ac_var= ;; #(
+      *) { eval $ac_var=; unset $ac_var;} ;;
+      esac ;;
+    esac
+  done
+
+  (set) 2>&1 |
+    case $as_nl`(ac_space=' '; set) 2>&1` in #(
+    *${as_nl}ac_space=\ *)
+      # `set' does not quote correctly, so add quotes: double-quote
+      # substitution turns \\\\ into \\, and sed turns \\ into \.
+      sed -n \
+	"s/'/'\\\\''/g;
+	  s/^\\([_$as_cr_alnum]*_cv_[_$as_cr_alnum]*\\)=\\(.*\\)/\\1='\\2'/p"
+      ;; #(
+    *)
+      # `set' quotes correctly as required by POSIX, so do not add quotes.
+      sed -n "/^[_$as_cr_alnum]*_cv_[_$as_cr_alnum]*=/p"
+      ;;
+    esac |
+    sort
+) |
+  sed '
+     /^ac_cv_env_/b end
+     t clear
+     :clear
+     s/^\([^=]*\)=\(.*[{}].*\)$/test "${\1+set}" = set || &/
+     t end
+     s/^\([^=]*\)=\(.*\)$/\1=${\1=\2}/
+     :end' >>confcache
+if diff "$cache_file" confcache >/dev/null 2>&1; then :; else
+  if test -w "$cache_file"; then
+    if test "x$cache_file" != "x/dev/null"; then
+      { $as_echo "$as_me:${as_lineno-$LINENO}: updating cache $cache_file" >&5
+$as_echo "$as_me: updating cache $cache_file" >&6;}
+      if test ! -f "$cache_file" || test -h "$cache_file"; then
+	cat confcache >"$cache_file"
+      else
+        case $cache_file in #(
+        */* | ?:*)
+	  mv -f confcache "$cache_file"$$ &&
+	  mv -f "$cache_file"$$ "$cache_file" ;; #(
+        *)
+	  mv -f confcache "$cache_file" ;;
+	esac
+      fi
+    fi
+  else
+    { $as_echo "$as_me:${as_lineno-$LINENO}: not updating unwritable cache $cache_file" >&5
+$as_echo "$as_me: not updating unwritable cache $cache_file" >&6;}
+  fi
+fi
+rm -f confcache
+
+test "x$prefix" = xNONE && prefix=$ac_default_prefix
+# Let make expand exec_prefix.
+test "x$exec_prefix" = xNONE && exec_prefix='${prefix}'
+
+DEFS=-DHAVE_CONFIG_H
+
+ac_libobjs=
+ac_ltlibobjs=
+U=
+for ac_i in : $LIBOBJS; do test "x$ac_i" = x: && continue
+  # 1. Remove the extension, and $U if already installed.
+  ac_script='s/\$U\././;s/\.o$//;s/\.obj$//'
+  ac_i=`$as_echo "$ac_i" | sed "$ac_script"`
+  # 2. Prepend LIBOBJDIR.  When used with automake>=1.10 LIBOBJDIR
+  #    will be set to the directory where LIBOBJS objects are built.
+  as_fn_append ac_libobjs " \${LIBOBJDIR}$ac_i\$U.$ac_objext"
+  as_fn_append ac_ltlibobjs " \${LIBOBJDIR}$ac_i"'$U.lo'
+done
+LIBOBJS=$ac_libobjs
+
+LTLIBOBJS=$ac_ltlibobjs
+
+
+
+: "${CONFIG_STATUS=./config.status}"
+ac_write_fail=0
+ac_clean_files_save=$ac_clean_files
+ac_clean_files="$ac_clean_files $CONFIG_STATUS"
+{ $as_echo "$as_me:${as_lineno-$LINENO}: creating $CONFIG_STATUS" >&5
+$as_echo "$as_me: creating $CONFIG_STATUS" >&6;}
+as_write_fail=0
+cat >$CONFIG_STATUS <<_ASEOF || as_write_fail=1
+#! $SHELL
+# Generated by $as_me.
+# Run this file to recreate the current configuration.
+# Compiler output produced by configure, useful for debugging
+# configure, is in config.log if it exists.
+
+debug=false
+ac_cs_recheck=false
+ac_cs_silent=false
+
+SHELL=\${CONFIG_SHELL-$SHELL}
+export SHELL
+_ASEOF
+cat >>$CONFIG_STATUS <<\_ASEOF || as_write_fail=1
+## -------------------- ##
+## M4sh Initialization. ##
+## -------------------- ##
+
+# Be more Bourne compatible
+DUALCASE=1; export DUALCASE # for MKS sh
+if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then :
+  emulate sh
+  NULLCMD=:
+  # Pre-4.2 versions of Zsh do word splitting on ${1+"$@"}, which
+  # is contrary to our usage.  Disable this feature.
+  alias -g '${1+"$@"}'='"$@"'
+  setopt NO_GLOB_SUBST
+else
+  case `(set -o) 2>/dev/null` in #(
+  *posix*) :
+    set -o posix ;; #(
+  *) :
+     ;;
+esac
+fi
+
+
+as_nl='
+'
+export as_nl
+# Printing a long string crashes Solaris 7 /usr/bin/printf.
+as_echo='\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'
+as_echo=$as_echo$as_echo$as_echo$as_echo$as_echo
+as_echo=$as_echo$as_echo$as_echo$as_echo$as_echo$as_echo
+# Prefer a ksh shell builtin over an external printf program on Solaris,
+# but without wasting forks for bash or zsh.
+if test -z "$BASH_VERSION$ZSH_VERSION" \
+    && (test "X`print -r -- $as_echo`" = "X$as_echo") 2>/dev/null; then
+  as_echo='print -r --'
+  as_echo_n='print -rn --'
+elif (test "X`printf %s $as_echo`" = "X$as_echo") 2>/dev/null; then
+  as_echo='printf %s\n'
+  as_echo_n='printf %s'
+else
+  if test "X`(/usr/ucb/echo -n -n $as_echo) 2>/dev/null`" = "X-n $as_echo"; then
+    as_echo_body='eval /usr/ucb/echo -n "$1$as_nl"'
+    as_echo_n='/usr/ucb/echo -n'
+  else
+    as_echo_body='eval expr "X$1" : "X\\(.*\\)"'
+    as_echo_n_body='eval
+      arg=$1;
+      case $arg in #(
+      *"$as_nl"*)
+	expr "X$arg" : "X\\(.*\\)$as_nl";
+	arg=`expr "X$arg" : ".*$as_nl\\(.*\\)"`;;
+      esac;
+      expr "X$arg" : "X\\(.*\\)" | tr -d "$as_nl"
+    '
+    export as_echo_n_body
+    as_echo_n='sh -c $as_echo_n_body as_echo'
+  fi
+  export as_echo_body
+  as_echo='sh -c $as_echo_body as_echo'
+fi
+
+# The user is always right.
+if test "${PATH_SEPARATOR+set}" != set; then
+  PATH_SEPARATOR=:
+  (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 && {
+    (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 ||
+      PATH_SEPARATOR=';'
+  }
+fi
+
+
+# IFS
+# We need space, tab and new line, in precisely that order.  Quoting is
+# there to prevent editors from complaining about space-tab.
+# (If _AS_PATH_WALK were called with IFS unset, it would disable word
+# splitting by setting IFS to empty value.)
+IFS=" ""	$as_nl"
+
+# Find who we are.  Look in the path if we contain no directory separator.
+as_myself=
+case $0 in #((
+  *[\\/]* ) as_myself=$0 ;;
+  *) as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    test -r "$as_dir/$0" && as_myself=$as_dir/$0 && break
+  done
+IFS=$as_save_IFS
+
+     ;;
+esac
+# We did not find ourselves, most probably we were run as `sh COMMAND'
+# in which case we are not to be found in the path.
+if test "x$as_myself" = x; then
+  as_myself=$0
+fi
+if test ! -f "$as_myself"; then
+  $as_echo "$as_myself: error: cannot find myself; rerun with an absolute file name" >&2
+  exit 1
+fi
+
+# Unset variables that we do not need and which cause bugs (e.g. in
+# pre-3.0 UWIN ksh).  But do not cause bugs in bash 2.01; the "|| exit 1"
+# suppresses any "Segmentation fault" message there.  '((' could
+# trigger a bug in pdksh 5.2.14.
+for as_var in BASH_ENV ENV MAIL MAILPATH
+do eval test x\${$as_var+set} = xset \
+  && ( (unset $as_var) || exit 1) >/dev/null 2>&1 && unset $as_var || :
+done
+PS1='$ '
+PS2='> '
+PS4='+ '
+
+# NLS nuisances.
+LC_ALL=C
+export LC_ALL
+LANGUAGE=C
+export LANGUAGE
+
+# CDPATH.
+(unset CDPATH) >/dev/null 2>&1 && unset CDPATH
+
+
+# as_fn_error STATUS ERROR [LINENO LOG_FD]
+# ----------------------------------------
+# Output "`basename $0`: error: ERROR" to stderr. If LINENO and LOG_FD are
+# provided, also output the error to LOG_FD, referencing LINENO. Then exit the
+# script with STATUS, using 1 if that was 0.
+as_fn_error ()
+{
+  as_status=$1; test $as_status -eq 0 && as_status=1
+  if test "$4"; then
+    as_lineno=${as_lineno-"$3"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+    $as_echo "$as_me:${as_lineno-$LINENO}: error: $2" >&$4
+  fi
+  $as_echo "$as_me: error: $2" >&2
+  as_fn_exit $as_status
+} # as_fn_error
+
+
+# as_fn_set_status STATUS
+# -----------------------
+# Set $? to STATUS, without forking.
+as_fn_set_status ()
+{
+  return $1
+} # as_fn_set_status
+
+# as_fn_exit STATUS
+# -----------------
+# Exit the shell with STATUS, even in a "trap 0" or "set -e" context.
+as_fn_exit ()
+{
+  set +e
+  as_fn_set_status $1
+  exit $1
+} # as_fn_exit
+
+# as_fn_unset VAR
+# ---------------
+# Portably unset VAR.
+as_fn_unset ()
+{
+  { eval $1=; unset $1;}
+}
+as_unset=as_fn_unset
+# as_fn_append VAR VALUE
+# ----------------------
+# Append the text in VALUE to the end of the definition contained in VAR. Take
+# advantage of any shell optimizations that allow amortized linear growth over
+# repeated appends, instead of the typical quadratic growth present in naive
+# implementations.
+if (eval "as_var=1; as_var+=2; test x\$as_var = x12") 2>/dev/null; then :
+  eval 'as_fn_append ()
+  {
+    eval $1+=\$2
+  }'
+else
+  as_fn_append ()
+  {
+    eval $1=\$$1\$2
+  }
+fi # as_fn_append
+
+# as_fn_arith ARG...
+# ------------------
+# Perform arithmetic evaluation on the ARGs, and store the result in the
+# global $as_val. Take advantage of shells that can avoid forks. The arguments
+# must be portable across $(()) and expr.
+if (eval "test \$(( 1 + 1 )) = 2") 2>/dev/null; then :
+  eval 'as_fn_arith ()
+  {
+    as_val=$(( $* ))
+  }'
+else
+  as_fn_arith ()
+  {
+    as_val=`expr "$@" || test $? -eq 1`
+  }
+fi # as_fn_arith
+
+
+if expr a : '\(a\)' >/dev/null 2>&1 &&
+   test "X`expr 00001 : '.*\(...\)'`" = X001; then
+  as_expr=expr
+else
+  as_expr=false
+fi
+
+if (basename -- /) >/dev/null 2>&1 && test "X`basename -- / 2>&1`" = "X/"; then
+  as_basename=basename
+else
+  as_basename=false
+fi
+
+if (as_dir=`dirname -- /` && test "X$as_dir" = X/) >/dev/null 2>&1; then
+  as_dirname=dirname
+else
+  as_dirname=false
+fi
+
+as_me=`$as_basename -- "$0" ||
+$as_expr X/"$0" : '.*/\([^/][^/]*\)/*$' \| \
+	 X"$0" : 'X\(//\)$' \| \
+	 X"$0" : 'X\(/\)' \| . 2>/dev/null ||
+$as_echo X/"$0" |
+    sed '/^.*\/\([^/][^/]*\)\/*$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\/\(\/\/\)$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\/\(\/\).*/{
+	    s//\1/
+	    q
+	  }
+	  s/.*/./; q'`
+
+# Avoid depending upon Character Ranges.
+as_cr_letters='abcdefghijklmnopqrstuvwxyz'
+as_cr_LETTERS='ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+as_cr_Letters=$as_cr_letters$as_cr_LETTERS
+as_cr_digits='0123456789'
+as_cr_alnum=$as_cr_Letters$as_cr_digits
+
+ECHO_C= ECHO_N= ECHO_T=
+case `echo -n x` in #(((((
+-n*)
+  case `echo 'xy\c'` in
+  *c*) ECHO_T='	';;	# ECHO_T is single tab character.
+  xy)  ECHO_C='\c';;
+  *)   echo `echo ksh88 bug on AIX 6.1` > /dev/null
+       ECHO_T='	';;
+  esac;;
+*)
+  ECHO_N='-n';;
+esac
+
+rm -f conf$$ conf$$.exe conf$$.file
+if test -d conf$$.dir; then
+  rm -f conf$$.dir/conf$$.file
+else
+  rm -f conf$$.dir
+  mkdir conf$$.dir 2>/dev/null
+fi
+if (echo >conf$$.file) 2>/dev/null; then
+  if ln -s conf$$.file conf$$ 2>/dev/null; then
+    as_ln_s='ln -s'
+    # ... but there are two gotchas:
+    # 1) On MSYS, both `ln -s file dir' and `ln file dir' fail.
+    # 2) DJGPP < 2.04 has no symlinks; `ln -s' creates a wrapper executable.
+    # In both cases, we have to default to `cp -pR'.
+    ln -s conf$$.file conf$$.dir 2>/dev/null && test ! -f conf$$.exe ||
+      as_ln_s='cp -pR'
+  elif ln conf$$.file conf$$ 2>/dev/null; then
+    as_ln_s=ln
+  else
+    as_ln_s='cp -pR'
+  fi
+else
+  as_ln_s='cp -pR'
+fi
+rm -f conf$$ conf$$.exe conf$$.dir/conf$$.file conf$$.file
+rmdir conf$$.dir 2>/dev/null
+
+
+# as_fn_mkdir_p
+# -------------
+# Create "$as_dir" as a directory, including parents if necessary.
+as_fn_mkdir_p ()
+{
+
+  case $as_dir in #(
+  -*) as_dir=./$as_dir;;
+  esac
+  test -d "$as_dir" || eval $as_mkdir_p || {
+    as_dirs=
+    while :; do
+      case $as_dir in #(
+      *\'*) as_qdir=`$as_echo "$as_dir" | sed "s/'/'\\\\\\\\''/g"`;; #'(
+      *) as_qdir=$as_dir;;
+      esac
+      as_dirs="'$as_qdir' $as_dirs"
+      as_dir=`$as_dirname -- "$as_dir" ||
+$as_expr X"$as_dir" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
+	 X"$as_dir" : 'X\(//\)[^/]' \| \
+	 X"$as_dir" : 'X\(//\)$' \| \
+	 X"$as_dir" : 'X\(/\)' \| . 2>/dev/null ||
+$as_echo X"$as_dir" |
+    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)[^/].*/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\).*/{
+	    s//\1/
+	    q
+	  }
+	  s/.*/./; q'`
+      test -d "$as_dir" && break
+    done
+    test -z "$as_dirs" || eval "mkdir $as_dirs"
+  } || test -d "$as_dir" || as_fn_error $? "cannot create directory $as_dir"
+
+
+} # as_fn_mkdir_p
+if mkdir -p . 2>/dev/null; then
+  as_mkdir_p='mkdir -p "$as_dir"'
+else
+  test -d ./-p && rmdir ./-p
+  as_mkdir_p=false
+fi
+
+
+# as_fn_executable_p FILE
+# -----------------------
+# Test if FILE is an executable regular file.
+as_fn_executable_p ()
+{
+  test -f "$1" && test -x "$1"
+} # as_fn_executable_p
+as_test_x='test -x'
+as_executable_p=as_fn_executable_p
+
+# Sed expression to map a string onto a valid CPP name.
+as_tr_cpp="eval sed 'y%*$as_cr_letters%P$as_cr_LETTERS%;s%[^_$as_cr_alnum]%_%g'"
+
+# Sed expression to map a string onto a valid variable name.
+as_tr_sh="eval sed 'y%*+%pp%;s%[^_$as_cr_alnum]%_%g'"
+
+
+exec 6>&1
+## ----------------------------------- ##
+## Main body of $CONFIG_STATUS script. ##
+## ----------------------------------- ##
+_ASEOF
+test $as_write_fail = 0 && chmod +x $CONFIG_STATUS || ac_write_fail=1
+
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+# Save the log message, to keep $0 and so on meaningful, and to
+# report actual input values of CONFIG_FILES etc. instead of their
+# values after options handling.
+ac_log="
+This file was extended by $as_me, which was
+generated by GNU Autoconf 2.69.  Invocation command line was
+
+  CONFIG_FILES    = $CONFIG_FILES
+  CONFIG_HEADERS  = $CONFIG_HEADERS
+  CONFIG_LINKS    = $CONFIG_LINKS
+  CONFIG_COMMANDS = $CONFIG_COMMANDS
+  $ $0 $@
+
+on `(hostname || uname -n) 2>/dev/null | sed 1q`
+"
+
+_ACEOF
+
+case $ac_config_files in *"
+"*) set x $ac_config_files; shift; ac_config_files=$*;;
+esac
+
+case $ac_config_headers in *"
+"*) set x $ac_config_headers; shift; ac_config_headers=$*;;
+esac
+
+
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+# Files that config.status was made for.
+config_files="$ac_config_files"
+config_headers="$ac_config_headers"
+
+_ACEOF
+
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+ac_cs_usage="\
+\`$as_me' instantiates files and other configuration actions
+from templates according to the current configuration.  Unless the files
+and actions are specified as TAGs, all are instantiated by default.
+
+Usage: $0 [OPTION]... [TAG]...
+
+  -h, --help       print this help, then exit
+  -V, --version    print version number and configuration settings, then exit
+      --config     print configuration, then exit
+  -q, --quiet, --silent
+                   do not print progress messages
+  -d, --debug      don't remove temporary files
+      --recheck    update $as_me by reconfiguring in the same conditions
+      --file=FILE[:TEMPLATE]
+                   instantiate the configuration file FILE
+      --header=FILE[:TEMPLATE]
+                   instantiate the configuration header FILE
+
+Configuration files:
+$config_files
+
+Configuration headers:
+$config_headers
+
+Report bugs to the package provider."
+
+_ACEOF
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
+ac_cs_version="\\
+config.status
+configured by $0, generated by GNU Autoconf 2.69,
+  with options \\"\$ac_cs_config\\"
+
+Copyright (C) 2012 Free Software Foundation, Inc.
+This config.status script is free software; the Free Software Foundation
+gives unlimited permission to copy, distribute and modify it."
+
+ac_pwd='$ac_pwd'
+srcdir='$srcdir'
+test -n "\$AWK" || AWK=awk
+_ACEOF
+
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+# The default lists apply if the user does not specify any file.
+ac_need_defaults=:
+while test $# != 0
+do
+  case $1 in
+  --*=?*)
+    ac_option=`expr "X$1" : 'X\([^=]*\)='`
+    ac_optarg=`expr "X$1" : 'X[^=]*=\(.*\)'`
+    ac_shift=:
+    ;;
+  --*=)
+    ac_option=`expr "X$1" : 'X\([^=]*\)='`
+    ac_optarg=
+    ac_shift=:
+    ;;
+  *)
+    ac_option=$1
+    ac_optarg=$2
+    ac_shift=shift
+    ;;
+  esac
+
+  case $ac_option in
+  # Handling of the options.
+  -recheck | --recheck | --rechec | --reche | --rech | --rec | --re | --r)
+    ac_cs_recheck=: ;;
+  --version | --versio | --versi | --vers | --ver | --ve | --v | -V )
+    $as_echo "$ac_cs_version"; exit ;;
+  --config | --confi | --conf | --con | --co | --c )
+    $as_echo "$ac_cs_config"; exit ;;
+  --debug | --debu | --deb | --de | --d | -d )
+    debug=: ;;
+  --file | --fil | --fi | --f )
+    $ac_shift
+    case $ac_optarg in
+    *\'*) ac_optarg=`$as_echo "$ac_optarg" | sed "s/'/'\\\\\\\\''/g"` ;;
+    '') as_fn_error $? "missing file argument" ;;
+    esac
+    as_fn_append CONFIG_FILES " '$ac_optarg'"
+    ac_need_defaults=false;;
+  --header | --heade | --head | --hea )
+    $ac_shift
+    case $ac_optarg in
+    *\'*) ac_optarg=`$as_echo "$ac_optarg" | sed "s/'/'\\\\\\\\''/g"` ;;
+    esac
+    as_fn_append CONFIG_HEADERS " '$ac_optarg'"
+    ac_need_defaults=false;;
+  --he | --h)
+    # Conflict between --help and --header
+    as_fn_error $? "ambiguous option: \`$1'
+Try \`$0 --help' for more information.";;
+  --help | --hel | -h )
+    $as_echo "$ac_cs_usage"; exit ;;
+  -q | -quiet | --quiet | --quie | --qui | --qu | --q \
+  | -silent | --silent | --silen | --sile | --sil | --si | --s)
+    ac_cs_silent=: ;;
+
+  # This is an error.
+  -*) as_fn_error $? "unrecognized option: \`$1'
+Try \`$0 --help' for more information." ;;
+
+  *) as_fn_append ac_config_targets " $1"
+     ac_need_defaults=false ;;
+
+  esac
+  shift
+done
+
+ac_configure_extra_args=
+
+if $ac_cs_silent; then
+  exec 6>/dev/null
+  ac_configure_extra_args="$ac_configure_extra_args --silent"
+fi
+
+_ACEOF
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+if \$ac_cs_recheck; then
+  set X $SHELL '$0' $ac_configure_args \$ac_configure_extra_args --no-create --no-recursion
+  shift
+  \$as_echo "running CONFIG_SHELL=$SHELL \$*" >&6
+  CONFIG_SHELL='$SHELL'
+  export CONFIG_SHELL
+  exec "\$@"
+fi
+
+_ACEOF
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+exec 5>>config.log
+{
+  echo
+  sed 'h;s/./-/g;s/^.../## /;s/...$/ ##/;p;x;p;x' <<_ASBOX
+## Running $as_me. ##
+_ASBOX
+  $as_echo "$ac_log"
+} >&5
+
+_ACEOF
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+_ACEOF
+
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+
+# Handling of arguments.
+for ac_config_target in $ac_config_targets
+do
+  case $ac_config_target in
+    "rktio_config.h") CONFIG_HEADERS="$CONFIG_HEADERS rktio_config.h" ;;
+    "$makefiles") CONFIG_FILES="$CONFIG_FILES $makefiles" ;;
+
+  *) as_fn_error $? "invalid argument: \`$ac_config_target'" "$LINENO" 5;;
+  esac
+done
+
+
+# If the user did not use the arguments to specify the items to instantiate,
+# then the envvar interface is used.  Set only those that are not.
+# We use the long form for the default assignment because of an extremely
+# bizarre bug on SunOS 4.1.3.
+if $ac_need_defaults; then
+  test "${CONFIG_FILES+set}" = set || CONFIG_FILES=$config_files
+  test "${CONFIG_HEADERS+set}" = set || CONFIG_HEADERS=$config_headers
+fi
+
+# Have a temporary directory for convenience.  Make it in the build tree
+# simply because there is no reason against having it here, and in addition,
+# creating and moving files from /tmp can sometimes cause problems.
+# Hook for its removal unless debugging.
+# Note that there is a small window in which the directory will not be cleaned:
+# after its creation but before its name has been assigned to `$tmp'.
+$debug ||
+{
+  tmp= ac_tmp=
+  trap 'exit_status=$?
+  : "${ac_tmp:=$tmp}"
+  { test ! -d "$ac_tmp" || rm -fr "$ac_tmp"; } && exit $exit_status
+' 0
+  trap 'as_fn_exit 1' 1 2 13 15
+}
+# Create a (secure) tmp directory for tmp files.
+
+{
+  tmp=`(umask 077 && mktemp -d "./confXXXXXX") 2>/dev/null` &&
+  test -d "$tmp"
+}  ||
+{
+  tmp=./conf$$-$RANDOM
+  (umask 077 && mkdir "$tmp")
+} || as_fn_error $? "cannot create a temporary directory in ." "$LINENO" 5
+ac_tmp=$tmp
+
+# Set up the scripts for CONFIG_FILES section.
+# No need to generate them if there are no CONFIG_FILES.
+# This happens for instance with `./config.status config.h'.
+if test -n "$CONFIG_FILES"; then
+
+
+ac_cr=`echo X | tr X '\015'`
+# On cygwin, bash can eat \r inside `` if the user requested igncr.
+# But we know of no other shell where ac_cr would be empty at this
+# point, so we can use a bashism as a fallback.
+if test "x$ac_cr" = x; then
+  eval ac_cr=\$\'\\r\'
+fi
+ac_cs_awk_cr=`$AWK 'BEGIN { print "a\rb" }' </dev/null 2>/dev/null`
+if test "$ac_cs_awk_cr" = "a${ac_cr}b"; then
+  ac_cs_awk_cr='\\r'
+else
+  ac_cs_awk_cr=$ac_cr
+fi
+
+echo 'BEGIN {' >"$ac_tmp/subs1.awk" &&
+_ACEOF
+
+
+{
+  echo "cat >conf$$subs.awk <<_ACEOF" &&
+  echo "$ac_subst_vars" | sed 's/.*/&!$&$ac_delim/' &&
+  echo "_ACEOF"
+} >conf$$subs.sh ||
+  as_fn_error $? "could not make $CONFIG_STATUS" "$LINENO" 5
+ac_delim_num=`echo "$ac_subst_vars" | grep -c '^'`
+ac_delim='%!_!# '
+for ac_last_try in false false false false false :; do
+  . ./conf$$subs.sh ||
+    as_fn_error $? "could not make $CONFIG_STATUS" "$LINENO" 5
+
+  ac_delim_n=`sed -n "s/.*$ac_delim\$/X/p" conf$$subs.awk | grep -c X`
+  if test $ac_delim_n = $ac_delim_num; then
+    break
+  elif $ac_last_try; then
+    as_fn_error $? "could not make $CONFIG_STATUS" "$LINENO" 5
+  else
+    ac_delim="$ac_delim!$ac_delim _$ac_delim!! "
+  fi
+done
+rm -f conf$$subs.sh
+
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+cat >>"\$ac_tmp/subs1.awk" <<\\_ACAWK &&
+_ACEOF
+sed -n '
+h
+s/^/S["/; s/!.*/"]=/
+p
+g
+s/^[^!]*!//
+:repl
+t repl
+s/'"$ac_delim"'$//
+t delim
+:nl
+h
+s/\(.\{148\}\)..*/\1/
+t more1
+s/["\\]/\\&/g; s/^/"/; s/$/\\n"\\/
+p
+n
+b repl
+:more1
+s/["\\]/\\&/g; s/^/"/; s/$/"\\/
+p
+g
+s/.\{148\}//
+t nl
+:delim
+h
+s/\(.\{148\}\)..*/\1/
+t more2
+s/["\\]/\\&/g; s/^/"/; s/$/"/
+p
+b
+:more2
+s/["\\]/\\&/g; s/^/"/; s/$/"\\/
+p
+g
+s/.\{148\}//
+t delim
+' <conf$$subs.awk | sed '
+/^[^""]/{
+  N
+  s/\n//
+}
+' >>$CONFIG_STATUS || ac_write_fail=1
+rm -f conf$$subs.awk
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+_ACAWK
+cat >>"\$ac_tmp/subs1.awk" <<_ACAWK &&
+  for (key in S) S_is_set[key] = 1
+  FS = ""
+
+}
+{
+  line = $ 0
+  nfields = split(line, field, "@")
+  substed = 0
+  len = length(field[1])
+  for (i = 2; i < nfields; i++) {
+    key = field[i]
+    keylen = length(key)
+    if (S_is_set[key]) {
+      value = S[key]
+      line = substr(line, 1, len) "" value "" substr(line, len + keylen + 3)
+      len += length(value) + length(field[++i])
+      substed = 1
+    } else
+      len += 1 + keylen
+  }
+
+  print line
+}
+
+_ACAWK
+_ACEOF
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+if sed "s/$ac_cr//" < /dev/null > /dev/null 2>&1; then
+  sed "s/$ac_cr\$//; s/$ac_cr/$ac_cs_awk_cr/g"
+else
+  cat
+fi < "$ac_tmp/subs1.awk" > "$ac_tmp/subs.awk" \
+  || as_fn_error $? "could not setup config files machinery" "$LINENO" 5
+_ACEOF
+
+# VPATH may cause trouble with some makes, so we remove sole $(srcdir),
+# ${srcdir} and @srcdir@ entries from VPATH if srcdir is ".", strip leading and
+# trailing colons and then remove the whole line if VPATH becomes empty
+# (actually we leave an empty line to preserve line numbers).
+if test "x$srcdir" = x.; then
+  ac_vpsub='/^[	 ]*VPATH[	 ]*=[	 ]*/{
+h
+s///
+s/^/:/
+s/[	 ]*$/:/
+s/:\$(srcdir):/:/g
+s/:\${srcdir}:/:/g
+s/:@srcdir@:/:/g
+s/^:*//
+s/:*$//
+x
+s/\(=[	 ]*\).*/\1/
+G
+s/\n//
+s/^[^=]*=[	 ]*$//
+}'
+fi
+
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+fi # test -n "$CONFIG_FILES"
+
+# Set up the scripts for CONFIG_HEADERS section.
+# No need to generate them if there are no CONFIG_HEADERS.
+# This happens for instance with `./config.status Makefile'.
+if test -n "$CONFIG_HEADERS"; then
+cat >"$ac_tmp/defines.awk" <<\_ACAWK ||
+BEGIN {
+_ACEOF
+
+# Transform confdefs.h into an awk script `defines.awk', embedded as
+# here-document in config.status, that substitutes the proper values into
+# config.h.in to produce config.h.
+
+# Create a delimiter string that does not exist in confdefs.h, to ease
+# handling of long lines.
+ac_delim='%!_!# '
+for ac_last_try in false false :; do
+  ac_tt=`sed -n "/$ac_delim/p" confdefs.h`
+  if test -z "$ac_tt"; then
+    break
+  elif $ac_last_try; then
+    as_fn_error $? "could not make $CONFIG_HEADERS" "$LINENO" 5
+  else
+    ac_delim="$ac_delim!$ac_delim _$ac_delim!! "
+  fi
+done
+
+# For the awk script, D is an array of macro values keyed by name,
+# likewise P contains macro parameters if any.  Preserve backslash
+# newline sequences.
+
+ac_word_re=[_$as_cr_Letters][_$as_cr_alnum]*
+sed -n '
+s/.\{148\}/&'"$ac_delim"'/g
+t rset
+:rset
+s/^[	 ]*#[	 ]*define[	 ][	 ]*/ /
+t def
+d
+:def
+s/\\$//
+t bsnl
+s/["\\]/\\&/g
+s/^ \('"$ac_word_re"'\)\(([^()]*)\)[	 ]*\(.*\)/P["\1"]="\2"\
+D["\1"]=" \3"/p
+s/^ \('"$ac_word_re"'\)[	 ]*\(.*\)/D["\1"]=" \2"/p
+d
+:bsnl
+s/["\\]/\\&/g
+s/^ \('"$ac_word_re"'\)\(([^()]*)\)[	 ]*\(.*\)/P["\1"]="\2"\
+D["\1"]=" \3\\\\\\n"\\/p
+t cont
+s/^ \('"$ac_word_re"'\)[	 ]*\(.*\)/D["\1"]=" \2\\\\\\n"\\/p
+t cont
+d
+:cont
+n
+s/.\{148\}/&'"$ac_delim"'/g
+t clear
+:clear
+s/\\$//
+t bsnlc
+s/["\\]/\\&/g; s/^/"/; s/$/"/p
+d
+:bsnlc
+s/["\\]/\\&/g; s/^/"/; s/$/\\\\\\n"\\/p
+b cont
+' <confdefs.h | sed '
+s/'"$ac_delim"'/"\\\
+"/g' >>$CONFIG_STATUS || ac_write_fail=1
+
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+  for (key in D) D_is_set[key] = 1
+  FS = ""
+}
+/^[\t ]*#[\t ]*(define|undef)[\t ]+$ac_word_re([\t (]|\$)/ {
+  line = \$ 0
+  split(line, arg, " ")
+  if (arg[1] == "#") {
+    defundef = arg[2]
+    mac1 = arg[3]
+  } else {
+    defundef = substr(arg[1], 2)
+    mac1 = arg[2]
+  }
+  split(mac1, mac2, "(") #)
+  macro = mac2[1]
+  prefix = substr(line, 1, index(line, defundef) - 1)
+  if (D_is_set[macro]) {
+    # Preserve the white space surrounding the "#".
+    print prefix "define", macro P[macro] D[macro]
+    next
+  } else {
+    # Replace #undef with comments.  This is necessary, for example,
+    # in the case of _POSIX_SOURCE, which is predefined and required
+    # on some systems where configure will not decide to define it.
+    if (defundef == "undef") {
+      print "/*", prefix defundef, macro, "*/"
+      next
+    }
+  }
+}
+{ print }
+_ACAWK
+_ACEOF
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+  as_fn_error $? "could not setup config headers machinery" "$LINENO" 5
+fi # test -n "$CONFIG_HEADERS"
+
+
+eval set X "  :F $CONFIG_FILES  :H $CONFIG_HEADERS    "
+shift
+for ac_tag
+do
+  case $ac_tag in
+  :[FHLC]) ac_mode=$ac_tag; continue;;
+  esac
+  case $ac_mode$ac_tag in
+  :[FHL]*:*);;
+  :L* | :C*:*) as_fn_error $? "invalid tag \`$ac_tag'" "$LINENO" 5;;
+  :[FH]-) ac_tag=-:-;;
+  :[FH]*) ac_tag=$ac_tag:$ac_tag.in;;
+  esac
+  ac_save_IFS=$IFS
+  IFS=:
+  set x $ac_tag
+  IFS=$ac_save_IFS
+  shift
+  ac_file=$1
+  shift
+
+  case $ac_mode in
+  :L) ac_source=$1;;
+  :[FH])
+    ac_file_inputs=
+    for ac_f
+    do
+      case $ac_f in
+      -) ac_f="$ac_tmp/stdin";;
+      *) # Look for the file first in the build tree, then in the source tree
+	 # (if the path is not absolute).  The absolute path cannot be DOS-style,
+	 # because $ac_f cannot contain `:'.
+	 test -f "$ac_f" ||
+	   case $ac_f in
+	   [\\/$]*) false;;
+	   *) test -f "$srcdir/$ac_f" && ac_f="$srcdir/$ac_f";;
+	   esac ||
+	   as_fn_error 1 "cannot find input file: \`$ac_f'" "$LINENO" 5;;
+      esac
+      case $ac_f in *\'*) ac_f=`$as_echo "$ac_f" | sed "s/'/'\\\\\\\\''/g"`;; esac
+      as_fn_append ac_file_inputs " '$ac_f'"
+    done
+
+    # Let's still pretend it is `configure' which instantiates (i.e., don't
+    # use $as_me), people would be surprised to read:
+    #    /* config.h.  Generated by config.status.  */
+    configure_input='Generated from '`
+	  $as_echo "$*" | sed 's|^[^:]*/||;s|:[^:]*/|, |g'
+	`' by configure.'
+    if test x"$ac_file" != x-; then
+      configure_input="$ac_file.  $configure_input"
+      { $as_echo "$as_me:${as_lineno-$LINENO}: creating $ac_file" >&5
+$as_echo "$as_me: creating $ac_file" >&6;}
+    fi
+    # Neutralize special characters interpreted by sed in replacement strings.
+    case $configure_input in #(
+    *\&* | *\|* | *\\* )
+       ac_sed_conf_input=`$as_echo "$configure_input" |
+       sed 's/[\\\\&|]/\\\\&/g'`;; #(
+    *) ac_sed_conf_input=$configure_input;;
+    esac
+
+    case $ac_tag in
+    *:-:* | *:-) cat >"$ac_tmp/stdin" \
+      || as_fn_error $? "could not create $ac_file" "$LINENO" 5 ;;
+    esac
+    ;;
+  esac
+
+  ac_dir=`$as_dirname -- "$ac_file" ||
+$as_expr X"$ac_file" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
+	 X"$ac_file" : 'X\(//\)[^/]' \| \
+	 X"$ac_file" : 'X\(//\)$' \| \
+	 X"$ac_file" : 'X\(/\)' \| . 2>/dev/null ||
+$as_echo X"$ac_file" |
+    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)[^/].*/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\).*/{
+	    s//\1/
+	    q
+	  }
+	  s/.*/./; q'`
+  as_dir="$ac_dir"; as_fn_mkdir_p
+  ac_builddir=.
+
+case "$ac_dir" in
+.) ac_dir_suffix= ac_top_builddir_sub=. ac_top_build_prefix= ;;
+*)
+  ac_dir_suffix=/`$as_echo "$ac_dir" | sed 's|^\.[\\/]||'`
+  # A ".." for each directory in $ac_dir_suffix.
+  ac_top_builddir_sub=`$as_echo "$ac_dir_suffix" | sed 's|/[^\\/]*|/..|g;s|/||'`
+  case $ac_top_builddir_sub in
+  "") ac_top_builddir_sub=. ac_top_build_prefix= ;;
+  *)  ac_top_build_prefix=$ac_top_builddir_sub/ ;;
+  esac ;;
+esac
+ac_abs_top_builddir=$ac_pwd
+ac_abs_builddir=$ac_pwd$ac_dir_suffix
+# for backward compatibility:
+ac_top_builddir=$ac_top_build_prefix
+
+case $srcdir in
+  .)  # We are building in place.
+    ac_srcdir=.
+    ac_top_srcdir=$ac_top_builddir_sub
+    ac_abs_top_srcdir=$ac_pwd ;;
+  [\\/]* | ?:[\\/]* )  # Absolute name.
+    ac_srcdir=$srcdir$ac_dir_suffix;
+    ac_top_srcdir=$srcdir
+    ac_abs_top_srcdir=$srcdir ;;
+  *) # Relative name.
+    ac_srcdir=$ac_top_build_prefix$srcdir$ac_dir_suffix
+    ac_top_srcdir=$ac_top_build_prefix$srcdir
+    ac_abs_top_srcdir=$ac_pwd/$srcdir ;;
+esac
+ac_abs_srcdir=$ac_abs_top_srcdir$ac_dir_suffix
+
+
+  case $ac_mode in
+  :F)
+  #
+  # CONFIG_FILE
+  #
+
+_ACEOF
+
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+# If the template does not know about datarootdir, expand it.
+# FIXME: This hack should be removed a few years after 2.60.
+ac_datarootdir_hack=; ac_datarootdir_seen=
+ac_sed_dataroot='
+/datarootdir/ {
+  p
+  q
+}
+/@datadir@/p
+/@docdir@/p
+/@infodir@/p
+/@localedir@/p
+/@mandir@/p'
+case `eval "sed -n \"\$ac_sed_dataroot\" $ac_file_inputs"` in
+*datarootdir*) ac_datarootdir_seen=yes;;
+*@datadir@*|*@docdir@*|*@infodir@*|*@localedir@*|*@mandir@*)
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $ac_file_inputs seems to ignore the --datarootdir setting" >&5
+$as_echo "$as_me: WARNING: $ac_file_inputs seems to ignore the --datarootdir setting" >&2;}
+_ACEOF
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+  ac_datarootdir_hack='
+  s&@datadir@&$datadir&g
+  s&@docdir@&$docdir&g
+  s&@infodir@&$infodir&g
+  s&@localedir@&$localedir&g
+  s&@mandir@&$mandir&g
+  s&\\\${datarootdir}&$datarootdir&g' ;;
+esac
+_ACEOF
+
+# Neutralize VPATH when `$srcdir' = `.'.
+# Shell code in configure.ac might set extrasub.
+# FIXME: do we really want to maintain this feature?
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+ac_sed_extra="$ac_vpsub
+$extrasub
+_ACEOF
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+:t
+/@[a-zA-Z_][a-zA-Z_0-9]*@/!b
+s|@configure_input@|$ac_sed_conf_input|;t t
+s&@top_builddir@&$ac_top_builddir_sub&;t t
+s&@top_build_prefix@&$ac_top_build_prefix&;t t
+s&@srcdir@&$ac_srcdir&;t t
+s&@abs_srcdir@&$ac_abs_srcdir&;t t
+s&@top_srcdir@&$ac_top_srcdir&;t t
+s&@abs_top_srcdir@&$ac_abs_top_srcdir&;t t
+s&@builddir@&$ac_builddir&;t t
+s&@abs_builddir@&$ac_abs_builddir&;t t
+s&@abs_top_builddir@&$ac_abs_top_builddir&;t t
+$ac_datarootdir_hack
+"
+eval sed \"\$ac_sed_extra\" "$ac_file_inputs" | $AWK -f "$ac_tmp/subs.awk" \
+  >$ac_tmp/out || as_fn_error $? "could not create $ac_file" "$LINENO" 5
+
+test -z "$ac_datarootdir_hack$ac_datarootdir_seen" &&
+  { ac_out=`sed -n '/\${datarootdir}/p' "$ac_tmp/out"`; test -n "$ac_out"; } &&
+  { ac_out=`sed -n '/^[	 ]*datarootdir[	 ]*:*=/p' \
+      "$ac_tmp/out"`; test -z "$ac_out"; } &&
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $ac_file contains a reference to the variable \`datarootdir'
+which seems to be undefined.  Please make sure it is defined" >&5
+$as_echo "$as_me: WARNING: $ac_file contains a reference to the variable \`datarootdir'
+which seems to be undefined.  Please make sure it is defined" >&2;}
+
+  rm -f "$ac_tmp/stdin"
+  case $ac_file in
+  -) cat "$ac_tmp/out" && rm -f "$ac_tmp/out";;
+  *) rm -f "$ac_file" && mv "$ac_tmp/out" "$ac_file";;
+  esac \
+  || as_fn_error $? "could not create $ac_file" "$LINENO" 5
+ ;;
+  :H)
+  #
+  # CONFIG_HEADER
+  #
+  if test x"$ac_file" != x-; then
+    {
+      $as_echo "/* $configure_input  */" \
+      && eval '$AWK -f "$ac_tmp/defines.awk"' "$ac_file_inputs"
+    } >"$ac_tmp/config.h" \
+      || as_fn_error $? "could not create $ac_file" "$LINENO" 5
+    if diff "$ac_file" "$ac_tmp/config.h" >/dev/null 2>&1; then
+      { $as_echo "$as_me:${as_lineno-$LINENO}: $ac_file is unchanged" >&5
+$as_echo "$as_me: $ac_file is unchanged" >&6;}
+    else
+      rm -f "$ac_file"
+      mv "$ac_tmp/config.h" "$ac_file" \
+	|| as_fn_error $? "could not create $ac_file" "$LINENO" 5
+    fi
+  else
+    $as_echo "/* $configure_input  */" \
+      && eval '$AWK -f "$ac_tmp/defines.awk"' "$ac_file_inputs" \
+      || as_fn_error $? "could not create -" "$LINENO" 5
+  fi
+ ;;
+
+
+  esac
+
+done # for ac_tag
+
+
+as_fn_exit 0
+_ACEOF
+ac_clean_files=$ac_clean_files_save
+
+test $ac_write_fail = 0 ||
+  as_fn_error $? "write failure creating $CONFIG_STATUS" "$LINENO" 5
+
+
+# configure is writing to config.log, and then calls config.status.
+# config.status does its own redirection, appending to config.log.
+# Unfortunately, on DOS this fails, as config.log is still kept open
+# by configure, so config.status won't be able to write to it; its
+# output is simply discarded.  So we exec the FD to /dev/null,
+# effectively closing config.log, so it can be properly (re)opened and
+# appended to by config.status.  When coming back to configure, we
+# need to make the FD available again.
+if test "$no_create" != yes; then
+  ac_cs_success=:
+  ac_config_status_args=
+  test "$silent" = yes &&
+    ac_config_status_args="$ac_config_status_args --quiet"
+  exec 5>/dev/null
+  $SHELL $CONFIG_STATUS $ac_config_status_args || ac_cs_success=false
+  exec 5>>config.log
+  # Use ||, not &&, to avoid exiting from the if with $? = 1, which
+  # would make configure fail if this is the last instruction.
+  $ac_cs_success || as_fn_exit 1
+fi
+if test -n "$ac_unrecognized_opts" && test "$enable_option_checking" != no; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: unrecognized options: $ac_unrecognized_opts" >&5
+$as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2;}
+fi
+
diff --git a/racket/src/rktio/configure.ac b/racket/src/rktio/configure.ac
new file mode 100644
index 0000000000..bbfb58e625
--- /dev/null
+++ b/racket/src/rktio/configure.ac
@@ -0,0 +1,196 @@
+
+#################################################################
+# This is the source for the `configure` script, to be compiled #
+# by autoconf (use `make-configure` in "../racket").            #
+#################################################################
+
+AC_INIT([rktio.h])
+AC_CONFIG_HEADERS([rktio_config.h])
+
+AC_CONFIG_AUX_DIR(../lt)
+AC_CANONICAL_SYSTEM
+
+###### Autoconfigure #######
+
+AC_PROG_CC
+
+AC_CHECK_LIB(dl, dlopen)
+
+############## platform tests ################
+
+case "$host_os" in
+  *)
+    ;;
+esac
+
+############## C flags ################
+
+AC_LANG_C
+
+AC_TYPE_INTPTR_T
+AC_TYPE_UINTPTR_T
+
+AC_MSG_CHECKING([for getaddrinfo])
+AC_TRY_LINK([#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>],
+	[getaddrinfo(0, 0, 0, 0);],
+   AC_DEFINE(HAVE_GETADDRINFO,1,[Have getaddrinfo])
+   have_getaddrinfo=yes,
+   have_getaddrinfo=no)
+AC_MSG_RESULT($have_getaddrinfo)
+
+iconv_lib_flag=""
+if test "${skip_iconv_check}" = "no" ; then
+ if test "${enable_iconv}" = "yes" ; then
+  AC_CHECK_HEADER(iconv.h, enable_iconv=yes, enable_iconv=no)
+  if test "${enable_iconv}" = "yes" ; then  
+    # Does it all work, now?
+    AC_TRY_RUN(
+[   #include <iconv.h>]
+[   #include <langinfo.h>]
+    int main() {
+[     iconv_open("UTF-8", "UTF-8");]
+      return 0;
+    }, enable_iconv=yes, enable_iconv=no, enable_iconv=yes)
+    if test "${enable_iconv}" = "no" ; then  
+      # Try adding -liconv ?
+      #  We did not use AC_CHECK_LIB because iconv is sometimes macro-renamed
+      ORIG_LIBS="$LIBS"
+      LIBS="$LIBS -liconv"
+      AC_TRY_RUN(
+[     #include <iconv.h>]
+[     #include <langinfo.h>]
+      int main() {
+[     iconv_open("UTF-8", "UTF-8");]
+      return 0;
+      }, enable_iconv=yes, enable_iconv=no, enable_iconv=yes)
+      if test "${enable_iconv}" = "no" ; then
+        LIBS="$ORIG_LIBS"
+      else
+        iconv_lib_flag=" -liconv"      
+      fi
+    fi
+  fi
+ fi
+ [ msg="iconv is usable" ]
+ AC_MSG_CHECKING($msg)
+ iconv_usage_result="$enable_iconv$iconv_lib_flag"
+ AC_MSG_RESULT($iconv_usage_result)
+ if test "${enable_iconv}" = "no" ; then
+  CFLAGS="$CFLAGS -DRKTIO_NO_ICONV"  
+ fi
+fi
+
+[ msg="for mbsrtowcs" ]
+AC_MSG_CHECKING($msg)
+AC_LINK_IFELSE([AC_LANG_SOURCE([
+   #include <wchar.h>
+   #include <strings.h>
+   int main() {
+     mbstate_t state;
+     char *src = "X";
+     bzero(&state, sizeof(mbstate_t));
+     mbsrtowcs(0, &src, 0, &state);
+     return 0;
+   }])], mbsrtowcs=yes, mbsrtowcs=no)
+if test "$mbsrtowcs" = "no" ; then
+  CFLAGS="$CFLAGS -DNO_MBTOWC_FUNCTIONS"
+fi
+AC_MSG_RESULT($mbsrtowcs)
+
+if test "${try_poll_syscall}" = "yes" ; then
+  [ msg="for poll" ]
+  AC_MSG_CHECKING($msg)
+  AC_LINK_IFELSE([AC_LANG_SOURCE([
+     #include <poll.h>
+     int main() {
+      struct pollfd pfd;
+      int r;
+      pfd.fd = 0;
+      pfd.events = POLLIN;
+      r = poll(&pfd, 1, 0);
+      return 0;
+     }])], use_poll=yes, use_poll=no)
+  AC_MSG_RESULT($use_poll)
+  if test "${use_poll}" = "yes" ; then
+     AC_DEFINE(HAVE_POLL_SYSCALL,1,[Have poll])
+  fi
+fi
+
+if test "${try_epoll_syscall}" = "yes" ; then
+  [ msg="for epoll" ]
+  AC_MSG_CHECKING($msg)
+  AC_LINK_IFELSE([AC_LANG_SOURCE([
+    #include <sys/epoll.h>
+    int main() {
+      int fd;
+      struct epoll_event ev;
+      fd = epoll_create(5);
+      ev.events = EPOLLIN | EPOLLONESHOT;
+      epoll_ctl(fd, EPOLL_CTL_ADD, 0, &ev);
+      return 0;
+    }])], use_epoll=yes, use_epoll=no)
+  AC_MSG_RESULT($use_epoll)
+  if test "${use_epoll}" = "yes" ; then
+     AC_DEFINE(HAVE_EPOLL_SYSCALL,1,[Have epoll])
+  fi
+fi
+
+if test "${try_inotify_syscall}" = "yes" ; then
+  [ msg="for inotify" ]
+  AC_MSG_CHECKING($msg)
+  AC_LINK_IFELSE([AC_LANG_SOURCE([
+    #include <sys/inotify.h> 
+    int main() {
+      int fd;
+      int wd;
+      fd = inotify_init();
+      wd = inotify_add_watch(fd, "/tmp", 
+                             (IN_CREATE | IN_DELETE | IN_DELETE_SELF
+                              | IN_MODIFY | IN_MOVE_SELF | IN_MOVED_TO));
+      return 0;
+    }])], use_inotify=yes, use_inotify=no)
+  AC_MSG_RESULT($use_inotify)
+  if test "${use_inotify}" = "yes" ; then
+     AC_DEFINE(HAVE_INOTIFY_SYSCALL,1,[Have inotify])
+  fi
+fi
+
+if test "${try_kqueue_syscall}" = "yes" ; then
+  [ msg="for kqueue" ]
+  AC_MSG_CHECKING($msg)
+  AC_LINK_IFELSE([AC_LANG_SOURCE([
+     #include <sys/types.h>
+     #include <sys/event.h>
+     #include <sys/time.h>
+     int main() {
+        int kq;
+        struct kevent kev;
+        struct timespec timeout = {0, 0};
+        kq = kqueue();
+        EV_SET(&kev, 0, EVFILT_READ, EV_ADD, 0, 0, NULL);
+        kevent(kq, &kev, 1, NULL, 0, &timeout);
+        return 0;
+     }])], use_kqueue=yes, use_kqueue=no)
+  AC_MSG_RESULT($use_kqueue)
+  if test "${use_kqueue}" = "yes" ; then
+     AC_DEFINE(HAVE_KQUEUE_SYSCALL,1,[Have kqueue])
+  fi
+fi
+
+LFS_CFLAGS=`getconf LFS_CFLAGS 2> /dev/null`
+if test "${LFS_CFLAGS}" != "" && test "${LFS_CFLAGS}" != "undefined"; then
+  echo "Large-file support: ${LFS_CFLAGS}"
+  CFLAGS="${CFLAGS} ${LFS_CFLAGS}"  
+fi
+
+############## final output ################
+
+AC_SUBST(CC)
+AC_SUBST(CFLAGS)
+AC_SUBST(LDFLAGS)
+
+makefiles="Makefile"
+
+AC_OUTPUT($makefiles)
diff --git a/racket/src/rktio/rktio.h b/racket/src/rktio/rktio.h
new file mode 100644
index 0000000000..84e1f10a20
--- /dev/null
+++ b/racket/src/rktio/rktio.h
@@ -0,0 +1,167 @@
+#ifndef __RKTIO_H__
+#define __RKTIO_H__
+
+#include "rktio_config.h"
+
+/*************************************************/
+/* Reading and writing files                     */
+
+typedef struct rktio_fd_t rktio_fd_t;
+
+#define RKTIO_OPEN_READ        (1<<0)
+#define RKTIO_OPEN_WRITE       (1<<1)
+#define RKTIO_OPEN_TRUNCATE    (1<<2)
+#define RKTIO_OPEN_APPEND      (1<<3)
+#define RKTIO_OPEN_REPLACE     (1<<4)
+#define RKTIO_OPEN_MUST_EXIST  (1<<5)
+#define RKTIO_OPEN_CAN_EXIST   (1<<6)
+
+rktio_fd_t *rktio_fd(intptr_t system_fd, int modes);
+
+rktio_fd_t *rktio_open(char *src, int modes);
+int rktio_close(rktio_fd_t *fd);
+
+#define RKTIO_READ_EOF   (-1)
+#define RKTIO_READ_ERROR (-2)
+#define RKTIO_WRITE_ERROR (-2)
+#define RKTIO_POLL_ERROR (-2)
+
+intptr_t rktio_read(rktio_fd_t *fd, char *buffer, intptr_t len);
+intptr_t rktio_write(rktio_fd_t *fd, char *buffer, intptr_t len);
+
+int rktio_poll_read_ready(rktio_fd_t *rfd);
+int rktio_poll_write_ready(rktio_fd_t *rfd);
+int rktio_poll_write_flushed(rktio_fd_t *rfd);
+
+/*************************************************/
+/* File-descriptor sets                          */
+
+typedef struct rktio_poll_set_t rktio_poll_set_t;
+
+#define RKTIO_POLL_READ   RKTIO_OPEN_READ
+#define RKTIO_POLL_WRITE  RKTIO_OPEN_WRITE
+
+void rktio_poll_add(rktio_fd_t *rfd, rktio_poll_set_t *fds, int modes);
+
+/*************************************************/
+/* Files, directories, and links                 */
+
+int rktio_file_exists(char *filename);
+int rktio_directory_exists(char *dirname);
+int rktio_link_exists(char *filename);
+int rktio_is_regular_file(char *filename);
+
+int rktio_delete_file(char *fn, int enable_write_on_fail);
+int rktio_rename_file(char *dest, char *src, int exists_ok);
+
+char *rktio_get_current_directory();
+int rktio_set_current_directory(char *expanded);
+int rktio_make_directory(char *filename);
+int rktio_delete_directory(char *filename, char *current_directory, int enable_write_on_fail);
+
+char *rktio_readlink(char *fullfilename);
+int rktio_make_link(char *src, char *dest, int dest_is_directory);
+
+/*************************************************/
+/* File attributes                               */
+
+typedef struct {
+  unsigned lo, hi;
+} rktio_size_t;
+
+typedef intptr_t rktio_timestamp_t;
+
+typedef struct {
+  uintptr_t a, b, c;
+} rktio_identity_t;
+
+rktio_size_t *rktio_file_size(char *filename);
+
+rktio_timestamp_t *rktio_get_file_modify_seconds(char *file);
+int rktio_set_file_modify_seconds(char *file, rktio_timestamp_t secs);
+
+rktio_identity_t *rktio_get_fd_identity(intptr_t fd, char *path);
+
+/*************************************************/
+/* Permissions                                   */
+
+/* Must match OS bits: */
+#define RKTIO_PERMISSION_READ  0x1
+#define RKTIO_PERMISSION_WRITE 0x2
+#define RKTIO_PERMISSION_EXEC  0x4
+
+int rktio_get_file_or_directory_permissions(char *filename, int all_bits);
+int rktio_set_file_or_directory_permissions(char *filename, int new_bits);
+
+/*************************************************/
+/* Directory listing                             */
+
+typedef struct rktio_directory_list_t rktio_directory_list_t;
+
+rktio_directory_list_t *rktio_directory_list_start(char *filename, int is_drive);
+char *rktio_directory_list_step(rktio_directory_list_t *dl);
+
+char **rktio_filesystem_root_list();
+
+/*************************************************/
+/* File copying                                  */
+
+typedef struct rktio_file_copy_t rktio_file_copy_t;
+
+rktio_file_copy_t *rktio_copy_file_start(char *dest, char *src, int exists_ok);
+int rktio_copy_file_is_done(rktio_file_copy_t *fc);
+int rktio_copy_file_step(rktio_file_copy_t *fc);
+void rktio_copy_file_stop(rktio_file_copy_t *fc);
+
+/*************************************************/
+/* System paths                                  */
+
+enum {
+  RKTIO_PATH_SYS_DIR,
+  RKTIO_PATH_TEMP_DIR,
+  RKTIO_PATH_PREF_DIR,
+  RKTIO_PATH_PREF_FILE,
+  RKTIO_PATH_ADDON_DIR,
+  RKTIO_PATH_HOME_DIR,
+  RKTIO_PATH_DESK_DIR,
+  RKTIO_PATH_DOC_DIR,
+  RKTIO_PATH_INIT_DIR,
+  RKTIO_PATH_INIT_FILE
+};
+
+char *rktio_system_path(int which);
+char *rktio_expand_user_tilde(char *filename);
+
+/*************************************************/
+/* Errors                                        */
+
+/* Kinds of error values: */
+enum {
+  RKTIO_ERROR_KIND_POSIX,
+  RKTIO_ERROR_KIND_WINDOWS,
+  RKTIO_ERROR_KIND_GAI,
+  RKTIO_ERROR_KIND_RACKET
+};
+
+/* Error IDs of kind RKTIO_ERROR_KIND_RACKET */
+enum {
+  RKTIO_ERROR_UNSUPPORTED,
+  RKTIO_ERROR_EXISTS,
+  RKTIO_ERROR_LINK_FAILED,
+  RKTIO_ERROR_NOT_A_LINK,
+  RKTIO_ERROR_BAD_PERMISSION,
+  RKTIO_ERROR_IS_A_DIRECTORY,
+  RKTIO_ERROR_NOT_A_DIRECTORY,
+  RKTIO_ERROR_NO_TILDE,
+  RKTIO_ERROR_ILL_FORMED_USER,
+  RKTIO_ERROR_UNKNOWN_USER
+};
+
+int rktio_get_last_error(void);
+int rktio_get_last_error_kind(void);
+
+char *rktio_get_error_string(int kind, int errid);
+
+/*************************************************/
+
+#endif
diff --git a/racket/src/rktio/rktio_config.h.in b/racket/src/rktio/rktio_config.h.in
new file mode 100644
index 0000000000..659d3f1fc2
--- /dev/null
+++ b/racket/src/rktio/rktio_config.h.in
@@ -0,0 +1,21 @@
+/* Whether `intptr_t' is available. */
+#undef HAVE_INTPTR_T
+
+/* Whether `uintptr_t' is available. */
+#undef HAVE_UINTPTR_T
+
+#ifdef HAVE_INTPTR_T
+# include <inttypes.h>
+#endif
+#ifndef HAVE_INTPTR_T
+typedef long intptr_t;
+#endif
+#ifndef HAVE_UINTPTR_T
+typedef unsigned long uintptr_t;
+#endif
+
+/* When poll(), epoll(), kqueue(), etc. is available: */
+#undef HAVE_POLL_SYSCALL
+#undef HAVE_EPOLL_SYSCALL
+#undef HAVE_INOTIFY_SYSCALL
+#undef HAVE_KQUEUE_SYSCALL
diff --git a/racket/src/rktio/rktio_error.c b/racket/src/rktio/rktio_error.c
new file mode 100644
index 0000000000..f673ef3d8c
--- /dev/null
+++ b/racket/src/rktio/rktio_error.c
@@ -0,0 +1,44 @@
+#include "rktio.h"
+#include "rktio_private.h"
+#ifdef RKTIO_SYSTEM_WINDOWS
+# include <windows.h>
+#endif
+#include <errno.h>
+
+THREAD_LOCAL_DECL(static intptr_t errid);
+THREAD_LOCAL_DECL(static int errkind);
+
+void rktio_get_posix_error(void)
+{
+  errid = errno;
+  errkind = RKTIO_ERROR_KIND_POSIX;
+}
+
+void rktio_set_racket_error(int new_errid)
+{
+  errid = new_errid;
+  errkind = RKTIO_ERROR_KIND_RACKET;
+}
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+void rktio_get_windows_error(void)
+{
+  errid = GetLastError();
+  errkind = RKTIO_ERROR_KIND_WINDOWS;
+}
+#endif
+
+int rktio_get_last_error(void)
+{
+  return errid;
+}
+
+int rktio_get_last_error_kind(void)
+{
+  return errkind;
+}
+
+char *rktio_get_error_string(int kind, int errid)
+{
+  return "???";
+}
diff --git a/racket/src/rktio/rktio_filesystem.c b/racket/src/rktio/rktio_filesystem.c
new file mode 100644
index 0000000000..60f1d50455
--- /dev/null
+++ b/racket/src/rktio/rktio_filesystem.c
@@ -0,0 +1,1964 @@
+#include "rktio.h"
+#include "rktio_private.h"
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <utime.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#ifdef RKTIO_SYSTEM_UNIX
+# include <fcntl.h>
+#include <pwd.h>
+#include <grp.h>
+#include <uuid/uuid.h>
+#include <dirent.h>
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+# include <windows.h>
+#endif
+
+#ifdef RKTIO_SYSTEM_UNIX
+# define A_PATH_SEP '/'
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+# define A_PATH_SEP '\\'
+# define IS_A_DOS_SEP(c) IS_A_SEP(c)
+#endif
+#define IS_A_SEP(c) ((c) == A_PATH_SEP)
+
+#ifdef USE_TRANSITIONAL_64_FILE_OPS
+# define BIG_OFF_T_IZE(n) n ## 64
+#else
+# define BIG_OFF_T_IZE(n) n
+#endif
+
+#if defined(RKTIO_SYSTEM_UNIX) && !defined(NO_UNIX_USERS)
+static int have_user_ids = 0;
+static uid_t uid;
+static uid_t euid;
+static gid_t gid;
+static gid_t egid;
+
+#define GROUP_MEMBER_CACHE_STATE_UNUSED 0
+#define GROUP_MEMBER_CACHE_STATE_IN     1
+#define GROUP_MEMBER_CACHE_STATE_NOT_IN 2
+typedef struct {
+  int state;
+  gid_t gid;
+  uid_t uid;
+} group_member_cache_entry_t;
+THREAD_LOCAL_DECL(static group_member_cache_entry_t *group_member_cache);
+# define GROUP_CACHE_SIZE 10
+#endif
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+static int procs_initied = 0;
+typedef BOOLEAN (WINAPI*CreateSymbolicLinkProc_t)(wchar_t *dest, wchar_t *src, DWORD flags);
+static CreateSymbolicLinkProc_t CreateSymbolicLinkProc = NULL;
+
+typedef BOOL (WINAPI*DeviceIoControlProc_t)(HANDLE hDevice, DWORD dwIoControlCode, LPVOID lpInBuffer,
+					    DWORD nInBufferSize, LPVOID lpOutBuffer, DWORD nOutBufferSize,
+					    LPDWORD lpBytesReturned, LPOVERLAPPED lpOverlapped);
+static DeviceIoControlProc_t DeviceIoControlProc;
+#endif
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+static void init_procs()
+{
+  if (!procs_inited) {
+    HMODULE hm;
+
+    procs_inited = 1;
+    
+    hm = LoadLibrary("kernel32.dll");
+
+    CreateSymbolicLinkProc = (CreateSymbolicLinkProc_t)GetProcAddress(hm, "CreateSymbolicLinkW");
+    DeviceIoControlProc = (DeviceIoControlProc_t)GetProcAddress(hm, "DeviceIoControl");
+
+    FreeLibrary(hm);
+  }
+}
+#endif
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+# define MZ_UNC_READ  RKTIO_PERMISSION_READ
+# define MZ_UNC_WRITE RKTIO_PERMISSION_WRITE
+# define MZ_UNC_EXEC  RKTIO_PERMISSION_EXEC
+
+# define FIND_FIRST FindFirstFileW
+# define FIND_NEXT FindNextFileW
+# define FIND_CLOSE FindClose
+# define FF_TYPE WIN32_FIND_DATAW
+# define FF_HANDLE_TYPE HANDLE
+# define FIND_FAILED(h) (h == INVALID_HANDLE_VALUE)
+# define FF_A_RDONLY FILE_ATTRIBUTE_READONLY
+# define FF_A_DIR FILE_ATTRIBUTE_DIRECTORY
+# define FF_A_LINK 0x400
+# define GET_FF_ATTRIBS(fd) (fd.dwFileAttributes)
+# define GET_FF_MODDATE(fd) convert_date(&fd.ftLastWriteTime)
+# define GET_FF_NAME(fd) fd.cFileName
+
+static time_t convert_date(const FILETIME *ft)
+{
+  LONGLONG l, delta;
+  FILETIME ft2;
+  SYSTEMTIME st;
+  TIME_ZONE_INFORMATION tz;
+
+  /* FindFirstFile incorrectly shifts for daylight saving. It
+     subtracts an hour to get to UTC when daylight saving is in effect
+     now, even when daylight saving was not in effect when the file
+     was saved.  Counteract the difference. There's a race condition
+     here, because we might cross the daylight-saving boundary between
+     the time that FindFirstFile runs and GetTimeZoneInformation
+     runs. Cross your fingers... */
+  FileTimeToLocalFileTime(ft, &ft2);
+  FileTimeToSystemTime(&ft2, &st);
+  
+  delta = 0;
+  if (GetTimeZoneInformation(&tz) == TIME_ZONE_ID_DAYLIGHT) {
+    /* Daylight saving is in effect now, so there may be a bad
+       shift. Check the file's date. */
+    int start_day_of_month, end_day_of_month, first_day_of_week, diff, end_shift;
+
+    /* Valid only when the months match: */
+    first_day_of_week = (st.wDayOfWeek - (st.wDay - 1 - (((st.wDay - 1) / 7) * 7)));
+    if (first_day_of_week < 0)
+      first_day_of_week += 7;
+
+    diff = (tz.DaylightDate.wDayOfWeek - first_day_of_week);
+    if (diff < 0)
+      diff += 7;
+    start_day_of_month = 1 + (((tz.DaylightDate.wDay - 1) * 7)
+			      + diff);
+	
+    diff = (tz.StandardDate.wDayOfWeek - first_day_of_week);
+    if (diff < 0)
+      diff += 7;
+    end_day_of_month = 1 + (((tz.StandardDate.wDay - 1) * 7)
+			    + diff);
+
+    /* Count ambigious range (when the clock goes back) as
+       in standard time. We assume that subtracting the 
+       ambiguous range does not go back into the previous day,
+       and that the shift is a multiple of an hour. */
+    end_shift = ((tz.StandardBias - tz.DaylightBias) / 60);
+
+    if ((st.wMonth < tz.DaylightDate.wMonth)
+	|| ((st.wMonth == tz.DaylightDate.wMonth)
+	    && ((st.wDay < start_day_of_month)
+		|| ((st.wDay == start_day_of_month)
+		    && (st.wHour < tz.DaylightDate.wHour))))) {
+      /* Daylight saving had not yet started. */
+      delta = ((tz.StandardBias - tz.DaylightBias) * 60);
+    } else if ((st.wMonth > tz.StandardDate.wMonth)
+	       || ((st.wMonth == tz.StandardDate.wMonth)
+		   && ((st.wDay > end_day_of_month)
+		       || ((st.wDay == end_day_of_month)
+			   && (st.wHour >= (tz.StandardDate.wHour
+					    - end_shift)))))) {
+      /* Daylight saving was already over. */
+      delta = ((tz.StandardBias - tz.DaylightBias) * 60);
+    }
+  }
+
+  l = ((((LONGLONG)ft->dwHighDateTime << 32) | ft->dwLowDateTime)
+       - (((LONGLONG)0x019DB1DE << 32) | 0xD53E8000));
+  l /= 10000000;
+  l += delta;
+
+  return (time_t)l;
+}
+
+typedef struct mz_REPARSE_DATA_BUFFER {
+  ULONG  ReparseTag;
+  USHORT ReparseDataLength;
+  USHORT Reserved;
+  union {
+    struct {
+      USHORT SubstituteNameOffset;
+      USHORT SubstituteNameLength;
+      USHORT PrintNameOffset;
+      USHORT PrintNameLength;
+      ULONG  Flags;
+      WCHAR  PathBuffer[1];
+    } SymbolicLinkReparseBuffer;
+    struct {
+      USHORT SubstituteNameOffset;
+      USHORT SubstituteNameLength;
+      USHORT PrintNameOffset;
+      USHORT PrintNameLength;
+      WCHAR  PathBuffer[1];
+    } MountPointReparseBuffer;
+    struct {
+      UCHAR DataBuffer[1];
+    } GenericReparseBuffer;
+  } u;
+} mz_REPARSE_DATA_BUFFER;
+
+#define mzFILE_FLAG_OPEN_REPARSE_POINT 0x200000
+#define mzFSCTL_GET_REPARSE_POINT 0x900A8
+
+static char *UNC_readlink(const char *fn)
+{
+  HANDLE h;
+  DWORD got;
+  char *buffer;
+  int size = 1024;
+  mz_REPARSE_DATA_BUFFER *rp;
+  int len, off;
+  wchar_t *lk;
+
+  init_procs();
+
+  if (!DeviceIoControlProc) return NULL;
+
+  h = CreateFileW(WIDE_PATH_temp(fn), FILE_READ_ATTRIBUTES,
+		  FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
+		  OPEN_EXISTING,
+		  FILE_FLAG_BACKUP_SEMANTICS | mzFILE_FLAG_OPEN_REPARSE_POINT,
+		  NULL);
+
+  if (h == INVALID_HANDLE_VALUE) {
+    get_windows_error();
+    return NULL;
+  }
+
+  while (1) {
+    buffer = (char *)malloc(size);
+    if (DeviceIoControlProc(h, mzFSCTL_GET_REPARSE_POINT, NULL, 0, buffer, size,
+			    &got, NULL))
+      break;
+    else if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
+      size *= 2;
+      free(buffer);
+      buffer = (char *)malloc(size);
+    } else {
+      get_windows_error();
+      CloseHandle(h);
+      free(buffer);
+      return NULL;
+    }
+  }
+
+  CloseHandle(h);
+
+  rp = (mz_REPARSE_DATA_BUFFER *)buffer;
+  if ((rp->ReparseTag != IO_REPARSE_TAG_SYMLINK)
+      && (rp->ReparseTag != IO_REPARSE_TAG_MOUNT_POINT)) {
+    free(buffer);
+    set_racket_error(RKTIO_ERROR_LINK_FAILED);
+    return NULL;
+  }
+
+  if (rp->ReparseTag == IO_REPARSE_TAG_SYMLINK) {
+    off = rp->u.SymbolicLinkReparseBuffer.SubstituteNameOffset;
+    len = rp->u.SymbolicLinkReparseBuffer.SubstituteNameLength;
+    if (!len) {
+      off = rp->u.SymbolicLinkReparseBuffer.PrintNameOffset;
+      len = rp->u.SymbolicLinkReparseBuffer.PrintNameLength;
+    }
+  } else {
+    off = rp->u.MountPointReparseBuffer.SubstituteNameOffset;
+    len = rp->u.MountPointReparseBuffer.SubstituteNameLength;
+    if (!len) {
+      off = rp->u.MountPointReparseBuffer.PrintNameOffset;
+      len = rp->u.MountPointReparseBuffer.PrintNameLength;
+    }
+  }
+
+  lk = (wchar_t *)malloc(len + 2);
+
+  if (rp->ReparseTag == IO_REPARSE_TAG_SYMLINK)
+    memcpy(lk, (char *)rp->u.SymbolicLinkReparseBuffer.PathBuffer + off, len);
+  else
+    memcpy(lk, (char *)rp->u.MountPointReparseBuffer.PathBuffer + off, len);
+  
+  lk[len>>1] = 0;
+
+  if ((lk[0] == '\\') && (lk[1] == '?') && (lk[2] == '?') && (lk[3] == '\\')) {
+    /* "?\\" is a prefix that means "unparsed", or something like that */
+    memmove(lk, lk+4, len - 8);
+    len -= 8;
+    lk[len>>1] = 0;
+
+    if ((lk[0] == 'U') && (lk[1] == 'N') && (lk[2] == 'C') && (lk[3] == '\\')) {
+      /* "UNC\" is a further prefix that means "UNC"; replace "UNC" with "\" */
+      memmove(lk, lk+2, len - 4);
+      lk[0] = '\\';
+      len -= 4;
+      lk[len>>1] = 0;
+    }
+  }
+
+  free(buffer);
+
+  /* Make sure it's not empty, because that would form a bad path: */
+  if (!lk[0]) {
+    free(lk);
+    set_racket_error(RKTIO_ERROR_LINK_FAILED);
+    return NULL;
+  }
+
+  buffer = NARROW_PATH_copy(lk);
+  free(lk);
+
+  return buffer;
+}
+
+static int UNC_stat(const char *dirname, int *flags, int *isdir, int *islink, 
+		    rktio_timestamp_t **date, rktio_file_size_t *filesize,
+		    const char **resolved_path, int set_flags)
+/* dirname must be absolute */
+{
+  /* Note: stat() doesn't work with UNC "drive" names or \\?\ paths.
+     Also, stat() doesn't distinguish between the ability to
+     list a directory's content and whether the directory exists. 
+     So, we use GetFileAttributesExW(). */
+  char *copy;
+  WIN32_FILE_ATTRIBUTE_DATA fad;
+  int len, must_be_dir = 0;
+
+  if (resolved_path)
+    *resolved_path = NULL;
+
+ retry:
+
+  if (islink)
+    *islink = 0;
+  if (isdir)
+    *isdir = 0;
+  if (date)
+    *date = NULL;
+
+  len = strlen(dirname);
+
+  copy = malloc(len+1);
+  memcpy(copy, dirname, len+1);
+
+  if (!rktio_windows_nt_or_later()
+      || ((len >= 4)
+          && (copy[0] == '\\')
+          && (copy[1] == '\\')
+          && (copy[2] == '?')
+          && (copy[3] == '\\'))) {
+    /* Keep `copy` as-is */
+  } else {
+    /* Strip trailing separators */
+    while (IS_A_DOS_SEP(copy[len - 1])) {
+      --len;
+      copy[len] = 0;
+      must_be_dir = 1;
+    }
+  }
+
+  /* If we ended up with "\\?\X:" (and nothing after), then drop the "\\?\" */
+  if ((copy[0] == '\\')&& (copy[1] == '\\') && (copy[2] == '?') && (copy[3] == '\\') 
+      && is_drive_letter(copy[4]) && (copy[5] == ':') && !copy[6]) {
+    memmove(copy, copy + 4, len - 4);
+    len -= 4;
+    copy[len] = 0;
+  }
+  /* If we ended up with "\\?\\X:" (and nothing after), then drop the "\\?\\" */
+  if ((copy[0] == '\\') && (copy[1] == '\\') && (copy[2] == '?') && (copy[3] == '\\') 
+      && (copy[4] == '\\') && is_drive_letter(copy[5]) && (copy[6] == ':') && !copy[7]) {
+    memmove(copy, copy + 5, len - 5);
+    len -= 5;
+    copy[len] = 0;
+  }
+  /* If we ended up with "X:[/]", then add a "." at the end so that we get information
+     for the drive, not the current directory of the drive: */
+  if (is_drive_letter(copy[0]) && (copy[1] == ':')
+      && (!copy[2]
+	  || (IS_A_DOS_SEP(copy[2]) && !copy[3]))) {
+    copy[2] = '\\';
+    copy[3] = '.';
+    copy[4] = 0;
+  }
+
+  if (!GetFileAttributesExW(WIDE_PATH_temp(copy), GetFileExInfoStandard, &fad)) {
+    get_windows_error();
+    free(copy);
+    return 0;
+  } else {
+    if (GET_FF_ATTRIBS(fad) & FF_A_LINK) {
+      if (islink) {
+	*islink = 1;
+	return 1;
+      } else {
+	/* Resolve a link by opening the link and then getting
+           the path from the handle. */
+        HANDLE h;
+        wchar_t *dest = NULL;
+        DWORD len = 255;
+
+        h = CreateFileW(WIDE_PATH_temp(copy), FILE_READ_ATTRIBUTES,
+                        FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
+                        OPEN_EXISTING,
+                        FILE_FLAG_BACKUP_SEMANTICS,
+                        NULL);
+
+        if (!h) {
+          get_windows_error();
+          free(copy);
+	  return 0;
+	}
+
+        do {
+          if (dest) free(dest);
+          dest_len = len + 1;
+          dest = malloc(dest_len);
+          len = GetFinalPathNameByHandleW(h, dest, dest_len, FILE_NAME_NORMALIZED);
+        } while (len > dest_len);
+
+        if (!len) {
+          get_windows_error();
+          CloseHandle(h);
+          free(copy);
+          free(dest);
+	  return 0;
+        }
+
+        CloseHandle(h);
+
+        dirname = NARROW_PATH_copy(dest);
+	if (resolved_path)
+	  *resolved_path = dirname;
+
+        free(dest);
+        free(copy);
+
+	goto retry;
+      }
+    }
+
+    if (set_flags != -1) {
+      DWORD attrs = GET_FF_ATTRIBS(fad);
+
+      if (!(set_flags & MZ_UNC_WRITE))
+        attrs |= FF_A_RDONLY;
+      else if (attrs & FF_A_RDONLY)
+        attrs -= FF_A_RDONLY;
+      
+      if (!SetFileAttributesW(WIDE_PATH_temp(copy), attrs)) {
+        get_windows_error();
+        free(copy);
+        return 0;
+      }
+    } else {
+      if (must_be_dir && !(GET_FF_ATTRIBS(fad) & FF_A_DIR)) {
+        set_racket_error(RKTIO_ERROR_NOT_A_DIRECTORY);
+        free(copy);
+        return 0;
+      }
+      if (flags)
+        *flags = MZ_UNC_READ | MZ_UNC_EXEC | ((GET_FF_ATTRIBS(fad) & FF_A_RDONLY) ? 0 : MZ_UNC_WRITE);
+      if (date) {
+        rktio_timestamp_t *dt;
+        time_t mdt;
+        mdt = GET_FF_MODDATE(fad);
+        dt = malloc(sizeof(rktio_timestamp_t));
+        *dt = mdt;
+        *date = dt;
+      }
+      if (isdir) {
+        *isdir = (GET_FF_ATTRIBS(fad) & FF_A_DIR);
+      }
+      if (filesize) {
+        rktio_size_t *fsz;
+        fsz = malloc(sizeof(rktio_size_t));
+        fsz->lo = fad.nFileSizeLow;
+        fsz->hi = fad.nFileSizeHigh;
+      }
+    }
+    free(copy);
+    return 1;
+  }
+}
+#endif
+
+int rktio_file_exists(char *filename)
+/* Windows: check for special filenames before calling */
+{
+# ifdef NO_STAT_PROC
+  int fd;
+
+  fd = open(filename, O_RDONLY);
+  if (fd != -1) {
+    fclose(fd);
+    return 1;
+  } else
+    return 0;
+# else
+#  ifdef RKTIO_SYSTEM_WINDOWS
+  {
+    int isdir;
+    return (UNC_stat(filename, NULL, &isdir, NULL, NULL, NULL, NULL, -1)
+	    && !isdir);
+  }
+#  else
+  struct MSC_IZE(stat) buf;
+  int ok;
+
+  do {
+    ok = MSC_W_IZE(stat)(MSC_WIDE_PATH_temp(filename), &buf);
+  } while ((ok == -1) && (errno == EINTR));
+
+  return !ok && !S_ISDIR(buf.st_mode);
+#  endif
+# endif
+}
+
+int rktio_directory_exists(char *dirname)
+{
+# ifdef NO_STAT_PROC
+  return 0;
+# else
+#  ifdef RKTIO_SYSTEM_WINDOWS
+  int isdir;
+
+  return (UNC_stat(dirname, NULL, &isdir, NULL, NULL, NULL, NULL, -1)
+	  && isdir);
+#  else
+  struct MSC_IZE(stat) buf;
+
+  while (1) {
+    if (!MSC_IZE(stat)(dirname, &buf))
+      break;
+    else if (errno != EINTR)
+      return 0;
+  }
+
+  return S_ISDIR(buf.st_mode);
+#  endif
+# endif
+}
+
+int rktio_is_regular_file(char *filename)
+/* Windows: check for special filenames before calling */
+{
+# ifdef NO_STAT_PROC
+  return 0;
+# else
+  struct MSC_IZE(stat) buf;
+
+  while (1) {
+    if (!MSC_W_IZE(stat)(MSC_WIDE_PATH_temp(filename), &buf))
+      break;
+    else if (errno != EINTR)
+      return 0;
+  }
+
+  return S_ISREG(buf.st_mode);
+# endif  
+}
+
+int rktio_link_exists(char *filename)
+{
+#ifdef RKTIO_SYSTEM_WINDOWS
+  {
+    int islink;
+    if (UNC_stat(filename, NULL, NULL, &islink, NULL, NULL, NULL, -1)
+	&& islink)
+      return 1;
+    else
+      return 0;
+  }
+#else
+  {
+    struct MSC_IZE(stat) buf;
+    while (1) {
+      if (!MSC_W_IZE(lstat)(MSC_WIDE_PATH_temp(filename), &buf))
+	break;
+      else if (errno != EINTR)
+	return 0;
+    }
+
+    if (S_ISLNK(buf.st_mode))
+      return 1;
+    else
+      return 0;
+  }
+#endif
+}
+
+char *rktio_get_current_directory()
+{
+#ifdef RKTIO_SYSTEM_WINDOWS
+ int need_l, bl = 256;
+ wchar_t *wbuf;
+ char *r;
+
+ wbuf = malloc(bl);
+ while (1) {
+   need_l = GetCurrentDirectoryW(bl, wbuf);
+   if (need_l > bl) {
+     free(wbuf);
+     wbuf = malloc(need_l * sizeof(wchar_t));
+     bl = need_l;
+   } else
+     break;
+ }
+
+ if (!need_l) {
+   get_windows_error();
+   return NULL;
+ }
+
+ r = NARROW_PATH_copy_then_free(wbuf);
+
+ return r;
+#else
+ char *r, *s;
+ int len = 256;
+
+ s = malloc(len);
+ while (1) {
+   r = MSC_IZE(getcwd)(s, len);
+   if (r)
+     break;
+   if (errno == ERANGE) {
+     free(s);
+     len *= 2;
+     s = malloc(len);
+   } else
+     break;
+ }
+ if (!r)
+   get_posix_error();
+ return r;
+#endif
+}
+
+int rktio_set_current_directory(char *expanded)
+{
+  int err;
+
+  while (1) {
+    err = MSC_W_IZE(chdir)(MSC_WIDE_PATH_temp(expanded));
+    if (!err || (errno != EINTR))
+      break;
+  }
+
+  get_posix_error();
+
+  return !err;
+}
+
+rktio_identity_t *rktio_get_fd_identity(intptr_t fd, char *path)
+/* If path is supplied, then fd is 0 for stat, 1 for lstat */
+{
+  uintptr_t devi = 0, inoi = 0, inoi2 = 0;
+
+#ifdef FILES_HAVE_FDS
+  int errid = 0;
+  struct MSC_IZE(stat) buf;
+
+  while (1) {
+    if (!path && !MSC_IZE(fstat)(fd, &buf))
+      break;
+    else if (path && !fd && !MSC_IZE(stat)(path, &buf))
+      break;
+    else if (path && fd && !MSC_IZE(lstat)(path, &buf))
+      break;
+    else if (errno != EINTR) {
+      errid = errno;
+      break;
+    }
+  }
+
+  if (errid) {
+    get_posix_error();
+    return NULL;
+  } else {
+    /* Warning: we assume that dev_t and ino_t fit in a pointer-sized integer. */
+    devi = (uintptr_t)buf.st_dev;
+    inoi = (uintptr_t)buf.st_ino;
+  }
+#endif
+#ifdef WINDOWS_FILE_HANDLES
+  BY_HANDLE_FILE_INFORMATION info;
+  HANDLE fdh = (HANDLE)fd;
+
+  init_procs();
+
+  if (path) {
+    fdh = CreateFileW(WIDE_PATH_temp(path),
+                      0, /* not even read access => just get info */
+                      FILE_SHARE_READ | FILE_SHARE_WRITE,
+                      NULL,
+                      OPEN_EXISTING,
+                      FILE_FLAG_BACKUP_SEMANTICS 
+                      | ((fd && CreateSymbolicLinkProc)
+                         ? mzFILE_FLAG_OPEN_REPARSE_POINT 
+                         : 0),
+                      NULL);
+    if (fdh == INVALID_HANDLE_VALUE) {
+      get_windows_error();
+      return NULL;
+    }
+  }
+
+  if (!GetFileInformationByHandle(fdh, &info)) {
+    get_windows_error();
+    if (path) CloseHandle(fdh);
+    return NULL;
+  }
+      
+  if (path) CloseHandle(fdh);
+
+  devi = info.dwVolumeSerialNumber;
+  inoi = info.nFileIndexLow;
+  inoi2 = info.nFileIndexHigh;
+#endif
+
+  {
+    rktio_identity_t *id;
+    
+    id = malloc(sizeof(rktio_identity_t));
+    
+    id->a = devi;
+    id->b = inoi;
+    id->c = inoi2;
+
+    return id;
+  }
+}
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+static int enable_write_permission(const char *fn)
+{
+  int flags;
+
+  return UNC_stat(fn, &flags, NULL, NULL, NULL, NULL, NULL, MZ_UNC_WRITE);
+}
+#endif
+
+int rktio_delete_file(char *fn, int enable_write_on_fail)
+{
+  int errid;
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+  if (DeleteFileW(WIDE_PATH_temp(fn)))
+    return 1;
+  errid = GetLastError();
+  if ((errid == ERROR_ACCESS_DENIED) && enable_write_on_fail) {
+    /* Maybe it's just that the file has no write permission. Provide a more
+       Unix-like experience by attempting to change the file's permission. */
+    if (enable_write_permission(fn)) {
+      if (DeleteFileW(WIDE_PATH_temp(fn)))
+        return 1;
+    }
+  }
+
+  get_windows_error();
+  return 0;
+#else
+  while (1) {
+    if (!MSC_W_IZE(unlink)(MSC_WIDE_PATH_temp(fn)))
+      return 1;
+    else if (errno != EINTR)
+      break;
+  }
+  
+  get_posix_error();
+  return 0;
+#endif
+}
+
+int rktio_rename_file(char *dest, char *src, int exists_ok)
+{
+# ifdef RKTIO_SYSTEM_WINDOWS
+  int errid;
+  wchar_t *src_w = WIDE_PATH_copy(src);
+  
+  if (MoveFileExW(src_w, WIDE_PATH_temp(dest), (exists_ok ? MOVEFILE_REPLACE_EXISTING : 0))) {
+    free(src_w);
+    return 1;
+  }
+  
+  errid = GetLastError();
+
+  if (errid == ERROR_CALL_NOT_IMPLEMENTED) {
+    /* Then we have the great misfortune of running in Windows 9x. If
+       exists_ok, then do something no less stupid than the OS
+       itself: */
+    int errid;
+    if (exists_ok)
+      MSC_W_IZE(unlink)(MSC_WIDE_PATH_temp(dest));
+    if (MoveFileW(src_w, WIDE_PATH_temp(dest))) {
+      free(src_w);
+      return 1;
+    }
+    get_windows_error();
+  } else
+    get_windows_error();
+  
+  free(src_w);
+  return 0;
+# else
+  if (!exists_ok && (rktio_file_exists(dest) || rktio_directory_exists(dest))) {
+    /* We use a specialized error here, because it's not
+       a system error (e.g., setting `errval` to `EEXIST` would
+       be a lie). */
+    set_racket_error(RKTIO_ERROR_EXISTS);
+    return 0;
+  }
+  
+  while (1) {
+    if (!rename(src, dest))
+      return 1;
+    else if (errno != EINTR)
+      break;
+  }
+
+  get_posix_error();  
+  return 0;
+# endif
+}
+
+char *rktio_readlink(char *fullfilename)
+{
+#ifdef RKTIO_SYSTEM_WINDOWS
+  if (UNC_stat(fullfilename, NULL, NULL, &is_link, NULL, NULL, NULL, -1)
+      && is_link) {
+    return UNC_readlink(fullfilename);
+  } else {
+    set_racket_error(RKTIO_ERROR_NOT_A_LINK);
+    return NULL;
+  }
+#else
+  int len, buf_len = 256;
+  char *buffer = malloc(buf_len);
+
+  while (1) {
+    len = readlink(fullfilename, buffer, buf_len);
+    if (len == -1) {
+      if (errno != EINTR) {
+        get_posix_error();
+        return NULL;
+      }
+    } else if (len == buf_len) {
+      /* maybe too small */
+      free(buffer);
+      buf_len *= 2;
+      buffer = malloc(buf_len);
+    } else
+      break;
+  }
+  buffer[len] = 0;
+  return buffer;
+#endif
+}
+
+int rktio_make_directory(char *filename)
+{
+#ifdef NO_MKDIR
+  set_racket_error(RKTIO_ERROR_UNSUPPORTED);
+  return 0;
+#else
+  int exists_already = 0;
+  int len, copied = 0;
+
+  /* Make sure path doesn't have trailing separator: */
+  len = strlen(filename);
+  while (len && IS_A_SEP(filename[len - 1])) {
+    if (!copied) {
+      filename = strdup(filename);
+      copied = 1;
+    }
+    filename[--len] = 0;
+  }
+
+  while (1) {
+    if (!MSC_W_IZE(mkdir)(MSC_WIDE_PATH_temp(filename)
+# ifndef MKDIR_NO_MODE_FLAG
+			  , 0777
+# endif
+			  )) {
+      if (copied) free(filename);
+      return 1;
+    } else if (errno != EINTR)
+      break;
+  }
+
+  if (errno == EEXIST)
+    set_racket_error(RKTIO_ERROR_EXISTS);
+  else
+    get_posix_error();
+
+  if (copied) free(filename);
+
+  return 0;
+}
+
+int rktio_delete_directory(char *filename, char *current_directory, int enable_write_on_fail)
+{
+#ifdef RKTIO_SYSTEM_WINDOWS
+  int tried_cwd = 0, tried_perm = 0;
+#endif
+  
+  while (1) {
+    if (!MSC_W_IZE(rmdir)(MSC_WIDE_PATH_temp(filename)))
+      return 1;
+# ifdef RKTIO_SYSTEM_WINDOWS
+    else if ((errno == EACCES) && !tried_cwd) {
+      /* Maybe we're using the target directory. Try a real setcwd. */
+      (void)rktio_set_current_directory(current_directory);
+      tried_cwd = 1;
+    } else if ((errno == EACCES) && !tried_perm && enable_write_on_fail) {
+      /* Maybe the directory doesn't have write permission. */
+      (void)enable_write_permission(filename);
+      tried_perm = 1;
+    }
+# endif
+    else if (errno != EINTR)
+      break;
+  }
+
+  get_posix_error();
+  return 0;
+#endif
+}
+
+int rktio_make_link(char *src, char *dest, int dest_is_directory)
+/* `src` is the file that is written, and `dest` is written to that
+   file */
+{
+#if defined(RKTIO_SYSTEM_WINDOWS)
+  init_procs();
+    
+  if (CreateSymbolicLinkProc) {
+    int flags;
+    wchar_t *src_w = WIDE_PATH_COPY(src);
+
+    if (dest_is_directory)
+      flags = 0x1; /* directory */
+    else
+      flags = 0; /* file */
+
+    if (CreateSymbolicLinkProc(src_w, WIDE_PATH_temp(dest), flags)) {
+      free(src_w);
+      return 1;
+    }
+    get_windows_error();
+    free(src_w);
+  } else
+    set_racket_error(RKTIO_ERROR_UNSUPPORTED);
+  
+  return 0;
+#else
+  while (1) {
+    if (!symlink(dest, src))
+      return 1;
+    else if (errno != EINTR)
+      break;
+  }
+  get_posix_error();
+  return 0;
+#endif
+}
+
+rktio_timestamp_t *rktio_get_file_modify_seconds(char *file)
+{
+#ifdef RKTIO_SYSTEM_WINDOWS
+  rktio_timestamp_t *secs;
+  
+  if (UNC_stat(file, NULL, NULL, NULL, &secs, NULL, NULL, -1))
+    return secs;
+  return NULL;
+#else
+  struct MSC_IZE(stat) buf;
+  
+  while (1) {
+    if (!MSC_W_IZE(stat)(MSC_WIDE_PATH_temp(file), &buf)){
+      rktio_timestamp_t *ts = malloc(sizeof(rktio_timestamp_t));
+      *ts = buf.st_mtime;
+      return ts;
+    }
+    if (errno != EINTR)
+      break;
+  }
+
+  get_posix_error();
+  return NULL;
+#endif
+}
+
+int rktio_set_file_modify_seconds(char *file, rktio_timestamp_t secs)
+{
+  while (1) {
+    struct MSC_IZE(utimbuf) ut;
+    ut.actime = secs;
+    ut.modtime = secs;
+    if (!MSC_W_IZE(utime)(MSC_WIDE_PATH_temp(file), &ut))
+      return 1;
+    if (errno != EINTR)
+      break;
+  }
+
+  get_posix_error();
+  return 0;
+}
+
+#if defined(RKTIO_SYSTEM_UNIX) && !defined(NO_UNIX_USERS)
+static int user_in_group(uid_t uid, gid_t gid)
+{
+  struct group *g;
+  struct passwd *pw;
+  int i, in;
+
+  if (!group_member_cache)
+    group_member_cache = calloc(GROUP_CACHE_SIZE, sizeof(group_member_cache_entry_t));
+
+  for (i = 0; i < GROUP_CACHE_SIZE; i++) {
+    if ((group_member_cache[i].state != GROUP_MEMBER_CACHE_STATE_UNUSED)
+        && (group_member_cache[i].gid == gid)
+        && (group_member_cache[i].uid == uid))
+      return (group_member_cache[i].state == GROUP_MEMBER_CACHE_STATE_IN);
+  }
+
+  pw = getpwuid(uid);
+  if (!pw)
+    return 0;
+
+  g = getgrgid(gid);
+  if (!g)
+    return 0;
+
+  for (i = 0; g->gr_mem[i]; i++) {
+    if (!strcmp(g->gr_mem[i], pw->pw_name))
+      break;
+  }
+
+  in = !!(g->gr_mem[i]);
+
+  for (i = 0; i < GROUP_CACHE_SIZE; i++) {
+    if (group_member_cache[i].state == GROUP_MEMBER_CACHE_STATE_UNUSED) {
+      group_member_cache[i].gid = gid;
+      group_member_cache[i].uid = uid;
+      group_member_cache[i].state = (in
+                                     ? GROUP_MEMBER_CACHE_STATE_IN
+                                     : GROUP_MEMBER_CACHE_STATE_NOT_IN);
+      break;
+    }
+  }
+
+  return in;
+}
+#endif
+
+int rktio_get_file_or_directory_permissions(char *filename, int all_bits)
+/* -1 result indicates an error */
+{
+# ifdef NO_STAT_PROC
+  set_racket_error(RKTIO_ERROR_UNSUPPORTED);
+  return -1;
+# else
+#  ifdef RKTIO_SYSTEM_UNIX
+  /* General strategy for permissions (to deal with setuid)
+     taken from euidaccess() in coreutils... */
+#   ifndef NO_UNIX_USERS
+  if (have_user_ids == 0) {
+    have_user_ids = 1;
+    uid = getuid();
+    gid = getgid();
+    euid = geteuid();
+    egid = getegid();
+  }
+
+  if (!all_bits && (uid == euid) && (gid == egid)) {
+    /* Not setuid; use access() */
+    int read, write, execute, ok;
+    
+    do {
+      ok = access(filename, R_OK);
+    } while ((ok == -1) && (errno == EINTR));
+    read = !ok;
+
+    if (ok && (errno != EACCES)) {
+      get_posix_error();
+      return -1;
+    } else {
+      do {
+	ok = access(filename, W_OK);
+      } while ((ok == -1) && (errno == EINTR));
+      write = !ok;
+      
+      /* Don't fail at the exec step if errno is EPERM; under Mac OS
+         X, at least, such a failure seems to mean that the file is
+         not writable. (We assume it's not a directory-access issue,
+         since the read test succeeded.) */
+      if (ok && (errno != EACCES) && (errno != EPERM) && (errno != EROFS)) {
+	get_posix_error();
+        return -1;
+      } else {
+	do {
+	  ok = access(filename, X_OK);
+	} while ((ok == -1) && (errno == EINTR));
+	execute = !ok;
+      
+        /* Don't fail at the exec step if errno is EPERM; under Mac OS
+           X, at least, such a failure simply means that the file is
+           not executable. */
+	if (ok && (errno != EACCES) && (errno != EPERM)) {
+	  get_posix_error();
+          return -1;
+	} else {
+          return ((read ? S_IRUSR : 0)
+                  | (write ? S_IWUSR : 0)
+                  | (execute ? S_IXUSR : 0));
+	}
+      }
+    }
+  }
+#  endif
+  {
+    /* Use stat, because setuid, or because or no user info available */
+    struct stat buf;
+    int ok, read, write, execute;
+
+    do {
+      ok = stat(filename, &buf);
+    } while ((ok == -1) && (errno == EINTR));
+
+    if (ok) {
+      get_posix_error();
+      return -1;
+    } else {
+      if (all_bits) {
+        int bits = buf.st_mode;
+#   ifdef S_IFMT
+        bits -= (bits & S_IFMT);
+#   endif
+        return bits;
+      } else {
+#   ifndef NO_UNIX_USERS
+        if (euid == 0) {
+          /* Super-user can read/write anything, and can
+             execute anything that someone can execute */
+          read = 1;
+          write = 1;
+          execute = !!(buf.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH));
+        } else if (buf.st_uid == euid) {
+          read = !!(buf.st_mode & S_IRUSR);
+          write = !!(buf.st_mode & S_IWUSR);
+          execute = !!(buf.st_mode & S_IXUSR);
+        } else if ((egid == buf.st_gid) || user_in_group(euid, buf.st_gid)) {
+          read = !!(buf.st_mode & S_IRGRP);
+          write = !!(buf.st_mode & S_IWGRP);
+          execute = !!(buf.st_mode & S_IXGRP);
+        } else {
+          read = !!(buf.st_mode & S_IROTH);
+          write = !!(buf.st_mode & S_IWOTH);
+          execute = !!(buf.st_mode & S_IXOTH);
+        }
+#   else
+        read = !!(buf.st_mode & (S_IRUSR | S_IRGRP | S_IROTH));
+        write = !!(buf.st_mode & (S_IWUSR | S_IWGRP | S_IWOTH));
+        execute = !!(buf.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH));
+#   endif
+
+        return ((read ? S_IRUSR : 0)
+                | (write ? S_IWUSR : 0)
+                | (execute ? S_IXUSR : 0));
+      }
+    }
+  }
+#  endif  
+#  ifdef RKTIO_SYSTEM_WINDOWS
+  {
+    int flags;
+
+    if (UNC_stat(filename, &flags, NULL, NULL, NULL, NULL, NULL, -1)) {
+      if (as_bits)
+        return (flags | (flags << 3) | (flags << 6));
+      else {
+        return ((read ? MZ_UNC_READ : 0)
+                | (write ? MZ_UNC_WRITE : 0)
+                | (execute ? MZ_UNC_EXEC : 0));
+      }
+    } else {
+      return -1;
+    }
+  }
+#  endif
+# endif
+}
+
+int rktio_set_file_or_directory_permissions(char *filename, int new_bits)
+{
+# ifdef NO_STAT_PROC
+  set_racket_error(RKTIO_ERROR_UNSUPPORTED);
+  return -1;
+# else
+#  ifdef RKTIO_SYSTEM_UNIX
+  {
+    int r;
+    
+    do {
+      r = chmod(filename, new_bits);
+    } while ((r == -1) && (errno == EINTR));
+    if (r) {
+      get_posix_error();
+      return 0;
+    } else
+      return 1;
+  }
+#  endif  
+#  ifdef RKTIO_SYSTEM_WINDOWS
+  {
+    int len = strlen(filename);
+    int ALWAYS_SET_BITS = ((MZ_UNC_READ | MZ_UNC_EXEC)
+                           | ((MZ_UNC_READ | MZ_UNC_EXEC) << 3)
+                           | ((MZ_UNC_READ | MZ_UNC_EXEC) << 6));
+    if (((new_bits & ALWAYS_SET_BITS) != ALWAYS_SET_BITS)
+        || ((new_bits & MZ_UNC_WRITE) != ((new_bits & (MZ_UNC_WRITE << 3)) >> 3))
+        || ((new_bits & MZ_UNC_WRITE) != ((new_bits & (MZ_UNC_WRITE << 6)) >> 6))
+        || (new_bits >= (1 << 9))) {
+      set_racket_error(RKTIO_ERROR_BAD_PERMISSION);
+      return 0;
+    }
+    
+    if (UNC_stat(filename, NULL, NULL, NULL, NULL, NULL, NULL, new_bits))
+      return 1;
+    
+    return 0;
+  }
+#  endif
+# endif
+}
+
+rktio_size_t *rktio_file_size(char *filename)
+{
+  rktio_size_t *sz = NULL;
+#ifdef RKTIO_SYSTEM_WINDOWS
+ {
+   if (UNC_stat(filename, NULL, NULL, NULL, NULL, &sz, NULL, -1)) {
+     return sz;
+   }
+   return NULL;
+ }
+#else
+  {
+    struct BIG_OFF_T_IZE(stat) buf;
+
+    while (1) {
+      if (!BIG_OFF_T_IZE(stat)(MSC_WIDE_PATH_temp(filename), &buf))
+	break;
+      else if (errno != EINTR) {
+        get_posix_error();
+	return NULL;
+      }
+    }
+
+    if (S_ISDIR(buf.st_mode)) {
+      set_racket_error(RKTIO_ERROR_IS_A_DIRECTORY);
+      return NULL;
+    }
+
+    sz = malloc(sizeof(rktio_size_t));
+    sz->lo = ((unsigned)buf.st_size & 0xFFFFFFFF);
+    if (sizeof(buf.st_size) > 4)
+      sz->hi = (buf.st_size >> 32);
+    else
+      sz->hi = 0;
+
+    return sz;
+  }
+#endif
+}
+
+/*************************************************************/
+/* directory list                                            */
+/*************************************************************/
+
+#ifdef USE_FINDFIRST
+
+struct rktio_directory_list_t {
+  FF_HANDLE_TYPE hfile;
+  FF_TYPE info;
+};
+
+rktio_directory_list_t *rktio_directory_list_start(char *filename, int is_drive)
+/* path must be normalized */
+{
+  char *pattern;
+  int len;
+  FF_HANDLE_TYPE hfile;
+  FF_TYPE info;
+  rktio_directory_list_t *dl;
+
+ retry:
+
+  {
+    char *nf;
+    int is_ssq = 0, is_unc = 0, d, nd;
+    len = strlen(filename);
+    pattern = malloc(len + 14);
+
+    if (IS_A_DOS_SEP(filename[0])
+        && IS_A_DOS_SEP(filename[1])) {
+      if (filename[2] == '?') 
+        is_ssq = 1;
+      else
+        is_unc = 1;
+    }
+
+    if (is_ssq) {
+      d = 0;
+      nd = 0;
+    } else {
+      pattern[0] = '\\';
+      pattern[1] = '\\';
+      pattern[2] = '?';
+      pattern[3] = '\\';
+      if (is_unc) {
+	pattern[4] = 'U';
+	pattern[5] = 'N';
+	pattern[6] = 'C';
+	pattern[7] = '\\';
+	d = 8;
+	nd = 2;
+      } else {
+	d = 4;
+	nd = 0;
+      }
+    }
+    memcpy(pattern + d, nf + nd, len - nd);
+    len += (d - nd);
+    if (len && !IS_A_DOS_SEP(pattern[len - 1]))
+      pattern[len++] = '\\';      
+    memcpy(pattern + len, "*.*", 4);
+  }
+
+  hfile = FIND_FIRST(WIDE_PATH_temp(pattern), &info);
+  if (FIND_FAILED(hfile)) {
+    int err_val;
+    err_val = GetLastError();
+    if ((err_val == ERROR_DIRECTORY) && CreateSymbolicLinkProc) {
+      /* check for symbolic link */
+      const char *resolved;
+      if (UNC_stat(filename, NULL, NULL, NULL, NULL, NULL, &resolved, -1)) {
+	if (resolved) {
+	  filename = (char *)resolved;
+	  goto retry;
+	}
+      }
+    }
+    get_windows_error();
+    return NULL;
+  }
+
+  dl = malloc(sizeof(rktio_directory_list_t));
+  memcpy(&dl->info, &info);
+  dl->hfile = hfile;
+
+  return dl;
+}
+
+char *rktio_directory_list_step(rktio_directory_list_t *dl)
+/* empty-strng result (don't deallocate) means done */
+{
+  while (dl->first_ready || FIND_NEXT(dl->hfile, &dl->info)) {
+    dl->first_ready = 0;
+    if ((GET_FF_NAME(dl->info)[0] == '.')
+	&& (!GET_FF_NAME(dl->info)[1] || ((GET_FF_NAME(dl->info)[1] == '.')
+                                          && !GET_FF_NAME(dl->info)[2]))) {
+      /* skip . and .. */
+    } else {
+      return NARROW_PATH_copy(info.cFileName);
+    }
+  }
+
+  FIND_CLOSE(dl->hfile);
+
+  free(dl);
+
+  return "";
+}
+
+# elif !defined(NO_READDIR)
+
+struct rktio_directory_list_t {
+  DIR *dir;
+};
+
+rktio_directory_list_t *rktio_directory_list_start(char *filename, int is_drive)
+{
+  rktio_directory_list_t *dl;
+  DIR *dir;
+  int nlen;
+
+  dir = opendir(filename ? filename : ".");
+  if (!dir) {
+    get_posix_error();
+    return NULL;
+  }
+
+  dl = malloc(sizeof(rktio_directory_list_t));
+  dl->dir = dir;
+
+  return dl;
+}
+
+char *rktio_directory_list_step(rktio_directory_list_t *dl)
+/* empty-strng result (don't deallocate) means done */
+{
+  struct dirent *e;  
+  
+  while ((e = readdir(dl->dir))) {
+    int nlen;
+
+# ifdef DIRENT_NO_NAMLEN
+    nlen = strlen(e->d_name);
+# elif defined(__QNX__) || defined(__QNXNTO__)
+    nlen = e->d_namelen;
+# else
+    nlen = e->d_namlen;
+# endif
+
+# if defined(RKTIO_SYSTEM_UNIX) || defined(RKTIO_SYSTEM_WINDOWS)
+    if (nlen == 1 && e->d_name[0] == '.')
+      continue;
+    if (nlen == 2 && e->d_name[0] == '.' && e->d_name[1] == '.')
+      continue;
+# endif
+
+    return strndup(e->d_name, nlen);
+  }
+
+  closedir(dl->dir);
+  free(dl);
+
+  return "";
+}
+
+#else
+
+rktio_directory_list_t *rktio_directory_list_start(char *filename, int is_drive)
+{
+  set_racket_error(RKTIO_ERROR_UNSUPPORTED);
+  return NULL;
+}
+
+char *rktio_directory_list_step(rktio_directory_list_t *dl)
+{
+  set_racket_error(RKTIO_ERROR_UNSUPPORTED);
+  return NULL;
+}
+
+#endif
+
+/*************************************************************/
+/* copy file                                                 */
+/*************************************************************/
+
+struct rktio_file_copy_t {
+  int done;
+  rktio_fd_t *src_fd, *dest_fd;
+};
+
+rktio_file_copy_t *rktio_copy_file_start(char *dest, char *src, int exists_ok)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  {
+# define COPY_BUFFER_SIZE 2048
+    int ok;
+    struct stat buf;
+    rktio_fd_t *src_fd, *dest_fd;
+
+    src_fd = rktio_open(src, RKTIO_OPEN_READ);
+    if (!src_fd)
+      return NULL;
+
+    do {
+      ok = fstat(rktio_fd_value(src_fd), &buf);
+    } while ((ok == -1) && (errno == EINTR));
+
+    if (ok || S_ISDIR(buf.st_mode)) {
+      if (ok)
+        get_posix_error();
+      else
+        set_racket_error(RKTIO_ERROR_IS_A_DIRECTORY);
+      rktio_close(src_fd);
+      return NULL;
+    }
+
+    dest_fd = rktio_open(dest, (RKTIO_OPEN_WRITE
+                                    | (exists_ok ? RKTIO_OPEN_TRUNCATE : 0)));
+    if (!dest_fd) {
+      rktio_close(src_fd);
+      return NULL;
+    }
+
+    {
+      rktio_file_copy_t *fc;
+
+      fc = malloc(sizeof(rktio_file_copy_t));
+
+      fc->done = 0;
+      fc->src_fd = src_fd;
+      fc->dest_fd = dest_fd;
+
+      return fc;
+    }
+  }
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  int err_val = 0;
+  wchar_t *src_w = WIDE_PATH_copy(src);
+
+  if (CopyFileW(src_w, WIDE_PATH_temp(dest), !exists_ok)) {
+    rktio_file_copy_t *fc;
+    free(src_w);
+    /* Return a pointer to indicate success: */
+    fc = malloc(sizeof(rktio_file_copy_t));
+    fc->done = 1;
+    return fc;
+  }
+  
+  err_val = GetLastError();
+  if ((err_val == ERROR_FILE_EXISTS)
+      || (err_val == ERROR_ALREADY_EXISTS))
+    set_racket_error(RKTIO_ERROR_EXISTS);
+  else
+    get_windows_error();
+
+  free(src_w);
+
+  return NULL;
+#endif
+}
+
+int rktio_copy_file_is_done(rktio_file_copy_t *fc)
+{
+  return fc->done;
+}
+
+int rktio_copy_file_step(rktio_file_copy_t *fc)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  char buffer[4096];
+  intptr_t len;
+
+  if (fc->done)
+    return 1;
+
+  len = rktio_read(fc->src_fd, buffer, sizeof(buffer));
+  if (len == RKTIO_READ_EOF) {
+    fc->done = 1;
+    return 1;
+  } else if (len == RKTIO_READ_ERROR) {
+    return 0;
+  } else {
+    intptr_t done = 0, amt;
+    
+    while (done < len) {
+      amt = rktio_write(fc->dest_fd, buffer + done, len - done);
+      if (amt < 0)
+        return 0;
+      done += amt;
+    }
+    return 1;
+  }
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  return 1;
+#endif
+}
+
+void rktio_copy_file_stop(rktio_file_copy_t *fc)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  rktio_close(fc->src_fd);
+  rktio_close(fc->dest_fd);
+#endif
+  free(fc);
+}
+
+/*************************************************************/
+/* filesystem root list                                      */
+/*************************************************************/
+
+char **rktio_filesystem_root_list(void)
+/* returns a NULL-terminated array of strings */
+{
+#ifdef RKTIO_SYSTEM_WINDOWS
+  {
+#   define DRIVE_BUF_SIZE 1024
+    char drives[DRIVE_BUF_SIZE], *s;
+    intptr_t len, ds, ss_len, ss_count = 0;
+    UINT oldmode;
+    char **ss, *new_ss;
+
+    len = GetLogicalDriveStrings(DRIVE_BUF_SIZE, drives);
+    if (len <= DRIVE_BUF_SIZE)
+      s = drives;
+    else {
+      s = malloc(len + 1);
+      GetLogicalDriveStrings(len + 1, s);
+    }
+
+    ss_len = 8;
+    ss = malloc(sizeof(char*) * ss_len);
+
+    ds = 0;
+    oldmode = SetErrorMode(SEM_FAILCRITICALERRORS);      
+    while (s[ds]) {
+      DWORD a, b, c, d;
+      /* GetDiskFreeSpace effectively checks whether we can read the disk: */
+      if (GetDiskFreeSpace(s XFORM_OK_PLUS ds, &a, &b, &c, &d)) {
+        if ((ss_count + 1) == ss_len) {
+          new_ss = malloc(sizeof(char*) * ss_len * 2);
+          mempcy(ss, new_ss, ss_count * sizeof(char*));
+          ss = new_ss;
+          ss_len *= 2;
+        }
+
+        ss[ss_count++] = strdup(s + ds);
+      }
+      ds += strlen(s XFORM_OK_PLUS ds) + 1;
+    }
+    SetErrorMode(oldmode);
+
+    if (s != drived)
+      free(s);
+
+    ss[ss_count] = 0;
+
+    return ss;
+  }
+#else
+  char **ss;
+  
+  ss = malloc(sizeof(char*) * 2);
+  ss[1] = strdup("/");
+  ss[0] = NULL;
+
+  return ss;
+#endif
+}
+
+/*************************************************************/
+/* expand user tilde & system paths                          */
+/*************************************************************/
+
+char *rktio_expand_user_tilde(char *filename) {
+#ifdef RKTIO_SYSTEM_WINDOWS
+  set_racket_error(RKTIO_ERROR_UNSUPPORTED);
+  return NULL;
+#else
+  char user[256], *home = NULL, *naya;
+  struct passwd *who = NULL;
+  intptr_t u, f, len, flen, ilen;
+
+  if (filename[0] != '~') {
+    set_racket_error(RKTIO_ERROR_NO_TILDE);
+    return NULL;
+  }
+  
+  for (u = 0, f = 1; 
+       u < 255 && filename[f] && filename[f] != '/'; 
+       u++, f++) {
+    user[u] = filename[f];
+  }
+
+  if (filename[f] && filename[f] != '/') {
+    set_racket_error(RKTIO_ERROR_ILL_FORMED_USER);
+    return NULL;
+  }
+  user[u] = 0;
+
+  if (!user[0]) {
+    if (!(home = getenv("HOME"))) {
+      char *ptr;
+          
+      ptr = getenv("USER");
+      if (!ptr)
+        ptr = getenv("LOGNAME");
+          
+      who = ptr ? getpwnam(ptr) : NULL;
+          
+      if (!who)
+        who = getpwuid(getuid());
+    }
+  } else
+    who = getpwnam(user);
+
+  if (!home && who)
+    home = who->pw_dir;
+
+  if (!home) {
+    set_racket_error(RKTIO_ERROR_UNKNOWN_USER);
+    return NULL;
+  }
+
+  ilen = strlen(filename);
+  len = strlen(home);
+  if (f < ilen) 
+    flen = ilen - f - 1;
+  else
+    flen = 0;
+  naya = (char *)malloc(len + flen + 2);
+  memcpy(naya, home, len);
+  naya[len] = '/';
+  memcpy(naya + len + 1, filename + f + 1, flen);
+  naya[len + flen + 1] = 0;
+
+  filename = naya;
+
+  return filename;
+#endif
+}
+
+static char *append_paths(char *a, char *b, int free_a, int free_b)
+{
+  int alen = strlen(a);
+  int blen = strlen(b);
+  int sep_len = 0;
+  char *s;
+
+  if (!IS_A_SEP(a[alen]))
+    sep_len = 1;
+
+  s = malloc(alen + sep_len + blen + 1);
+
+  memcpy(s, a, alen);
+  if (sep_len)
+    s[alen] = A_PATH_SEP;
+  memcpy(s+alen+sep_len, b, blen);
+  s[alen + blen] = 0;
+
+  if (free_a) free(a);
+  if (free_b) free(b);
+
+  return s;
+}
+
+char *rktio_system_path(int which)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  if (which == RKTIO_PATH_SYS_DIR) {
+    return strdup("/");
+  }
+
+  if (which == RKTIO_PATH_TEMP_DIR) {
+    char *p;
+    
+    if ((p = getenv("TMPDIR"))) {
+      if (rktio_directory_exists(p))
+	return strdup(p);
+    }
+
+    if (rktio_directory_exists("/var/tmp"))
+      return strdup("/var/tmp");
+
+    if (rktio_directory_exists("/usr/tmp"))
+      return strdup("/usr/tmp");
+
+    if (rktio_directory_exists("/tmp"))
+      return strdup("/tmp");
+
+    return rktio_get_current_directory();
+  }
+  
+  {
+    /* Everything else is in ~: */
+    char *home_str, *ex_home, *alt_home, *home;
+
+    /* cast here avoids a clang warning: */
+# define mz_STR_OFFSET(s, d) ((const char *)s XFORM_OK_PLUS d)
+
+    if ((which == RKTIO_PATH_PREF_DIR) 
+	|| (which == RKTIO_PATH_PREF_FILE)
+	|| (which == RKTIO_PATH_ADDON_DIR)) {
+#if defined(OS_X) && !defined(XONX)
+      if (which == RKTIO_PATH_ADDON_DIR)
+	home_str = "~/Library/Racket/";
+      else
+	home_str = "~/Library/Preferences/";
+#else
+      home_str = "~/.racket/";
+#endif 
+    } else {
+#if defined(OS_X) && !defined(XONX)
+      if (which == RKTIO_PATH_DESK_DIR)
+	home_str = "~/Desktop/";
+      else if (which == RKTIO_PATH_DOC_DIR)
+	home_str = "~/Documents/";
+      else
+#endif
+        home_str = "~/";
+    }
+
+    alt_home = getenv("PLTUSERHOME");
+    if (alt_home)
+      home = append_paths(alt_home, home_str + 2, 0, 0);
+    else {
+      home = rktio_expand_user_tilde(home_str);
+      
+      if (!home) {
+        /* Something went wrong with the user lookup. Just drop "~'. */
+        int h_len = strlen(home_str);
+        home = (char *)malloc(h_len - 2 + 1);
+        strcpy(home, home_str+2);
+      }
+    }
+    
+    if ((which == RKTIO_PATH_PREF_DIR) || (which == RKTIO_PATH_INIT_DIR) 
+	|| (which == RKTIO_PATH_HOME_DIR) || (which == RKTIO_PATH_ADDON_DIR)
+	|| (which == RKTIO_PATH_DESK_DIR) || (which == RKTIO_PATH_DOC_DIR))
+      return home;
+
+    if (which == RKTIO_PATH_INIT_FILE)
+      return append_paths(home, ".racketrc", 1, 0);
+    if (which == RKTIO_PATH_PREF_FILE) {
+#if defined(OS_X) && !defined(XONX)
+      return append_paths(home, "org.racket-lang.prefs.rktd", 1, 0);
+#else      
+      return append_paths(home, "racket-prefs.rktd", 1, 0);
+#endif
+    } else
+      return strdup("/");
+  }
+#endif
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+  if (which == RKTIO_PATH_SYS_DIR) {
+    int size;
+    wchar_t *s;
+    size = GetSystemDirectoryW(NULL, 0);
+    s = (wchar_t *)malloc((size + 1) * sizeof(wchar_t));
+    GetSystemDirectoryW(s, size + 1);
+    return NARROW_PATH_copy_then_free(s);
+  }
+
+  {
+    char *d, *p;
+    Scheme_Object *home;
+    
+    if (which == RKTIO_PATH_TEMP_DIR) {
+      if ((p = getenv("TMP")) || (p = getenv("TEMP"))) {
+	if (p && rktio_directory_exists(p))
+	  return strdup(p);
+      }
+      
+      return rktio_current_drectory();
+    }
+
+    home = NULL;
+
+    p = getenv("PLTUSERHOME");
+    if (p)
+      home = strdup(p);
+
+    if (!home) {
+      /* Try to get Application Data directory: */
+      LPITEMIDLIST items;
+      int which_folder;
+
+      if ((which == RKTIO_PATH_ADDON_DIR)
+	  || (which == RKTIO_PATH_PREF_DIR)
+	  || (which == RKTIO_PATH_PREF_FILE)) 
+	which_folder = CSIDL_APPDATA;
+      else if (which == RKTIO_PATH_DOC_DIR) {
+#       ifndef CSIDL_PERSONAL
+#         define CSIDL_PERSONAL 0x0005
+#       endif
+	which_folder = CSIDL_PERSONAL;
+      } else if (which == RKTIO_PATH_DESK_DIR)	
+	which_folder = CSIDL_DESKTOPDIRECTORY;
+      else {
+#       ifndef CSIDL_PROFILE
+#         define CSIDL_PROFILE 0x0028
+#       endif
+	which_folder = CSIDL_PROFILE;
+      }
+
+      if (SHGetSpecialFolderLocation(NULL, which_folder, &items) == S_OK) {
+	int ok;
+	IMalloc *mi;
+	wchar_t *buf;
+
+	buf = (wchar_t *)malloc(MAX_PATH * sizeof(wchar_t));
+	ok = SHGetPathFromIDListW(items, buf);
+
+	SHGetMalloc(&mi);
+	mi->lpVtbl->Free(mi, items);
+	mi->lpVtbl->Release(mi);
+
+        home = NARROW_PATH_copy_then_free(buf);
+      }
+    }
+
+    if (!home) {
+      /* Back-up: try USERPROFILE environment variable */
+      d = getenv("USERPROFILE");
+      if (d && rktio_directory_exists(d))
+        return strdup(d);
+    }
+
+    if (!home) {
+      /* Last-ditch effort: try HOMEDRIVE+HOMEPATH */
+      d = getenv("HOMEDRIVE");
+      p = getenv("HOMEPATH");
+
+      if (d && p) {
+        home = append_paths(d, p);
+      
+	if (rktio_directory_exists(home))
+          return home;
+        else {
+          free(home);
+          home = NULL;
+        }
+      } else 
+	home = NULL;
+    
+      if (!home) {
+	wchar_t name[1024];
+      
+	if (!GetModuleFileNameW(NULL, name, 1024)) {
+	  /* Disaster. Use CWD. */
+	  home = rktio_current_drectory();
+          if (!home)
+            return NULL;
+	} else {
+	  int i;
+	  wchar_t *s;
+	
+	  s = name;
+	
+	  i = wc_strlen(s) - 1;
+	
+	  while (i && (s[i] != '\\')) {
+	    --i;
+	  }
+	  s[i] = 0;
+	  home = NARROW_PATH_copy(s);
+	}
+      }
+    }
+    
+    if ((which == RKTIO_PATH_INIT_DIR)
+	|| (which == RKTIO_PATH_HOME_DIR)
+	|| (which == RKTIO_PATH_DOC_DIR)
+	|| (which == RKTIO_PATH_DESK_DIR))
+      return home;
+
+    if ((which == RKTIO_PATH_ADDON_DIR)
+	|| (which == RKTIO_PATH_PREF_DIR)
+	|| (which == RKTIO_PATH_PREF_FILE)) {
+      home = append_paths(home, "Racket", 1, 0);
+    }
+
+    if (which == RKTIO_PATH_INIT_FILE)
+      return append_paths(home, "racketrc.rktl", 1, 0);
+    if (which == RKTIO_PATH_PREF_FILE)
+      return append_paths(home, "racket-prefs.rktd", 1, 0);
+    return home;
+  }
+#endif
+}
diff --git a/racket/src/rktio/rktio_poll_set.c b/racket/src/rktio/rktio_poll_set.c
new file mode 100644
index 0000000000..a1c8649503
--- /dev/null
+++ b/racket/src/rktio/rktio_poll_set.c
@@ -0,0 +1,779 @@
+#include "rktio.h"
+#include "rktio_private.h"
+#ifdef RKTIO_SYSTEM_UNIX
+# include <sys/select.h>
+# include <unistd.h>
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+# include <windows.h>
+#endif
+#include <stdlib.h>
+
+/* Generalize fd arrays (FD_SET, etc) with a runtime-determined size,
+   special hooks for Windows "descriptors" like even queues and
+   semaphores, etc. */
+
+#ifdef USE_FAR_RKTIO_FDCALLS
+THREAD_LOCAL_DECL(rktio_poll_set_t *rktio_global_poll_set);
+#endif
+
+void rktio_alloc_global_poll_set() {
+#ifdef USE_FAR_RKTIO_FDCALLS
+  rktio_global_poll_set = rktio_alloc_fdset_array(3);
+#endif
+}
+
+/************************************************************/
+/* Poll variant                                             */
+/************************************************************/
+
+#ifdef HAVE_POLL_SYSCALL
+
+# define PFD_EXTRA_SPACE 1
+
+struct rktio_poll_set_t {
+  struct rktio_fd_set_data_t *data;
+  rktio_poll_set_t *w;
+  rktio_poll_set_t *e;
+  int flags;
+};
+
+struct rktio_fd_set_data_t {
+  struct pollfd *pfd;
+  intptr_t size, count;
+};
+
+rktio_poll_set_t *rktio_alloc_fdset_array(int count)
+{
+  struct rktio_fd_set_data_t *data;
+  rktio_poll_set_t *r, *w, *e;
+  struct pollfd *pfd;
+
+  data = malloc(sizeof(struct rktio_fd_set_data_t));
+  r = malloc(sizeof(struct rktio_poll_set_t));
+  w = malloc(sizeof(struct rktio_poll_set_t));
+  e = malloc(sizeof(struct rktio_poll_set_t));
+
+  r->w = w;
+  r->e = e;
+  r->data = data;
+  w->data = data;
+  e->data = data;
+
+  r->flags = POLLIN;
+  w->flags = POLLOUT;
+  e->flags = 0;
+
+  data->size = 32;
+  data->count = 0;
+
+  pfd = malloc(sizeof(struct pollfd) * (32 + PFD_EXTRA_SPACE));
+  data->pfd = pfd;
+
+  return data;
+}
+
+rktio_poll_set_t *rktio_init_fdset_array(rktio_poll_set_t *fdarray, int count)
+{
+  ((struct rktio_fd_set *)fdarray)->data->count = 0;
+  return fdarray;
+}
+
+rktio_poll_set_t *rktio_get_fdset(rktio_poll_set_t *fdarray, int pos)
+{
+  switch (pos) {
+  case 0: 
+    return fdarray;
+  case 1: 
+    return fdarray->w;
+  case 2: 
+  default:
+    return fdarray->e;
+  }
+}
+
+void rktio_fdzero(rktio_poll_set_t *fd)
+{
+  fd->data->count = 0;
+}
+
+static int find_fd_pos(struct rktio_fd_set_data_t *data, int n)
+{
+  intptr_t count = data->count;
+  intptr_t i;
+  
+  /* This linear search probably isn't good enough for hundreds or
+     thousands of descriptors, but epoll()/kqueue() mode should handle
+     that case, anyway. */
+  for (i = 0; i < count; i++) {
+    if (data->pfd[i].fd == n) {
+      return i;
+    }
+  }
+
+  return -1;
+}
+
+void rktio_fdclr(rktio_poll_set_t *fd, int n)
+{
+  struct rktio_fd_set_data_t *data = fd->data;
+  intptr_t flag = fd->flags;
+  intptr_t pos;
+
+  if (!flag) return;
+
+  pos = find_fd_pos(data, n);
+  if (pos >= 0) {
+    data->pfd[pos].events -= (data->pfd[pos].events & flag);
+  }
+}
+
+void rktio_fdset(rktio_poll_set_t *fd, int n)
+{
+  struct rktio_fd_set_data_t *data = fd->data;
+  intptr_t flag = fd->flags;
+  intptr_t count, size, pos;
+  struct pollfd *pfd;
+
+  if (!flag) return;
+
+  pos = find_fd_pos(data, n);
+  if (pos >= 0) {
+    data->pfd[pos].events |= flag;
+    return;
+  }
+
+  count = data->count;
+  size = data->size;
+  if (count >= size) {
+    size = size * 2;
+    pfd = malloc(sizeof(struct pollfd) * (size + PFD_EXTRA_SPACE));
+    memcpy(pfd, data->pfd, sizeof(struct pollfd) * count);
+    free(data->pfd);
+    data->pfd = pfd;
+    data->size = size;
+  }
+
+  data->pfd[count].fd = n;
+  data->pfd[count].events = flag;
+  count++;
+  data->count = count;
+}
+
+int rktio_fdisset(rktio_poll_set_t *fd, int n)
+{
+  struct rktio_fd_set_data_t *data = data->data;
+  intptr_t flag = fd->flags;
+  intptr_t pos;
+
+  if (!flag) flag = (POLLERR | POLLHUP);
+
+  pos = find_fd_pos(data, n);
+  if (pos >= 0) {
+    if (data->pfd[pos].revents & flag)
+      return 1;
+    else
+      return 0;
+  }
+
+  return 0;
+}
+
+static int cmp_fd(const void *_a, const void *_b)
+{
+  struct pollfd *a = (struct pollfd *)_a;
+  struct pollfd *b = (struct pollfd *)_b;
+  return a->fd - b->fd;
+}
+
+rktio_poll_set_t *rktio_merge_fd_sets(rktio_poll_set_t *fds, rktio_poll_set_t *src_fds)
+{
+  struct rktio_fd_set_data_t *data = fds->data;
+  struct rktio_fd_set_data_t *src_data = src_fds->data;
+  int i, si, c, sc, j, nc;
+  struct pollfd *pfds;
+
+  rktio_clean_fd_set(fds);
+  rktio_clean_fd_set(src_fds);
+
+  c = data->count;
+  sc = src_data->count;
+
+  if (!c)
+    return src_fds;
+  if (!sc)
+    return fds;
+
+  qsort(data->pfd, c, sizeof(struct pollfd), cmp_fd);
+  qsort(src_data->pfd, sc, sizeof(struct pollfd), cmp_fd);
+
+  nc = c + sc;
+  pfds = (struct pollfd *)rktio_malloc_atomic(sizeof(struct pollfd) * (nc + PFD_EXTRA_SPACE));
+  j = 0;
+  for (i = 0, si = 0; (i < c) && (si < sc); ) {
+    if (data->pfd[i].fd == src_data->pfd[si].fd) {
+      pfds[j].fd = data->pfd[i].fd;
+      pfds[j].events = (data->pfd[i].events | src_data->pfd[si].events);
+      i++;
+      si++;
+    } else if (data->pfd[i].fd < src_data->pfd[si].fd) {
+      pfds[j].fd = data->pfd[i].fd;
+      pfds[j].events = data->pfd[i].events;
+      i++;
+    } else {
+      pfds[j].fd = src_data->pfd[si].fd;
+      pfds[j].events = src_data->pfd[si].events;
+      si++;
+    }
+    j++;
+  }
+  for ( ; i < c; i++, j++) {
+    pfds[j].fd = data->pfd[i].fd;
+    pfds[j].events = data->pfd[i].events;
+  }
+  for ( ; si < sc; si++, j++) {
+    pfds[j].fd = src_data->pfd[si].fd;
+    pfds[j].events = src_data->pfd[si].events;
+  }
+
+  if (nc > RKTIO_INT_VAL(data->size)) {
+    data->pfd = pfds;
+    data->size = rktio_make_integer(nc);
+  } else
+    memcpy(data->pfd, pfds, j * sizeof(struct pollfd));
+  data->count = rktio_make_integer(j);
+
+  return fds;
+}
+
+void rktio_clean_fd_set(rktio_poll_set_t *fds)
+{
+  struct rktio_fd_set_data_t *data = fds->data;
+  intptr_t count = data->count;
+  intptr_t i, j = 0;
+
+  for (i = 0; i < count; i++) {
+    if (data->pfd[i].events) {
+      if (j < i) {
+        data->pfd[j].fd = data->pfd[i].fd;
+        data->pfd[j].events = data->pfd[i].events;
+      }
+      j++;
+    }
+  }
+  
+  count = j;
+  data->count = count;
+}
+
+int rktio_get_fd_limit(rktio_poll_set_t *fds)
+{
+  return 0;
+}
+
+#elif defined(USE_DYNAMIC_FDSET_SIZE)
+
+/************************************************************/
+/* Variant with run-time determined fd_set length           */
+/************************************************************/
+
+struct rktio_poll_set_t {
+  fd_set data;
+};
+
+/* initialized early via rktio_alloc_global_poll_set */
+static int dynamic_fd_size;
+
+# define STORED_ACTUAL_FDSET_LIMIT
+# define FDSET_LIMIT(fd) (*(int *)((char *)fd + dynamic_fd_size))
+
+rktio_poll_set_t *rktio_alloc_fdset_array(int count)
+{
+  if (!dynamic_fd_size) {
+# ifdef USE_ULIMIT
+    dynamic_fd_size = ulimit(4, 0);
+# else
+    dynamic_fd_size = getdtablesize();
+# endif
+    /* divide by bits-per-byte: */
+    dynamic_fd_size = (dynamic_fd_size + 7) >> 3;
+    /* word-align: */
+    if (dynamic_fd_size % sizeof(void*))
+      dynamic_fd_size += sizeof(void*) - (dynamic_fd_size % sizeof(void*));
+  }
+
+  return malloc(count * (dynamic_fd_size + sizeof(intptr_t)));
+}
+
+rktio_poll_set_t *rktio_init_fdset_array(rktio_poll_set_t *fdarray, int count)
+{
+  return fdarray;
+}
+
+rktio_poll_set_t *rktio_get_fdset(rktio_poll_set_t *fdarray, int pos)
+{
+  return (rktio_poll_set_t *)(((char *)fdarray) + (pos * (dynamic_fd_size + sizeof(intptr_t))));
+}
+
+void rktio_fdzero(rktio_poll_set_t *fd)
+{
+  memset(fd, 0, dynamic_fd_size + sizeof(intptr_t));
+}
+
+#elif defined (RKTIO_SYSTEM_WINDOWS)
+
+/************************************************************/
+/* Windows variant                                          */
+/************************************************************/
+
+typedef struct {
+  SOCKET *sockets;
+
+  intptr_t added, alloc, last_alloc;
+
+  intptr_t num_handles, alloc_handles, last_alloc_handles;
+  OS_SEMAPHORE_TYPE *handles;
+
+  int *repost_sema;
+
+  int no_sleep; /* boolean */
+
+  intptr_t wait_event_mask;
+
+  HANDLE *wait_array;
+
+  HANDLE *combined_wait_array;
+  intptr_t combined_len;
+} rktio_poll_set_t;
+
+rktio_poll_set_t *rktio_alloc_fdset_array(int count)
+{
+  rktio_poll_set_t *fdarray;
+  if (count) {
+    fdarray = calloc(count, sizeof(rktio_poll_set_t));
+    rktio_init_fdset_array(fdarray, count);
+  } else
+    fdarray = NULL;
+
+  return fdarray;
+}
+
+static void reset_wait_array(rktio_poll_set_t *efd)
+{
+  /* Allocate an array that may be big enough to hold all events
+     when we eventually call WaitForMultipleObjects. One of the three
+     arrays will be big enough. */
+  int sz = (3 * (efd->alloc + efd->alloc_handles)) + 2;
+  HANDLE *wa;
+  if (efd->wait_array) free(efd->wait_array);
+  wa = calloc(sz, sizeof(HANDLE));
+  efd->wait_array = wa;
+}
+
+rktio_poll_set_t *rktio_init_fdset_array(rktio_poll_set_t *fdarray, int count)
+{
+  if (count) {
+    int i;
+    rktio_poll_set_t *fd;
+    for (i = 0; i < count; i++) {
+      int reset = 0;
+      fd = rktio_get_fdset(fdarray, i);
+      fd->added = 0;
+      if (RKTIO_INT_VAL(fd->alloc) > (2 * RKTIO_INT_VAL(fd->last_alloc))) {
+	fd->alloc = 0;
+        if (fd->sockets) free(fd->sockets);
+	fd->sockets = NULL;
+	reset = 1;
+      }
+      fd->last_alloc = 0;
+      fd->num_handles = 0;
+      if (RKTIO_INT_VAL(fd->alloc_handles) > (2 * RKTIO_INT_VAL(fd->last_alloc_handles))) {
+	fd->alloc_handles = 0;
+        if (fd->handles) free(fd->handles);
+        if (fd->repost_sema) free(fd->repost_sema);
+	fd->handles = NULL;
+	fd->repost_sema = NULL;
+	reset = 1;
+      }
+      fd->last_alloc_handles = 0;
+      fd->no_sleep = 0;
+      fd->wait_event_mask = 0;
+      if (reset)
+	reset_wait_array(fdarray);
+    }
+  }
+}
+
+rktio_poll_set_t *rktio_get_fdset(rktio_poll_set_t *fdarray, int pos)
+{
+  return fdarray + pos;
+}
+
+void rktio_fdzero(rktio_poll_set_t *fd)
+{
+  rktio_init_fdset_array(fd, 1);
+}
+
+void rktio_fdclr(rktio_poll_set_t *fd, int n)
+{
+  int i;
+  for (i = fd->added; i--; ) {
+    if (fd->sockets[i] == n)
+      fd->sockets[i] = INVALID_SOCKET;
+  }
+}
+
+static int next_size(int v) { return (v ? (2 * v) : 10); }
+
+void rktio_fdset(rktio_poll_set_t *fd, int n)
+{
+  if (fd->added >= fd->last_alloc) {
+    int na;
+    na = next_size(fd->last_alloc);
+    efd->last_alloc = na;
+  }
+  if (fd->added >= fd->alloc) {
+    SOCKET *naya;
+    int na;
+    na = next_size(fd->alloc);
+    naya = malloc(na * sizeof(SOCKET));
+    memcpy(naya, fd->sockets, RKTIO_INT_VAL(fd->alloc) * sizeof(SOCKET));
+    if (fd->sockets) free(fd->sockets);
+    fd->sockets = naya;
+    fd->alloc = na;
+    reset_wait_array(fd);
+  }
+  fd->sockets[fd->added++] = n;
+}
+
+int rktio_fdisset(rktio_poll_set_t *fd, int n)
+{
+  int i;
+  for (i = fd->added; i--; ) {
+    if (fd->sockets[i] == n)
+      return 1;
+  }
+  return 0;
+}
+
+rktio_poll_set_t *rktio_merge_fd_sets(rktio_poll_set_t *fds, rktio_poll_set_t *src_fds)
+{
+  int i;
+  for (i = src_fd->added; i--; ) {
+    if (stv_fd->sockets[i] != INVALID_SOCKET)
+      rktio_fdset(fds, src_fd->sockets[i]);
+  }
+  return fds;
+}
+
+void rktio_clean_fd_set(rktio_poll_set_t *fds)
+{
+}
+
+int rktio_get_fd_limit(rktio_poll_set_t *fds)
+{
+  return 0;
+}
+
+void rktio_fdset_add_handle(HANDLE h, rktio_poll_set_t *fds, int repost)
+{
+  rktio_poll_set_t *efd = fds;
+  OS_SEMAPHORE_TYPE *hs;
+  int i, new_i, *rps;
+
+  if (efd->num_handles == efd->last_alloc_handles) {
+    i = next_size(efd->last_alloc_handles);
+    efd->last_alloc_handles = 1;
+  }
+  if (efd->num_handles == efd->alloc_handles) {
+    i = efd->alloc_handles;
+    new_i = next_size(i);
+    hs = malloc(sizeof(HANDLE) * new_i);
+    rps = malloc(sizeof(int) * new_i);
+    memcpy(hs, efd->handles, sizeof(HANDLE)*i);
+    memcpy(rps, efd->repost_sema, sizeof(int)*i);
+    if (efd->handles) free(efd->handles);
+    if (efd->repost_sema) free(efd->repost_sema);
+    efd->handles = hs;
+    efd->repost_sema = rps;
+    efd->alloc_handles = new_i;
+    reset_wait_array(efd);
+  }
+  i = efd->num_handles;
+  efd->handles[i] = h;
+  efd->repost_sema[i] = repost;
+  efd->num_handles++;
+}
+
+void rktio_add_fd_nosleep(rktio_poll_set_t *fds)
+{
+  fds->no_sleep = 1;
+}
+
+void rktio_fdset_add_eventmask(rktio_poll_set_t *fds, int mask)
+{
+  fds->wait_event_mask |= mask;
+}
+
+void WSAEventSelect_plus_check(SOCKET s, WSAEVENT e, long mask)
+{
+  fd_set rd[1], wr[1], ex[1];
+  struct timeval t = {0, 0};
+
+  WSAEventSelect(s, e, mask);
+  
+  /* double-check with select(), because WSAEventSelect only
+     handles new activity (I think) */
+  FD_ZERO(rd);
+  FD_ZERO(wr);
+  FD_ZERO(ex);
+
+  if (mask & FD_READ)
+    FD_SET(s, rd);
+  if (mask & FD_WRITE)
+    FD_SET(s, wr);
+  if (mask & FD_OOB)
+    FD_SET(s, ex);
+
+  if (select(1, rd, wr, ex, &t)) {
+    /* already ready */
+    WSAEventSelect(s, NULL, 0);
+    SetEvent(e);
+  }
+}
+
+void rktio_collapse_win_fd(rktio_poll_set_t *fds)
+{
+  rktio_poll_set_t *rfd, *wfd, *efd;
+  HANDLE *wa, e;
+  int i, p = 0, mask, j;
+  SOCKET s;
+
+  rfd = fds;
+  wfd = rktio_get_fdset(fds, 1);
+  efd = rktio_get_fdset(fds, 2);
+
+  if (rfd->combined_wait_array) {
+    /* clean up */
+    for (i = rfd->added; i--; ) {
+      if (rfd->sockets[i] != INVALID_SOCKET)
+	WSAEventSelect(rfd->sockets[i], NULL, 0);
+    }
+    for (i = wfd->added; i--; ) {
+      if (wfd->sockets[i] != INVALID_SOCKET)
+	WSAEventSelect(wfd->sockets[i], NULL, 0);
+    }
+    for (i = efd->added; i--; ) {
+      if (efd->sockets[i] != INVALID_SOCKET)
+	WSAEventSelect(efd->sockets[i], NULL, 0);
+    }
+    p = rfd->num_handles;
+    for (i = rfd->combined_len; i-- > p; ) {
+      WSACloseEvent(rfd->combined_wait_array[i]);
+    }
+    rfd->combined_wait_array = NULL;
+  } else {
+    /* merge */
+    if (rfd->alloc < RKTIO_INT_VAL(wfd->alloc)) {
+      if (wfd->alloc < efd->alloc)
+	wa = efd->wait_array;
+      else
+	wa = wfd->wait_array;
+    } else {
+      if (rfd->alloc < efd->alloc)
+	wa = efd->wait_array;
+      else
+	wa = rfd->wait_array;
+    }
+
+    rfd->combined_wait_array = wa;
+
+    p = rfd->num_handles;
+    for (i = 0; i < p; i++) {
+      wa[i] = rfd->handles[i];
+    }
+  
+    for (i = rfd->added; i--; ) {
+      s = rfd->sockets[i];
+      if (s != INVALID_SOCKET) {
+	mask = FD_READ | FD_ACCEPT | FD_CLOSE;
+	
+	for (j = wfd->added; j--; ) {
+	  if (wfd->sockets[j] == s) {
+	    mask |= FD_WRITE;
+	    break;
+	  }
+	}
+
+	for (j = efd->added; j--; ) {
+	  if (efd->sockets[j] == s) {
+	    mask |= FD_OOB;
+	    break;
+	  }
+	}
+
+	e = WSACreateEvent();
+	wa[p++] = e;
+	WSAEventSelect_plus_check(s, e, mask);
+      }
+    }
+
+    for (i = wfd->added; i--; ) {
+      s = wfd->sockets[i];
+      if (s != INVALID_SOCKET) {
+	mask = FD_WRITE | FD_CONNECT | FD_CLOSE;
+	
+	for (j = rfd->added; j--; ) {
+	  if (rfd->sockets[j] == s) {
+	    mask = 0;
+	    break;
+	  }
+	}
+
+	if (mask) {
+	  for (j = efd->added; j--; ) {
+	    if (efd->sockets[j] == s) {
+	      mask |= FD_OOB;
+	      break;
+	    }
+	  }
+	  
+	  e = WSACreateEvent();
+	  wa[p++] = e;
+	  WSAEventSelect_plus_check(s, e, mask);
+	}
+      }
+    }
+
+    for (i = efd->added; i--; ) {
+      s = efd->sockets[i];
+      if (s != INVALID_SOCKET) {
+	mask = FD_OOB | FD_CLOSE;
+	
+	for (j = rfd->added; j--; ) {
+	  if (rfd->sockets[j] == s) {
+	    mask = 0;
+	    break;
+	  }
+	}
+
+	if (mask) {
+	  for (j = wfd->added; j--; ) {
+	    if (wfd->sockets[j] == s) {
+	      mask = 0;
+	      break;
+	    }
+	  }
+	  
+	  if (mask) {
+	    e = WSACreateEvent();
+	    wa[p++] = e;
+	    WSAEventSelect_plus_check(s, e, mask);
+	  }
+	}
+      }
+    }
+
+    rfd->combined_len = p;
+  }
+}
+
+#else
+
+/************************************************************/
+/* Plain fd_set variant                                     */
+/************************************************************/
+
+rktio_poll_set_t *rktio_alloc_fdset_array(int count)
+{
+  return malloc(count * sizeof(fd_set));
+}
+
+rktio_poll_set_t *rktio_init_fdset_array(rktio_poll_set_t *fdarray, int count)
+{
+  return fdarray;
+}
+
+rktio_poll_set_t *rktio_get_fdset(rktio_poll_set_t *fdarray, int pos)
+{
+  return fdarray + pos;
+}
+
+void rktio_fdzero(rktio_poll_set_t *fd)
+{
+  FD_ZERO(&(fd)->data);
+}
+
+void rktio_fdclr(rktio_poll_set_t *fd, int n)
+{
+  FD_CLR(n, &(fd)->data);
+}
+
+void rktio_fdset(rktio_poll_set_t *fd, int n)
+{
+# ifdef STORED_ACTUAL_FDSET_LIMIT
+  int mx;
+  mx = FDSET_LIMIT(fd);
+  if (n > mx)
+    FDSET_LIMIT(fd) = n;
+# endif
+  FD_SET(n, &(fd)->data);
+}
+
+int rktio_fdisset(rktio_poll_set_t *fd, int n)
+{
+  return FD_ISSET(n, &(fd)->data);
+}
+
+rktio_poll_set_t *rktio_merge_fd_sets(rktio_poll_set_t *fds, rktio_poll_set_t *src_fds)
+{
+  int i, j;
+  unsigned char *p, *sp;
+  for (j = 0; j < 3; j++) {
+    p = (unsigned char *)rktio_get_fdset(fds, j);
+    sp = (unsigned char *)rktio_get_fdset(src_fds, j);
+# ifdef STORED_ACTUAL_FDSET_LIMIT
+    if (FDSET_LIMIT(sp) > FDSET_LIMIT(p)) {
+      i = FDSET_LIMIT(sp);
+      FDSET_LIMIT(p) = i;
+    }
+# endif
+# if defined(USE_DYNAMIC_FDSET_SIZE)
+    i = dynamic_fd_size;
+# else
+    i = sizeof(fd_set);
+# endif
+    for (; i--; p++, sp++) {
+      *p |= *sp;
+    }
+  }
+  return fds;
+}
+
+void rktio_clean_fd_set(rktio_poll_set_t *fds)
+{
+}
+
+int rktio_get_fd_limit(rktio_poll_set_t *fds)
+{
+  int actual_limit;
+
+# ifdef STORED_ACTUAL_FDSET_LIMIT
+  actual_limit = FDSET_LIMIT(rd);
+  if (FDSET_LIMIT(wr) > actual_limit)
+    actual_limit = FDSET_LIMIT(wr);
+  if (FDSET_LIMIT(ex) > actual_limit)
+    actual_limit = FDSET_LIMIT(ex);
+  actual_limit++;
+# elif defined (USE_ULIMIT)
+  actual_limit = ulimit(4, 0);
+#elif defined(FIXED_FD_LIMIT)
+  actual_limit = FIXED_FD_LIMIT;
+#else
+  actual_limit = getdtablesize();
+# endif
+
+  return actual_limit;
+}
+
+#endif
diff --git a/racket/src/rktio/rktio_private.h b/racket/src/rktio/rktio_private.h
new file mode 100644
index 0000000000..5463121634
--- /dev/null
+++ b/racket/src/rktio/rktio_private.h
@@ -0,0 +1,86 @@
+#if ((defined(_MSC_VER) || defined(__MINGW32__)) \
+     && (defined(__WIN32__) || defined(WIN32) || defined(_WIN32)))
+# define RKTIO_SYSTEM_WINDOWS
+# define MSC_IZE(n) _ ## n
+# define MSC_W_IZE(n) _w ## n
+# define MSC_WIDE_PATH_temp(n) WIDE_PATH_temp(n)
+#else
+# define RKTIO_SYSTEM_UNIX
+# define MSC_IZE(n) n
+# define MSC_W_IZE(n) MSC_IZE(n)
+# define MSC_WIDE_PATH_temp(n) n
+#endif
+
+#define THREAD_LOCAL_DECL(decl) decl
+
+void rktio_get_posix_error(void);
+#define get_posix_error() rktio_get_posix_error()
+
+void rktio_set_racket_error(int errid);
+#define set_racket_error(e) rktio_set_racket_error(e)
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+void rktio_get_windows_error(void);
+# define get_windows_error() rktio_get_windows_error()
+#endif
+
+intptr_t rktio_fd_value(rktio_fd_t *fd);
+
+/*******************************************************************/
+
+typedef struct rktio_poll_set_t rktio_poll_set_t;
+
+#if RKTIO_SYSTEM_WINDOWS
+# define USE_FAR_RKTIO_FDCALLS
+#endif
+#ifdef USE_DYNAMIC_FDSET_SIZE
+# define USE_FAR_RKTIO_FDCALLS
+#endif
+#ifdef HAVE_POLL_SYSCALL
+# define USE_FAR_RKTIO_FDCALLS
+#endif
+
+#ifdef USE_FAR_RKTIO_FDCALLS
+/* A single fdset that can be reused for immediate actions: */
+THREAD_LOCAL_DECL(extern rktio_poll_set_t *rktio_global_fd_set);
+
+# define DECL_FDSET(n, c) fd_set *n
+# define INIT_DECL_FDSET(r, w, e) { \
+   r = RKTIO_GET_FDSET(rktio_global_poll_set, 0 ); \
+   w = RKTIO_GET_FDSET(rktio_global_poll_set, 1 ); \
+   e = RKTIO_GET_FDSET(rktio_global_poll_set, 2 ); \
+ }
+# define INIT_DECL_RD_FDSET(r) r = RKTIO_GET_FDSET(rktio_global_poll_set, 0 )
+# define INIT_DECL_WR_FDSET(r) r = RKTIO_GET_FDSET(rktio_global_poll_set, 1 )
+# define INIT_DECL_ER_FDSET(r) r = RKTIO_GET_FDSET(rktio_global_poll_set, 2 )
+
+# define RKTIO_GET_FDSET(p, n) rktio_get_fdset(p, n)
+# define RKTIO_FD_ZERO(p) rktio_fdzero(p)
+# define RKTIO_FD_SET(n, p) rktio_fdset(p, n)
+# define RKTIO_FD_CLR(n, p) rktio_fdclr(p, n)
+# define RKTIO_FD_ISSET(n, p) rktio_fdisset(p, n)
+
+#else
+
+#include <sys/select.h>
+struct rktio_poll_set_t { fd_set data; };
+
+# define DECL_FDSET(n, c) rktio_poll_set_t n[c]
+# define INIT_DECL_FDSET(r, w, e) /* empty */
+# define INIT_DECL_RD_FDSET(r) /* empty */
+# define INIT_DECL_WR_FDSET(r) /* empty */
+# define INIT_DECL_ER_FDSET(r) /* empty */
+
+# define RKTIO_FDS(p) (&(p)->data)
+
+# define RKTIO_GET_FDSET(p, n) ((p)+(n))
+# define RKTIO_FD_ZERO(p) FD_ZERO(RKTIO_FDS(p))
+# define RKTIO_FD_SET(n, p) FD_SET(n, RKTIO_FDS(p))
+# define RKTIO_FD_CLR(n, p) FD_CLR(n, RKTIO_FDS(p))
+# define RKTIO_FD_ISSET(n, p) FD_ISSET(n, RKTIO_FDS(p))
+
+#endif
+
+rktio_poll_set_t *rktio_merge_fd_sets(rktio_poll_set_t *fds, rktio_poll_set_t *src_fds);
+void rktio_clean_fd_set(rktio_poll_set_t *fds);
+int rktio_get_fd_limit(rktio_poll_set_t *fds);
diff --git a/racket/src/rktio/rktio_read_write.c b/racket/src/rktio/rktio_read_write.c
new file mode 100644
index 0000000000..60d3a37b99
--- /dev/null
+++ b/racket/src/rktio/rktio_read_write.c
@@ -0,0 +1,1168 @@
+#include "rktio.h"
+#include "rktio_private.h"
+#include <errno.h>
+#include <stdlib.h>
+#ifdef RKTIO_SYSTEM_UNIX
+# include <sys/stat.h>
+# include <fcntl.h>
+# include <unistd.h>
+# include <sys/select.h>
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+# include <windows.h>
+#endif
+
+#if defined(USE_FCNTL_O_NONBLOCK)
+# define RKTIO_NONBLOCKING O_NONBLOCK
+#else
+# define RKTIO_NONBLOCKING FNDELAY
+#endif
+
+#ifndef RKTIO_BINARY
+# define RKTIO_BINARY 0
+#endif
+
+struct rktio_fd_t {
+  int modes;
+
+#ifdef RKTIO_SYSTEM_UNIX
+  intptr_t fd;
+# ifdef SOME_FDS_ARE_NOT_SELECTABLE
+  int bufcount;
+  char buffer[1];
+# endif
+#endif
+  
+#ifdef RKTIO_SYSTEM_WINDOWS
+  HANDLE fd;
+  Win_FD_Input_Thread *th; /* input mode */
+  Win_FD_Output_Thread *oth; /* output mode */
+#endif
+
+  int regfile;
+};
+
+/*************************************************************/
+/* creating an fd                                            */
+/*************************************************************/
+
+static void init_read_fd(rktio_fd_t *rfd)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+# ifdef SOME_FDS_ARE_NOT_SELECTABLE
+  rfd->bufcount = 0;
+# endif
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  if (!rfd->regfile) {
+    /* To get non-blocking I/O for anything that can block, we create
+       a separate reader thread.
+
+       Yes, Windows NT pipes support non-blocking reads, but there
+       doesn't seem to be any way to use WaitForSingleObject to sleep
+       until characters are ready. PeekNamedPipe can be used for
+       polling, but not sleeping. */
+
+    Win_FD_Input_Thread *th;
+    DWORD id;
+    HANDLE h;
+    OS_SEMAPHORE_TYPE sm;
+
+    th = malloc(sizeof(Win_FD_Input_Thread));
+    rfd->th = th;
+
+    /* Replace buffer with a malloced one: */
+    bfr = malloc(MZPORT_FD_BUFFSIZE);
+    fip->buffer = bfr;
+    th->buffer = bfr;
+
+    th->fd = (HANDLE)fd;
+    th->avail = 0;
+    th->err = 0;
+    th->eof = NULL;
+    th->checking = 0;
+    
+    sm = CreateSemaphore(NULL, 0, 1, NULL);
+    th->checking_sema = sm;
+    sm = CreateSemaphore(NULL, 0, 1, NULL);
+    th->ready_sema = sm;
+    sm = CreateSemaphore(NULL, 1, 1, NULL);
+    th->you_clean_up_sema = sm;
+    th->refcount = refcount;
+
+    h = CreateThread(NULL, 4096, (LPTHREAD_START_ROUTINE)WindowsFDReader, th, 0, &id);
+
+    th->thread = h;
+  }
+#endif
+}
+
+rktio_fd_t *rktio_fd(intptr_t system_fd, int modes)
+{
+  rktio_fd_t *rfd;
+
+  rfd = malloc(sizeof(rktio_fd_t));
+  rfd->modes = modes;
+  
+
+#ifdef RKTIO_SYSTEM_UNIX
+  rfd->fd = system_fd;
+  {
+    struct stat buf;
+    int cr;
+    do {
+      cr = fstat(rfd->fd, &buf);
+    } while ((cr == -1) && (errno == EINTR));
+    rfd->regfile = S_ISREG(buf.st_mode);
+  }
+#endif
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+  rfd->fd = (HANDLE)system_fd;
+  rfd->regfile = (GetFileType(rfd->fd) == FILE_TYPE_DISK);
+#endif
+  
+  if (modes & RKTIO_OPEN_READ)
+    init_read_fd(rfd);
+  
+  return rfd;
+}
+
+/*************************************************************/
+/* opening a file fd                                         */
+/*************************************************************/
+
+static rktio_fd_t *open_read(char *filename)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  int fd;
+  struct stat buf;
+  rktio_fd_t *rfd;
+
+  do {
+    fd = open(filename, O_RDONLY | RKTIO_NONBLOCKING | RKTIO_BINARY);
+  } while ((fd == -1) && (errno == EINTR));
+
+  if (fd == -1) {
+    get_posix_error();
+    return NULL;
+  } else {
+    int cr;
+
+    do {
+      cr = fstat(fd, &buf);
+    } while ((cr == -1) && (errno == EINTR));
+
+    if (cr) {
+      get_posix_error();
+      do {
+	cr = close(fd);
+      } while ((cr == -1) && (errno == EINTR));
+      return NULL;
+    }
+
+    if (S_ISDIR(buf.st_mode)) {
+      do {
+	cr = close(fd);
+      } while ((cr == -1) && (errno == EINTR));
+      set_racket_error(RKTIO_ERROR_IS_A_DIRECTORY);
+      return NULL;
+    } else {
+      rfd = malloc(sizeof(rktio_fd_t));
+      rfd->modes = RKTIO_OPEN_READ;
+      rfd->fd = fd;
+      rfd->regfile = S_ISREG(buf.st_mode);
+
+      init_read_fd(rfd);
+
+      return rfd;
+    }
+  }
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  HANDLE fd;
+  rktio_fd_t *rfd;
+  
+  fd = CreateFileW(WIDE_PATH(filename),
+		   GENERIC_READ,
+		   FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+		   NULL,
+		   OPEN_EXISTING,
+		   0,
+		   NULL);
+
+  if (fd == INVALID_HANDLE_VALUE) {
+    get_windows_error();
+    return NULL;
+  }
+
+  rfd = malloc(sizeof(rktio_fd_t));
+  rfd->modes = RKTIO_OPEN_READ;
+  rfd->fd = fd;
+  rfd->regfile = (GetFileType(fd) == FILE_TYPE_DISK);
+
+  init_read_fd(rfd);
+  
+  return rfd;
+#endif
+}
+
+static rktio_fd_t *open_write(char *filename, int modes)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  int fd;
+  int flags;
+  struct stat buf;
+  int cr;
+  rktio_fd_t *rfd;
+
+  flags = (((modes & RKTIO_OPEN_READ) ? O_RDWR : O_WRONLY)
+           | ((modes & RKTIO_OPEN_MUST_EXIST ? 0 : O_CREAT)));
+
+  if (modes & RKTIO_OPEN_APPEND)
+    flags |= O_APPEND;
+  else if (modes & RKTIO_OPEN_TRUNCATE)
+    flags |= O_TRUNC;
+  else if (!(modes & RKTIO_OPEN_CAN_EXIST))
+    flags |= O_EXCL;
+
+  do {
+    fd = open(filename, flags | RKTIO_NONBLOCKING | RKTIO_BINARY, 0666);
+  } while ((fd == -1) && (errno == EINTR));
+
+  if (errno == ENXIO) {
+    /* FIFO with no reader? Try opening in RW mode: */
+    flags -= O_WRONLY;
+    flags |= O_RDWR;
+    do {
+      fd = open(filename, flags | RKTIO_NONBLOCKING | RKTIO_BINARY, 0666);
+    } while ((fd == -1) && (errno == EINTR));
+  }
+
+  if (fd == -1) {
+    if (errno == EISDIR) {
+      set_racket_error(RKTIO_ERROR_IS_A_DIRECTORY);
+      return NULL;
+    } else if (errno == EEXIST) {
+      if (!(modes & RKTIO_OPEN_REPLACE)) {
+        set_racket_error(RKTIO_ERROR_EXISTS);
+        return NULL;
+      } else {
+	do {
+	  cr = unlink(filename);
+	} while ((cr == -1) && (errno == EINTR));
+
+	if (cr) {
+          get_posix_error();
+          return NULL;
+        }
+        
+	do {
+	  fd = open(filename, flags | RKTIO_BINARY, 0666);
+	} while ((fd == -1) && (errno == EINTR));
+      }
+    }
+
+    if (fd == -1) {
+      get_posix_error();
+      return NULL;
+    }
+  }
+
+  do {
+    cr = fstat(fd, &buf);
+  } while ((cr == -1) && (errno == EINTR));
+
+  if (cr) {
+    get_posix_error();
+    do {
+      cr = close(fd);
+    } while ((cr == -1) && (errno == EINTR));
+    return NULL;
+  }
+
+  rfd = malloc(sizeof(rktio_fd_t));
+  rfd->modes = modes;
+  rfd->fd = fd;
+  rfd->regfile = S_ISREG(buf.st_mode);
+  return rfd;
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  HANDLE fd;
+  int hmode, regfile;
+  BY_HANDLE_FILE_INFORMATION info;
+  rktio_fd_t *rfd;
+
+  if (modes & RKTIO_OPEN_MUST_EXIST) {
+    if (modes & RKTIO_OPEN_TRUNNCATE)
+      hmode = TRUNCATE_EXISTING;
+    else
+      hmode = OPEN_EXISTING;
+  } else if (modes & RKTIO_OPEN_CAN_EXIST)
+    hmode = OPEN_ALWAYS;
+  else
+    hmode = CREATE_NEW;
+
+  fd = CreateFileW(WIDE_PATH_temp(filename),
+		   GENERIC_WRITE | ((modes & RKTIO_OPEN_READ) ? GENERIC_READ : 0),
+		   FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+		   NULL,
+		   hmode,
+		   FILE_FLAG_BACKUP_SEMANTICS, /* lets us detect directories in NT */
+		   NULL);
+
+  if (fd == INVALID_HANDLE_VALUE) {
+    int errv;
+    errv = GetLastError();
+    if ((errv == ERROR_ACCESS_DENIED) && (existsok < -1)) {
+      /* Delete and try again... */
+      if (DeleteFileW(WIDE_PATH_temp(filename))) {
+	fd = CreateFileW(WIDE_PATH_temp(filename),
+                         GENERIC_WRITE | ((modes & RKTIO_OPEN_READ) ? GENERIC_READ : 0),
+                         FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+                         NULL,
+                         hmode,
+                         0,
+                         NULL);
+	if (fd == INVALID_HANDLE_VALUE) {
+	  get_windows_error();
+          return NULL;
+        }
+      } else {
+        get_windows_error();
+        return NULL;
+      }
+    } else if (errv == ERROR_FILE_EXISTS) {
+      set_racket_error(RKTIO_ERROR_EXISTS);
+      return NULL;
+    }
+
+    if (fd == INVALID_HANDLE_VALUE) {
+      get_windows_error();
+      return NULL;
+    }
+  }
+
+  if (GetFileInformationByHandle(fd, &info)) {
+    if (info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
+      CloseHandle(fd);
+      set_racket_error(RKTIO_ERROR_IS_A_DIRECTORY);
+      return NULL;
+    }
+  }
+
+  rfd = malloc(sizeof(rktio_fd_t));
+  rfd->modes = modes;
+  rfd->fd = fd;
+  rfd->regfile = (GetFileType(fd) == FILE_TYPE_DISK);
+
+  if (rfd->regfile && (modes & RKTIO_OPEN_APPEND)) {
+    SetFilePointer(fd, 0, NULL, FILE_END);
+  }
+
+  return rfd;
+#endif
+}
+
+rktio_fd_t *rktio_open(char *filename, int modes)
+{
+  if (modes & RKTIO_OPEN_WRITE)
+    return open_write(filename, modes);
+  else
+    return open_read(filename);
+}
+
+/*************************************************************/
+/* closing                                                   */
+/*************************************************************/
+
+int rktio_close(rktio_fd_t *rfd)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  int cr;
+  
+# ifdef USE_FCNTL_AND_FORK_FOR_FILE_LOCKS
+  release_lockf(rfd->fd);
+# endif
+
+  do {
+    cr = close(rfd->fd);
+  } while ((cr == -1) && (errno == EINTR));
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  if (rfd->th) {
+    CSI_proc csi;
+
+    /* -1 for checking means "shut down" */
+    rfd->th->checking = -1;
+    ReleaseSemaphore(rfd->th->checking_sema, 1, NULL);
+
+    if (rfd->th->eof && (rfd->th->eof != INVALID_HANDLE_VALUE)) {
+      ReleaseSemaphore(rfd->th->eof, 1, NULL);
+      rfd->th->eof = NULL;
+    }
+
+    csi = get_csi();
+    if (csi) {
+      /* Helps thread wake up. Otherwise, it's possible for the
+         thread to stay stuck trying to read, in which case the
+         file handle (probably a pipe) doesn't get closed. */
+      csi(rfd->th->thread);
+    }
+
+    /* Try to get out of cleaning up the records (since they can't be
+       cleaned until the thread is also done: */
+    if (WaitForSingleObject(rfd->th->you_clean_up_sema, 0) != WAIT_OBJECT_0) {
+      /* The other thread exited and left us with clean-up: */
+      WindowsFDICleanup(rfd->th);
+    } /* otherwise, thread is responsible for clean-up */
+  }
+  if (rfd->oth) {
+    CSI_proc csi;
+
+    csi = get_csi();
+
+    if (csi) {
+      /* See also call to csi in fd_close_input */
+      csi(rfd->oth->thread);
+    }
+    CloseHandle(rfd->oth->thread);
+    rfd->oth->done = 1;
+    ReleaseSemaphore(rfd->oth->work_sema, 1, NULL);
+
+    /* Try to leave clean-up to the other thread: */
+    if (WaitForSingleObject(rfd->oth->you_clean_up_sema, 0) != WAIT_OBJECT_0) {
+      /* Other thread is already done, so we're stuck with clean-up: */
+      WindowsFDOCleanup(rfd->oth);
+    } /* otherwise, thread is responsible for clean-up */
+  }
+  if (!rfp->th && !rfp->oth) {
+    CloseHandle(rfd->fd);
+  }
+#endif
+
+  free(rfd);
+  
+  return 1;
+}
+
+/*************************************************************/
+/* polling                                                   */
+/*************************************************************/
+
+#ifdef SOME_FDS_ARE_NOT_SELECTABLE
+static int try_get_fd_char(int fd, int *ready)
+{
+  int old_flags, c;
+  unsigned char buf[1];
+
+  old_flags = fcntl(fd, F_GETFL, 0);
+  if (!(old_flags & RKTIO_NONBLOCKING))
+    fcntl(fd, F_SETFL, old_flags | RKTIO_NONBLOCKING);
+  do {
+    c = read(fd, buf, 1);
+  } while ((c == -1) && errno == EINTR);
+  if (!(old_flags & RKTIO_NONBLOCKING))
+    fcntl(fd, F_SETFL, old_flags);
+
+  if (c < 0) {
+    *ready = 0;
+    return 0;
+  } else {
+    *ready = 1;
+    if (!c)
+      return EOF;
+    else
+      return buf[0];
+  }
+}
+#endif
+
+int rktio_poll_read_ready(rktio_fd_t *rfd)
+{
+  if (rfd->regfile)
+    return 1;
+
+#ifdef RKTIO_SYSTEM_UNIX
+  {
+    int r;
+
+# ifdef SOME_FDS_ARE_NOT_SELECTABLE
+    if (rfd->bufcount)
+      return 1;
+# endif
+
+# ifdef HAVE_POLL_SYSCALL
+    struct pollfd pfd[1];
+    pfd[0].fd = rfd->fd;
+    pfd[0].events = POLLIN;
+    do {
+      r = poll(pfd, 1, 0);
+    } while ((r == -1) && (errno == EINTR));
+# else
+    DECL_FDSET(readfds, 1);
+    DECL_FDSET(exnfds, 1);
+    struct timeval time = {0, 0};
+
+    INIT_DECL_RD_FDSET(readfds);
+    INIT_DECL_ER_FDSET(exnfds);
+
+    RKTIO_FD_ZERO(readfds);
+    RKTIO_FD_ZERO(exnfds);
+    RKTIO_FD_SET(rfd->fd, readfds);
+    RKTIO_FD_SET(rfd->fd, exnfds);
+
+    do {
+      r = select(rfd->fd + 1, RKTIO_FDS(readfds), NULL, RKTIO_FDS(exnfds), &time);
+    } while ((r == -1) && (errno == EINTR));
+# endif
+
+# ifdef SOME_FDS_ARE_NOT_SELECTABLE
+    /* Try a non-blocking read: */
+    if (!r && !rfd->textmode) {
+      int c, ready;
+
+      c = try_get_fd_char(rfd->fd, &ready);
+      if (ready) {
+        if (c != EOF) {
+          rfd->buffpos = 0;
+          rfd->buffer[0] = (unsigned char)c;
+          rfd->bufcount = 1;
+        }
+        r = 1;
+      }
+    }
+# endif
+
+    return r != 0;
+  }
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  if (!rfd->th) {
+    /* No thread -- so wait works. This case isn't actually used
+       right now, because wait doesn't seem to work reliably for
+       anything that we can recognize other than regfiles, which are
+       handled above. */
+    if (WaitForSingleObject(rfd->fd, 0) == WAIT_OBJECT_0)
+      return 1;
+  } else {
+    /* Has the reader thread pulled in data? */
+    if (rfd->th->checking) {
+      /* The thread is still trying, last we knew. Check the
+         data-is-ready sema: */
+      if (WaitForSingleObject(rfd->th->ready_sema, 0) == WAIT_OBJECT_0) {
+        rfd->th->checking = 0;
+        return 1;
+      }
+    } else if (rfd->th->avail || rfd->th->err || rfd->th->eof)
+      return 1; /* other thread found data */
+    else {
+      /* Doesn't have anything, and it's not even looking. Tell it
+         to look: */
+      rfd->th->checking = 1;
+      ReleaseSemaphore(rfd->th->checking_sema, 1, NULL);
+    }
+  }
+
+  return 0;
+#endif
+}
+
+int poll_write_ready_or_flushed(rktio_fd_t *rfd, int check_flushed)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  if (check_flushed)
+    return 1;
+  else {
+    int sr;
+# ifdef HAVE_POLL_SYSCALL
+    GC_CAN_IGNORE struct pollfd pfd[1];
+    pfd[0].fd = rfd->fd;
+    pfd[0].events = POLLOUT;
+    do {
+      sr = poll(pfd, 1, 0);
+    } while ((sr == -1) && (errno == EINTR));
+# else
+    DECL_FDSET(writefds, 1);
+    DECL_FDSET(exnfds, 1);
+    struct timeval time = {0, 0};
+  
+    INIT_DECL_WR_FDSET(writefds);
+    INIT_DECL_ER_FDSET(exnfds);
+  
+    RKTIO_FD_ZERO(writefds);
+    RKTIO_FD_ZERO(exnfds);
+    RKTIO_FD_SET(rfd->fd, writefds);
+    RKTIO_FD_SET(rfd->fd, exnfds);
+  
+    do {
+      /* Mac OS X 10.8 and 10.9: select() seems to claim that a pipe
+         is always ready for output. To work around that problem,
+         kqueue() support is enabled for pipes, so we shouldn't get
+         here much for pipes. */
+      sr = select(rfd->fd + 1, NULL, RKTIO_FDS(writefds), RKTIO_FDS(exnfds), &time);
+    } while ((sr == -1) && (errno == EINTR));
+# endif
+
+    if (sr == -1) {
+      get_posix_error();
+      return RKTIO_POLL_ERROR;
+    } else
+      return (sr != 0);
+  }
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  if (rfd->oth) {
+    /* Pipe output that can block... */
+    int retval;
+    Win_FD_Output_Thread *oth = rfd->oth;
+
+    WaitForSingleObject(oth->lock_sema, INFINITE);
+    if (oth->nonblocking) {
+      if (oth->needflush) {
+	oth->needflush = 0;
+	oth->flushed = 0;
+	ReleaseSemaphore(oth->work_sema, 1, NULL); /* start trying to flush */
+	retval = 0;
+      } else
+	retval = oth->flushed;
+    } else
+      retval = (oth->err_no || (check_flushed
+                                ? !oth->buflen
+                                : (oth->buflen < MZPORT_FD_BUFFSIZE)));
+    if (!retval && !check_flushed)
+      WaitForSingleObject(oth->ready_sema, 0); /* clear any leftover state */
+    ReleaseSemaphore(oth->lock_sema, 1, NULL);
+
+    return retval;
+  } else
+    return 1; /* non-blocking output, such as a console, or haven't written yet */
+#endif
+}
+
+int rktio_poll_write_ready(rktio_fd_t *rfd)
+{
+  return poll_write_ready_or_flushed(rfd, 0);
+}
+
+int rktio_poll_write_flushed(rktio_fd_t *rfd)
+{
+  return poll_write_ready_or_flushed(rfd, 1);
+}
+
+void rktio_poll_add(rktio_fd_t *rfd, rktio_poll_set_t *fds, int modes)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  rktio_poll_set_t *fds2;
+
+  if (modes & RKTIO_POLL_READ) {
+    RKTIO_FD_SET(rfd->fd, fds);
+  }
+  if (modes & RKTIO_POLL_WRITE) {
+    fds2 = RKTIO_GET_FDSET(fds, 1);
+    RKTIO_FD_SET(rfd->fd, fds2);
+  }
+  fds2 = RKTIO_GET_FDSET(fds, 2);
+  RKTIO_FD_SET(rfd->fd, fds2);
+#endif  
+#ifdef RKTIO_SYSTEM_WINDOWS
+  if (modes & RKTIO_POLL_READ) {
+    if (rfd->th) {
+      /* See fd_byte_ready */
+      if (!rfd->th->checking) {
+        if (rfd->th->avail || rfd->th->err || rfd->th->eof) {
+          /* Data is ready. We shouldn't be trying to sleep, so force an
+             immediate wake-up: */
+          rktio_fdset_add_nosleep(fds);
+        } else {
+          rfd->th->checking = 1;
+          ReleaseSemaphore(rfd->th->checking_sema, 1, NULL);
+          rktio_fdset_add_handle(rfd->th->ready_sema, fds, 1);
+        }
+      } else
+        rktio_fdset_add_handle(rfd->th->ready_sema, fds, 1);
+    } else if (rfd->regfile) {
+      /* regular files never block */
+      rktio_fdset_add_nosleep(fds);
+    } else {
+      /* This case is not currently used. See fd_byte_ready. */
+      rktio_fdset_add_handle(rfd->fd, fds, 0);
+    }
+  }
+
+  if (modes & RKTIO_POLL_WRITE) {
+    if (rfp->oth && !fd_write_ready(port))
+      rktio_fdset_add_handle(rfp->oth->ready_sema, fds, 1);
+    else
+      rktio_fdset_nosleep(fds);
+  }
+#endif
+}
+
+/*************************************************************/
+/* reading                                                   */
+/*************************************************************/
+
+intptr_t rktio_read(rktio_fd_t *rfd, char *buffer, intptr_t len)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  intptr_t bc;
+  
+  if (rfd->regfile) {
+    /* Reading regular file never blocks */
+    do {
+      bc = read(rfd->fd, buffer, len);
+    } while ((bc == -1) && (errno == EINTR));
+
+    if (bc == -1) {
+      get_posix_error();
+      return RKTIO_READ_ERROR;
+    } else if (bc == 0)
+      return RKTIO_READ_EOF;
+    else
+      return bc;
+  } else {
+    /* We use a non-blocking read here, even though we've waited
+       for input above, because an external process might have
+       gobbled the characters that we expected to get. */
+    int old_flags;
+    
+    old_flags = fcntl(rfd->fd, F_GETFL, 0);
+    if (!(old_flags & RKTIO_NONBLOCKING))
+      fcntl(rfd->fd, F_SETFL, old_flags | RKTIO_NONBLOCKING);
+    
+    do {
+      bc = read(rfd->fd, buffer, len);
+    } while ((bc == -1) && errno == EINTR);
+
+    if ((bc == -1) && (errno != EAGAIN))
+      get_posix_error();
+    
+    if (!(old_flags & RKTIO_NONBLOCKING))
+      fcntl(rfd->fd, F_SETFL, old_flags);
+    
+    if (bc == -1) {
+      if (errno == EAGAIN)
+        return 0; /* no bytes from a non-blocking read */
+      else
+        return RKTIO_READ_ERROR;
+    } else if (bc == 0)
+      return RKTIO_READ_EOF;
+    else
+      return bc;
+  }
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  if (!rfd->th) {
+    /* We can read directly. This must be a regular file, where
+       reading never blocks. */
+    DWORD rgot, delta;
+    
+    if (!ReadFile((HANDLE)rfd->fd, buffer, len, &rgot, NULL)) {
+      get_windows_error();
+      return RKTIO_READ_ERROR;
+    }
+    
+    if (!rgot)
+      return RKTIO_READ_EOF;
+    else
+      return rgot;
+  } else {
+    if (!rktio_poll_read(rfd))
+      return 0;
+    
+    /* If we get this far, there's definitely data available.
+       Extract data made available by the reader thread. */
+    if (rfd->th->eof) {
+      if (rfd->th->eof != INVALID_HANDLE_VALUE) {
+        ReleaseSemaphore(rfd->th->eof, 1, NULL);
+        rfd->th->eof = NULL;
+      }
+      return RKTIO_READ_EOF;
+    } else if (rfd->th->err) {
+      set_windows_error(rfd->th->err);
+      return RKTIO_READ_ERROR;
+    } else {
+      intptr_t bc = rfd->th->avail;
+      rfd->th->avail = 0;
+      FIXME read the data;
+      return bc;
+    }
+  }
+#endif
+}
+
+#ifdef RKTIO_SYSTEM_WINDOWS
+
+static long WINAPI WindowsFDReader(Win_FD_Input_Thread *th)
+{
+  DWORD toget, got;
+  int perma_eof = 0;
+  HANDLE eof_wait = NULL;
+
+  if (GetFileType((HANDLE)th->fd) == FILE_TYPE_PIPE) {
+    /* Reading from a pipe will return early when data is available. */
+    toget = MZPORT_FD_BUFFSIZE;
+  } else {
+    /* Non-pipe: get one char at a time: */
+    toget = 1;
+  }
+
+  while (!perma_eof && !th->err) {
+    /* Wait until we're supposed to look for input: */
+    WaitForSingleObject(th->checking_sema, INFINITE);
+
+    if (th->checking < 0)
+      break;
+
+    if (ReadFile(th->fd, th->buffer, toget, &got, NULL)) {
+      th->avail = got;
+      if (!got) {
+	/* We interpret a send of 0 bytes as a mid-stream EOF. */
+	eof_wait = CreateSemaphore(NULL, 0, 1, NULL);
+	th->eof = eof_wait;
+      }
+    } else {
+      int err;
+      err = GetLastError();
+      if (err == ERROR_BROKEN_PIPE) {
+	th->eof = INVALID_HANDLE_VALUE;
+	perma_eof = 1;
+      } else
+	th->err = err;
+    }
+
+    /* Notify main program that we found something: */
+    ReleaseSemaphore(th->ready_sema, 1, NULL);
+
+    if (eof_wait) {
+      WaitForSingleObject(eof_wait, INFINITE);
+      eof_wait = NULL;
+    }
+  }
+
+  /* We have to clean up if the main program has abandoned us: */
+  if (WaitForSingleObject(th->you_clean_up_sema, 0) != WAIT_OBJECT_0) {
+    WindowsFDICleanup(th);
+  } /* otherwise, main program is responsible for clean-up */
+
+  return 0;
+}
+
+static void WindowsFDICleanup(Win_FD_Input_Thread *th)
+{
+  int rc;
+
+  CloseHandle(th->checking_sema);
+  CloseHandle(th->ready_sema);
+  CloseHandle(th->you_clean_up_sema);
+
+  rc = adj_refcount(th->refcount, -1);
+  if (!rc) CloseHandle(th->fd);
+
+  free(th->buffer);
+  free(th);
+}
+
+#endif
+
+/*************************************************************/
+/* writing                                                   */
+/*************************************************************/
+
+intptr_t rktio_write(rktio_fd_t *rfd, char *buffer, intptr_t len)
+{
+#ifdef RKTIO_SYSTEM_UNIX
+  int flags;
+  intptr_t amt;
+  
+  flags = fcntl(rfd->fd, F_GETFL, 0);
+  if (!(flags & RKTIO_NONBLOCKING))
+    fcntl(rfd->fd, F_SETFL, flags | RKTIO_NONBLOCKING);
+  
+  amt = len;
+  
+  do {
+    do {
+      len = write(rfd->fd, buffer, amt);
+    } while ((len == -1) && (errno == EINTR));
+    
+    /* If there was no room to write `amt` bytes, then it's
+       possible that writing fewer bytes will succeed. That seems
+       to be the case with FIFOs on Mac OS X, for example. */
+    amt = amt >> 1;
+  } while ((len == -1) && (errno == EAGAIN) && (amt > 0));
+
+  if (len == -1)
+    get_posix_error();
+  
+  if (!(flags & RKTIO_NONBLOCKING))
+    fcntl(rfd->fd, F_SETFL, flags);
+
+  if (len == -1)
+    return RKTIO_WRITE_ERROR;
+  else
+    return len;
+#endif
+#ifdef RKTIO_SYSTEM_WINDOWS
+  DWORD winwrote;
+  
+  if (rfd->regfile) {
+    /* Regular files never block, so this code looks like the Unix
+       code.  We've cheated in the make_fd proc and called
+       consoles regular files, because they cannot block, either. */
+
+    /* If we try to write too much at once, the result
+       is ERROR_NOT_ENOUGH_MEMORY (as opposed to a partial write). */
+    int ok;
+    intptr_t towrite = len;
+    
+    while (1) {
+      ok = WriteFile((HANDLE)rfd->fd, buffer, towrite, &winwrote, NULL);
+      if (!ok)
+        errsaved = GetLastError();
+	    
+      if (!ok && (errsaved == ERROR_NOT_ENOUGH_MEMORY)) {
+        towrite = towrite >> 1;
+        if (!towrite)
+          break;
+      } else
+        break;
+    }
+
+    if (!ok) {
+      get_windows_error();
+      return RKTIO_WRITE_ERROR;
+    }
+
+    return winwrote;
+  } else {
+    /* If we don't have a thread yet, we'll need to start it. If
+       we have a non-blocking pipe, we can try the write (and
+       we'll still need the thread to determine when the data is
+       flushed). */
+    intptr_t out_len = 0;
+    int ok, errsaved;
+    
+    if (!rfd->oth || rfd->oth->nonblocking) {
+      int nonblocking;
+
+      /* If we don't have a thread, this is our first write attempt.
+         Determine whether this is a non-blocking pipe: */
+      if (!rfd->oth) {
+        /* The FILE_TYPE_PIPE test is currently redundant, I think,
+           but better safe than sorry. */
+        nonblocking = (rktio_windows_nt_or_later()
+                       && (GetFileType((HANDLE)rfd->fd) == FILE_TYPE_PIPE));
+      } else
+        nonblocking = 1; /* must be, or we would not have gotten here */
+
+      if (nonblocking) {
+        /* Unless we're still trying to flush old data, write to the
+           pipe and have the other thread start flushing it. */
+        DWORD nonblock = PIPE_NOWAIT;
+        int flushed;
+
+        if (rfd->oth) {
+          if (rfd->oth->needflush) {
+            /* Not flushed, but we haven't promised not to block: */
+            flushed = 1;
+          } else {
+            WaitForSingleObject(rfd->oth->lock_sema, INFINITE);
+            flushed = rfd->oth->flushed;
+            ReleaseSemaphore(rfd->oth->lock_sema, 1, NULL);
+          }
+        } else
+          flushed = 1; /* haven't written anything before */
+
+        if (flushed) {
+          /* Put the pipe in non-blocking mode and write. */
+          int towrite;
+
+          towrite = len;
+
+          /* Apparently, the semantics of non-blocking pipe writes
+             is not partial writes, but giving up entirely when
+             the other end isn't being read. In other words, if we
+             try to write too much and nothing is being pulled
+             from the pipe, winwrote will be set to 0. Also, if
+             we try to write too much at once, the result is a
+             ERROR_NOT_ENOUGH_MEMORY error. Account for these
+             behaviors by trying to write less each iteration when the
+             write fails. (Yuck.) */
+          while (1) {
+            if (!rfd->unblocked) {
+              ok = SetNamedPipeHandleState((HANDLE)rfd->fd, &nonblock, NULL, NULL);
+              if (ok)
+                rfd->unblocked = 1;
+              else
+                errsaved = GetLastError();
+            } else
+              ok = 1;
+            if (ok) {
+              ok = WriteFile((HANDLE)rfd->fd, buffer, towrite, &winwrote, NULL);
+              if (!ok)
+                errsaved = GetLastError();
+            }
+
+            if ((ok && !winwrote)
+                || (!ok && (errsaved == ERROR_NOT_ENOUGH_MEMORY))) {
+              towrite = towrite >> 1;
+              if (!towrite) {
+                set_windows_error();
+                return RKTIO_WRITE_ERROR;
+              }
+            } else
+              break;
+          }
+        } else {
+          /* Don't try to write while flushing. */
+          ok = 1;
+          winwrote = 0;
+        }
+
+        if (ok)
+          out_len = winwrote;
+      }
+      /* and create the writer thread... */
+
+      if (!rfd->oth) {
+        /* We create a thread even for pipes that can be put in
+           non-blocking mode, because that seems to be the only
+           way to get evt behavior. */
+        Win_FD_Output_Thread *oth;
+        HANDLE h;
+        DWORD id;
+        unsigned char *bfr;
+        OS_SEMAPHORE_TYPE sm;
+
+        oth = malloc(sizeof(Win_FD_Output_Thread));
+        rfd->oth = oth;
+
+        oth->nonblocking = nonblocking;
+
+        if (!nonblocking) {
+          bfr = malloc(MZPORT_FD_BUFFSIZE);
+          oth->buffer = bfr;
+          oth->flushed = 0;
+          oth->needflush = 0;
+        } else {
+          oth->buffer = NULL;
+          oth->flushed = 1;
+          oth->needflush = 1;
+        }
+
+        oth->buflen = 0;
+        oth->bufstart = 0;
+        oth->bufend = 0;
+
+        oth->fd = (HANDLE)rfd->fd;
+        oth->err_no = 0;
+        oth->done = 0;
+        sm = CreateSemaphore(NULL, 1, 1, NULL);
+        oth->lock_sema = sm;
+        sm = CreateSemaphore(NULL, 0, 1, NULL);
+        oth->work_sema = sm;
+        sm = CreateSemaphore(NULL, 1, 1, NULL);
+        oth->ready_sema = sm;
+        sm = CreateSemaphore(NULL, 1, 1, NULL);
+        oth->you_clean_up_sema = sm;
+        oth->refcount = rfd->refcount;
+            
+        h = CreateThread(NULL, 4096, (LPTHREAD_START_ROUTINE)WindowsFDWriter, oth, 0, &id);
+
+        oth->thread = h;
+      }
+    }
+
+    /* We have a thread, if only to watch when the flush is
+       done... */
+    
+    if (!rfd->oth->nonblocking) {
+      /* This case is for Win 95/98/Me anonymous pipes and
+         character devices.  We haven't written anything yet! We
+         write to a buffer read by the other thread, and return --
+         the other thread takes care of writing. Thus, as long as
+         there's room in the buffer, we don't block, and we can
+         tell whether there's room. Technical problem: if multiple
+         ports are attched to the same underlying pipe (different
+         handle, same "device"), the port writes can get out of
+         order. We try to avoid the problem by sleeping. */
+
+      Win_FD_Output_Thread *oth = rfd->oth;
+
+      WaitForSingleObject(oth->lock_sema, INFINITE);
+      if (oth->err_no) {
+        errsaved = oth->err_no;
+        ok = 0;
+      } else if (oth->buflen == MZPORT_FD_BUFFSIZE) {
+        WaitForSingleObject(oth->ready_sema, 0); /* clear any leftover state */
+        ok = 1;
+      } else {
+        intptr_t topp;
+        int was_pre;
+
+        if (!oth->buflen) {
+          /* Avoid fragmenting in circular buffer: */
+          oth->bufstart = 0;
+          oth->bufend = 0;
+        }
+
+        /* Write to top part of circular buffer, then bottom part
+           if anything's left. */
+
+        if (oth->bufstart <= oth->bufend) {
+          was_pre = 1;
+          topp = MZPORT_FD_BUFFSIZE;
+        } else {
+          was_pre = 0;
+          topp = oth->bufstart;
+        }
+
+        winwrote = topp - oth->bufend;
+        if (winwrote > len)
+          winwrote = len;
+
+        memcpy(oth->buffer + oth->bufend, buffer, winwrote);
+        oth->buflen += winwrote;
+        out_len = winwrote;
+
+        oth->bufend += winwrote;
+        if (oth->bufend == MZPORT_FD_BUFFSIZE)
+          oth->bufend = 0;
+
+        if (was_pre) {
+          if (winwrote < len) {
+            /* Try continuing with a wrap-around: */
+            winwrote = oth->bufstart - oth->bufend;
+            if (winwrote > len - out_len)
+              winwrote = len - out_len;
+
+            memcpy(oth->buffer + oth->bufend, buffer + out_len, winwrote);
+            oth->buflen += winwrote;
+            oth->bufend += winwrote;
+            out_len += winwrote;
+          }
+        }
+        /* Let the other thread know that it should start trying
+           to write, if it isn't already: */
+        ReleaseSemaphore(oth->work_sema, 1, NULL);
+        Sleep(0); /* to decrease the chance of re-ordering flushes */
+
+        ok = 1;
+      }
+      ReleaseSemaphore(oth->lock_sema, 1, NULL);
+    } else if (out_len > 0) {
+      /* We've already written, which implies that no flush is
+         in progress. We'll need a flush check in the future. */
+      rfd->oth->needflush = 1;
+    }
+
+    if (ok)
+      return out_len;
+
+    set_windows_error(errsaved);
+    return RKTIO_WRITE_ERROR;
+  }
+#endif
+}