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.TH MRED 1 "25 March 1998"
.UC 4
.SH NAME
mred \- The Rice PLT Scheme GUI engine
.SH SYNOPSIS
.B mred
[
.B --pre 
.I expression
]
[
.I X flag ...
]
[
.B -s
.I collection
]
[
.B -a 
.I collection
.I unit-filename
.I sig-filename
]
[
.B -A 
.I collection
]
[
.B -u
|
.B --non-unitized
]
[
.B -p
.I image-filename
.I splash-title
.I splash-count
]
[
.B -b
|
.B --no-splash
]
[
.B -w
.I filename
]
[
.B
--
[
.B -q
|
.B --no-init-file
]
[
.B -f
.I file
]
[
.B -e
.I expr
]
[
.B --
.I file ...
] ]

.SH DESCRIPTION
.I MrEd
is the Rice University PLT Scheme GUI
execution engine.
It extends 
.I MzScheme
with graphics
and provides the underlying architecture for
.I DrScheme.
.SH SYSTEM SETUP FLAGS
The
.B --pre 
flag directs
.I MrEd
to evaluate its argument in an environment without the wx primitives,
before doing anything else. This must be the first flag.
.PP
MrEd accepts the standard
.I X flags
:
.B -display
.IR disp ,
.B -geometry
.IR geom ,
.B -bg
.IR color ,
.B -background
.IR color ,
.B -fg
.IR color ,
.B -foreground
.IR color ,
.B -fn
.IR font ,
.B -font
.IR font ,
.BR -iconic ,
.B -name
.IR name ,
.BR -rv ,
.BR -reverse ,
.BR +rv ,
.B -selectionTimeout
.IR time ,
.BR -synchronous ,
.B -title
.IR name ,
.B -xnllanguage
.IR lang ,
.B -xrm
.IR file .
These flags must appear after the
.B --pre
flag (if present) and before all other flags.
.PP
The
.B -s
flag directs
.I MrEd
to load the startup system from
a particular collection. The default collection is "system".
This flag must be specified after the
.B --pre
and
.I X flags
and before all other flags.
.SH SYSTEM TO APPLICATION FLAGS
The remaining flags apply when the standard system is used.
.PP
The
.B -A
flag directs 
.I MrEd 
to look in the collection for an application.
See the Toolbox manual for more information on how to write your own
application using 
.IR MrEd .
.PP
The
.B -a
flag directs 
.I MrEd 
to look in the collection for the next two files. The first file should
contain a unit/sig (not a definition of a unit, just a unit) and the
second file should contain signatures that the unit/sig needs. That unit
will be used to start a new appliaction built on top of
.IR MrEd . 
See the Toolbox manual for more information on how to write your own
application using 
.IR MrEd .
.PP
The
.B -u
or
.B --non-unitized
flag specifies a non-unit startup. See the Toolbox Manual for more
details on 
.I MrEd's
startup and how to build your own application with 
.IR MrEd .
.PP
The
.B -w
flag causes filename to be written over with a Static Debugger
file, which can be used to analyze your application. You must use the
.B -a
flag and have written a Static Debugger conformant application to use this
flag. See the Static Debugger and the Toolbox manuals for more information
on Static Debugger conformancy and the
.B -a
flag, respectively.
.PP
The
.B -p
flag specifies a splash screen filename. The splash screen must be
an image file supported by wx:bitmap% objects. See the Toolbox manual for more
information on what image types are supported by wx:bitmap% objects. The
second argument to
.B -p
names the splash screen, and the third is a count
indicating how many files will be loaded.
.PP
The
.B -b
or
.B --no-splash
flag supresses the splash screen.
.SH APPLICATION-SPECIFIC FLAGS
The remaining flags apply only when an application is not specified
or the
.B -u
flag is used. If an application is specified, other application-specific
flags may apply. In either case, the
.B -- 
flag must be specified before the flags.
.PP
The
.B -q
or
.B --no-init-file
flag prevents 
.I MrEd
from loading
the user's startup file "~/.mredrc".
.PP
Multiple
.B
-f
and
.B -e
flags can be specified. For each
.B -e
flag, the corresponding
expression is evaluated. For each
.B -f
flag, the corresponding file
is loaded (with its directory as the working directory).
.PP
If a file appears on the command line with no switches, then in the default
application it is opened for editing in 
.IR MrEd .
If the
.B -u
flag was specified, then the arguments are passed on to mred:setup.
The
.B --
flag indicates that no remaining arguments are flags (at this level; a program
loaded with
.B -u
may read them as flags).
.PP
Once all command line arguments are handled the scheme procedure
mred:startup is called. This procedure is defined by the standard
system, but it can be redefined with the
.B -f
or
.B -e
flags for
application-specific startup sequences in conjunction with the
.B -u
flag.
.PP
For further information on
.I MrEd,
please consult the on-line
documentation in the Help menu of the console 
and other information available at
.PP
.ce 1
http://www.cs.rice.edu/CS/PLT/packages/mred/

.SH FILES
The library collections search path is read
from the PLTCOLLECTS environment variable
(as a colon-separated list of paths). Wherever the empty path
appears appears in PLTCOLLECTS, it is replaced with the default
collections directory. If PLTCOLLECTS is not defined, the default
collections directory is used as the only element in the search path.
.PP
.I MrEd
looks for the default collections directory as one of the 
following (tried in order):
.IP
The path in the environment variable PLTHOME is checked
for a "collects" subdirectory.
.IP
If
.I MrEd
was invoked with an absolute pathname, the directory
of the invoked executable is checked. If the executable 
is a link, the directory of the referenced file is also 
checked, recursively following links.
.IP
If
.I MrEd
is invoked with a relative pathname, the
directories in the PATH environment variable containing
a file with the name of the program as invoked (usually
"mzscheme") are checked. Links are followed as in the 
first case.
.IP
The "/usr/local/lib/plt/collects" directory is 
tried.
.PP
.I MrEd
also looks for X resources in "~/.mred.resources".
X resources in that file override any other resources settings.

.SH BUGS
Submit bug reports via
.ce 1
http://www.cs.rice.edu/CS/PLT/Bugs/ (encouraged)
or by e-mail to
.ce 1
plt-bugs@cs.rice.edu (discouraged)
.SH AUTHOR
.I MrEd
was implemented by Matthew Flatt (mflatt@cs.rice.edu) and Robby Findler
(robby@cs.rice.edu) using wxWindows by Julian Smart et al. and
the conservative garbage collector by Hans Boehm et al.
.SH SEE ALSO
.BR drscheme(1),
.BR mzscheme(1)