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.TH MRED 1 "8 June 1996"
.UC 4
.SH NAME
mred \- The Rice PLT Scheme GUI engine
.SH SYNOPSIS
.B mred
[-s
.I sysfile
]
[-a 
.I unit-filename
.I sig-filename
]
[-w
.I filename
]
[-p
.I image-filename
.I splash-title
.I splash-count
]
[-b ]
[-q | --no-init-file]
[-nu ]
[-f
.I file
]
[-e
.I expr
]
[--
.I arguments
]
[
.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.
.PP
The -s flag directs
.I MrEd
to load the startup system from
a particular file. This overrides the system directory
search path described below in FILES and must come before all other
arguments.
.PP
The -a flag directs 
.I MrEd 
to look in the first file for a unit/sig (not a
definition of a unit, just a plain unit) and the second file for signatures
that the unit/sig needs. That unit will be used to start a new appliaction
built on top of
.I MrEd. 
See the Toolbox manual for more information on how to write your own
application using 
.I MrEd.
.PP
The -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 -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 -a flag respectively.
.PP
The -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 -p names the splash screen, and the third is a count
indicating how many files will be loaded.
.PP
The -b flags supresses the splash screen.
.PP
The -q or --no-init-file flag prevents 
.I MrEd
from loading
the user's startup file ".mredrc" in the user's home
directory.
.PP
multiple -f
and -e flags can be specified. For each -e flag, the corresponding
expression is evaluated. For each -f flag, the corresponding file
is loaded (with its directory as the working cirectory).
.PP
If a file appears on the command line with no switches, then it is opened
for editing in 
.I MrEd.
The -- flag means to treat the next argument as a file
to be opened for editing, even if it is "-e" or "-f".
.PP
The -nu 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 
.I MrEd.
.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 -f or -e flags for
application-specific startup sequences. 
.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
If the -s flag is not specified, 
.I MrEd
looks for its standard system file "mrsystem.ss" with the following 
search path:
.IP
* the search path defined by the MREDSYS system evironment 
variable
.IP
* "$PLTHOME/mred/system"
.IP
* "/usr/local/lib/plt/mred/system" 
.IP
* "/usr/lib/plt/mred/system"
.IP
* "/usr/local/lib/mred/system"
.IP
* "/usr/lib/mred/system"
.PP

The standard system finds the
.I MrEd
collections directory and loads the
.I MrEd
library.  The
I. MrEd 
collections directory is
"../mred/collects" relative to the system's directory.

The standard system also finds the
.I MzScheme 
collection
directory and loads the core
.I MzLib 
library. The
.I MzScheme 
collection directory is found with
the following search path:
.IP
* "$PLTHOME/mzscheme/collects/standard" (if PLTHOME is not defined,
/usr/local/lib/ is used as it's value).
.IP
* "../mzscheme/collects/" relative to the system's directory
.IP
* "../../mzscheme/collects/standard"  relative to the system's directory
.IP
.PP

The `require-library-collections-paths' parameter is set
to a list containing the 
.I MzScheme
collections
directory and the 
.I MrEd 
collections directory. 

.I MrEd
also looks for Xresources in 
.IP
* "~/.mred.resources"
.PP
Xresources in that file override any other resources settings.

.SH BUGS
Submit bug reports via
.ce 1
http://www.cs.rice.edu/CS/PLT/Gnats/ (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)