.\" dummy line
.TH MZSCHEME 1 "June 2003"
.UC 4
.SH NAME
mzscheme \- The PLT Scheme implementation
.SH SYNOPSIS
.B mzscheme
[
.I option ...
] [
.I argument ...
]
.SH DESCRIPTION
.I MzScheme
is the PLT
Scheme implementation.  It implements the language as
described in the
.I Revised^5 Report on
.I the Algorithmic Language Scheme
and adds numerous extensions.
.PP
.I MrEd
embeds and extends MzScheme with a graphical user interface (GUI) toolbox.
.PP
.I DrScheme
is the graphical development environment for creating
.I MzScheme
and
.I MrEd
applications.

.SH STARTUP FILE AND EXPRESSION OPTIONS

.TP
.BI \-e \ expr
.TP
.BI \--eval \ expr
Evaluates
.I expr
after
.I MzScheme
starts.
.TP
.BI \-f \ file
.TP
.BI \--load \ file
Loads
.I file
after
.I MzScheme
starts.
.TP
.BI \-d \ file
.TP
.BI \--load-cd \ file
Load/cds
.I file
after
.I MzScheme
starts.
.TP
.BI \-t \ file
.TP
.BI \--require \ file
Requires
.I file
after
.I MzScheme
starts.
.TP
.B \-F
.TP
.B \--Load
.br
Loads all remaining arguments after
.I MzScheme
starts.
.TP
.B \-D
.TP
.B \--Load-cd
.br
Load/cds all remaining arguments after
.I MzScheme
starts.
.TP
.B \-T
.TP
.B \--Require
.br
Requires all remaining arguments after
.I MzScheme
starts.
.TP
.BI \-l \ file
.TP
.BI \--mzlib \ file
Same as
.BR -e \ '(require\ (lib\ "\|\c
.I file\|\c
"))'.
.TP
.BI \-L \ file \  coll
Same as
.BR -e \ '(require\ (lib\ "\|\c
.I file\|\c
" "\|\c
.I coll\|\c
"))'.
.TP
.BI \-M \ coll
Same as
.BR -e \ '(require\ (lib\ "\|\c
.I coll\|\c
\|.ss" "\|\c
.I coll\|\c
"))'.
.TP
.B \-r
.TP
.B \--script
Script mode: use as last flag for scripts.
Same as
.BR -fmv- .
.TP
.B \-i
.TP
.B \--script-cd
Like -r, but also sets the directory.
Same as 
.BR -dmv- .
.TP
.B \-u
.TP
.B --require-script
Like -r, but requires a module.
Same as
.BR -tmv- .
.TP
.B \-i
.TP
.B \-w
.TP
.B \--awk
Same as
.B -l
.BR awk.ss .
.TP
.BI \-k \ n \  m
Load executable-embedded code from file offset
.I n
to
.IR m .
.TP
.B \-C
.TP
.B \--main
Like -r, then calls `main' with a list of argument strings. The first 
string in the list is the name of the loaded file, and
the rest of the list contains leftover command-line arguments.
.PP

.SH INITIALIZATION OPTIONS
.TP
.B \-x
.TP
.B \--no-lib-path
Skips trying to set current-library-collection-paths.
.TP
.B \-q
.TP
.B \--no-init-file
Skips trying to load "~/.mzschemerc".
.TP
.B \-A
.TP
.B \--no-argv
Skips defining `argv' and `program'.
.PP

.SH LANGUAGE SETTING OPTIONS
.TP
.B \-g
.TP
.B \--case-sens
Identifiers and symbols are initially case-sensitive.
.B \-s
.TP
.B \--set-undef
Set! works on undefined identifiers.
.PP

.SH MISCELLANEOUS OPTIONS
.TP
.B \--
.br
No argument following this switch is used as a switch.
.TP
.B \-p
.TP
.B \--persistent
Catches AIX SIGDANGER (low page space) signal. (AIX only)
.TP
.B \-m
.TP
.B \--mute-banner
Suppresses the startup banner.
.TP
.B \-v
.TP
.B \--version
Suppresses the read-eval-print loop.
.TP
.B \-h
.TP
.B \--help
Shows help for command-line arguments.
.TP
.BI \-R file
.TP
.BI \--restore \ file
Restores an image; must be the only switch. (Special versions only)

.SH OPTION CONVENTIONS

Multiple single-letter switches can be collapsed, with arguments placed
after the collapsed switches; the first collapsed switch cannot be
.BR -- .
E.g.:
.B -vfme file expr
is the same as
.B -v -f file -m -e
.BR expr .
.PP
Extra arguments following the last switch are put into the Scheme global
variable `argv' as a vector of strings. The name used to start 
.I MzScheme
is put into the global variable `program' as a string.
.PP
Extra arguments after a 
.B --restore
file are returned as a vector of
strings to the continuation of the `write-image-to-file' call that created
the image.
.PP
Expressions/files are evaluated/loaded in order as provided, including
calls to
.B main
implied by
.BR --main ,
embedded segments loaded by
.BR -k ,
and so on. An uncaught exception during an evaluation/load causes later
evaluations/loads to be skipped.
.PP
The current-library-collections-paths parameter is automatically set before any
expressions/files are evaluated/loaded, unless the
.B -x
or
.B --no-lib-path
switch is used.  

.SH EXECUTABLE NAME
If the executable name has the form scheme-\|\c
.I dialect\|\c
, then the command line is effectively prefixed with
.ce 1
-qAeC '(require (lib "init.ss" "script-lang" "\|\c
.I dialect\|\c
"))'
The first actual command-line argument thus serves as the name of a file
to load. The file should define
.BR main ,
which is called with the command-line arguments---starting with the
loaded file name---as a list of immutable strings.

.SH FILES
The file "~/.mzschemerc" is loaded before any provided
expressions/files are evaluated/loaded, unless the
.B -q 
or 
.B --no-init-file 
switch is used.
.PP
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 MzScheme
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 MzScheme
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. The
parent directories and the parent's parent directories are also
checked (in case
.I MzScheme
is in a "bin" directory or a ".bin/\c
.I platform\|\c
" directory).
.IP
If
.I MzScheme
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 and parent directories
are followed as in the first case.
.IP
The "/usr/local/lib/plt/collects" directory is 
tried.

.SH EXECUTABLE SCRIPTS
The most flexible way to create an executable script file is to
trampoline through /bin/sh, using a #| ... |# block-comment trick to make the first few lines
parseable by both /bin/sh and mzscheme. Here's an example:
.PP
.PD 0
.PP
  #! /bin/sh
.PP
  #|
.PP
  exec mzscheme -qr "$0" ${1+"$@"}
.PP
  |#
.PP
  (display "Hello, world!")
.PP
  (newline)
.PD

.SH MORE INFORMATION
For further information on
.IR MzScheme ,
please consult the on-line
documentation and other information available at
.PP
.ce 1
http://www.plt-scheme.org/software/mzscheme/

.SH BUGS
Submit bug reports via
.ce 1
http://bugs.plt-scheme.org/ (encouraged)
or by e-mail to
.ce 1
bugs@plt-scheme.org (discouraged)
.SH AUTHOR
.I MzScheme
was implemented by Matthew Flatt (mflatt@plt-scheme.org).
It uses the conservative garbage collector implemented by Hans 
Boehm and extended by John Ellis. MzScheme was originally based 
on libscheme, written by Brent Benson.
.SH SEE ALSO
.BR help-desk(1),
.BR drscheme(1),
.BR mred(1)