Ubuntu Manpage: scm - a Scheme Language Interpreter

NAME

       scm - a Scheme Language Interpreter

SYNOPSIS

       scm [-a kbytes ] [-muvqib] [--version] [--help]
       [[-]-no-init-file] [--no-symbol-case-fold]
       [-p int ] [-r feature ] [-h feature ]
       [-d filename ] [-f filename ] [-l filename ]
       [-c expression ] [-e expression ] [-o dumpname ]
       [-- | - | -s] [ filename ] [ arguments ...  ]

DESCRIPTION

       Scm is a Scheme interpreter.

       Upon  startup  scm  loads  the  file  specified  by  by  the environment variable SCM_INIT_PATH or by the
       parameter IMPLINIT in the makefile (or scmfig.h) if SCM_INIT_PATH is not defined.  The makefiles  attempt
       to set IMPLINIT to "Init.scm" in the source directory.

       Unless  the  option -no-init-file or --no-init-file occurs in the command line or if scm is being invoked
       as a script, "Init.scm" checks to see if there is  file  "ScmInit.scm"  in  the  path  specified  by  the
       environment  variable  HOME (or in the current directory if HOME is undefined).  If it finds such a file,
       then it is loaded.

       "Init.scm" then looks for command input from one of three sources: From an option on  the  command  line,
       from a file named on the command line, or from standard input.

OPTIONS

The options are processed in the order specified on the command line.

-akbytes
specifies that scm should allocate an initial heapsize of kbytes. This option, if present, must be
the first on the command line.

--no-init-file
Inhibits the loading of "ScmInit.scm" as described above.

--no-symbol-case-fold
Symbol (and identifier) names are case-sensitive.

-eexpression

-cexpression
specifies that the scheme expression expression is to be evaluated. These options are inspired by
perl and sh respectively. On Amiga systems the entire option and argument need to be enclosed in
quotes. For instance "-e(newline)".

-rfeature
requires feature. This will load a file from SLIB if that feature is not already supported. If
feature is 2, 3, 4, or 5 scm will require the features necessary to support R2RS, R3RS, R4RS, or
R5RS, respectively.

-hfeature
provides feature.

-lfilename

-ffilename
loads filename. Scm will load the first (unoptioned) file named on the command line if no -c, -e,
-f, -l, or -s option precedes it.

-dfilename
opens (read-only) the extended relational database filename. If filename contains initialization
code, it will be run when the database is opened.

-odumpname
saves the current SCM session as the executable program dumpname. This option works only in SCM
builds supporting dump.

If options appear on the command line after -o dumpname, then the saved session will continue with
processing those options when it is invoked. Otherwise the (new) command line is processed as usual
when the saved image is invoked.

-plevel
sets the prolixity (verboseness) to level. This is the same as the scm command (verbose level ).

-v (verbose mode) specifies that scm will print prompts, evaluation times, notice of loading files, and
garbage collection statistics. This is the same as -p3.

-q (quiet mode) specifies that scm will print no extra information. This is the same as -p0.

-m specifies that subsequent loads, evaluations, and user interactions will be with R4RS macro
capability. To use a specific R4RS macro implementation from SLIB (instead of SLIB's default) put
-r macropackage before -m on the command line.

-u specifies that subsequent loads, evaluations, and user interactions will be without R4RS macro
capability. R4RS macro capability can be restored by a subsequent -m on the command line or from
Scheme code.

-i specifies that scm should run interactively. That means that scm will not terminate until the
(quit) or (exit) command is given, even if there are errors. It also sets the prolixity level to 2
if it is less than 2. This will print prompts, evaluation times, and notice of loading files. The
prolixity level can be set by subsequent options. If scm is started from a tty, it will assume that
it should be interactive unless given a subsequent -b option.

-b specifies that scm should run non-interactively. That means that scm will terminate after
processing the command line or if there are errors.

-s specifies, by analogy with sh, that further options are to be treated as program arguments.

- -- specifies that there are no more options on the command line.

ENVIRONMENT VARIABLES

       SCM_INIT_PATH
            is the pathname where scm will look for its initialization code.  The default is the file "Init.scm"
            in the source directory.

       SCHEME_LIBRARY_PATH
            is the SLIB Scheme library directory.

       HOME is the directory where "Init.scm" will look for the user initialization file "ScmInit.scm".

SCHEME VARIABLES

       *argv*
            contains the list of arguments to the program.  *argv* can change during argument processing.   This
            list is suitable for use as an argument to SLIB getopt.

       *R4RS-macro*
            controls whether loading and interaction support R4RS macros.  Define this in "ScmInit.scm" or files
            specified on the command line.  This can be overridden by subsequent -m and -u options.

       *interactive*
            controls interactivity as explained for the -i and -b options.   Define  this  in  "ScmInit.scm"  or
            files specified on the command line.  This can be overridden by subsequent -i and -b options.

EXAMPLES

       % scm foo.scm arg1 arg2 arg3
            Load  and  execute  the contents of foo.scm.  Parameters arg1 arg2 and arg3 are stored in the global
            list *argv*.

       % scm -f foo.scm arg1 arg2 arg3
            The same.

       % scm -s foo.scm arg1 arg2
            Set *argv* to ("foo.scm" "arg1" "arg2") and enter interactive session.

       % scm -e '(display (list-ref *argv* *optind*))' bar
            Print ``bar''

       % scm -rpretty-print -r format -i
            Load pretty-print and format and enter interactive mode.

       % scm -r5
            Load dynamic-wind, values, and R4RS macros and enter interactive (with macros) mode.

       % scm -r5 -r4
            Like above but rev4-optional-procedures are also loaded.

FEATURES

       Runs under Amiga, Atari-ST, MacOS, MS-DOS, OS/2, NOS/VE, Unicos, VMS, Unix and similar systems.   Support
       for ASCII and EBCDIC character sets.

       Conforms to Revised^5 Report on the Algorithmic Language Scheme and the IEEE P1178 specification.

       Support for SICP, R2RS, R3RS, and R4RS scheme code.

       Many  Common  Lisp  functions: logand, logor, logxor, lognot, ash, logcount, integer-length, bit-extract,
       defmacro, macroexpand, macroexpand1, gentemp, defvar, force-output, software-type, get-decoded-time, get-
       internal-run-time, get-internal-real-time, delete-file, rename-file, copy-tree, acons, and eval.

       Char-code-limit,    most-positive-fixnum,    most-negative-fixnum,   and   internal-time-units-per-second
       constants.  *Features* and *load-pathname* variables.

       Arrays and bit-vectors.  String ports and software emulation ports.  I/O  extensions  providing  most  of
       ANSI C and POSIX.1 facilities.

       User  definable  responses  to  interrupts and errors, Process-synchronization primitives, String regular
       expression matching, and the CURSES screen management package.

       Available add-on packages including an interactive debugger, database, X-window graphics,  BGI  graphics,
       Motif, and Open-Windows packages.

       A compiler (HOBBIT, available separately) and dynamic linking of compiled modules.

       Setable  levels  of  monitoring  and  timing  information printed interactively (the `verbose' function).
       Restart, quit, and exec.

FILES

       scm.texi
              Texinfo documentation of scm enhancements, internal representations, and how to extend or  include
              scm in other programs.

AUTHORS

       Aubrey Jaffer (agj@alum.mit.edu)
       Radey Shouman