NAME

       scheme48 - a Scheme interpreter

SYNOPSIS

       scheme48 [-i image] [-h heapsize] [-a argument]

DESCRIPTION

       scheme48  is an implementation of the Scheme programming language as described in the Revised^5 Report on
       the Algorithmic Language Scheme.  A runnable system  requires  two  parts,  an  executable  program  that
       implements  the  Scheme  48  virtual  machine,  and  an image that is used to initialize the store of the
       virtual machine.  scheme48 is a shell script that starts the virtual machine with an image that runs in a
       Scheme command loop.

       The  scheme48  command  loop reads Scheme expressions, evaluates them, and prints their results.  It also
       executes commands, which are identified by an initial comma character.  Type the command ,help to receive
       a list of available commands.

       The  meaning  of  the -h option depends on the type of garbage collector that was chosen at configuration
       time.  If heapsize is a positive number, it specifies the number of words that can be live at  any  given
       time.   One  word  is  four bytes.  Cons cells are currently 3 words, so if you want to make sure you can
       allocate, say, a million cons cells, you should specify -h 3000000 (actually a little  more,  to  account
       for the initial heap image and breathing room).

       If  you specify a maximum smaller than the memory needed to load the image file, the maximum is increased
       accordingly and a message is written to the console.

       For the BIBOP garbage collector, heapsize may be 0.  This means the heap will possibly keep growing until
       your  system runs out of memory. Because of this risk, a warning message is written to the console if you
       specify -h 0.

       The ,dump and ,build commands put heap images in files.  The -i option causes the initial heap  image  to
       be  taken  from  file  image.   The -a option causes a list of strings to be passed as the argument to an
       image generated using the ,build command.  The first argument to ,build is a procedure that is passed the
       arguments  following  -a  and  which should return an integer (which is the return value of the Scheme 48
       process).

            > ,build (lambda (a) (display a) (newline) 0) foo.image
            > ,exit
            $ scheme48 -i foo.image -a mumble
            mumble
            $

FILES

       /usr/lib/scheme48-1.9.2/scheme48vm      the virtual machine.

       /usr/lib/scheme48-1.9.2/scheme48.image  the default image.

                                                                                                     scheme48(1)