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/scheme48vm        the virtual machine.

       /usr/lib/scheme48-1.9/scheme48.image    the default image.

                                                                                      scheme48(1)