scheme-script

#!/bin/sh
#
# Copyright 2007 William D Clinger
#
# $Id$
#
# Script for running R6RS Scheme scripts.
#
# Please note that, as defined by R6RS non-normative appendix D,
# a Scheme script is unlikely to be a legal R6RS program because
# a Scheme script is likely to begin with an ignored first line
# of one of the forms
#
#     #!/...
#     #! ...
#
# Both of those lexical notations are illegal in R6RS top-level
# programs.

# This script tries to find the Larceny binaries and to select the correct
# pair.  If LARCENY_ROOT is set, it looks there; otherwise, if the directory
# this script is in is named Scripts, it looks in the parent; otherwise, it
# looks in the same directory as itself.

# You can specify a particular LARCENY_ROOT here:
# LARCENY_ROOT=/usr/local/lib/larceny

if [ -z "$LARCENY_ROOT" ]; then
    # To guess LARCENY_ROOT, we start with the directory containing this
    # script.  If it's a relative path, we make it absolute.  Then, if it ends
    # in Scripts, we chop off that component.

    script=`readlink -f $0`
    dir="`dirname "$script"`"
    dir="`( cd $dir; pwd )`"
    [ "`basename "$dir"`" = Scripts ] && dir="`dirname "$dir"`"

    # Now we have LARCENY_ROOT.
    LARCENY_ROOT="$dir"
fi

export LARCENY_ROOT

cmd=petit-larceny.bin
heap=petit-larceny.heap
if test -x $LARCENY_ROOT/$cmd; then
    :
else
    cmd=larceny.bin
    heap=larceny.heap
fi

cmd="$LARCENY_ROOT/$cmd"
heap="$LARCENY_ROOT/$heap"

case "`head -n +1 $1 | sed -e 's/^[#][!][/ ].*/ignore/'`" in
    ignore)
    exec "$cmd" -heap "$heap" -r6rs -program "$1" -ignore1 -- "$@"
    ;;
    *)
    exec "$cmd" -heap "$heap" -r6rs -program "$1" -- "$@"
    ;;
esac