#!/usr/bin/env bash

 #

 # $Id$

 # Author: Markus Wenzel, TU Muenchen

 # License: GPL (GNU GENERAL PUBLIC LICENSE)

 #

 # SML/NJ startup script (for 0.93).

 export -n INFILE OUTFILE COPYDB COMPRESS MLTEXT TERMINATE NOWRITE

 ## diagnostics

 function fail_out()

 {

   echo "Unable to create output heap file: \"$OUTFILE\"" >&2

   exit 2

 }

 function check_mlhome_file()

 {

   if [ ! -f "$1" ]; then

     echo "Unable to locate $1" >&2

     echo "Please check your ML_HOME setting!" >&2

     exit 2

   fi

 }

 ## prepare databases

 if [ -z "$INFILE" ]; then

   INFILE="$ML_HOME/sml"

   check_mlhome_file "$INFILE"

   EXIT="val exit: int -> unit = System.Unsafe.CInterface.exit;"

 else

   EXIT=""

 fi

 MOVE=""

 if [ -z "$OUTFILE" ]; then

   COMMIT='fun commit () = (output (std_err, "Error - Database is not opened for writing.\n"); false);'

 else

   if [ "$INFILE" -ef "$OUTFILE" ]; then

     OUTDIR=$(dirname "$OUTFILE")/tmp

     OUTFILE="$OUTDIR"/$(basename "$OUTFILE")

     mkdir -p "$OUTDIR" || fail_out

     MOVE=true

   fi

   [ -f "$OUTFILE" ] && { chmod +w "$OUTFILE" || fail_out; }

   COMMIT="fun commit () = not (exportML\"$OUTFILE\");"

 fi

 ## run it!

 MLTEXT="$EXIT $COMMIT $MLTEXT"

 MLEXIT="commit();"

 if [ -z "$TERMINATE" ]; then

   FEEDER_OPTS=""

 else

   FEEDER_OPTS="-q"

 fi

 "$ISABELLE_HOME/lib/scripts/feeder" -p -h "$MLTEXT" -t "$MLEXIT" $FEEDER_OPTS | \

   { read FPID; "$INFILE" $ML_OPTIONS; RC="$?"; kill -HUP "$FPID"; exit "$RC"; }

 RC="$?"

 ## fix heap file

 [ -n "$OUTFILE" -a -f "$OUTFILE" -a -n "$NOWRITE" ] && chmod -w "$OUTFILE"

 if [ -n "$MOVE" -a -f "$OUTFILE" ]; then

   rm -f "$INFILE" || fail_out

   mv "$OUTFILE" "$INFILE" || fail_out

 fi

 exit "$RC"