#!/bin/bash

 #

 # $Id$

 #

 # SML/NJ startup script (for 0.93).

 #

 # Global vars: INFILE OUTFILE MLTEXT TERMINATE NOWRITE,

 # and from settings

 ## diagnostics

 function fail_out()

 {

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

   exit 2

 }

 ## prepare databases

 if [ -z "$INFILE" ]; then

   INFILE="$ML_HOME/sml"

   EXIT="val exit = 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

 MLTEXT="$EXIT $COMMIT $MLTEXT"

 MLEXIT="commit();"

 ## run it!

 START_SML="$INFILE $ML_OPTIONS"

 if [ -n "$TERMINATE" ]; then

   echo "$MLTEXT" "$MLEXIT" | $START_SML

   RC=$?

 elif [ -z "$MLTEXT" ]; then

   sh -c "{ $ISABELLE_HOME/lib/scripts/ucat; echo '$MLEXIT'; } | $START_SML"

   RC=$?

 else

   sh -c "{ echo '$MLTEXT'; $ISABELLE_HOME/lib/scripts/ucat; echo '$MLEXIT'; } | $START_SML"

   RC=$?

 fi

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

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

   rm -f "$INFILE" || fail_out

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

 fi

 exit $RC