#!/bin/sh
#
# Mono via BINFMT_MISC
#
# Author: Adam Drzewiecki
# e-mail: A.Drzewiecki@ztpnet.pl
# Last modified: 13 Dec 2008
#

# BINMFT_MISC config directory
CONF_DIR="/proc/sys/fs/binfmt_misc"
# Executable type name
NAME="mono"
# Interpreter filename
INTERPRETER="mono"

# Searching for interpreter
mono_location() {
	if [ -x "/usr/local/bin/$INTERPRETER" ] ; then
	    MONO="/usr/local/bin/$INTERPRETER"
	elif [ -x "/usr/bin/$INTERPRETER" ] ; then
	    MONO="/usr/bin/$INTERPRETER"
	elif [ -x "/bin/$INTERPRETER" ] ; then
	    MONO="/bin/$INTERPRETER"	    
	else
	    echo "no interpreter found"
	    exit -1
	fi
}

# BINFMT_MISC initialization
prepare_binfmt_misc() {
    if grep -qs binfmt_misc /proc/filesystems || modprobe binfmt_misc >/dev/null 2>&1 ; then
	if  ! grep -qs binfmt_misc /proc/mounts && \
	    ! mount binfmt_misc -t binfmt_misc $CONF_DIR >/dev/null 2>&1; then
	    echo "BINFMT_MISC can't be mounted"
	    exit -1
	fi
    else
	echo "BINFMT_MISC is not compiled in kernel"
	exit -1
    fi
}

# Attempt to unload BINFMT_MISC module
remove_binfmt_misc() {
    if lsmod | grep -qs binfmt_misc ; then
	if grep -qs binfmt_misc /proc/mounts && umount $CONF_DIR >/dev/null 2>&1 ; then
	    rmmod binfmt_misc >/dev/null 2>&1
	fi
    fi
}

# Setup environment for Mono
mono_start() {
	echo -n "Preparing environment for Mono: "
	prepare_binfmt_misc
	mono_location
	if [ ! -e "$CONF_DIR/$NAME" ] ; then
	    if echo ":$NAME:M::MZ::$MONO:" > $CONF_DIR/register 2>/dev/null ; then
		echo "success (interpreter: $MONO, version $($MONO --version | head -n 1 | tr '\ ' '\n' | grep ^[0-9]))"
	    else
		echo "registering error"
	    fi
	else
	    echo "Mono already registered"
	fi
}

# Cleanup environment
mono_stop() {
	echo -n "Shutting down environment for Mono: "
	if [ -e "$CONF_DIR/$NAME" ] && echo "-1" >$CONF_DIR/$NAME 2>/dev/null ; then
	    echo "done"
	else
	    echo "failed"
	fi
	remove_binfmt_misc
}

#
# int main()
#

case "$1" in
    start)
	mono_start
	;;
	
    stop)
	mono_stop
	;;
	
    restart)
	mono_stop
	mono_start
	;;
	
    *)
	echo "usage: $(basename $0) start|stop|restart" ;; 
esac