#!/bin/sh

# (C) 2008 Yann E. MORIN <yann.morin.1998@anciens.enib.fr>

# Licensed under the GPL v.2

LIBDUMA_SO=

case "$1" in

  -on)

    case "${LD_PRELOAD}" in

      *${LIBDUMA_SO}*) ;;

      *) LD_PRELOAD="${LIBDUMA_SO} ${LD_PRELOAD}";;

    esac

    shift

    ;;

  -off)

    # We use a suposedly POSIX-compliant shell: /bin/sh

    #  -> we can't use "${LD_PRELOAD//${LIBDUMA_SO}/}", it's not POSIX

    # We don't know if sed will be present on the target

    #  -> we can't use $(echo "${LD_PRELOAD}" |sed -r -e "s|${LIBDUMA_SO}||;")

    # So, iterate through LD_PRELOAD, and keep only those libs that

    # are not "${LIBDUMA_SO}"

    old_LD_PRELOAD="${LD_PRELOAD}"

    LD_PRELOAD=

    for lib in ${old_LD_PRELOAD}; do

      [ "${lib}" = "${LIBDUMA_SO}" ] || LD_PRELOAD="${LD_PRELOAD} ${lib}"

    done

    unset old_LD_PRELOAD

    shift

    ;;

  -show)

    case "${LD_PRELOAD}" in

      *${LIBDUMA_SO}*) echo "duma is enabled";;

      *)               echo "duma is disabled";;

    esac

    exit 0

    ;;

  "")

    cat <<_EOF_

Usage:

    . $0 <-on|-off|-show>

        Sets, unsets or show DUMA usage.

    $0 <executable [arg...]>

        Execute 'executable' (with arguments 'args') using DUMA.

_EOF_

    false # Don't 'exit', we could well be source'd

    ;;

  *)

    exec "$0" -on "$@"

    ;;

esac

export LD_PRELOAD

if [ -n "$1" ]; then

  exec "$@"

fi