#!/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