#!/bin/bash
#  $HeadURL$ $LastChangedRevision$
PROGNAME=$(/usr/bin/basename $0)
TMP_DIR=${TMP_DIR:-/var/tmp}

#  The purpose of this script is to workaround mail injectors that timeout if
#  the body is not provided quickly enough. (E.g. masqmail times out before
#  my backup script completes.)

main()
{
    local RECIPIENT STDERRREDIRECTION_FLAG RC CMD 

    #  Defaults for options
    RECIPIENT=$LOGNAME
    STDERRREDIRECTION_FLAG=true
    VERBOSELEVEL=2

    #  Process options
    while [ "X$1" != X ]; do
        case $1 in
	    -v|--verbose) VERBOSELEVEL=3 ;;
	    -d) VERBOSELEVEL=$2; shift ;;
	    --debug=*) VERBOSELEVEL=${1#*=} ;;
	    --to=*) RECIPIENT=${1#*=} ;;
	    --)     shift; break ;;
	    --no-stderr-redirection) STDERRREDIRECTION_FLAG=false ;;
	    -h|--help) usage 0 ;;
	    -*)     usage ;;
	    *)      break ;;
	esac
	shift
    done

    #  Process arguments
    [ "X$1" != X -a "X$2" = X ] || usage
    CMD="$1"

    #  Sanity checks
    [ "X$RECIPIENT" != X ] || error "recipients not specified/determinable"

    #  Run command
    if $STDERRREDIRECTION_FLAG; then
        eval "$CMD" > $TMP_DIR/$PROGNAME.$$.cmdout 2>&1
    else
        eval "$CMD" > $TMP_DIR/$PROGNAME.$$.cmdout
    fi
    RC=$?
    CMDOUT_SIZE=$(stat -c %s $TMP_DIR/$PROGNAME.$$.cmdout)

    #  Catch silent errors
    if [ $RC != 0 -a $CMDOUT_SIZE = 0 ]; then
        echo "$PROGNAME: ERROR: command \"$CMD\" exited with exit code $RC, but produced no output" > $TMP_DIR/$PROGNAME.$$.cmdout
        CMDOUT_SIZE=$(stat -c %s $TMP_DIR/$PROGNAME.$$.cmdout)
    fi

    #  Mail output if there is any
    if [ $CMDOUT_SIZE != 0 ]; then
        mail -s "$PROGNAME <$LOGNAME@$HOSTNAME> $CMD" $RECIPIENT < $TMP_DIR/$PROGNAME.$$.cmdout > $TMP_DIR/$PROGNAME.$$.mailout
    fi

    #  Clean up
    rm -f $TMP_DIR/$PROGNAME.$$.cmdout $TMP_DIR/$PROGNAME.$$.mailout
    return $RC
}

usage()
{
    local RC

    RC=${1:-1}

    {
        echo "Usage:   $PROGNAME [ <options> ] <command>"
        echo
        echo "Options: -v         | --verbose                       be verbose"
        echo "         -d <level> | --debug=<level>                 be very verbose"
        echo "         -h         | --help                          show this text"
        echo "                      --no-stderr-redirection         don't capture stderr"
        echo "                      --to=<recipient>                mail output to <recipient> instead of \$LOGNAME"
        echo
    } | if [ $RC = 0 ]; then
        cat
    else
        cat >&2
    fi

    exit $RC
}

##############################################################################
#
#  Messaging functions
# 
##############################################################################

debug()    { [ ${VERBOSELEVEL:-2} -lt $1 ] || echo "$PROGNAME: DEBUG[$1]: $2"      >&2;         }
info()     { [ ${VERBOSELEVEL:-2} -lt 3  ] || echo "$PROGNAME: INFO: $1"           >&2;         }
warning()  { [ ${VERBOSELEVEL:-2} -lt 2  ] || echo "$PROGNAME: WARNING: $1"        >&2;         }
error()    { [ ${VERBOSELEVEL:-2} -lt 1  ] || echo "$PROGNAME: ERROR: $1"          >&2; exit 1; }
internal() {                                          echo "$PROGNAME: INTERNAL ERROR: $1" >&2; exit 2; }

##############################################################################
#
#  Entry point
# 
##############################################################################

main "$@"