#! /bin/sh
# #############################################################################

       NAME_="xmesg"
       HTML_="display X window message"
    PURPOSE_="display an X window message on a regular basis"
   SYNOPSIS_="$NAME_ [-hl] <n>s|m|h|d '<message to display>'"
   REQUIRES_="standard GNU commands"
    VERSION_="1.0"
       DATE_="2004-03-14; last update: 2004-03-14"
     AUTHOR_="Dawid Michalczyk <dm@eonworks.com>"
        URL_="www.comp.eonworks.com"
   CATEGORY_="desk"
   PLATFORM_="Linux"
      SHELL_="bash"
 DISTRIBUTE_="yes"

# #############################################################################
# This program is distributed under the terms of the GNU General Public License

usage () {

echo >&2 "$NAME_ $VERSION_ - $PURPOSE_
Usage: $SYNOPSIS_
Requires: $REQUIRES_
Options:
     <n>s|m|h|d, an integer referring to seconds|minutes|hours|days; the time
                 interval for how often to display the message
     '<message to display>', a single quoted message to display
     -h, usage and options (this help)
     -l, see this script"
    exit 1
}

# enabling extended globbing
shopt -s extglob

# option handling
case $1 in
    -h) usage ;;
    -l) more $0; exit 1 ;;
    +([0-9])[smhd] )

        [[ $2 ]] || { echo >&2 missing second argument, type $NAME_ -h for help; exit 1; }

        while :;do

            sleep ${1}
            # display windowed message if x is running
            ps -aux | grep -q xinit
            [ $? = 0 ] && xmessage -center $2

        done ;;

    *) echo invalid or missing argument, type $NAME_ -h for help; exit 1 ;;

esac