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

       NAME_="timelykill"
       HTML_="process pid"
    PURPOSE_="kill process pid after n time"
   SYNOPSIS_="$NAME_ [-hl] <pid> <n>s|m|h|d"
   REQUIRES_="standard GNU commands"
    VERSION_="1.0"
       DATE_="2004-06-20; last update: 2005-02-28"
     AUTHOR_="Dawid Michalczyk <dm@eonworks.com>"
        URL_="www.comp.eonworks.com"
   CATEGORY_="sys"
   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:
     <pid> <n>s|m|h|d, pid and n seconds|minutes|hours|days to wait before killing the process
     -h, usage and options (this help)
     -l, see this script"
exit 1
}

# enabling extended globbing
shopt -s extglob 

# local func
check_pid() {

    kill -0 $1 &>/dev/null # using bash kill built in
    [ $? = 0 ] && return 0 || return 1

}

time_validateSleepArg() {

    case $1 in
        +([0-9])[smhd] ) return 0 ;;
        *) return 1 ;;
    esac
}

# option handling
case $1 in
    -h) usage ;;
    -l) more $0; exit 1 ;;
    +([0-9])) # arg1 can only be an integer

        # sleep arg check
        time_validateSleepArg $2
        [ $? = 0 ] || { echo >&2 second argument invalid, type $NAME_ -h for help; exit 1; }

        check_pid $1 ; [ $? != 0 ] && { echo >&2 pid $1 does not exits; exit 1; }
        sleep ${2} # before the kill

        while kill -0 $1 &>/dev/null ;do
              
            kill -15 $1; check_pid; [ $? == 1 ] && exit 0
            kill  -3 $1; check_pid; [ $? == 1 ] && exit 0
            kill  -9 $1; check_pid; [ $? == 1 ] && exit 0
            echo process can not be killed, possibly due to lack of ownership rights
            exit 1

        done ;;

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

esac