djcev.com

#!/bin/sh
#
#  Copyright (c) 2015-2021, Cameron Vanderzanden. Available under the
#  terms of the 2-clause BSD license. Please see the file "LICENSE" in
#  the root dir of this repository for more information.
#
#- toggle.sh 2015/01/05 cev, last updated 2021/12/07.
## Usage: toggle.sh [-hrstV] program <program options ...>
##  
##       -h     Show help options.
##       -r     Run program only if not already running.
##       -s     Stop (pkill) program.
##       -t     Toggle program; start if not running, stop if running.
##       -V     Print version info.
## 

[ -x $HOME/.local/bin/cev_print.sh ] && . $HOME/.local/bin/cev_print.sh

self="${0##*'/'}"
exe=""
program=""
action="runonce"

die_noargument() {
    print_self error
    printf "%bno argument.%b\n" "$_norm" "$_clear" >&2
    exit 1
}

die_notanexecutable() {
    print_noexe "$*"
    exit 1
}

# next three functions should be obvious.
check() { pgrep -o -u $USER -q -x $exe 1>/dev/null 2>&1 ; }
stop() { pkill -o -u $USER -x $exe ; }
start() { exec $program 1>/dev/null 2>&1 & }

runonce() {
    if check; then 
        print_self
        printf "%b%s%b: already running" "$_high" "$exe" "$_norm"
        printf "%b\n" "$_clear"
    else start
    fi
    exit 0
}

toggle() {
    if check; then stop
    else start
    fi
    exit 0
}

while getopts "hrstV?" option; do
    case $option in
        h) print_help && exit ;;
        r) action="runonce" ;;
        s) action="stop" ;;
        t) action="toggle" ;;
        V) print_version && exit ;;
        "?") print_help && exit ;;
    esac
    shift $((OPTIND - 1))
done

[ $# -lt 1 ] && die_noargument

# allergic to spaces in binary names / paths to binaries.
exe="${@%%' '*}"
fullexe="$(which $exe)"
program="$@"

[ ! -x "$fullexe" ] && die_notanexecutable "$exe"

case $action in
    "runonce") runonce ;;
    "stop") stop ;;
    "toggle") toggle ;;
esac