How to kill known running pids if one of the pids terminated?

Question

I have this script.sh where I pass the path to the binaries, all apps run in the background:

./script.sh path/to/app_1 path/to/app_2 ... path/to/app_n

Here is the script:

#!/bin/bash

for app in "$@"
do
    $app &
done

All my apps are running as I expected. Some of them are just console applications without windows, but some apps have interface and I can close the window app.

I can get pid of the app, something like this:

pgrep "${app##*/}"

How to kill all apps by pids that I passed through script.bash as arguments? When I close one of the windows it should kill all known running apps.

Answer 1

This should work.

declare -a _procid

_kill_them_all()
{
    for p in ${_procid[@]} ; do
        kill -9 $p 2>/dev/null
    done
    exit
}

trap _kill_them_all SIGCHLD

for app in "$@"
do
    $app  &
    _procid+=($!)
done

wait ${_procid[@]}

echo "doesn't get here if there were children"

The bash script keeps an array list of the child pids, and traps when any of the child processes exit, then the trap handler kills all the child processes.