Stopping a running bash script from another script

Question

I have a script called first.sh and this script calls another script using " ./second.sh ". In second.sh there are commands to play songs. For example, the content of second.sh could be:

play song1.mp3
play song2.mp3
...

I want to stop the script second.sh at certain times during the day, the problem is that using killall (and similar commands) do not help because the name of the script " second.sh " does not appear among the list of commands when I use " ps aux ", I only see " play song1.mp3 " and then " play song2.mp3 " once song2 starts playing.

What can I do to stop second.sh using a command in the terminal? Or at least tie all the commands in it to a single process so I can kill that particular process?

Any help is appreciated, I've tried many ideas I found online but nothing seems to work.

Answer 1

Because you said :

at certain times during the day,

I would recommend crontab .

Use crontab -e and append the below line

0 12 * * * kill -9 `ps aux | awk '/play/{print $2}'`

This kills the parent shell that invoked play

The syntax for the crontab file is

m h  dom mon dow   command

where:

m - minute
h - hours
dom - day of month
mon - month
dow - day of week
command - the command that you wish to execute.

Edit

Or you could do something like this :

0 12 * * * killall -sSIGSTOP play
0 16 * * * killall -sSIGCONT play

which will pause all the play processes from 12 hours till 16 hours.

Requirement

You need to have the cron daemon up and running on your system.

Answer 2

You can save the pgid of the process explicitly, and then use the signals SIGSTOP and SIGCONT to start and stop the process group.

first.sh

#!/bin/bash

nohup ./second.sh > /dev/null 2>&1 &
echo $$ > /tmp/play.pid ### save process group id

second.sh

#!/bin/bash

play ...
play ...

third.sh

#!/bin/bash

case $1 in
    (start)
        kill -CONT -$(cat /tmp/play.pid)
        ;;

    (stop)
        kill -STOP -$(cat /tmp/play.pid)
        ;;
esac

Now you can launch and control the play as follows:

./first.sh

./third.sh stop
./third.sh start

Answer 3

您只需要停止second.sh，它就会自动杀死其所有子进程。

killall second.sh