for example if exaile it running then covergloobus starts, if exaile stops – covergloobus stops too. Maybe a plugin to exaile?
lifeisfoo
[ Editor ]
Exaile is written in python: you can start an application when starting exaile, using a plugin that fork (os.fork()), save the pid of the child process, and exec the external program you want(e.g. covergloobus) in the child.
After, you can stop the external process using os.kill(pid,sig) handling with your plugin the exaile shutting down.
Otherwise, if you want only kill the external program without using pid, you can do that using the killall command(man killall). Just write a small plugin that exec “killall covergloobus-process-name” when exaile is shutting down.