What is start-stop-daemon and how should it be used?
I am trying to automate a particular program to run. Whenever the system starts, the program should run. For that I am writing script in /etc/init.d/ location.
It is a program to manage the start and stop of system level background processes (daemons). You use it by passing in parameters (such as the pid file to create/check) and command arguments for the process you want to launch.
Then, you do one of two things:
start-stop-daemon -S [other arguments] something
start something, if something wasn't already running. If it was running, do nothing.
start-stop-daemon -K [other arguments] something
stop something. If something wasn't running, do nothing.
The man page provides more information on the various arguments. Typically a template is provided in /etc/init.d/ which has other commands for the init process that controls the running of background processes.
start-stop-daemon --start --background -m --oknodo --pidfile ${PIDFILE} --exec ${DAEMON} -- ${TARGETDIR}
--background = launch as a background process-m = make a PID file. This is used when your process doesn't create its own PID file, and is used with --background--oknodo = return 0, not 1 if no actions are taken by the daemon--pidfile ${PIDFILE} = check whether the PID file has been created or not--exec = make sure the processes are instances of this executable (in your case, DAEMON)