How to know if a process had been started but crashed in Linux

Question

Consider the following situation: - I am using Linux. I have doubt that my application has crashed. I had not enabled core dump. There is no information in the log.

How can I be sure that, after the system restart my app was started, but now it is not running, because it has crashed.

My app is configured as a service, written in C/C++.

In a way: how can I get all the process/service names that have executed since the system start? Is it even possible?

I know, I can enable logging and start the process again to get the crash.

Answer 1

Standard practice is to have a pid file for your daemon (/var/run/$NAME.pid), in which you can find its process id without having to parse the process tree manually. You can then either check the state of that process, or make your daemon respond to a signal (usually SIGHUP), and report its status. It's a good idea to make sure that this pid still belongs to your process too, and the easiest way is to check /proc/$PID/cmdline.

Addendum: If you're only using newer fedora or ubuntu, your init system is upstart, which has monitoring and triggering capabilities built in.

As @emg-2 noted, BSD process accounting is available, but I don't think it's the correct approach for this situation.