Re: Forking & Signals

[Neil Bowers]

I have a perl script (modified from one of Chris
Nandor's) that I run as a background-process/daemon
via fork(). Now I know I can use kill to end it, but I
was wondering if there was a way that I can catch the
SIGTERM to do one last thing before quitting?
You just need to install a TERM handler routine in the child process. 
Eg:

        $pid = fork;
        if ($pid) {
                # parent process prints message and exits
                print "Running background process ($pid)\n";
                exit;
        }
        else
        {
           # child process installs handler then sits in a loop
            $SIG{TERM} = \&cleanup;
            while (1)
            {
            }
        }
    sub cleanup {
        print "Hello, World!\n";
        exit 0;
    }
You should get the following:
        ./foo.pl
        Running background process (15117)
        ~% kill 15117
        ~% Hello, World
Neil