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Based on the description of your requirement, it sounds like you will need to fork two children - one to check the server, one to do the countdown. Something like this:

use strict; use warnings; use feature qw(:5.10); # Fork off two child processes my ($who_am_i, $countdown_pid, $checking_pid); $countdown_pid = fork(); if ($countdown_pid == 0){ $who_am_i = "countdown process"; } elsif ($countdown_pid){ $checking_pid = fork(); if ($checking_pid == 0){ $who_am_i = "checking process"; } elsif ($checking_pid){ $who_am_i = "controlling process"; } else{ die "Error forking: $!"; } } else{ die "Error forking: $!"; } # Each process does different things: given($who_am_i){ when ("countdown process"){ sleep_count(3, 'Verifying with Nagios that resin is down: '); } when ("checking process"){ # repeatedly do server check via "nagios" } when ("controlling process"){ # Wait on the "checking process" to complete. waitpid($checking_pid, 0); # Kill countdown timer kill("TERM", $countdown_pid); waitpid($countdown_pid, 0); } }

You should probably check the exit status of your child processes (via $? after the waitpid calls).

Hope this helps.

Update: Actually, there's no need to have three processes. Two is enough, as in your post, although conceptually I like the idea of delegating each subtask to separate child processes.

Perhaps the only piece that was really missing from your code was killing off the countdown timer.


In reply to Re: Having a difficult time understanding fork() by crashtest
in thread Having a difficult time understanding fork() by walkingthecow

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