Perl fork and kill - kill(0, $pid) always returns 1, and can't kill the child

Question

I am running a perl script on a Linux host. I\'m trying to write a script that forks, where the child starts a program that takes forever and the parent times out after 5 s

Answer 1

From perldoc fork:

If you fork without ever waiting on your children, you will accumulate zombies. On some systems, you can avoid this by setting $SIG{CHLD} to "IGNORE" .

I was able to get the desired behavior when adding $SIG{CHLD} = 'IGNORE'; to the top of your code.

[ben@imac ~]$ perl test.pl
numKilled: 1
[ben@imac ~]$ 

Alternatively, adding waitpid($childPid, 0); after kill did the trick as well.