Re^11: Doing every X seconds


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Re^11: Doing every X seconds

by anonymized user 468275 (Curate)

on Aug 08, 2018 at 06:38 UTC ( [id://1220054]=note: print w/replies, xml )

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Re^12: Doing every X seconds
by hippo (Bishop) on Aug 08, 2018 at 09:12 UTC

the OP only wants two processes in parallel which is too obviously not a case where undef can occur.

$ cat cantfork.pl 
#!/usr/bin/perl
use strict;
use warnings;

my $child = fork;
die "Well that's odd - the fork failed" unless defined $child;

if ($child) {
    print "Parent! Child is $child\n";
} else {
    print "Child!\n";
}

sleep 1;
exit;
$ ./cantfork.pl 
Parent! Child is 17198
Child!
$ ulimit -u 9
$ ./cantfork.pl 
Well that's odd - the fork failed at ./cantfork.pl line 6.
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Always code defensively, especially when using system calls as they can fail at any time for any reason.

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