EDIT: I was mistaken, this has nothing to do with Perl, see my reply to Anonymous Monk below.

Here's a sample perl code:

system("rm -f x; ulimit -f 5; while [ 1 ]; do echo 1 >>x; done");

[download]

If I run this on Redhat EL6 (perl 5.10.1), I get a file that's 2560 bytes long. If I run it on Redhat EL5 (perl 5.8.8), I get a file that's 5120 bytes long.

If I run the command in the shell as opposed to via perl, I get a 5120 byte file on both platforms, on both sh and bash (I do know sh is a symbolic link to bash here, but figured it's worth a try since you can base behaviour on $0). This is consistent with bash ulimit documentation which states that blocks for -f are 1024 bytes long.

The really weird thing is I managed to call the 5.8 perl from RHEL5 on my RHEL6 system and it still made a 2560 byte file, so it's not dependent on the perl configuration.

So I am at a complete loss. I'd like to know:

  1. What causes the different behavior?
  2. How can I avoid it and have perl make a 5120 byte file in all cases?

Thank you very much.

In reply to [Resolved] Call to ulimit in perl's system() causes unexplainable behavior by chengiz5

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