You are viewing the version of this documentation from Perl 5.32.0-RC0. This is a development release of Perl.



perl5184delta - what is new for perl v5.18.4


This document describes differences between the 5.18.4 release and the 5.18.2 release. Please note: This document ignores perl 5.18.3, a broken release which existed for a few hours only.

If you are upgrading from an earlier release such as 5.18.1, first read perl5182delta, which describes differences between 5.18.1 and 5.18.2.

Modules and Pragmata

Updated Modules and Pragmata

Platform Support

Platform-Specific Notes

  • Introduced by perl #113536, a memory leak on every call to system and backticks ( `` ), on most Win32 Perls starting from 5.18.0 has been fixed. The memory leak only occurred if you enabled pseudo-fork in your build of Win32 Perl, and were running that build on Server 2003 R2 or newer OS. The leak does not appear on WinXP SP3. [perl #121676]

Selected Bug Fixes


Perl 5.18.4 represents approximately 9 months of development since Perl 5.18.2 and contains approximately 2,000 lines of changes across 53 files from 13 authors.

Perl continues to flourish into its third decade thanks to a vibrant community of users and developers. The following people are known to have contributed the improvements that became Perl 5.18.4:

Daniel Dragan, David Mitchell, Doug Bell, Father Chrysostomos, Hiroo Hayashi, James E Keenan, Karl Williamson, Mark Shelor, Ricardo Signes, Shlomi Fish, Smylers, Steve Hay, Tony Cook.

The list above is almost certainly incomplete as it is automatically generated from version control history. In particular, it does not include the names of the (very much appreciated) contributors who reported issues to the Perl bug tracker.

Many of the changes included in this version originated in the CPAN modules included in Perl's core. We're grateful to the entire CPAN community for helping Perl to flourish.

For a more complete list of all of Perl's historical contributors, please see the AUTHORS file in the Perl source distribution.

Reporting Bugs

If you find what you think is a bug, you might check the articles recently posted to the comp.lang.perl.misc newsgroup and the perl bug database at . There may also be information at , the Perl Home Page.

If you believe you have an unreported bug, please run the perlbug program included with your release. Be sure to trim your bug down to a tiny but sufficient test case. Your bug report, along with the output of perl -V, will be sent off to to be analysed by the Perl porting team.

If the bug you are reporting has security implications, which make it inappropriate to send to a publicly archived mailing list, then please send it to This points to a closed subscription unarchived mailing list, which includes all the core committers, who will be able to help assess the impact of issues, figure out a resolution, and help co-ordinate the release of patches to mitigate or fix the problem across all platforms on which Perl is supported. Please only use this address for security issues in the Perl core, not for modules independently distributed on CPAN.


The Changes file for an explanation of how to view exhaustive details on what changed.

The INSTALL file for how to build Perl.

The README file for general stuff.

The Artistic and Copying files for copyright information.