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perl5202delta - Man Page

what is new for perl v5.20.2


This document describes differences between the 5.20.1 release and the 5.20.2 release.

If you are upgrading from an earlier release such as 5.20.0, first read perl5201delta, which describes differences between 5.20.0 and 5.20.1.

Incompatible Changes

There are no changes intentionally incompatible with 5.20.1.  If any exist, they are bugs, and we request that you submit a report.  See "Reporting Bugs" below.

Modules and Pragmata

Updated Modules and Pragmata

  • attributes has been upgraded from version 0.22 to 0.23.

    The usage of memEQs in the XS has been corrected. [GH #14072] <https://github.com/Perl/perl5/issues/14072>

  • Data::Dumper has been upgraded from version 2.151 to 2.151_01.

    Fixes CVE-2014-4330 by adding a configuration variable/option to limit recursion when dumping deep data structures.

  • Errno has been upgraded from version 1.20_03 to 1.20_05.

    Warnings when building the XS on Windows with the Visual C++ compiler are now avoided.

  • feature has been upgraded from version 1.36 to 1.36_01.

    The postderef feature has now been documented.  This feature was actually added in Perl 5.20.0 but was accidentally omitted from the feature documentation until now.

  • IO::Socket has been upgraded from version 1.37 to 1.38.

    Document the limitations of the connected() method. [GH #14199] <https://github.com/Perl/perl5/issues/14199>

  • Module::CoreList has been upgraded from version 5.020001 to 5.20150214.

    The list of Perl versions covered has been updated.

  • PathTools has been upgraded from version 3.48 to 3.48_01.

    A warning from the gcc compiler is now avoided when building the XS.

  • PerlIO::scalar has been upgraded from version 0.18 to 0.18_01.

    Reading from a position well past the end of the scalar now correctly returns end of file. [GH #14342] <https://github.com/Perl/perl5/issues/14342>

    Seeking to a negative position still fails, but no longer leaves the file position set to a negation location.

    eof() on a PerlIO::scalar handle now properly returns true when the file position is past the 2GB mark on 32-bit systems.

  • Storable has been upgraded from version 2.49 to 2.49_01.

    Minor grammatical change to the documentation only.

  • VMS::DCLsym has been upgraded from version 1.05 to 1.05_01.

    Minor formatting change to the documentation only.

  • VMS::Stdio has been upgraded from version 2.4 to 2.41.

    Minor formatting change to the documentation only.


New Documentation


This document, by Tom Christiansen, provides examples of handling Unicode in Perl.

Changes to Existing Documentation


  • Added reference to subroutine signatures.  This feature was actually added in Perl 5.20.0 but was accidentally omitted from the experimental feature documentation until now.


  • The process whereby features may graduate from experimental status has now been formally documented.



The following additions or changes have been made to diagnostic output, including warnings and fatal error messages.  For the complete list of diagnostic messages, see perldiag.

Changes to Existing Diagnostics

  • Bad symbol for scalar is now documented. This error is not new, but was not previously documented here.
  • Missing right brace on \N{} is now documented.  This error is not new, but was not previously documented here.


Platform Support

Regained Platforms

IRIX and Tru64 platforms are working again.  (Some make test failures remain.)

Selected Bug Fixes

Known Problems

Errata From Previous Releases


Perl 5.20.2 represents approximately 5 months of development since Perl 5.20.1 and contains approximately 6,300 lines of changes across 170 files from 34 authors.

Excluding auto-generated files, documentation and release tools, there were approximately 1,900 lines of changes to 80 .pm, .t, .c and .h files.

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 5.20.2:

Aaron Crane, Abigail, Andreas Voegele, Andy Dougherty, Anthony Heading, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry, Daniel Dragan, Doug Bell, Ed J, Father Chrysostomos, Glenn D. Golden, H.Merijn Brand, Hugo van der Sanden, James E Keenan, Jarkko Hietaniemi, Jim Cromie, Karen Etheridge, Karl Williamson, kmx, Matthew Horsfall, Max Maischein, Peter Martini, Rafael Garcia-Suarez, Ricardo Signes, Shlomi Fish, Slaven Rezic, Steffen Müller, Steve Hay, Tadeusz Sośnierz, Tony Cook, Yves Orton, Ævar Arnfjörð Bjarmason.

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 https://rt.perl.org/ .  There may also be information at http://www.perl.org/ , 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 perlbug@perl.org 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 perl5-security-report@perl.org.  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.

See Also

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.


2024-06-12 perl v5.40.0 Perl Programmers Reference Guide