This document describes differences between the 5.12.0 release and the
If you are upgrading from an earlier release such as 5.10.0, first read
perl5120delta, which describes differences between 5.10.0 and 5.12.0.
"safe signals" optimization
Signal dispatch has been moved from the runloop into control ops. This
should give a few percent speed increase, and eliminates almost all of
the speed penalty caused by the introduction of "safe signals" in
5.8.0. Signals should still be dispatched within the same statement as
they were previously - if this is not the case, or it is possible to
create uninterruptible loops, this is a bug, and reports are encouraged
of how to recreate such issues.
Assignment to $0 sets the legacy process name with "prctl()" on Linux
On Linux the legacy process name will be set with prctl(2), in addition
to altering the POSIX name via "argv" as perl has done since version
4.000. Now system utilities that read the legacy process name such as
ps, top and killall will recognize the name you set when assigning to
$0. The string you supply will be cut off at 16 bytes, this is a
limitation imposed by Linux.
Optimization of shift; and pop; calls without arguments
Additional two OPs are not added anymore into op tree for shift and pop
calls without argument (when it works on @_). Makes "shift;" 5% faster
over "shift @_;" on not threaded perl and 25% faster on threaded.
Modules and Pragmata
CGI Updated to version 3.49.
Updated to version 2.126.
Updated to 3.09.
Updated to version 1.77
Updated to version 1.33
Installation and Configuration Improvements
Platform Specific Changes
AIX Allow building on AIX 4.2.
Perl 5.13.0 represents eight days of development since Perl 5.12.0 and
contains 3,766 lines of changes across 151 files from 29 authors and
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 http://rt.perl.org/perlbug/ . 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 firstname.lastname@example.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 email@example.com. This points to a closed
subscription unarchived mailing list, which includes all the core
committers, who 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.
perl v5.14.2 2011-09-26 PERL5130DELTA(1)
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