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Source   Latest Release: perl-5.19.11


perl5198delta - what is new for perl v5.19.8


This document describes differences between the 5.19.7 release and the 5.19.8 release.

If you are upgrading from an earlier release such as 5.19.6, first read perl5197delta, which describes differences between 5.19.6 and 5.19.7.

Core Enhancements ^

New \p{Unicode} regular expression pattern property

This is a synonym for \p{Any} and matches the set of Unicode-defined code points 0 - 0x10FFFF.

Incompatible Changes ^

do can no longer be used to call subroutines

The do SUBROUTINE(LIST) form has resulted in a deprecation warning since Perl v5.0.0, and is now a syntax error.

\p{}, \P{} matching has changed for non-Unicode code points.

\p{} and \P{} are defined by Unicode only on Unicode-defined code points (U+0000 through U+10FFFF). Their behavior on matching these legal Unicode code points is unchanged, but there are changes for code points 0x110000 and above. Previously, Perl treated the result of matching \p{} and \P{} against these as undef, which translates into "false". For \P{}, this was then complemented into "true". A warning was supposed to be raised when this happened. However, various optimizations could prevent the warning, and the results were often counter-intuitive, with both a match and its seeming complement being false. Now all non-Unicode code points are treated as typical unassigned Unicode code points. This generally is more Do-What-I-Mean. A warning is raised only if the results are arguably different from a strict Unicode approach, and from what Perl used to do. Code that needs to be strictly Unicode compliant can make this warning fatal, and then Perl always raises the warning.

Details are in "Beyond Unicode code points" in perlunicode.

\p{All} has been expanded to match all possible code points

The Perl-defined regular expression pattern element \p{All}, unused on CPAN, used to match just the Unicode code points; now it matches all possible code points; that is, it is equivalent to qr/./s. Thus \p{All} is no longer synonymous with \p{Any}, which continues to match just the Unicode code points, as Unicode says it should.

Deprecations ^

XXX Any deprecated features, syntax, modules etc. should be listed here.

Module removals

XXX Remove this section if inapplicable.

The following modules will be removed from the core distribution in a future release, and will at that time need to be installed from CPAN. Distributions on CPAN which require these modules will need to list them as prerequisites.

The core versions of these modules will now issue "deprecated"-category warnings to alert you to this fact. To silence these deprecation warnings, install the modules in question from CPAN.

Note that these are (with rare exceptions) fine modules that you are encouraged to continue to use. Their disinclusion from core primarily hinges on their necessity to bootstrapping a fully functional, CPAN-capable Perl installation, not usually on concerns over their design.

XXX Note that deprecated modules should be listed here even if they are listed as an updated module in the "Modules and Pragmata" section.

Modules and Pragmata ^

New Modules and Pragmata

Updated Modules and Pragmata

Documentation ^

Changes to Existing Documentation

Diagnostics ^

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.

New Warnings

Utility Changes ^


Configuration and Compilation ^

Platform Support ^

Platform-Specific Notes


recv() on a connected handle would populate the returned sender address with whatever happened to be in the working buffer. recv() now uses a workaround similar to the Win32 recv() wrapper and returns an empty string when recvfrom(2) doesn't modify the supplied address length. [perl #118843]

Internal Changes ^

newATTRSUB is now a macro

The public API newATTRSUB was previously a macro to the private function Perl_newATTRSUB. Function Perl_newATTRSUB has been removed. newATTRSUB is now macro to a different internal function.

Changes in warnings raised by utf8n_to_uvchr()

This bottom level function decodes the first character of a UTF-8 string into a code point. It is accessible to XS level code, but it's discouraged from using it directly. There are higher level functions that call this that should be used instead, such as "utf8_to_uvchr_buf" in perlapi. For completeness though, this documents some changes to it. Now, tests for malformations are done before any tests for other potential issues. One of those issues involves code points so large that they have never appeared in any official standard (the current standard has scaled back the highest acceptable code point from earlier versions). It is possible (though not done in CPAN) to warn and/or forbid these code points, while accepting smaller code points that are still above the legal Unicode maximum. The warning message for this now includes the code point if representable on the machine. Previously it always displayed raw bytes, which is what it still does for non-representable code points.

Selected Bug Fixes ^

Acknowledgements ^

Perl 5.19.8 represents approximately 4 weeks of development since Perl 5.19.7 and contains approximately 38,000 lines of changes across 420 files from 26 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 5.19.8:

Abigail, Alan Hourihane, Brian Fraser, Brian Gottreu, Chris 'BinGOs' Williams, Christian Millour, Craig A. Berry, Dagfinn Ilmari Mannsåker, Daniel Dragan, David Mitchell, Dominic Hargreaves, Father Chrysostomos, H.Merijn Brand, James E Keenan, Jess Robinson, John Peacock, Karl Williamson, Martin McGrath, Matthew Horsfall, Nicholas Clark, Ricardo Signes, Shlomi Fish, Steve Hay, Tobias Leich, Tony Cook, 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.


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.

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