perl5142delta - what is new for perl v5.14.2


   This document describes differences between the 5.14.1 release and the
   5.14.2 release.

   If you are upgrading from an earlier release such as 5.14.0, first read
   perl5141delta, which describes differences between 5.14.0 and 5.14.1.

Core Enhancements

   No changes since 5.14.0.


   "File::Glob::bsd_glob()" memory error with GLOB_ALTDIRFUNC (CVE-2011-2728).
   Calling "File::Glob::bsd_glob" with the unsupported flag
   GLOB_ALTDIRFUNC would cause an access violation / segfault.  A Perl
   program that accepts a flags value from an external source could expose
   itself to denial of service or arbitrary code execution attacks.  There
   are no known exploits in the wild.  The problem has been corrected by
   explicitly disabling all unsupported flags and setting unused function
   pointers to null.  Bug reported by Clment Lecigne.

   "Encode" decode_xs n-byte heap-overflow (CVE-2011-2939)
   A bug in "Encode" could, on certain inputs, cause the heap to overflow.
   This problem has been corrected.  Bug reported by Robert Zacek.

Incompatible Changes

   There are no changes intentionally incompatible with 5.14.0. If any
   exist, they are bugs and reports are welcome.


   There have been no deprecations since 5.14.0.

Modules and Pragmata

   New Modules and Pragmata

   Updated Modules and Pragmata
   *   CPAN has been upgraded from version 1.9600 to version 1.9600_01.

       CPAN::Distribution has been upgraded from version 1.9602 to

       Backported bugfixes from CPAN version 1.9800.  Ensures proper
       detection of "configure_requires" prerequisites from CPAN Meta
       files in the case where "dynamic_config" is true.  [

       Also ensures that "configure_requires" is only checked in META
       files, not MYMETA files, so protect against MYMETA generation that
       drops "configure_requires".

   *   Encode has been upgraded from version 2.42 to 2.42_01.

       See "Security".

   *   File::Glob has been upgraded from version 1.12 to version 1.13.

       See "Security".

   *   PerlIO::scalar has been upgraded from version 0.11 to 0.11_01.

       It fixes a problem with "open my $fh, ">", \$scalar" not working if
       $scalar is a copy-on-write scalar.

   Removed Modules and Pragmata

Platform Support

   New Platforms

   Discontinued Platforms

   Platform-Specific Notes
   HP-UX PA-RISC/64 now supports gcc-4.x
       A fix to correct the socketsize now makes the test suite pass on
       HP-UX PA-RISC for 64bitall builds.

   Building on OS X 10.7 Lion and Xcode 4 works again
       The build system has been updated to work with the build tools
       under Mac OS X 10.7.

Bug Fixes

   *   In @INC filters (subroutines returned by subroutines in @INC), $_
       used to misbehave: If returned from a subroutine, it would not be
       copied, but the variable itself would be returned; and freeing $_
       (e.g., with "undef *_") would cause perl to crash.  This has been
       fixed [perl #91880].

   *   Perl 5.10.0 introduced some faulty logic that made "U*" in the
       middle of a pack template equivalent to "U0" if the input string
       was empty.  This has been fixed [perl #90160].

   *   "caller" no longer leaks memory when called from the DB package if
       @DB::args was assigned to after the first call to "caller".  Carp
       was triggering this bug [perl #97010].

   *   "utf8::decode" had a nasty bug that would modify copy-on-write
       scalars' string buffers in place (i.e., skipping the copy).  This
       could result in hashes having two elements with the same key [perl

   *   Localising a tied variable used to make it read-only if it
       contained a copy-on-write string.

   *   Elements of restricted hashes (see the fields pragma) containing
       copy-on-write values couldn't be deleted, nor could such hashes be
       cleared ("%hash = ()").

   *   Locking a hash element that is a glob copy no longer causes
       subsequent assignment to it to corrupt the glob.

   *   A panic involving the combination of the regular expression
       modifiers "/aa" introduced in 5.14.0 and the "	" escape sequence
       has been fixed [perl #95964].

Known Problems

   This is a list of some significant unfixed bugs, which are regressions
   from 5.12.0.

   *   "PERL_GLOBAL_STRUCT" is broken.

       Since perl 5.14.0, building with "-DPERL_GLOBAL_STRUCT" hasn't been
       possible. This means that perl currently doesn't work on any
       platforms that require it to be built this way, including Symbian.

       While "PERL_GLOBAL_STRUCT" now works again on recent development
       versions of perl, it actually working on Symbian again hasn't been

       We'd be very interested in hearing from anyone working with Perl on


   Perl 5.14.2 represents approximately three months of development since
   Perl 5.14.1 and contains approximately 1200 lines of changes across 61
   files from 9 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 5.14.2:

   Craig A. Berry, David Golden, Father Chrysostomos, Florian Ragwitz,
   H.Merijn Brand, Karl Williamson, Nicholas Clark, Pau Amma and Ricardo

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 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.


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.