{ "content": [ { "type": "text", "text": "# perl5201delta (man)\n\n## NAME\n\nperl5201delta - what is new for perl v5.20.1\n\n## DESCRIPTION\n\nThis document describes differences between the 5.20.0 release and the 5.20.1 release.\n\n## Sections\n\n- **NAME**\n- **DESCRIPTION** (4 subsections)\n- **Documentation** (1 subsections)\n- **Diagnostics** (6 subsections)\n- **Acknowledgements** (1 subsections)\n- **SEE ALSO**\n\nUse structuredContent.sections for detailed options, examples, and full documentation.\n" } ], "structuredContent": { "command": "perl5201delta", "section": "", "mode": "man", "summary": "perl5201delta - what is new for perl v5.20.1", "synopsis": null, "tldr_summary": null, "tldr_examples": [], "tldr_source": null, "flags": [], "examples": [], "see_also": [], "section_outline": [ { "name": "NAME", "lines": 2, "subsections": [] }, { "name": "DESCRIPTION", "lines": 5, "subsections": [ { "name": "Incompatible Changes", "lines": 3 }, { "name": "Performance Enhancements", "lines": 7 }, { "name": "Modules and Pragmata", "lines": 1 }, { "name": "Updated Modules and Pragmata", "lines": 45 } ] }, { "name": "Documentation", "lines": 1, "subsections": [ { "name": "Changes to Existing Documentation", "lines": 52 } ] }, { "name": "Diagnostics", "lines": 3, "subsections": [ { "name": "Changes to Existing Diagnostics", "lines": 4 }, { "name": "Configuration and Compilation", "lines": 3 }, { "name": "Platform Support", "lines": 1 }, { "name": "Platform-Specific Notes", "lines": 17 }, { "name": "Internal Changes", "lines": 5 }, { "name": "Selected Bug Fixes", "lines": 18 } ] }, { "name": "Acknowledgements", "lines": 27, "subsections": [ { "name": "Reporting Bugs", "lines": 17 } ] }, { "name": "SEE ALSO", "lines": 11, "subsections": [] } ], "sections": { "NAME": { "content": "perl5201delta - what is new for perl v5.20.1\n", "subsections": [] }, "DESCRIPTION": { "content": "This document describes differences between the 5.20.0 release and the 5.20.1 release.\n\nIf you are upgrading from an earlier release such as 5.18.0, first read perl5200delta, which\ndescribes differences between 5.18.0 and 5.20.0.\n", "subsections": [ { "name": "Incompatible Changes", "content": "There are no changes intentionally incompatible with 5.20.0. If any exist, they are bugs,\nand we request that you submit a report. See \"Reporting Bugs\" below.\n" }, { "name": "Performance Enhancements", "content": "• An optimization to avoid problems with COW and deliberately overallocated PVs has been\ndisabled because it interfered with another, more important, optimization, causing a\nslowdown on some platforms. [GH #13878] \n\n• Returning a string from a lexical variable could be slow in some cases. This has now\nbeen fixed. [GH #13880] \n" }, { "name": "Modules and Pragmata", "content": "" }, { "name": "Updated Modules and Pragmata", "content": "• Config::Perl::V has been upgraded from version 0.20 to 0.22.\n\nThe list of Perl versions covered has been updated and some flaws in the parsing have\nbeen fixed.\n\n• Exporter has been upgraded from version 5.70 to 5.71.\n\nIllegal POD syntax in the documentation has been corrected.\n\n• ExtUtils::CBuilder has been upgraded from version 0.280216 to 0.280217.\n\nAndroid builds now link to both -lperl and $Config::Config{perllibs}.\n\n• File::Copy has been upgraded from version 2.29 to 2.30.\n\nThe documentation now notes that \"copy\" will not overwrite read-only files.\n\n• Module::CoreList has been upgraded from version 3.11 to 5.020001.\n\nThe list of Perl versions covered has been updated.\n\n• The PathTools module collection has been upgraded from version 3.47 to 3.48.\n\nFallbacks are now in place when cross-compiling for Android and $Config::Config{sh} is\nnot yet defined. [GH #13872] \n\n• PerlIO::via has been upgraded from version 0.14 to 0.15.\n\nA minor portability improvement has been made to the XS implementation.\n\n• Unicode::UCD has been upgraded from version 0.57 to 0.58.\n\nThe documentation includes many clarifications and fixes.\n\n• utf8 has been upgraded from version 1.13 to 1.1301.\n\nThe documentation has some minor formatting improvements.\n\n• version has been upgraded from version 0.9908 to 0.9909.\n\nExternal libraries and Perl may have different ideas of what the locale is. This is\nproblematic when parsing version strings if the locale's numeric separator has been\nchanged. Version parsing has been patched to ensure it handles the locales correctly.\n[GH #13863] \n" } ] }, "Documentation": { "content": "", "subsections": [ { "name": "Changes to Existing Documentation", "content": "perlapi\n\n• \"avlen\" - Emphasize that this returns the highest index in the array, not the size of\nthe array. [GH #13377] \n\n• Note that \"SvSetSV\" doesn't do set magic.\n\n• \"svusepvnflags\" - Fix documentation to mention the use of \"NewX\" instead of \"malloc\".\n[GH #13835] \n\n• Clarify where \"NUL\" may be embedded or is required to terminate a string.\n\nperlfunc\n\n• Clarify the meaning of \"-B\" and \"-T\".\n\n• \"-l\" now notes that it will return false if symlinks aren't supported by the file system.\n[GH #13695] \n\n• Note that \"each\", \"keys\" and \"values\" may produce different orderings for tied hashes\ncompared to other perl hashes. [GH #13650] \n\n• Note that \"exec LIST\" and \"system LIST\" may fall back to the shell on Win32. Only \"exec\nPROGRAM LIST\" and \"system PROGRAM LIST\" indirect object syntax will reliably avoid using\nthe shell. This has also been noted in perlport. [GH #13907]\n\n\n• Clarify the meaning of \"our\". [GH #13938] \n\nperlguts\n\n• Explain various ways of modifying an existing SV's buffer. [GH #12813]\n\n\nperlpolicy\n\n• We now have a code of conduct for the p5p mailing list, as documented in \"STANDARDS OF\nCONDUCT\" in perlpolicy.\n\nperlre\n\n• The \"/x\" modifier has been clarified to note that comments cannot be continued onto the\nnext line by escaping them.\n\nperlsyn\n\n• Mention the use of empty conditionals in \"for\"/\"while\" loops for infinite loops.\n\nperlxs\n\n• Added a discussion of locale issues in XS code.\n" } ] }, "Diagnostics": { "content": "The following additions or changes have been made to diagnostic output, including warnings\nand fatal error messages. For the complete list of diagnostic messages, see perldiag.\n", "subsections": [ { "name": "Changes to Existing Diagnostics", "content": "• Variable length lookbehind not implemented in regex m/%s/\n\nInformation about Unicode behaviour has been added.\n" }, { "name": "Configuration and Compilation", "content": "• Building Perl no longer writes to the source tree when configured with Configure's\n-Dmksymlinks option. [GH #13712] \n" }, { "name": "Platform Support", "content": "" }, { "name": "Platform-Specific Notes", "content": "Android\nBuild support has been improved for cross-compiling in general and for Android in\nparticular.\n\nOpenBSD\nCorrected architectures and version numbers used in configuration hints when building\nPerl.\n\nSolaris\nc99 options have been cleaned up, hints look for solstudio as well as SUNWspro, and\nsupport for native \"setenv\" has been added.\n\nVMS An old bug in feature checking, mainly affecting pre-7.3 systems, has been fixed.\n\nWindows\n%I64d is now being used instead of %lld for MinGW.\n" }, { "name": "Internal Changes", "content": "• Added \"synclocale\" in perlapi. Changing the program's locale should be avoided by XS\ncode. Nevertheless, certain non-Perl libraries called from XS, such as \"Gtk\" do so.\nWhen this happens, Perl needs to be told that the locale has changed. Use this function\nto do so, before returning to Perl.\n" }, { "name": "Selected Bug Fixes", "content": "• A bug has been fixed where zero-length assertions and code blocks inside of a regex could\ncause \"pos\" to see an incorrect value. [GH #14016]\n\n\n• Using \"s///e\" on tainted utf8 strings could issue bogus \"Malformed UTF-8 character\n(unexpected end of string)\" warnings. This has now been fixed. [GH #13948]\n\n\n• \"system\" and friends should now work properly on more Android builds.\n\nDue to an oversight, the value specified through -Dtargetsh to Configure would end up\nbeing ignored by some of the build process. This caused perls cross-compiled for Android\nto end up with defective versions of \"system\", \"exec\" and backticks: the commands would\nend up looking for /bin/sh instead of /system/bin/sh, and so would fail for the vast\nmajority of devices, leaving $! as \"ENOENT\".\n\n• Many issues have been detected by Coverity and fixed.\n" } ] }, "Acknowledgements": { "content": "Perl 5.20.1 represents approximately 4 months of development since Perl 5.20.0 and contains\napproximately 12,000 lines of changes across 170 files from 36 authors.\n\nExcluding auto-generated files, documentation and release tools, there were approximately\n2,600 lines of changes to 110 .pm, .t, .c and .h files.\n\nPerl continues to flourish into its third decade thanks to a vibrant community of users and\ndevelopers. The following people are known to have contributed the improvements that became\nPerl 5.20.1:\n\nAaron Crane, Abigail, Alberto Simões, Alexandr Ciornii, Alexandre (Midnite) Jousset, Andrew\nFresh, Andy Dougherty, Brian Fraser, Chris 'BinGOs' Williams, Craig A. Berry, Daniel Dragan,\nDavid Golden, David Mitchell, H.Merijn Brand, James E Keenan, Jan Dubois, Jarkko Hietaniemi,\nJohn Peacock, kafka, Karen Etheridge, Karl Williamson, Lukas Mai, Matthew Horsfall, Michael\nBunk, Peter Martini, Rafael Garcia-Suarez, Reini Urban, Ricardo Signes, Shirakata Kentaro,\nSmylers, Steve Hay, Thomas Sibley, Todd Rinaldo, Tony Cook, Vladimir Marek, Yves Orton.\n\nThe list above is almost certainly incomplete as it is automatically generated from version\ncontrol history. In particular, it does not include the names of the (very much appreciated)\ncontributors who reported issues to the Perl bug tracker.\n\nMany of the changes included in this version originated in the CPAN modules included in\nPerl's core. We're grateful to the entire CPAN community for helping Perl to flourish.\n\nFor a more complete list of all of Perl's historical contributors, please see the AUTHORS\nfile in the Perl source distribution.\n", "subsections": [ { "name": "Reporting Bugs", "content": "If you find what you think is a bug, you might check the articles recently posted to the\ncomp.lang.perl.misc newsgroup and the perl bug database at https://rt.perl.org/ . There may\nalso be information at http://www.perl.org/ , the Perl Home Page.\n\nIf you believe you have an unreported bug, please run the perlbug program included with your\nrelease. Be sure to trim your bug down to a tiny but sufficient test case. Your bug report,\nalong with the output of \"perl -V\", will be sent off to perlbug@perl.org to be analysed by\nthe Perl porting team.\n\nIf the bug you are reporting has security implications, which make it inappropriate to send\nto a publicly archived mailing list, then please send it to perl5-security-report@perl.org.\nThis points to a closed subscription unarchived mailing list, which includes all the core\ncommitters, who will be able to help assess the impact of issues, figure out a resolution,\nand help co-ordinate the release of patches to mitigate or fix the problem across all\nplatforms on which Perl is supported. Please only use this address for security issues in\nthe Perl core, not for modules independently distributed on CPAN.\n" } ] }, "SEE ALSO": { "content": "The Changes file for an explanation of how to view exhaustive details on what changed.\n\nThe INSTALL file for how to build Perl.\n\nThe README file for general stuff.\n\nThe Artistic and Copying files for copyright information.\n\n\n\nperl v5.34.0 2025-07-25 PERL5201DELTA(1)", "subsections": [] } } } }