PERL587DELTA(1) Perl Programmers Reference Guide PERL587DELTA(1)

perl587delta - what is new for perl v5.8.7

This document describes differences between the 5.8.6 release and the 5.8.7 release.

There are no changes incompatible with 5.8.6.

The copy of the Unicode Character Database included in Perl 5.8 has been updated to 4.1.0 from 4.0.1. See <http://www.unicode.org/versions/Unicode4.1.0/#NotableChanges> for the notable changes.

A pair of exploits in "suidperl" involving debugging code have been closed.

For new projects the core perl team strongly recommends that you use dedicated, single purpose security tools such as "sudo" in preference to "suidperl".

The perl interpreter can be built to allow the use of a site customization script. By default this is not enabled, to be consistent with previous perl releases. To use this, add "-Dusesitecustomize" to the command line flags when running the "Configure" script. See also "-f" in perlrun.

"Config.pm" is now about 3K rather than 32K, with the infrequently used code and %Config values loaded on demand. This is transparent to the programmer, but means that most code will save parsing and loading 29K of script (for example, code that uses "File::Find").

"find2perl" has new options "-iname", "-path" and "-ipath".

The internal pointer mapping hash used during ithreads cloning now uses an arena for memory allocation. In tests this reduced ithreads cloning time by about 10%.

  • Checksums with "b" or "B" formats were broken.
  • "unpack" checksums could overflow with the "C" format.
  • "U0" and "C0" are now scoped to "()" "pack" sub-templates.
  • Counted length prefixes now don't change "C0"/"U0" mode.
  • "pack" "Z0" used to destroy the preceding character.
  • "P"/"p" "pack" formats used to only recognise literal "undef"

There is a new taint error, "%ENV is aliased to %s". This error is thrown when taint checks are enabled and when *ENV has been aliased, so that %ENV has no env-magic anymore and hence the environment cannot be verified as taint-free.

The internals of "pack" and "unpack" have been updated. All legitimate templates should work as before, but there may be some changes in the error reported for complex failure cases. Any behaviour changes for non-error cases are bugs, and should be reported.

There has been a fair amount of refactoring of the "C" source code, partly to make it tidier and more maintainable. The resulting object code and the "perl" binary may well be smaller than 5.8.6, and hopefully faster in some cases, but apart from this there should be no user-detectable changes.

"${^UTF8LOCALE}" has been added to give perl space access to "PL_utf8locale".

The size of the arenas used to allocate SV heads and most SV bodies can now be changed at compile time. The old size was 1008 bytes, the new default size is 4080 bytes.

Unicode strings returned from overloaded operators can be buggy. This is a long standing bug reported since 5.8.6 was released, but we do not yet have a suitable fix for it.

On UNICOS, lib/Math/BigInt/t/bigintc.t hangs burning CPU. ext/B/t/bytecode.t and ext/Socket/t/socketpair.t both fail tests. These are unlikely to be resolved, as our valiant UNICOS porter's last Cray is being decommissioned.

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://bugs.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. You can browse and search the Perl 5 bugs at http://bugs.perl.org/

The Changes file for 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.

2023-11-28 perl v5.38.2