This document describes differences between the 5.8.1 release and the
If you are upgrading from an earlier release such as 5.6.1, first read
the perl58delta, which describes differences between 5.6.0 and 5.8.0,
and the perl581delta, which describes differences between 5.8.0 and
For threaded builds for modules calling certain re-entrant system
calls, binary compatibility was accidentally lost between 5.8.0 and
5.8.1. Binary compatibility with 5.8.0 has been restored in 5.8.2,
which necessitates breaking compatibility with 5.8.1. We see this as
the lesser of two evils.
This will only affect people who have a threaded perl 5.8.1, and
compiled modules which use these calls, and now attempt to run the
compiled modules with 5.8.2. The fix is to re-compile and re-install
the modules using 5.8.2.
The hash randomisation introduced with 5.8.1 has been amended. It
transpired that although the implementation introduced in 5.8.1 was
source compatible with 5.8.0, it was not binary compatible in certain
cases. 5.8.2 contains an improved implementation which is both source
and binary compatible with both 5.8.0 and 5.8.1, and remains robust
against the form of attack which prompted the change for 5.8.1.
We are grateful to the Debian project for their input in this area.
See "Algorithmic Complexity Attacks" in perlsec for the original
rationale behind this change.
Several memory leaks associated with variables shared between threads
have been fixed.
Modules and Pragmata
Updated Modules And Pragmata
The following modules and pragmata have been updated since Perl 5.8.1:
interpreter more than once in a single process.
Platform Specific Problems
Dynamic linker flags have been tweaked for Solaris and OS X, which
should solve problems seen while building some XS modules.
Bugs in OS/2 sockets and tmpfile have been fixed.
In OS X "setreuid" and friends are troublesome - perl will now work
around their problems as best possible.
Starting with 5.8.3 we intend to make more frequent maintenance
releases, with a smaller number of changes in each. The intent is to
propagate bug fixes out to stable releases more rapidly and make
upgrading stable releases less of an upheaval. This should give end
users more flexibility in their choice of upgrade timing, and allow
them easier assessment of the impact of upgrades. The current plan is
for code freezes as follows
o 5.8.3 23:59:59 GMT, Wednesday December 31st 2003
o 5.8.4 23:59:59 GMT, Wednesday March 31st 2004
o 5.8.5 23:59:59 GMT, Wednesday June 30th 2004
with the release following soon after, when testing is complete.
See "Future Directions" in perl581delta for more soothsaying.
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.com/, 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 email@example.com to be analysed by
the Perl porting team. You can browse and search the Perl 5 bugs at
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.
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