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perl585delta - what is new for perl v5.8.5


This document describes differences between the 5.8.4 release and the 5.8.5 release.

Incompatible Changes

There are no changes incompatible with 5.8.4.

Core Enhancements

Perl's regular expression engine now contains support for matching on the intersection of two Unicode character classes. You can also now refer to user-defined character classes from within other user defined character classes.

Modules and Pragmata

Utility Changes

Perl's debugger

The debugger can now emulate stepping backwards, by restarting and rerunning all bar the last command from a saved command history.


h2ph is now able to understand a very limited set of C inline functions -- basically, the inline functions that look like CPP macros. This has been introduced to deal with some of the headers of the newest versions of the glibc. The standard warning still applies; to quote h2ph's documentation, you may need to dicker with the files produced.

Installation and Configuration Improvements

Perl 5.8.5 should build cleanly from source on LynxOS.

Selected Bug Fixes

New or Changed Diagnostics

Changed Internals

The Unicode character class files used by the regular expression engine are now built at build time from the supplied Unicode consortium data files, instead of being shipped prebuilt. This makes the compressed Perl source tarball about 200K smaller. A side effect is that the layout of files inside lib/unicore has changed.

Known Problems

The regression test t/uni/class.t is now performing considerably more tests, and can take several minutes to run even on a fast machine.

Platform Specific Problems

This release is known not to build on Windows 95.

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. 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.