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perl584delta (1)


perl584delta - what is new for perl v5.8.4


Please see following description for synopsis


Perl Programmers Reference Guide                  PERL584DELTA(1)

     perl584delta - what is new for perl v5.8.4

     This document describes differences between the 5.8.3
     release and the 5.8.4 release.

Incompatible Changes
     Many minor bugs have been fixed. Scripts which happen to
     rely on previously erroneous behaviour will consider these
     fixes as incompatible changes :-) You are advised to perform
     sufficient acceptance testing on this release to satisfy
     yourself that this does not affect you, before putting this
     release into production.

     The diagnostic output of Carp has been changed slightly, to
     add a space after the comma between arguments. This makes it
     much easier for tools such as web browsers to wrap it, but
     might confuse any automatic tools which perform detailed
     parsing of Carp output.

     The internal dump output has been improved, so that non-
     printable characters such as newline and backspace are
     output in "\x" notation, rather than octal. This might just
     confuse non-robust tools which parse the output of modules
     such as Devel::Peek.

Core Enhancements
  Malloc wrapping
     Perl can now be built to detect attempts to assign
     pathologically large chunks of memory.  Previously such
     assignments would suffer from integer wrap-around during
     size calculations causing a misallocation, which would crash
     perl, and could theoretically be used for "stack smashing"
     attacks.  The wrapping defaults to enabled on platforms
     where we know it works (most AIX configurations, BSDi,
     Darwin, DEC OSF/1, FreeBSD, HP/UX, GNU Linux, OpenBSD,
     Solaris, VMS and most Win32 compilers) and defaults to
     disabled on other platforms.

  Unicode Character Database 4.0.1
     The copy of the Unicode Character Database included in Perl
     5.8 has been updated to 4.0.1 from 4.0.0.

  suidperl less insecure
     Paul Szabo has analysed and patched "suidperl" to remove
     existing known insecurities. Currently there are no known
     holes in "suidperl", but previous experience shows that we
     cannot be confident that these were the last. You may no
     longer invoke the set uid perl directly, so to preserve
     backwards compatibility with scripts that invoke
     #!/usr/bin/suidperl the only set uid binary is now

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     "sperl5.8."n ("sperl5.8.4" for this release). "suidperl" is
     installed as a hard link to "perl"; both "suidperl" and
     "perl" will invoke "sperl5.8.4" automatically the set uid
     binary, so this change should be completely transparent.

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

     In addition to bug fixes, "format"'s features have been
     enhanced. See perlform

Modules and Pragmata
     The (mis)use of "/tmp" in core modules and documentation has
     been tidied up.  Some modules available both within the perl
     core and independently from CPAN ("dual-life modules") have
     not yet had these changes applied; the changes will be
     integrated into future stable perl releases as the modules
     are updated on CPAN.

  Updated modules
         There is experimental support for Linux abstract Unix
         domain sockets.

         Synced with its CPAN version 2.10

         "syslog()" can now use numeric constants for facility
         names and priorities, in addition to strings.

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     Win32 has moved from the libwin32 module to
         core Perl

         Detached threads are now also supported on Windows.


Performance Enhancements
     o   Accelerated Unicode case mappings ("/i", "lc", "uc",

     o   In place sort optimised (eg "@a = sort @a")

     o   Unnecessary assignment optimised away in

           my $s = undef;
           my @a = ();
           my %h = ();

     o   Optimised "map" in scalar context

Utility Changes
     The Perl debugger (lib/ can now save all debugger
     commands for sourcing later, and can display the parent
     inheritance tree of a given class.

Installation and Configuration Improvements
     The build process on both VMS and Windows has had several
     minor improvements made. On Windows Borland's C compiler can
     now compile perl with PerlIO and/or USE_LARGE_FILES enabled.

     "perl.exe" on Windows now has a "Camel" logo icon. The use
     of a camel with the topic of Perl is a trademark of O'Reilly
     and Associates Inc., and is used with their permission (ie
     distribution of the source, compiling a Windows executable
     from it, and using that executable locally). Use of the
     supplied camel for anything other than a perl executable's
     icon is specifically not covered, and anyone wishing to
     redistribute perl binaries with the icon should check
     directly with O'Reilly beforehand.

     Perl should build cleanly on Stratus VOS once more.

Selected Bug Fixes
     More utf8 bugs fixed, notably in how "chomp", "chop",

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     "send", and "syswrite" and interact with utf8 data.
     Concatenation now works correctly when "use bytes;" is in

     Pragmata are now correctly propagated into (?{...})
     constructions in regexps.  Code such as

        my $x = qr{ ... (??{ $x }) ... };

     will now (correctly) fail under use strict. (As the inner $x
     is and has always referred to $::x)

     The "const in void context" warning has been suppressed for
     a constant in an optimised-away boolean expression such as
     "5 || print;"

     "perl -i" could "fchmod(stdin)" by mistake. This is serious
     if stdin is attached to a terminal, and perl is running as
     root. Now fixed.

New or Changed Diagnostics
     "Carp" and the internal diagnostic routines used by
     "Devel::Peek" have been made clearer, as described in
     "Incompatible Changes"

Changed Internals
     Some bugs have been fixed in the hash internals. Restricted
     hashes and their place holders are now allocated and deleted
     at slightly different times, but this should not be visible
     to user code.

Future Directions
     Code freeze for the next maintenance release (5.8.5) will be
     on 30th June 2004, with release by mid July.

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

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     See attributes(5) for descriptions of the following

     |Availability   | runtime/perl-512 |
     |Stability      | Uncommitted      |
     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.

     This software was built from source available at  The original
     community source was downloaded from

     Further information about this software can be found on the
     open source community website at

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