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PERL584DELTA(1) Perl Programmers Reference Guide PERL584DELTA(1)
NAME
perl584delta - what is new for perl v5.8.4
DESCRIPTION
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 previ-
ously 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 char-
acters 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 inte-
ger 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 "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" automat-
ically the set uid binary, so this change should be completely trans-
parent.
For new projects the core perl team would strongly recommend that you
use dedicated, single purpose security tools such as "sudo" in prefer-
ence to "suidperl".
format
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 inde-
pendently 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
Attribute::Handlers
B
Benchmark
CGI
Carp
Cwd
Exporter
File::Find
IO
IPC::Open3
Local::Maketext
Math::BigFloat
Math::BigInt
Math::BigRat
MIME::Base64
ODBM_File
POSIX
Shell
Socket
There is experimental support for Linux abstract Unix domain sock-
ets.
Storable
Switch
Synced with its CPAN version 2.10
Sys::Syslog
"syslog()" can now use numeric constants for facility names and
priorities, in addition to strings.
Term::ANSIColor
Time::HiRes
Unicode::UCD
Win32
Win32.pm/Win32.xs has moved from the libwin32 module to core Perl
base
open
threads
Detached threads are now also supported on Windows.
utf8
Performance Enhancements
o Accelerated Unicode case mappings ("/i", "lc", "uc", etc).
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/perl5db.pl) 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, com-
piling a Windows executable from it, and using that executable
locally). Use of the supplied camel for anything other than a perl exe-
cutable'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", "send", and
"syswrite" and interact with utf8 data. Concatenation now works cor-
rectly when "use bytes;" is in scope.
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 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 pro-
gram 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/
SEE ALSO
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.
perl v5.8.8 2006-01-07 PERL584DELTA(1)
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