- NAME
- DESCRIPTION
- Incompatible Changes
- Core Enhancements
- Modules and Pragmata
- Performance Enhancements
- Utility Changes
- Installation and Configuration Improvements
- Selected Bug Fixes
- New or Changed Diagnostics
- Changed Internals
- Future Directions
- Platform Specific Problems
- Reporting Bugs
- SEE ALSO
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 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 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
.
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 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
- 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 sockets.
- 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
-
In place sort optimised (eg
@a = sort @a
) -
Unnecessary assignment optimised away in
my $s = undef; my @a = (); my %h = ();
-
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, 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
, send
, and
syswrite
and interact with utf8 data. Concatenation now works correctly
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
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 protected] 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.