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".
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
- •
- Accelerated Unicode case mappings ("/i",
"lc", "uc", etc).
- •
- 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.
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 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.