PERL584DELTA(1) Perl Programmers Reference Guide PERL584DELTA(1)NAMEperl584delta - 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 out-
put 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 patholog-
ically large chunks of memory. Previously such assignments
would suffer from integer wrap-around during size calcula-
tions 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 plat-
forms.
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
perl v5.8.8 2006-06-30 1
PERL584DELTA(1) Perl Programmers Reference Guide PERL584DELTA(1)
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
perl v5.8.8 2006-06-30 2
PERL584DELTA(1) Perl Programmers Reference Guide PERL584DELTA(1)
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
+ 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 sup-
plied camel for anything other than a perl executable's icon
is specifically not covered, and anyone wishing to redistri-
bute perl binaries with the icon should check directly with
O'Reilly beforehand.
perl v5.8.8 2006-06-30 3
PERL584DELTA(1) Perl Programmers Reference Guide PERL584DELTA(1)
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. Concate-
nation now works correctly when "use bytes;" is in scope.
Pragmata are now correctly propagated into (?{...}) con-
structions 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 news-
group 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
perl v5.8.8 2006-06-30 4
PERL584DELTA(1) Perl Programmers Reference Guide PERL584DELTA(1)
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 2006-06-30 5
