=head1 DESCRIPTION
-This document describes differences between the 5.6.0 release and the
-5.8.0 release.
+This document describes differences between the 5.6.0 release
+and the 5.8.0 release.
+
+Many of the bug fixes in 5.8.0 were already seen in the 5.6.1
+maintenance release since the two releases were kept closely
+coordinated.
+
+If you are upgrading from Perl 5.005_03, you might also want
+to read L<perl56delta>.
+
+=head1 Highlights In 5.8.0
+
+=over 4
+
+=item *
+
+Better Unicode support
+
+=item *
+
+New Thread Implementation
+
+=item *
+
+Many New Modules
+
+=item *
+
+Better Numeric Accuracy
+
+=item *
+
+Safe Signals
+
+=item *
+
+More Extensive Regression Testing
+
+=back
=head1 Incompatible Changes
modules. The change was made to make Perl more compliant with other
applications like modperl which are using the AIX native interface.
+=head2 Attributes for C<my> variables now handled at run-time.
+
+The C<my EXPR : ATTRS> syntax now applies variable attributes at
+run-time. (Subroutine and C<our> variables still get attributes applied
+at compile-time.) See L<attributes> for additional details. In particular,
+however, this allows variable attributes to be useful for C<tie> interfaces,
+which was a deficiency of earlier releases. Note that the new semantics
+doesn't work with the Attribute::Handlers module (as of version 0.76).
+
=head2 Socket Extension Dynamic in VMS
The Socket extension is now dynamically loaded instead of being
TCP/IP stacks of VMS: we do not know since we weren't able to test
Perl in such configurations.
-=head2 Different Definition of the Unicode Character Classes \p{In...}
+=head2 IEEE-format Floating Point Default on OpenVMS Alpha
-As suggested by the Unicode consortium, the Unicode character classes
-now prefer I<scripts> as opposed to I<blocks> (as defined by Unicode);
-in Perl, when the C<\p{In....}> and the C<\p{In....}> regular expression
-constructs are used. This has changed the definition of some of those
-character classes.
+Perl now uses IEEE format (T_FLOAT) as the default internal floating
+point format on OpenVMS Alpha, potentially breaking binary compatibility
+with external libraries or existing data. G_FLOAT is still available as
+a configuration option. The default on VAX (D_FLOAT) has not changed.
-The difference between scripts and blocks is that scripts are the
-glyphs used by a language or a group of languages, while the blocks
-are more artificial groupings of 256 characters based on the Unicode
-numbering.
+=head2 New Unicode Properties
-In general this change results in more inclusive Unicode character
-classes, but changes to the other direction also do take place:
-for example while the script C<Latin> includes all the Latin
-characters and their various diacritic-adorned versions, it
-does not include the various punctuation or digits (since they
-are not solely C<Latin>).
+Unicode I<scripts> are now supported. Scripts are similar to (and superior
+to) Unicode I<blocks>. The difference between scripts and blocks is that
+scripts are the glyphs used by a language or a group of languages, while
+the blocks are more artificial groupings of (mostly) 256 characters based
+on the Unicode numbering.
-Changes in the character class semantics may have happened if a script
-and a block happen to have the same name, for example C<Hebrew>.
-In such cases the script wins and C<\p{InHebrew}> now means the script
-definition of Hebrew. The block definition in still available,
-though, by appending C<Block> to the name: C<\p{InHebrewBlock}> means
-what C<\p{InHebrew}> meant in perl 5.6.0. For the full list
-of affected character classes, see L<perlunicode/Blocks>.
+In general, scripts are more inclusive, but not universally so. For
+example, while the script C<Latin> includes all the Latin characters and
+their various diacritic-adorned versions, it does not include the various
+punctuation or digits (since they are not solely C<Latin>).
-=head2 Perl Parser Stress Tested
+A number of other properties are now supported, including C<\p{L&}>,
+C<\p{Any}> C<\p{Assigned}>, C<\p{Unassigned}>, C<\p{Blank}> and
+C<\p{SpacePerl}> (along with their C<\P{...}> versions, of course).
+See L<perlunicode> for details, and more additions.
-The Perl parser has been stress tested using both random input and
-Markov chain input and the few found crashes and lockups have been
-fixed.
+The C<In> or C<Is> prefix to names used with the C<\p{...}> and C<\P{...}>
+are now almost always optional. The only exception is that a C<In> prefix
+is required to signify a Unicode block when a block name conflicts with a
+script name. For example, C<\p{Tibetan}> refers to the script, while
+C<\p{InTibetan}> refers to the block. When there is no name conflict, you
+can omit the C<In> from the block name (e.g. C<\p{BraillePatterns}>), but
+to be safe, it's probably best to always use the C<In>).
=head2 REF(...) Instead Of SCALAR(...)
of "SCALAR(0x81485ec)" in order to be more consistent with the return
value of ref().
+=head2 pack/unpack D/F recycled
+
+The undocumented pack/unpack template letters D/F have been recycled
+for better use: now they stand for long double (if supported by the
+platform) and NV (Perl internal floating point type). (They used
+to be aliases for d/f, but you never knew that.)
+
=head2 Deprecations
=over 4
=item *
+The builtin dump() function has probably outlived most of its
+usefulness. The core-dumping functionality will remain in future
+available as an explicit call to C<CORE::dump()>, but in future
+releases the behaviour of an unqualified C<dump()> call may change.
+
+=item *
+
The very dusty examples in the eg/ directory have been removed.
Suggestions for new shiny examples welcome but the main issue is that
the examples need to be documented, tested and (most importantly)
=item *
The list of filenames from glob() (or <...>) is now by default sorted
-alphabetically to be csh-compliant. (bsd_glob() does still sort platform
+alphabetically to be csh-compliant (which is what happened before
+in most UNIX platforms). (bsd_glob() does still sort platform
natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.)
=item *
+Spurious syntax errors generated in certain situations, when glob()
+caused File::Glob to be loaded for the first time, have been fixed.
+
+=item *
+
Although "you shouldn't do that", it was possible to write code that
depends on Perl's hashed key order (Data::Dumper does this). The new
algorithm "One-at-a-Time" produces a different hashed key order.
implemented differently. Not only is the current interface rather
ugly, but the current implementation slows down normal array and hash
use quite noticeably. The C<fields> pragma interface will remain
-available.
+available. The I<restricted hashes> interface is expected to
+be the replacement interface (see L<Hash::Util>).
=item *
-The syntaxes C<< @a->[...] >> and C<< %h->{...}>> have now been deprecated.
+The syntaxes C<< @a->[...] >> and C<< %h->{...} >> have now been deprecated.
=item *
the interface was a mistake. Sorry about that. For similar
functionality, see pack('U0', ...) and pack('C0', ...).
+=item *
+
+Earlier Perls treated "sub foo (@bar)" as equivalent to "sub foo (@)".
+The prototypes are now checked at compile-time for invalid characters.
+An optional warning is generated ("Illegal character in prototype...")
+but this may be upgraded to a fatal error in a future release.
+
=back
=head1 Core Enhancements
creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
the child process.
+=item *
+
+If your locale environment variables (LANGUAGE, LC_ALL, LC_CTYPE, LANG)
+contain the strings 'UTF-8' or 'UTF8' (case-insensitive matching),
+the default encoding of your STDIN, STDOUT, and STDERR, and of
+B<any subsequent file open>, is UTF-8.
+
+=item *
+
+If your filesystem supports returning UTF-8 encoded filenames,
+it is possible to make Perl to understand that the filenames
+returned by readdir() and glob() are in Unicode.
+
=back
-=head2 Signals Are Now Safe
+=head2 Safe Signals
Perl used to be fragile in that signals arriving at inopportune moments
could corrupt Perl's internal state. Now Perl postpones handling of
-signals until it's safe.
+signals until it's safe (between opcodes).
+
+This change may have surprising side effects because signals no longer
+interrupt Perl instantly. Perl will now first finish whatever it was
+doing, like finishing an internal operation (like sort()) or an
+external operation (like an I/O operation), and only then look at any
+arrived signals (and before starting the next operation). No more corrupt
+internal state since the current operation is always finished first,
+but the signal may take more time to get heard. Note that breaking
+out from potentially blocking operations should still work, though.
=head2 Unicode Overhaul
Unicode in general should be now much more usable than in Perl 5.6.0
(or even in 5.6.1). Unicode can be used in hash keys, Unicode in
regular expressions should work now, Unicode in tr/// should work now,
-Unicode in I/O should work now.
+Unicode in I/O should work now. See L<perluniintro> for introduction
+and L<perlunicode> for details.
=over 4
=item *
The Unicode Character Database coming with Perl has been upgraded
-to Unicode 3.1.1. For more information, see http://www.unicode.org/.
+to Unicode 3.2.0. For more information, see http://www.unicode.org/ .
=item *
For developers interested in enhancing Perl's Unicode capabilities:
almost all the UCD files are included with the Perl distribution in
-the lib/unicore subdirectory. The most notable omission, for space
+the F<lib/unicore subdirectory>. The most notable omission, for space
considerations, is the Unihan database.
=item *
-The Unicode character classes \p{Blank} and \p{SpacePerl} have been
-added. "Blank" is like C isblank(), that is, it contains only
-"horizontal whitespace" (the space character is, the newline isn't),
-and the "SpacePerl" is the Unicode equivalent of C<\s> (\p{Space}
-isn't, since that includes the vertical tabulator character, whereas
-C<\s> doesn't.)
+The properties \p{Blank} and \p{SpacePerl} have been added. "Blank" is like
+C isblank(), that is, it contains only "horizontal whitespace" (the space
+character is, the newline isn't), and the "SpacePerl" is the Unicode
+equivalent of C<\s> (\p{Space} isn't, since that includes the vertical
+tabulator character, whereas C<\s> doesn't.)
+
+See "New Unicode Properties" earlier in this document for additional
+information on changes with Unicode properties.
=back
arithmetics. (Previously Perl always preferred floating point numbers
in its math.)
-=head2 Miscellaneous Enhancements
+=head2 Miscellaneous Changes
=over 4
=item *
+The builtin dump() now gives an optional warning
+C<dump() better written as CORE::dump()>,
+meaning that by default C<dump(...)> is resolved as the builtin
+dump() which dumps core and aborts, not as (possibly) user-defined
+C<sub dump>. To call the latter, qualify the call as C<&dump(...)>.
+(The whole dump() feature is to considered deprecated, and possibly
+removed/changed in future releases.)
+
+=item *
+
+chomp() and chop() are now overridable. Note, however, that their
+prototype (as given by C<prototype("CORE::chomp")> is undefined,
+because it cannot be expressed and therefore one cannot really write
+replacements to override these builtins.
+
+=item *
+
END blocks are now run even if you exit/die in a BEGIN block.
Internally, the execution of END blocks is now controlled by
PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new
=item *
Lvalue subroutines can now return C<undef> in list context.
+However, the lvalue subroutine feature still remains experimental.
+
+=item *
+
+A lost warning "Can't declare ... dereference in my" has been
+restored (Perl had it earlier but it became lost in later releases.)
=item *
=item *
+C<pack() / unpack()> now can group template letters with C<()> and then
+apply repetition/count modifiers on the groups.
+
+=item *
+
+C<pack() / unpack()> can now process the Perl internal numeric types:
+IVs, UVs, NVs-- and also long doubles, if supported by the platform.
+The template letters are C<j>, C<J>, C<F>, and C<D>.
+
+=item *
+
C<pack('U0a*', ...)> can now be used to force a string to UTF8.
=item *
print "%2\$s %1\$s\n", "foo", "bar";
-will print "bar foo\n"; This feature helps in writing
-internationalised software.
+will print "bar foo\n". This feature helps in writing
+internationalised software, and in general when the order
+of the parameters can vary.
=item *
=item *
-UNTIE method is now recognised.
+A new command-line option, C<-t> is available. It is the
+little brother of C<-T>: instead of dying on taint violations,
+lexical warnings are given. B<This is only meant as a temporary
+debugging aid while securing the code of old legacy applications.
+This is not a substitute for -T.>
+
+=item *
+
+In other taint news, the C<exec LIST> and C<system LIST> have now been
+considered too risky (think C<exec @ARGV>: it can start any program
+with any arguments), and now the said forms cause a warning.
+You should carefully launder the arguments to guarantee their
+validity. In future releases of Perl the forms will become fatal
+errors so consider starting laundering now.
+
+=item *
+
+If tr/// is just counting characters, it doesn't attempt to
+modify its target.
+
+=item *
+
+untie() will now call an UNTIE() hook if it exists. See L<perltie>
+for details.
=item *
have been relaxed and simplified: now you can have an underscore
simply B<between digits>.
+=item *
+
+Rather than relying on C's argv[0] (which may not contain a full pathname)
+where possible $^X is now set by asking the operating system.
+(eg by reading F</proc/self/exe> on Linux, F</proc/curproc/file> on FreeBSD)
+
+=item *
+
+A new variable, C<${^TAINT}>, indicates whether taint mode is enabled.
+
+=item *
+
+You can now override the readline() builtin, and this overrides also
+the <FILEHANDLE> angle bracket operator.
+
+=item *
+
+The command-line options -s and -F are now recognized on the shebang
+(#!) line.
+
+=item *
+
+Use of the C</c> match modifier without an accompanying C</g> modifier
+elicits a new warning: C<Use of /c modifier is meaningless without /g>.
+
+Use of C</c> in substitutions, even with C</g>, elicits
+C<Use of /c modifier is meaningless in s///>.
+
+Use of C</g> with C<split> elicits C<Use of /g modifier is meaningless
+in split>.
+
=back
=head1 Modules and Pragmata
=item *
+The new bignum, bigint, and bigrat pragmas implement transparent
+bignum support (using the Math::BigInt, Math::BigFloat, and
+Math::BigRat backends), by Tels.
+
+=item *
+
C<Class::ISA> for reporting the search path for a class's ISA tree,
by Sean Burke, has been added. See L<Class::ISA>.
C<Devel::PPPort>, originally from Kenneth Albanowski and now
maintained by Paul Marquess, has been added. It is primarily used
-by C<h2xs> to enhance portability of of XS modules between different
+by C<h2xs> to enhance portability of XS modules between different
versions of Perl.
=item *
=item *
-C<Encode>, by Nick Ing-Simmons, provides a mechanism to translate
-between different character encodings. Support for Unicode,
-ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
-compiled in to the module. Several other encodings (like Japanese,
-Chinese, and MacIntosh encodings) are included and will be loaded at
-runtime. See L<Encode>.
+C<Encode>, by Nick Ing-Simmons and Dan Kogai, provides a mechanism to
+translate between different character encodings. Support for Unicode,
+ISO-8859-1, and ASCII are compiled in to the module. Several other
+encodings (like the rest of the ISO-8859, CP*/Win*, Mac, KOI8-R, three
+variants EBCDIC, Chinese, Japanese, and Korean encodings) are included
+and can be loaded at runtime. (For space considerations, the largest
+Chinese encodings have been separated into their own CPAN module,
+Encode::HanExtra, which Encode will use if available). See L<Encode>.
Any encoding supported by Encode module is also available to the
":encoding()" layer if PerlIO is used.
=item *
+C<Hash::Util> is the interface to the new I<restricted hashes>
+feature. A restricted hash is restricted to a certain set of keys,
+no keys outside the set can be added. Also individual keys can be
+restricted so that the key cannot be deleted and the value cannot be
+changed. (Implemented by Jeffrey Friedl, Nick Ing-Simmons, and
+Michael Schwern.)
+
+=item *
+
C<I18N::Langinfo> can be use to query locale information.
See L<I18N::Langinfo>.
=item *
+C<if> is a new pragma for conditional inclusion of modules, from
+Ilya Zakharevich.
+
+=item *
+
L<libnet> is a collection of perl5 modules related to network
programming, from Graham Barr. See L<Net::FTP>, L<Net::NNTP>,
-L<Net::Ping>, L<Net::POP3>, L<Net::SMTP>, and L<Net::Time>.
+L<Net::Ping> (not part of libnet, but related), L<Net::POP3>,
+L<Net::SMTP>, and L<Net::Time>.
Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure.
=item *
+Math::BigRat for big rational numbers, to accompany Math::BigInt and
+Math::BigFloat, from Tels.
+
+=item *
+
C<Memoize> can make your functions faster by trading space for time,
from Mark-Jason Dominus. See L<Memoize>.
=item *
C<Pod::ParseLink>, by Russ Allbery, has been added,
-to parse L<> links in pods as described in the new
+to parse LZ<><> links in pods as described in the new
perlpodspec.
=item *
=item *
-C<Test::Simple> has the- basic utilities for writing tests, by Michael
+C<Test::Simple> has basic utilities for writing tests, by Michael
Schwern. See L<Test::Simple>.
=item *
=item *
+C<Tie::File>, by Mark-Jason Dominus, associates a Perl array with the
+lines of a file.
+
+=item *
+
+C<Tie::Memoize>, by Ilya Zakharevich, provides on-demand loaded hashes.
+
+=item *
+
C<Tie::RefHash::Nestable>, by Edward Avis, allows storing hash
references (unlike the standard Tie::RefHash) The module is contained
within Tie::RefHash, see L<Tie::RefHash>.
=item *
+DB_File now supports newer Berkeley DB versions, among
+other improvements.
+
+=item *
+
The English module can now be used without the infamous performance
hit by saying
- use English '-no_performance_hit';
+ use English '-no_match_vars';
(Assuming, of course, that one doesn't need the troublesome variables
C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
=item *
+File::Find now chdir()s correctly when chasing symbolic links.
+
+=item *
+
File::Find now has pre- and post-processing callbacks. It also
correctly changes directories when chasing symbolic links. Callbacks
(naughtily) exiting with "next;" instead of "return;" now work.
=item *
+The warnings issued by File::Find now belong to their own category.
+You can enable/disable them with C<use/no warnings 'File::Find';>.
+
+=item *
+
File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
prototype mismatch with CORE::glob().
=item *
+ExtUtils::MakeMaker now uses File::Spec internally, which hopefully
+leads into better portability.
+
+=item *
+
Math::BigFloat and Math::BigInt have undergone a full rewrite.
They are now magnitudes faster, and they support various
bignum libraries such as GMP and PARI as their backends.
=item *
-Net::Ping has been enhanced. There is now "external" protocol which
-uses Net::Ping::External module which runs external ping(1) and parses
-the output. An alpha version of Net::Ping::External is available in
-CPAN and in 5.7.2 the Net::Ping::External may be integrated to Perl.
+Math::Complex handles inf, NaN etc., better.
=item *
-C<POSIX::sigaction()> is now much more flexible and robust.
+Net::Ping has been muchly enhanced: multihoming is now supported,
+Win32 functionality is better, there is now time measuring
+functionality (optionally high-resolution using Time::HiRes),
+and there is now "external" protocol which uses Net::Ping::External
+module which runs your external ping utility and parses the output.
+A version of Net::Ping::External is available in CPAN.
+
+Note that some of the Net::Ping tests are disabled when running
+under the Perl distribution since one cannot assume one or more
+of the following: enabled echo port at localhost, full Internet
+connectivity, or sympathetic firewalls. You can set the environment
+variable PERL_TEST_Net_Ping to "1" (one) before running the Perl test
+suite to enable all the Net::Ping tests.
+
+=item *
+
+POSIX::sigaction() is now much more flexible and robust.
You can now install coderef handlers, 'DEFAULT', and 'IGNORE'
handlers, installing new handlers was not atomic.
=item *
-C<%INC> now localised in a Safe compartment so that use/require work.
+In Safe the C<%INC> now localised in a Safe compartment so that
+use/require work.
+
+=item *
+
+In SDBM_File on dosish platforms, some keys went missing because of
+lack of support for files with "holes". A workaround for the problem
+has been added.
+
+=item *
+
+In Search::Dict one can now have a pre-processing hook for the
+lines being searched.
=item *
=item *
+In Sys::Syslog there is now a failover mechanism that will go
+through alternative connection mechanisms until the message
+is successfully logged.
+
+=item *
+
The Test module has been significantly enhanced.
=item *
-The C<vars> pragma now supports declaring fully qualified variables.
+Time::Local::timelocal() does not handle fractional seconds anymore.
+The rationale is that neither does localtime(), and timelocal() and
+localtime() are supposed to be inverses of each other.
+
+=item *
+
+The vars pragma now supports declaring fully qualified variables.
(Something that C<our()> does not and will not support.)
=item *
-The utf8:: name space (as in the pragma) provides various
+The C<utf8::> name space (as in the pragma) provides various
Perl-callable functions to provide low level access to Perl's
internal Unicode representation. At the moment only length()
has been implemented.
=item *
+C<enc2xs> is a tool for people adding their own encodings to the
+Encode module.
+
+=item *
+
C<h2ph> now supports C trigraphs.
=item *
C<perlcc> has been rewritten and its user interface (that is,
command line) is much more like that of the UNIX C compiler, cc.
+(The perlbc tools has been removed. Use C<perlcc -B> instead.)
+
+=item *
+
+C<perlivp> is a new Installation Verification Procedure utility
+for running any time after installing Perl.
=item *
-C<perlivp> is a new utility for doing Installation Verification
-Procedure after installing Perl.
+C<piconv> is an implementation of the character conversion utility
+C<iconv>, demonstrating the new Encode module.
=item *
=item *
+C<pod2html> now produces XHTML 1.0.
+
+=item *
+
+C<pod2html> now understands POD written using different line endings
+(PC-like CRLF versus UNIX-like LF versus MacClassic-like CR).
+
+=item *
+
C<s2p> has been completely rewritten in Perl. (It is in fact a full
implementation of sed in Perl: you can use the sed functionality by
using the C<psed> utility.)
=item *
perlebcdic contains considerations for running Perl on EBCDIC platforms.
-Note that unfortunately EBCDIC platforms that used to be supported back
-in Perl 5.005 are still unsupported by Perl 5.8.0; the plan, however, is
-to bring them back to the fold.
=item *
=item *
+perlpacktut is a pack() tutorial.
+
+=item *
+
perlpod has been rewritten to be clearer and to record the best
practices gathered over the years.
=item *
-perlposix-bc explains using Perl on the POSIX-BC platform
-(an EBCDIC mainframe platform).
-
-=item *
-
perlretut is a regular expression tutorial.
=item *
=item *
-perluniintro is an introduction to using Unicode in Perl
-(perlunicode is more of a reference)
+perluniintro is an introduction to using Unicode in Perl.
+(perlunicode is more of a detailed reference and background
+information)
=item *
=item *
-The documentation for the WinCE platform is called "CE", to avoid
-confusion with the perlwin32 documentation on 8.3-restricted filesystems.
+The documentation for the WinCE platform is called perlce (README.ce
+in the source code kit), to avoid confusion with the perlwin32
+documentation on 8.3-restricted filesystems.
=back
=item *
-map() that changes the size of the list should now work faster.
+map() could get pathologically slow when the result list it generates
+is larger than the source list. The performance has been improved for
+common scenarios.
=item *
=item *
Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm
-(http://burtleburtle.net/bob/hash/doobs.html). This algorithm is
+( http://burtleburtle.net/bob/hash/doobs.html ). This algorithm is
reasonably fast while producing a much better spread of values than
the old hashing algorithm (originally by Chris Torek, later tweaked by
Ilya Zakharevich). Hash values output from the algorithm on a hash of
=item *
+Configure support for pdp11-style memory models has been removed due
+to obsolescence.
+
+=item *
+
configure.gnu now works with options with whitespace in them.
=item *
But note that the Thread.pm interface is now shared by both
thread models.
+=item *
+
+The Gconvert macro ($Config{d_Gconvert}) used by perl for stringifying
+floating-point numbers is now more picky about using sprintf %.*g
+rules for the conversion. Some platforms that used to use gcvt may
+now resort to the slower sprintf.
+
=back
=head2 New Or Improved Platforms
=item *
-AtheOS (http://www.atheos.cx/) is a new platform.
+AtheOS ( http://www.atheos.cx/ ) is a new platform.
+
+=item *
+
+BeOS has been reclaimed.
=item *
=item *
+All the NetBSD specific patches (except for the installation
+specific ones) have been merged back to the main distribution.
+
+=item *
+
NetWare from Novell is now supported. See L<perlnetware>.
=item *
=item *
+NEC SUPER-UX is now supported.
+
+=item *
+
+All the OpenBSD specific patches (except for the installation
+specific ones) have been merged back to the main distribution.
+
+=item *
+
+Perl has been tested with the GNU pth userlevel thread package
+( http://www.gnu.org/software/pth/pth.html ) . All but one thread
+test worked, and that one failure was because of test results arriving
+in unexpected order.
+
+=item *
+
Amdahl UTS UNIX mainframe platform is now supported.
=item *
=item *
+caller() could cause core dumps in certain situations. Carp was sometimes
+affected by this problem.
+
+=item *
+
chop(@list) in list context returned the characters chopped in
reverse order. This has been reversed to be in the right order.
Several debugger fixes: exit code now reflects the script exit code,
condition C<"0"> now treated correctly, the C<d> command now checks
-line number, the C<$.> no longer gets corrupted, all debugger output now
-goes correctly to the socket if RemotePort is set.
+line number, the C<$.> no longer gets corrupted, all debugger output
+now goes correctly to the socket if RemotePort is set.
+
+=item *
+
+Perl 5.6.0 could emit spurious warnings about redefinition of dl_error()
+when statically building extensions into perl. This has been corrected.
=item *
=item *
C<*foo{FORMAT}> now works.
+=item *
+
+Infinity is now recognized as a number.
=item *
=item *
-Lexical warnings now propagating correctly between scopes.
+Lexical warnings now propagating correctly between scopes
+and into C<eval "...">.
+
+=item *
+
+C<use warnings qw(FATAL all)> did not work as intended. This has been
+corrected.
+
+=item *
+
+warnings::enabled() now reports the state of $^W correctly if the caller
+isn't using lexical warnings.
=item *
=item *
+Numeric conversions did not recognize changes in the string value
+properly in certain circumstances.
+
+=item *
+
Attributes (like :shared) didn't work with our().
=item *
=item *
+"our" variables of the same name declared in two sibling blocks
+resulted in bogus warnings about "redeclaration" of the variables.
+The problem has been corrected.
+
+=item *
+
pack "Z" now correctly terminates the string with "\0".
=item *
=item *
-C<q(a\\b)> now parses correctly as C<'a\\b'>.
+C<qw(a\\b)> now parses correctly as C<'a\\b'>.
+
+=item *
+
+pos() did not return the correct value within s///ge in earlier
+versions. This is now handled correctly.
=item *
sort() arguments are now compiled in the right wantarray context
(they were accidentally using the context of the sort() itself).
+The comparison block is now run in scalar context, and the arguments
+to be sorted are always provided list context.
=item *
=item *
+Some cases of inconsistent taint propagation (such as within hash
+values) have been fixed.
+
+=item *
+
+The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds
+of simple pattern matches. These are now handled better.
+
+=item *
+
+Regular expression debug output (whether through C<use re 'debug'>
+or via C<-Dr>) now looks better.
+
+=item *
+
+Multi-line matches like C<"a\nxb\n" =~ /(?!\A)x/m> were flawed. The
+bug has been fixed.
+
+=item *
+
+Use of $& could trigger a core dump under some situations. This
+is now avoided.
+
+=item *
+
The regular expression captured submatches ($1, $2, ...) are now
more consistently unset if the match fails, instead of leaving false
data lying around in them.
=item *
-C<Sys::Syslog> ignored the C<LOG_AUTH> constant.
+readline() on files opened in "slurp" mode could return an extra "" at
+the end in certain situations. This has been corrected.
+
+=item *
+
+Autovivification of symbolic references of special variables described
+in L<perlvar> (as in C<${$num}>) was accidentally disabled. This works
+again now.
+
+=item *
+
+Sys::Syslog ignored the C<LOG_AUTH> constant.
=item *
=item *
+If C<STDERR> is tied, warnings caused by C<warn> and C<die> now
+correctly pass to it.
+
+=item *
+
Several Unicode fixes.
=over 8
=item *
Comparing with utf8 data does not magically upgrade non-utf8 data
-into utf8.
+into utf8. (This was a problem for example if you were mixing data
+from I/O and Unicode data: your output might have got magically encoded
+as UTF-8.)
+
+=item *
+
+Generating illegal Unicode code points like U+FFFE, or the UTF-16
+surrogates, now also generates an optional warning.
=item *
=item *
+Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious warnings.
+This has been corrected.
+
+=item *
+
Zero entries were missing from the Unicode classes like C<IsDigit>.
=back
+=item *
+
+Large unsigned numbers (those above 2**31) could sometimes lose their
+unsignedness, causing bogus results in arithmetic operations.
+
=back
=head2 Platform Specific Changes and Fixes
Cygwin
-Numerous updates; currently synchronised with Cygwin 1.1.4.
+Numerous updates; currently synchronised with Cygwin 1.3.10.
=item *
HP-UX
-README.hpux updated; C<Configure -Duse64bitall> now almost works.
+README.hpux updated; C<Configure -Duse64bitall> now works.
=item *
chdir() now works better despite a CRT bug; now works with MULTIPLICITY
(see INSTALL); now works with Perl's malloc.
+The tainting of C<%ENV> elements via C<keys> or C<values> was previously
+unimplemented. It now works as documented.
+
+The C<waitpid> emulation has been improved. The worst bug (now fixed)
+was that a pid of -1 would cause a wildcard search of all processes on
+the system. The most significant enhancement is that we can now
+usually get the completion status of a terminated process.
+
+POSIX-style signals are now emulated much better on VMS versions prior
+to 7.0.
+
+The C<system> function and backticks operator have improved
+functionality and better error handling.
+
+File access tests now use current process privileges rather than the
+user's default privileges, which could sometimes result in a mismatch
+between reported access and actual access.
+
=item *
Windows
=item *
+Current directory entries in %ENV are now correctly propagated to child
+processes.
+
+=item *
+
$ENV{LIB} now used to search for libs under Visual C.
=item *
-Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
-Other bugs in chdir() and Cwd::cwd() have also been fixed.
+fork() emulation has been improved in various ways, but still continues
+to be experimental. See L<perlfork> for known bugs and caveats.
=item *
=item *
+Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
+Other bugs in chdir() and Cwd::cwd() have also been fixed.
+
+=item *
+
HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
=item *
=item *
+%SIG has been enabled under USE_ITHREADS, but its use is completely
+unsupported under all configurations.
+
+=item *
+
Less stack reserved per thread so that more threads can run
concurrently. (Still 16M per thread.)
=item *
-wait() and waitpid() now work much better.
+wait(), waitpid() and backticks now return the correct exit status under
+Windows 9x.
=item *
winsock handle leak fixed.
+=item *
+
+The Perl parser has been stress tested using both random input and
+Markov chain input and the few found crashes and lockups have been
+fixed.
+
=back
=back
=item *
+The lexical warnings category "deprecated" is no longer a sub-category
+of the "syntax" category. It is now a top-level category in its own
+right.
+
+=item *
+
All regular expression compilation error messages are now hopefully
easier to understand both because the error message now comes before
the failed regex and because the point of failure is now clearly
=item *
+The debugger (perl5db.pl) has been modified to present a more
+consistent commands interface, via (CommandSet=580). perl5db.t was
+also added to test the changes, and as a placeholder for further tests.
+
+See L<perldebug>.
+
+=item *
+
+The debugger has a new C<dumpDepth> option to control the maximum
+depth to which nested structures are dumped. The C<x> command has
+been extended so that C<x N EXPR> dumps out the value of I<EXPR> to a
+depth of at most I<N> levels.
+
+=item *
+
+The debugger can now show lexical variables if you have the CPAN
+module PadWalker installed.
+
+=item *
+
If an attempt to use a (non-blessed) reference as an array index
is made, a warning is given.
=item *
Certain regex modifiers such as C<(?o)> make sense only if applied to
-the entire regex. You will an optional warning if you try to do otherwise.
+the entire regex. You will get an optional warning if you try to do
+otherwise.
=item *
-Using arrays or hashes as references (e.g. C<< %foo->{bar} >>
+Using arrays or hashes as references (e.g. C<< %foo->{bar} >>
has been deprecated for a while. Now you will get an optional warning.
+=item *
+
+Using C<sort> in scalar context now issues an optional warning.
+This didn't do anything useful, as the sort was not performed.
+
=back
=head1 Changed Internals
=item *
-Now xsubs can have attributes just like subs.
+Now xsubs can have attributes just like subs. (Well, at least the
+built-in attributes.)
=item *
probably going to be removed in Perl 5.10. In any case, suidperl
should only be used by security experts who know exactly what they are
doing and why they are using suidperl instead of some other solution
-such as sudo (see http://www.courtesan.com/sudo/).
+such as sudo ( see http://www.courtesan.com/sudo/ ).
=head1 New Tests
-Several new tests have been added, especially for the F<lib> subsection.
+Several new tests have been added, especially for the F<lib>
+subsection. There are now about 56 000 individual tests (spread over
+about 620 test scripts), in the regression suite (5.6.1 has about
+11700 tests, in 258 test scripts) Many of the new tests are introduced
+by the new modules, but still in general Perl is now more thoroughly
+tested.
+
+Because of the large number of tests, running the regression suite
+will take considerably longer time than it used to: expect the suite
+to take up to 4-5 times longer to run than in perl 5.6. In a really
+fast machine you can hope to finish the suite in about 6-8 minutes
+(wallclock time).
The tests are now reported in a different order than in earlier Perls.
(This happens because the test scripts from under t/lib have been moved
=head1 Known Problems
-Note that unlike other sections in this document (which describe
-changes since 5.7.0) this section is cumulative containing known
-problems for all the 5.7 releases.
-
=head2 AIX
=over 4
resulting in few random tests failing, but when the failing tests
are run by hand, they succeed. We suggest upgrading to at least
vac version 5.0.1.0, that has been known to compile Perl correctly.
-"lslpp -L|grep vac.C" will tell you the vac version.
+"lslpp -L|grep vac.C" will tell you the vac version. See README.aix.
+
+=item *
+
+If building threaded Perl, you may get compilation warning from pp_sys.c:
+
+ "pp_sys.c", line 4651.39: 1506-280 (W) Function argument assignment between types "unsigned char*" and "const void*" is not allowed.
+
+This is harmless; it is caused by the getnetbyaddr() and getnetbyaddr_r()
+having slightly different types for their first argument.
=back
works, but for example C<bin:perl -v> doesn't. The exact reason isn't
known but the current suspect is the F<ixemul> library.
-=head2 lib/ftmp-security tests warn 'system possibly insecure'
+=head2 FreeBSD Failing locale Test 117 For ISO8859-15 Locales
-Don't panic. Read INSTALL 'make test' section instead.
+The ISO8859-15 locales may fail the locale test 117 in FreeBSD.
+This is caused by the characters \xFF (y with diaeresis) and \xBE
+(Y with diaeresis) not behaving correctly when being matched
+case-insensitively.
-=head2 Cygwin intermittent failures of lib/Memoize/t/expire_file 11 and 12
+=head2 mod_perl 1.26 Doesn't Build With Threaded Perl
-The subtests 11 and 12 sometimes fail and sometimes work.
+Use mod_perl 1.27 or higher.
-=head2 HP-UX lib/io_multihomed Fails When LP64-Configured
+=head2 lib/ftmp-security tests warn 'system possibly insecure'
-The lib/io_multihomed test may hang in HP-UX if Perl has been
-configured to be 64-bit. Because other 64-bit platforms do not hang in
-this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The
-test attempts to create and connect to "multihomed" sockets (sockets
-which have multiple IP addresses).
+Don't panic. Read INSTALL 'make test' section instead.
=head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
No known fix.
-=head2 OS/390
+=head2 Mac OS X
-OS/390 has rather many test failures but the situation is actually
-better than it was in 5.6.0, it's just that so many new modules and
-tests have been added.
+Please remember to set your environment variable LC_ALL to "C"
+(setenv LC_ALL C) before running "make test" to avoid a lot of
+warnings about the broken locales of Mac OS X.
+
+The following tests are known to fail:
- Failed Test Stat Wstat Total Fail Failed List of Failed
- -----------------------------------------------------------------------------
- ../ext/B/Deparse.t 14 1 7.14% 14
- ../ext/B/Showlex.t 1 1 100.00% 1
- ../ext/Encode/Encode/Tcl.t 610 13 2.13% 592 594 596 598
- 600 602 604-610
- ../ext/IO/lib/IO/t/io_unix.t 113 28928 5 3 60.00% 3-5
- ../ext/POSIX/POSIX.t 29 1 3.45% 14
- ../ext/Storable/t/lock.t 255 65280 5 3 60.00% 3-5
- ../lib/locale.t 129 33024 117 19 16.24% 99-117
- ../lib/warnings.t 434 1 0.23% 75
- ../lib/ExtUtils.t 27 1 3.70% 25
- ../lib/Math/BigInt/t/bigintpm.t 1190 1 0.08% 1145
- ../lib/Unicode/UCD.t 81 48 59.26% 1-16 49-64 66-81
- ../lib/User/pwent.t 9 1 11.11% 4
- op/pat.t 660 6 0.91% 242-243 424-425
- 626-627
- op/split.t 0 9 ?? ?? % ??
- op/taint.t 174 3 1.72% 156 162 168
- op/tr.t 70 3 4.29% 50 58-59
- Failed 16/422 test scripts, 96.21% okay. 105/23251 subtests failed, 99.55% okay.
-
-=head2 op/sprintf tests 129 and 130
-
-The op/sprintf tests 129 and 130 are known to fail on some platforms.
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ -------------------------------------------------------------------------
+ ../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ??
+ ../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65
+ ../ext/POSIX/t/posix.t 31 1 3.23% 10
+
+If you are building on a UFS partition, you will also probably see
+t/op/stat.t subtest #9 fail. This is caused by Darwin's UFS not
+supporting inode change time.
+
+=head2 op/sprintf tests 91, 129, and 130
+
+The op/sprintf tests 91, 129, and 130 are known to fail on some platforms.
Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
-The failing platforms do not comply with the ANSI C Standard, line
-19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce
-something other than "1" and "-1" when formatting 0.6 and -0.6 using
-the printf format "%.0f", most often they produce "0" and "-0".)
-=head2 Failure of Thread tests
+The test 91 is known to fail at QNX6 (nto), because C<sprintf '%e',0>
+incorrectly produces C<0.000000e+0> instead of C<0.000000e+00>.
+
+For the tests 129 and 130 the failing platforms do not comply with
+the ANSI C Standard, line 19ff on page 134 of ANSI X3.159 1989 to
+be exact. (They produce something other than "1" and "-1" when
+formatting 0.6 and -0.6 using the printf format "%.0f", most often
+they produce "0" and "-0".)
+
+=head2 Failure of Thread (5.005-style) tests
-B<Note that support for 5.005-style threading remains experimental.>
+B<Note that support for 5.005-style threading remains experimental
+and practically unsupported.>
The following tests are known to fail due to fundamental problems in
the 5.005 threading implementation. These are not new failures--Perl
5.005_0x has the same bugs, but didn't have these tests.
- lib/autouse.t 4
- t/lib/thr5005.t 19-20
+ ../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7
+ ../lib/English.t 2 512 54 2 3.70% 2-3
+ ../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3
+ ../lib/Filter/Simple/t/filter_onl 9 3 33.33% 1-2 5
+ ../lib/autouse.t 10 1 10.00% 4
+ op/flip.t 15 1 6.67% 15
+
+These failures are unlikely to get fixed as the 5.005-style
+threads are considered fundamentally broken.
=head2 UNICOS
-=over 4
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ -------------------------------------------------------------------------
+ ../ext/Socket/socketpair.t 1 256 45 1 2.22% 12
+ ../lib/Math/Trig.t 26 1 3.85% 25
+ ../lib/warnings.t 460 1 0.22% 425
+ io/fs.t 36 1 2.78% 31
+ op/numconvert.t 1440 13 0.90% 208 509-510
+ 657-658 665-666 829-830 989-990 1149-1150
-=item *
+=head2 UNICOS and UNICOS/mk
-ext/POSIX/sigaction subtests 6 and 13 may fail.
+The io/fs test #31 is failing because in UNICOS and UNICOS/mk the Perl
+truncate() cannot be used to grow the size of filehandles, only to
+reduce the size. The workaround is to truncate files instead of
+filehandles.
-=item *
+=head2 UNICOS/mk
-lib/ExtUtils may spuriously claim that subtest 28 failed,
-which is interesting since the test only has 27 tests.
+=over 4
=item *
-Numerous numerical test failures
+During Configure the test
- op/numconvert 209,210,217,218
- op/override 7
- ext/Time/HiRes/HiRes 9
- lib/Math/BigInt/t/bigintpm 1145
- lib/Math/Trig 25
+ Guessing which symbols your C compiler and preprocessor define...
-These tests fail because of yet unresolved floating point inaccuracies.
+will probably fail with error messages like
-=back
+ CC-20 cc: ERROR File = try.c, Line = 3
+ The identifier "bad" is undefined.
-=head2 UTS
+ bad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K
+ ^
-There are a few known test failures, see L<perluts>.
-
-=head2 VMS
+ CC-65 cc: ERROR File = try.c, Line = 3
+ A semicolon is expected at this point.
-Rather a lot of tests are failing in VMS, but actually more tests
-succeed in VMS than they used to; it's just that there are many,
-many more tests than there used to be.
+This is caused by a bug in awk utility of UNICOS/mk. You can ignore
+the error, but it does cause a slight problem: you cannot fully
+benefit from the h2ph utility (see L<h2ph>) that can be used to
+convert C headers to Perl libraries, mainly used to be able to access
+from Perl the constants defined using C preprocessor, cpp. Because of
+the above error parts of the converted headers will be invisible.
+Luckily, these days the need for h2ph is rare.
-Here are the known failures from some compiler/platform combinations.
+=item *
-DEC C V5.3-006 on OpenVMS VAX V6.2
+If building Perl with the interpreter threads (ithreads), the
+getgrent(), getgrnam(), and getgrgid() functions cannot return the
+list of the group members due to a bug in the multithreaded support of
+UNICOS/mk. What this means that in list context the functions will
+return only three values, not four.
- [-.ext.list.util.t]tainted..............FAILED on test 3
- [-.ext.posix]sigaction..................FAILED on test 7
- [-.ext.time.hires]hires.................FAILED on test 14
- [-.lib.file.find]taint..................FAILED on test 17
- [-.lib.math.bigint.t]bigintpm...........FAILED on test 1183
- [-.lib.test.simple.t]exit...............FAILED on test 1
- [.lib]vmsish............................FAILED on test 13
- [.op]sprintf............................FAILED on test 12
- Failed 8/399 tests, 91.23% okay.
+=back
-DEC C V6.0-001 on OpenVMS Alpha V7.2-1 and
-Compaq C V6.2-008 on OpenVMS Alpha V7.1
+=head2 UTS
- [-.ext.list.util.t]tainted..............FAILED on test 3
- [-.lib.file.find]taint..................FAILED on test 17
- [-.lib.test.simple.t]exit...............FAILED on test 1
- [.lib]vmsish............................FAILED on test 13
- Failed 4/399 tests, 92.48% okay.
+There are a few known test failures, see L<perluts>.
-Compaq C V6.4-005 on OpenVMS Alpha 7.2.1
+=head2 VMS
- [-.ext.b]showlex........................FAILED on test 1
- [-.ext.list.util.t]tainted..............FAILED on test 3
- [-.lib.file.find]taint..................FAILED on test 17
- [-.lib.test.simple.t]exit...............FAILED on test 1
- [.lib]vmsish............................FAILED on test 13
- [.op]misc...............................FAILED on test 49
- Failed 6/401 tests, 92.77% okay.
+There should be no reported test failures with a default configuration,
+though there are a number of tests marked TODO that point to areas
+needing further debugging and/or porting work.
=head2 Win32
In multi-CPU boxes there are some problems with the I/O buffering:
-some output may appear twice.
+some output may appear twice. The following Win32 failures are known
+as of 5.7.3:
+
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ -------------------------------------------------------------------------
+ ..\ext/threads/t/end.t 6 4 66.67% 3-6
+
+=head2 XML::Parser not working
+
+Use XML::Parser 2.31 or later.
=head2 Localising a Tied Variable Leaks Memory
Code like the above is known to leak memory every time the local()
is executed.
+=head2 z/OS (OS/390)
+
+z/OS has rather many test failures but the situation is actually
+better than it was in 5.6.0, it's just that so many new modules and
+tests have been added.
+
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ -------------------------------------------------------------------------
+ ../ext/Data/Dumper/t/dumper.t 321 2 0.62% 311 314
+ ../ext/IO/lib/IO/t/io_unix.t 5 4 80.00% 2-5
+ ../lib/utf8.t 94 13 13.83% 27 30-31 43 46 73
+ 76 79 82 85 88 91
+ 94
+ ../lib/Benchmark.t 1 256 159 1 0.63% 75
+ ../lib/ExtUtils/t/Constant.t 27 19 70.37% 5-23
+ ../lib/ExtUtils/t/Embed.t 9 9 100.00% 1-9
+ op/pat.t 864 9 1.04% 242-243 665 776
+ 785 832-834 845
+ op/sprintf.t 224 3 1.34% 98 100 136
+ op/tr.t 97 5 5.15% 63 71-74
+ uni/fold.t 780 6 0.77% 61 169 196 661
+ 710-711
+
+=head2 Localising Tied Arrays and Hashes Is Broken
+
+ local %tied_array;
+
+doesn't work as one would expect: the old value is restored
+incorrectly.
+
=head2 Self-tying of Arrays and Hashes Is Forbidden
Self-tying of arrays and hashes is broken in rather deep and
frustrated at the mysterious results (core dumps, most often) it is
for now forbidden (you will get a fatal error even from an attempt).
-=head2 Variable Attributes are not Currently Usable for Tieing
-
-This limitation will hopefully be fixed in future. (Subroutine
-attributes work fine for tieing, see L<Attribute::Handlers>).
-
=head2 Building Extensions Can Fail Because Of Largefiles
Some extensions like mod_perl are known to have issues with
all binaries with different ideas about file offsets, all this is
platform-dependent.
+=head2 Unicode Support on EBCDIC Still Spotty
+
+Though mostly working, Unicode support still has problem spots on
+EBCDIC platforms. One such known spot are the C<\p{}> and C<\P{}>
+regular expression constructs for code points less than 256: the
+pP are testing for Unicode code points, not knowing about EBCDIC.
+
=head2 The Compiler Suite Is Still Experimental
-The compiler suite is slowly getting better but is nowhere near
-working order yet.
+The compiler suite is slowly getting better but it continues to be
+highly experimental. Use in production environments is discouraged.
-=head2 The Long Double Support is Still Experimental
+=head2 The Long Double Support Is Still Experimental
The ability to configure Perl's numbers to use "long doubles",
floating point numbers of hopefully better accuracy, is still
operations are more likely to be executed by less optimised
libraries).
+=head2 Seen In Perl 5.7 But Gone Now
+
+C<Time::Piece> (previously known as C<Time::Object>) was removed
+because it was felt that it didn't have enough value in it to be a
+core module. It is still a useful module, though, and is available
+from the CPAN.
+
=head1 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.com/perl/, the Perl Home Page.
+bug database at http://bugs.perl.org/ There may also be
+information at http://www.perl.com/ , the Perl Home Page.
If you believe you have an unreported bug, please run the B<perlbug>
program included with your release. Be sure to trim your bug down