=head1 NAME
-perldelta - what's new for perl v5.7.0
+perldelta - what is new for perl v5.8.0
=head1 DESCRIPTION
-This document describes differences between the 5.6.0 release and
-the 5.7.0 release.
-
-=head1 Security Vulnerability Closed
-
-A potential security vulnerability in the optional suidperl component
-of Perl has been identified. suidperl is neither built nor installed
-by default. As of September the 2nd, 2000, the only known vulnerable
-platform is Linux, most likely all Linux distributions. CERT and
-various vendors have been alerted about the vulnerability.
-
-The problem was caused by Perl trying to report a suspected security
-exploit attempt using an external program, /bin/mail. On Linux
-platforms the /bin/mail program had an undocumented feature which
-when combined with suidperl gave access to a root shell, resulting in
-a serious compromise instead of reporting the exploit attempt. If you
-don't have /bin/mail, or if you have 'safe setuid scripts', or if
-suidperl is not installed, you are safe.
-
-The exploit attempt reporting feature has been completely removed from
-the Perl 5.7.0 release, so that particular vulnerability isn't there
-anymore. However, further security vulnerabilities are,
-unfortunately, always possible. The suidperl code is being reviewed
-and if deemed too risky to continue to be supported, it may be
-completely removed from future releases. 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/).
+This document describes differences between the 5.6.0 release and the
+5.8.0 release.
=head1 Incompatible Changes
=item *
-Arrays now always interpolate into double-quoted strings:
-constructs like "foo@bar" now always assume C<@bar> is an array,
-whether or not the compiler has seen use of C<@bar>.
-
-=item *
-
The semantics of bless(REF, REF) were unclear and until someone proves
it to make some sense, it is forbidden.
the interface was a mistake. Sorry about that. For similar
functionality, see pack('U0', ...) and pack('C0', ...).
+=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.
+More details are in L</"Performance Enhancements">.
+
+=item *
+
+The list of filenames from glob() (or <...>) is now by default sorted
+alphabetically to be csh-compliant. (bsd_glob() does still sort platform
+natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.)
+
=back
+=head2 64-bit platforms and malloc
+
+If your pointers are 64 bits wide, the Perl malloc is no more being
+used because it simply does not work with 8-byte pointers. Also,
+usually the system malloc on such platforms are much better optimized
+for such large memory models than the Perl malloc.
+
+=head2 AIX Dynaloading
+
+The AIX dynaloading now uses in AIX releases 4.3 and newer the native
+dlopen interface of AIX instead of the old emulated interface. This
+change will probably break backward compatibility with compiled
+modules. The change was made to make Perl more compliant with other
+applications like modperl which are using the AIX native interface.
+
+=head2 Socket Extension Dynamic in VMS
+
+The Socket extension is now dynamically loaded instead of being
+statically built in. This may or may not be a problem with ancient
+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...}
+
+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.
+
+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.
+
+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>).
+
+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>.
+
+=head2 Deprecations
+
+The current user-visible implementation of pseudo-hashes (the weird
+use of the first array element) is deprecated starting from Perl 5.8.0
+and will be removed in Perl 5.10.0, and the feature will be
+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.
+
+The syntaxes C<@a->[...]> and C<@h->{...}> have now been deprecated.
+
+The suidperl is also considered to be too much a risk to continue
+maintaining and the suidperl code is likely to be removed in a future
+release.
+
+The C<package;> syntax (C<package> without an argument has been
+deprecated. Its semantics were never that clear and its
+implementation even less so. If you have used that feature to
+disallow all but fully qualified variables, C<use strict;> instead.
+
+The chdir(undef) and chdir('') behaviors to match chdir() has been
+deprecated. In future versions, chdir(undef) and chdir('') will
+simply fail.
+
=head1 Core Enhancements
=over 4
=item *
-Formats now support zero-padded decimal fields.
-
-=item *
-
C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
in multiple arguments.)
=item *
-my __PACKAGE__ now works.
+my __PACKAGE__ $obj now works.
=item *
=item *
-The printf and sprintf now support parameter reordering using the
-C<%\d+\$> and C<*\d+\$> syntaxes.
+prototype(\&) is now available.
=item *
-prototype(\&) is now available.
+There is now an UNTIE method.
+
+=back
+
+=head2 AUTOLOAD Is Now Lvaluable
+
+AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
+to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
+
+=head2 PerlIO is Now The Default
+
+=over 4
=item *
-There is now an UNTIE method.
+IO is now by default done via PerlIO rather than system's "stdio".
+PerlIO allows "layers" to be "pushed" onto a file handle to alter the
+handle's behaviour. Layers can be specified at open time via 3-arg
+form of open:
+
+ open($fh,'>:crlf :utf8', $path) || ...
+
+or on already opened handles via extended C<binmode>:
+
+ binmode($fh,':encoding(iso-8859-7)');
+
+The built-in layers are: unix (low level read/write), stdio (as in
+previous Perls), perlio (re-implementation of stdio buffering in a
+portable manner), crlf (does CRLF <=> "\n" translation as on Win32,
+but available on any platform). A mmap layer may be available if
+platform supports it (mostly UNIXes).
+
+Layers to be applied by default may be specified via the 'open' pragma.
+
+See L</"Installation and Configuration Improvements"> for the effects
+of PerlIO on your architecture name.
+
+=item *
+
+File handles can be marked as accepting Perl's internal encoding of Unicode
+(UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" :
+
+ open($fh,">:utf8","Uni.txt");
+
+Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named
+for you since it's not UTF-8 what you will be getting but instead
+UTF-EBCDIC. See L<perlunicode>, L<utf8>, and
+http://www.unicode.org/unicode/reports/tr16/ for more information.
+In future releases this naming may change.
+
+=item *
+
+File handles can translate character encodings from/to Perl's internal
+Unicode form on read/write via the ":encoding()" layer.
+
+=item *
+
+File handles can be opened to "in memory" files held in Perl scalars via:
+
+ open($fh,'>', \$variable) || ...
+
+=item *
+
+Anonymous temporary files are available without need to
+'use FileHandle' or other module via
+
+ open($fh,"+>", undef) || ...
+
+That is a literal undef, not an undefined value.
+
+=item *
+
+The list form of C<open> is now implemented for pipes (at least on UNIX):
+
+ open($fh,"-|", 'cat', '/etc/motd')
+
+creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
+the child process.
+
+=item *
+
+The following builtin functions are now overridable: chop(), chomp(),
+each(), keys(), pop(), push(), shift(), splice(), unshift().
+
+=item *
+
+Formats now support zero-padded decimal fields.
+
+=item *
+
+Perl now tries internally to use integer values in numeric conversions
+and basic arithmetics (+ - * /) if the arguments are integers, and
+tries also to keep the results stored internally as integers.
+This change leads into often slightly faster and always less lossy
+arithmetics. (Previously Perl always preferred floating point numbers
+in its math.)
+
+=item *
+
+The printf() and sprintf() now support parameter reordering using the
+C<%\d+\$> and C<*\d+\$> syntaxes. For example
+
+ print "%2\$s %1\$s\n", "foo", "bar";
+
+will print "bar foo\n"; This feature helps in writing
+internationalised software.
+
+=item *
+
+Unicode in general should be now much more usable. Unicode can be
+used in hash keys, Unicode in regular expressions should work now,
+Unicode in tr/// should work now (though tr/// seems to be a
+particularly tricky to get right, so you have been warned)
+
+=item *
+
+The Unicode Character Database coming with Perl has been upgraded
+to Unicode 3.1. For more information, see http://www.unicode.org/,
+and http://www.unicode.org/unicode/reports/tr27/
+
+For developers interested in enhancing Perl's Unicode capabilities:
+almost all the UCD files are included with the Perl distribution in
+the lib/unicode 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.)
+
+=back
+
+=head2 Signals Are Now Safe
+
+Perl used to be fragile in that signals arriving at inopportune moments
+could corrupt Perl's internal state.
+
+=head2 Understanding of Numbers
+
+In general a lot of fixing has happened in the area of Perl's
+understanding of numbers, both integer and floating point. Since in
+many systems the standard number parsing functions like C<strtoul()>
+and C<atof()> seem to have bugs, Perl tries to work around their
+deficiencies. This results hopefully in more accurate numbers.
+
+=over 4
+
+=item *
+
+The rules for allowing underscores (underbars) in numeric constants
+have been relaxed and simplified: now you can have an underscore
+B<between digits>.
+
+=item *
+
+GMAGIC (right-hand side magic) could in many cases such as string
+concatenation be invoked too many times.
+
+=item *
+
+Lexicals I: lexicals outside an eval "" weren't resolved
+correctly inside a subroutine definition inside the eval "" if they
+were not already referenced in the top level of the eval""ed code.
+
+=item *
+
+Lexicals II: lexicals leaked at file scope into subroutines that
+were declared before the lexicals.
+
+=item *
+
+Lvalue subroutines can now return C<undef> in list context.
+
+=item *
+
+The C<op_clear> and C<op_null> are now exported.
+
+=item *
+
+A new special regular expression variable has been introduced:
+C<$^N>, which contains the most-recently closed group (submatch).
+
+=item *
+
+L<utime> now supports C<utime undef, undef, @files> to change the
+file timestamps to the current time.
+
+=item *
+
+The Perl parser has been stress tested using both random input and
+Markov chain input.
+
+=item *
+
+C<eval "v200"> now works.
+
+=item *
+
+VMS now works under PerlIO.
+
+=item *
+
+END blocks are now run even if you exit/die in a BEGIN block.
+The execution of END blocks is now controlled by
+PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new
+behaviour for perl embedders. This will default in 5.10. See
+L<perlembed>.
=back
=item *
-Storable gives persistence to Perl data structures by allowing the
-storage and retrieval of Perl data to and from files in a fast and
-compact binary format.
-
-=back
+Storable gives persistence to Perl data structures by allowing the
+storage and retrieval of Perl data to and from files in a fast and
+compact binary format.
+
+=item *
+
+B::Concise, by Stephen McCamant, is a new compiler backend for
+walking the Perl syntax tree, printing concise info about ops.
+The output is highly customisable.
+
+See L<B::Concise> for more information.
+
+=item *
+
+Class::ISA, by Sean Burke, for reporting the search path for a
+class's ISA tree, has been added.
+
+See L<Class::ISA> for more information.
+
+=item *
+
+Cwd has now a split personality: if possible, an extension is used,
+(this will hopefully be both faster and more secure and robust) but
+if not possible, the familiar Perl library implementation is used.
+
+=item *
+
+Digest, a frontend module for calculating digests (checksums),
+from Gisle Aas, has been added.
+
+See L<Digest> for more information.
+
+=item *
+
+Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas,
+has been added.
+
+ use Digest::MD5 'md5_hex';
+
+ $digest = md5_hex("Thirsty Camel");
+
+ print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
+
+NOTE: the MD5 backward compatibility module is deliberately not
+included since its use is discouraged.
+
+See L<Digest::MD5> for more information.
+
+=item *
+
+Encode, by Nick Ing-Simmons, provides a mechanism to translate
+between different character encodings. Support for Unicode,
+ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
+compiled in to the module. Several other encodings (like Japanese,
+Chinese, and MacIntosh encodings) are included and will be loaded at
+runtime.
+
+Any encoding supported by Encode module is also available to the
+":encoding()" layer if PerlIO is used.
+
+See L<Encode> for more information.
+
+=item *
+
+Filter::Simple is an easy-to-use frontend to Filter::Util::Call,
+from Damian Conway.
+
+ # in MyFilter.pm:
+
+ package MyFilter;
+
+ use Filter::Simple sub {
+ while (my ($from, $to) = splice @_, 0, 2) {
+ s/$from/$to/g;
+ }
+ };
+
+ 1;
+
+ # in user's code:
+
+ use MyFilter qr/red/ => 'green';
+
+ print "red\n"; # this code is filtered, will print "green\n"
+ print "bored\n"; # this code is filtered, will print "bogreen\n"
+
+ no MyFilter;
+
+ print "red\n"; # this code is not filtered, will print "red\n"
+
+See L<Filter::Simple> for more information.
+
+=item *
+
+Filter::Util::Call, by Paul Marquess, provides you with the
+framework to write I<Source Filters> in Perl. For most uses
+the frontend Filter::Simple is to be preferred.
+See L<Filter::Util::Call> for more information.
+
+=item *
+
+Locale::Constants, Locale::Country, Locale::Currency, and Locale::Language,
+from Neil Bowers, have been added. They provide the codes for various
+locale standards, such as "fr" for France, "usd" for US Dollar, and
+"jp" for Japanese.
+
+ use Locale::Country;
+
+ $country = code2country('jp'); # $country gets 'Japan'
+ $code = country2code('Norway'); # $code gets 'no'
+
+See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>,
+and L<Locale::Language> for more information.
+
+=item *
+
+MIME::Base64, by Gisle Aas, allows you to encode data in base64.
+
+ use MIME::Base64;
+
+ $encoded = encode_base64('Aladdin:open sesame');
+ $decoded = decode_base64($encoded);
+
+ print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
+
+See L<MIME::Base64> for more information.
+
+=item *
+
+MIME::QuotedPrint, by Gisle Aas, allows you to encode data in
+quoted-printable encoding.
+
+ use MIME::QuotedPrint;
+
+ $encoded = encode_qp("Smiley in Unicode: \x{263a}");
+ $decoded = decode_qp($encoded);
+
+ print $encoded, "\n"; # "Smiley in Unicode: =263A"
+
+MIME::QuotedPrint has been enhanced to provide the basic methods
+necessary to use it with PerlIO::Via as in :
+
+ use MIME::QuotedPrint;
+ open($fh,">Via(MIME::QuotedPrint)",$path)
+
+See L<MIME::QuotedPrint> for more information.
+
+=item *
+
+PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of
+IO to "in memory" Perl scalars as discussed above. It also serves as
+an example of a loadable layer. Other future possibilities include
+PerlIO::Array and PerlIO::Code. See L<PerlIO::Scalar> for more
+information.
+
+=item *
+
+PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
+PerlIO layer functionality provided by a class (typically implemented
+in perl code).
+
+ use MIME::QuotedPrint;
+ open($fh,">Via(MIME::QuotedPrint)",$path)
+
+This will automatically convert everything output to C<$fh>
+to Quoted-Printable. See L<PerlIO::Via> for more information.
+
+=item *
+
+Pod::Text::Overstrike, by Joe Smith, has been added.
+It converts POD data to formatted overstrike text.
+See L<Pod::Text::Overstrike> for more information.
+
+=item *
+
+Switch from Damian Conway has been added. Just by saying
+
+ use Switch;
+
+you have C<switch> and C<case> available in Perl.
+
+ use Switch;
+
+ switch ($val) {
+
+ case 1 { print "number 1" }
+ case "a" { print "string a" }
+ case [1..10,42] { print "number in list" }
+ case (@array) { print "number in list" }
+ case /\w+/ { print "pattern" }
+ case qr/\w+/ { print "pattern" }
+ case (%hash) { print "entry in hash" }
+ case (\%hash) { print "entry in hash" }
+ case (\&sub) { print "arg to subroutine" }
+ else { print "previous case not true" }
+ }
+
+See L<Switch> for more information.
+
+=item *
+
+Text::Balanced from Damian Conway has been added, for
+extracting delimited text sequences from strings.
+
+ use Text::Balanced 'extract_delimited';
+
+ ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
+
+$a will be "'never say never'", $b will be ', he never said'.
+
+In addition to extract_delimited() there are also extract_bracketed(),
+extract_quotelike(), extract_codeblock(), extract_variable(),
+extract_tagged(), extract_multiple(), gen_delimited_pat(), and
+gen_extract_tagged(). With these you can implement rather advanced
+parsing algorithms. See L<Text::Balanced> for more information.
+
+=item *
+
+Tie::RefHash::Nestable, by Edward Avis, allows storing hash references
+(unlike the standard Tie::RefHash) The module is contained within
+Tie::RefHash.
+
+=item *
+
+XS::Typemap, by Tim Jenness, is a test extension that exercises XS
+typemaps. Nothing gets installed but for extension writers the code
+is worth studying.
+
+=item *
+
+L<Attribute::Handlers> - Simpler definition of attribute handlers
+
+=item *
+
+L<ExtUtils::Constant> - generate XS code to import C header constants
+
+=item *
+
+L<I18N::Langinfo> - query locale information
+
+=item *
+
+L<I18N::LangTags> - functions for dealing with RFC3066-style language tags
+
+=item *
+
+L<libnet> - a collection of perl5 modules related to network programming
+
+Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure.
+
+=item *
+
+L<List::Util> - selection of general-utility list subroutines
+
+=item *
+
+L<Locale::Maketext> - framework for localization
+
+=item *
+
+L<Memoize> - Make your functions faster by trading space for time
+
+=item *
+
+L<NEXT> - pseudo-class for method redispatch
+
+=item *
+
+L<Scalar::Util> - selection of general-utility scalar subroutines
+
+=item *
+
+L<Test::More> - yet another framework for writing test scripts
+
+=item *
+
+L<Test::Simple> - Basic utilities for writing tests
+
+=item *
+
+L<Time::HiRes> - high resolution ualarm, usleep, and gettimeofday
+
+=item *
+
+L<Time::Piece> - Object Oriented time objects
+
+(Previously known as L<Time::Object>.)
+
+=item *
+
+L<Time::Seconds> - a simple API to convert seconds to other date values
+
+=item *
+
+L<UnicodeCD> - Unicode Character Database
+
+=back
+
+=head2 Updated And Improved Modules and Pragmata
+
+=over 4
+
+=item *
+
+The following independently supported modules have been updated to
+newer versions from CPAN: CGI, CPAN, DB_File, File::Spec, Getopt::Long,
+the podlators bundle, Pod::LaTeX, Pod::Parser, Term::ANSIColor, Test.
+
+=item *
+
+Bug fixes and minor enhancements have been applied to B::Deparse,
+Data::Dumper, IO::Poll, IO::Socket::INET, Math::BigFloat,
+Math::Complex, Math::Trig, Net::protoent, the re pragma, SelfLoader,
+Sys::SysLog, Test::Harness, Text::Wrap, UNIVERSAL, and the warnings
+pragma.
+
+=item *
+
+The attributes::reftype() now works on tied arguments.
+
+=item *
+
+AutoLoader can now be disabled with C<no AutoLoader;>,
+
+=item *
+
+The English module can now be used without the infamous performance
+hit by saying
+
+ use English '-no_performance_hit';
+
+(Assuming, of course, that one doesn't need the troublesome variables
+C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
+C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
+
+=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 *
+
+File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
+prototype mismatch with CORE::glob().
+
+=item *
+
+IPC::Open3 now allows the use of numeric file descriptors.
+
+=item *
+
+use lib now works identically to @INC. Removing directories
+with 'no lib' now works.
+
+=item *
+
+C<%INC> now localised in a Safe compartment so that use/require work.
+
+=item *
+
+The Shell module now has an OO interface.
+
+=item *
+
+B::Deparse should be now more robust. It still far from providing a full
+round trip for any random piece of Perl code, though, and is under active
+development: expect more robustness in 5.7.2.
+
+=item *
+
+Class::Struct can now define the classes in compile time.
+
+=item *
+
+Math::BigFloat has undergone much fixing, and in addition the fmod()
+function now supports modulus operations.
+
+(The fixed Math::BigFloat module is also available in CPAN for those
+who can't upgrade their Perl: http://www.cpan.org/authors/id/J/JP/JPEACOCK/)
+
+=item *
+
+Devel::Peek now has an interface for the Perl memory statistics
+(this works only if you are using perl's malloc, and if you have
+compiled with debugging).
+
+=item *
+
+IO::Socket has now atmark() method, which returns true if the socket
+is positioned at the out-of-band mark. The method is also exportable
+as a sockatmark() function.
+
+=item *
+
+IO::Socket::INET has support for ReusePort option (if your platform
+supports it). The Reuse option now has an alias, ReuseAddr. For clarity
+you may want to prefer ReuseAddr.
+
+=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.
-=head2 Updated And Improved Modules and Pragmata
+=item *
-=over 4
+The C<open> pragma allows layers other than ":raw" and ":crlf" when
+using PerlIO.
=item *
-The following independently supported modules have been updated to
-newer versions from CPAN: CGI, CPAN, DB_File, File::Spec, Getopt::Long,
-the podlators bundle, Pod::LaTeX, Pod::Parser, Term::ANSIColor, Test.
+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 *
-Bug fixes and minor enhancements have been applied to B::Deparse,
-Data::Dumper, IO::Poll, IO::Socket::INET, Math::BigFloat,
-Math::Complex, Math::Trig, Net::protoent, the re pragma, SelfLoader,
-Sys::SysLog, Test::Harness, Text::Wrap, UNIVERSAL, and the warnings
-pragma.
+The Test module has been significantly enhanced. Its use is
+greatly recommended for module writers.
=item *
-The attributes::reftype() now works on tied arguments.
+The 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 *
+=back
-AutoLoader can now be disabled with C<no AutoLoader;>,
+The following modules have been upgraded from the versions at CPAN:
+CPAN, CGI, DB_File, File::Temp, Getopt::Long, Pod::Man, Pod::Text,
+Storable, Text-Tabs+Wrap.
=item *
-The English module can now be used without the infamous performance
-hit by saying
+L<B::Deparse> module has been significantly enhanced. It now
+can deparse almost all of the standard test suite (so that the
+tests still succeed). There is a make target "test.deparse"
+for trying this out.
- use English '-no_performance_hit';
+=item *
-(Assuming, of course, that one doesn't need the troublesome variables
-C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
-C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
+L<Class::Struct> now assigns the array/hash element if the accessor
+is called with an array/hash element as the B<sole> argument.
=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.
+L<Cwd> extension is now (even) faster.
=item *
-File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
-prototype mismatch with CORE::glob().
+L<DB_File> extension has been updated to version 1.77.
=item *
-IPC::Open3 now allows the use of numeric file descriptors.
+L<Fcntl>, L<Socket>, and L<Sys::Syslog> have been rewritten to use the
+new-style constant dispatch section (see L<ExtUtils::Constant>).
=item *
-use lib now works identically to @INC. Removing directories
-with 'no lib' now works.
+L<File::Find> is now (again) reentrant. It also has been made
+more portable.
=item *
-C<%INC> now localised in a Safe compartment so that use/require work.
+L<File::Glob> now supports C<GLOB_LIMIT> constant to limit the
+size of the returned list of filenames.
=item *
-The Shell module now has an OO interface.
+L<IO::Socket::INET> now supports C<LocalPort> of zero (usually meaning
+that the operating system will make one up.)
=item *
+The L<vars> pragma now supports declaring fully qualified variables.
+(Something that C<our()> does not and will not support.)
+
=back
=head1 Utility Changes
The xsubpp utility for extension writers now understands POD
documentation embedded in the *.xs files.
+=item *
+
+h2xs now produces template README.
+
+=item *
+
+s2p has been completely rewritten in Perl. (It is in fact a full
+implementation of sed in Perl.)
+
+=item *
+
+xsubpp now supports OUT keyword.
+
+=item *
+
+The F<emacs/e2ctags.pl> is now much faster.
+
+=item *
+
+L<h2ph> now supports C trigraphs.
+
+=item *
+
+L<h2xs> uses the new L<ExtUtils::Constant> module which will affect
+newly created extensions that define constants. Since the new code is
+more correct (if you have two constants where the first one is a
+prefix of the second one, the first constant B<never> gets defined),
+less lossy (it uses integers for integer constant, as opposed to the
+old code that used floating point numbers even for integer constants),
+and slightly faster, you might want to consider regenerating your
+extension code (the new scheme makes regenerating easy).
+L<h2xs> now also supports C trigraphs.
+
+=item *
+
+L<libnetcfg> has been added to configure the libnet.
+
+=item *
+
+The F<Pod::Html> (and thusly L<pod2html>) now allows specifying
+a cache directory.
+
=back
=head1 New Documentation
=back
+=head2 perlclib
+
+Internal replacements for standard C library functions.
+(Interesting only for extension writers and Perl core hackers.)
+
+=head2 perliol
+
+Internals of PerlIO with layers.
+
+=head2 README.aix
+
+Documentation on compiling Perl on AIX has been added. AIX has
+several different C compilers and getting the right patch level
+is essential. On install README.aix will be installed as L<perlaix>.
+
+=head2 README.bs2000
+
+Documentation on compiling Perl on the POSIX-BC platform (an EBCDIC
+mainframe environment) has been added.
+
+This was formerly known as README.posix-bc but the name was considered
+to be too confusing (it has nothing to do with the POSIX module or the
+POSIX standard). On install README.bs2000 will be installed as L<perlbs2000>.
+
+=head2 README.macos
+
+In perl 5.7.1 (and in the 5.6.1) the MacPerl sources have been
+synchronised with the standard Perl sources. To compile MacPerl
+some additional steps are required, and this file documents those
+steps. On install README.macos will be installed as L<perlmacos>.
+
+=head2 README.mpeix
+
+The README.mpeix has been podified, which means that this information
+about compiling and using Perl on the MPE/iX miniframe platform will
+be installed as L<perlmpeix>.
+
+=head2 README.solaris
+
+README.solaris has been created and Solaris wisdom from elsewhere
+in the Perl documentation has been collected there. On install
+README.solaris will be installed as L<perlsolaris>.
+
+=head2 README.vos
+
+The README.vos has been podified, which means that this information
+about compiling and using Perl on the Stratus VOS miniframe platform
+will be installed as L<perlvos>.
+
+=head2 Porting/repository.pod
+
+Documentation on how to use the Perl source repository has been added.
+
+=over 4
+
+=item *
+
+L<Locale::Maketext::TPJ13> is an article about software localization,
+originally published in The Perl Journal #13, republished here with
+kind permission.
+
+=item *
+
+More README.$PLATFORM files have been converted into pod, which also
+means that they also be installed as perl$PLATFORM documentation
+files. The new files are L<perlapollo>, L<perlbeos>, L<perldgux>,
+L<perlhurd>, L<perlmint>, L<perlnetware>, L<perlplan9>, L<perlqnx>,
+and L<perltru64>.
+
+=item *
+
+The F<Todo> and F<Todo-5.6> files have been merged into L<perltodo>.
+
+=item *
+
+Use of the F<gprof> tool to profile Perl has been documented in
+L<perlhack>. There is a make target "perl.gprof" for generating a
+gprofiled Perl executable.
+
+=back
+
=head1 Performance Enhancements
=over 4
map() that changes the size of the list should now work faster.
=item *
-
+
sort() has been changed to use mergesort internally as opposed to the
earlier quicksort. For very small lists this may result in slightly
slower sorting times, but in general the speedup should be at least
and that sort() is now stable (meaning that elements with identical
keys will stay ordered as they were before the sort).
+=item *
+
+Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm
+(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
+all 3-char printable ASCII keys comes much closer to passing the
+DIEHARD random number generation tests. According to perlbench, this
+change has not affected the overall speed of Perl.
+
+=item *
+
+unshift() should now be noticeably faster.
+
=back
=head1 Installation and Configuration Improvements
=item *
-Configure no longer included the DBM libraries (dbm, gdbm, db, ndbm)
-when building the Perl binary. The only exception to this is SunOS 4.x,
-which needs them.
+Because PerlIO is now the default on most platforms, "-perlio" doesn't
+get appended to the $Config{archname} (also known as $^O) anymore.
+Instead, if you explicitly choose not to use perlio (Configure command
+line option -Uuseperlio), you will get "-stdio" appended.
+
+=item *
+
+Another change related to the architecture name is that "-64all"
+(-Duse64bitall, or "maximally 64-bit") is appended only if your
+pointers are 64 bits wide. (To be exact, the use64bitall is ignored.)
+
+=item *
+
+APPLLIB_EXP, a less-know configuration-time definition, has been
+documented. It can be used to prepend site-specific directories
+to Perl's default search path (@INC), see INSTALL for information.
+
+=item *
+
+Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
+has been documented in INSTALL.
+
+=item *
+
+If you are on IRIX or Tru64 platforms, new profiling/debugging options
+have been added, see L<perlhack> for more information about pixie and
+Third Degree.
+
+=item *
+
+In AFS installations one can configure the root of the AFS to be
+somewhere else than the default F</afs> by using the Configure
+parameter C<-Dafsroot=/some/where/else>.
+
+=item *
+
+The version of Berkeley DB used when the Perl (and, presumably, the
+DB_File extension) was built is now available as
+C<@Config{qw(db_version_major db_version_minor db_version_patch)}>
+from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG
+DB_VERSION_PATCH_CFG> from C.
+
+=item *
+
+The Thread extension is now not built at all under ithreads
+(C<Configure -Duseithreads>) because it wouldn't work anyway (the
+Thread extension requires being Configured with C<-Duse5005threads>).
+
+=item *
+
+The C<B::Deparse> compiler backend has been so significantly improved
+that almost the whole Perl test suite passes after being deparsed. A
+make target has been added to help in further testing: C<make test.deparse>.
+
+=back
+
+=head2 New Or Improved Platforms
+
+For the list of platforms known to support Perl,
+see L<perlport/"Supported Platforms">.
+
+=over 4
+
+=item *
+
+AIX dynamic loading should be now better supported.
+
+=item *
+
+After a long pause, AmigaOS has been verified to be happy with Perl.
+
+=item *
+
+EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA)
+have been regained. Many test suite tests still fail and the
+co-existence of Unicode and EBCDIC isn't quite settled, but the
+situation is much better than with Perl 5.6. See L<perlos390>,
+L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information.
+
+=item *
+
+Building perl with -Duseithreads or -Duse5005threads now works under
+HP-UX 10.20 (previously it only worked under 10.30 or later). You will
+need a thread library package installed. See README.hpux.
+
+=item *
+
+MacOS Classic (MacPerl has of course been available since
+perl 5.004 but now the source code bases of standard Perl
+and MacPerl have been synchronised)
+
+=item *
+
+NCR MP-RAS is now supported.
+
+=item *
+
+NonStop-UX is now supported.
+
+=item *
+
+Amdahl UTS is now supported.
+
+=item *
+
+z/OS (formerly known as OS/390, formerly known as MVS OE) has now
+support for dynamic loading. This is not selected by default,
+however, you must specify -Dusedl in the arguments of Configure.
+
+=item *
+
+AIX should now work better with gcc, threads, and 64-bitness. Also the
+long doubles support in AIX should be better now. See L<perlaix>.
+
+=item *
+
+AtheOS (http://www.atheos.cx/) is a new platform.
+
+=item *
+
+DG/UX platform now supports the 5.005-style threads. See L<perldgux>.
+
+=item *
+
+DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2.
+
+=item *
+
+Several MacOS (Classic) portability patches have been applied. We
+hope to get a fully working port by 5.8.0. (The remaining problems
+relate to the changed IO model of Perl.) See L<perlmacos>.
+
+=item *
+
+MacOS X (or Darwin) should now be able to build Perl even on HFS+
+filesystems. (The case-insensitivity confused the Perl build process.)
+
+=item *
+
+NetWare from Novell is now supported. See L<perlnetware>.
+
+=item *
+
+The Amdahl UTS UNIX mainframe platform is now supported.
=back
scalar() now forces scalar context even when used in void context.
=item *
-
+
sort() arguments are now compiled in the right wantarray context
(they were accidentally using the context of the sort() itself).
BOMs (byte order marks) in the beginning of Perl files
(scripts, modules) should now be transparently skipped.
-UTF-16 (UCS-2)encoded Perl files should now be read correctly.
+UTF-16 (UCS-2) encoded Perl files should now be read correctly.
+
+=item *
+
+The character tables have been updated to Unicode 3.0.1.
+
+=item *
+
+chr() for values greater than 127 now create utf8 when under use
+utf8.
+
+=item *
+
+Comparing with utf8 data does not magically upgrade non-utf8 data into
+utf8.
+
+=item *
+
+C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
+
+=item *
+
+Concatenation with the C<.> operator or via variable interpolation,
+C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
+substitution with C<s///>, single-quoted UTF8, should now work--in
+theory.
+
+=item *
+
+The C<tr///> operator now works I<slightly> better but is still rather
+broken. Note that the C<tr///CU> functionality has been removed (but
+see pack('U0', ...)).
+
+=item *
+
+vec() now refuses to deal with characters >255.
+
+=item *
+
+Zero entries were missing from the Unicode classes like C<IsDigit>.
+
+=back
+
+=item *
+
+UNIVERSAL::isa no longer caches methods incorrectly. (This broke
+the Tk extension with 5.6.0.)
+
+=item *
+
+Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
+when building the Perl binary. The only exception to this is SunOS 4.x,
+which needs them.
+
+=item *
+
+Some new Configure symbols, useful for extension writers:
+
+=over 8
+
+=item d_cmsghdr
+
+For struct cmsghdr.
+
+=item d_fcntl_can_lock
+
+Whether fcntl() can be used for file locking.
+
+=item d_fsync
+
+=item d_getitimer
+
+=item d_getpagsz
+
+For getpagesize(), though you should prefer POSIX::sysconf(_SC_PAGE_SIZE))
+
+=item d_msghdr_s
+
+For struct msghdr.
+
+=item need_va_copy
+
+Whether one needs to use Perl_va_copy() to copy varargs.
+
+=item d_readv
+
+=item d_recvmsg
-=item *
+=item d_sendmsg
-The character tables have been updated to Unicode 3.0.1.
+=item sig_size
-=item *
+The number of elements in an array needed to hold all the available signals.
-chr() for values greater than 127 now create utf8 when under use
-utf8.
+=item d_sockatmark
-=item *
+=item d_strtoq
-Comparing with utf8 data does not magically upgrade non-utf8 data into
-utf8.
+=item d_u32align
-=item *
+Whether one needs to access character data aligned by U32 sized pointers.
-C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
+=item d_ualarm
-=item *
+=item d_usleep
-Concatenation with the C<.> operator or via variable interpolation,
-C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
-substitution with C<s///>, single-quoted UTF8, should now work--in
-theory.
+=back
=item *
-The C<tr///> operator now works I<slightly> better but is still rather
-broken. Note that the C<tr///CU> functionality has been removed (but
-see pack('U0', ...)).
+Removed Configure symbols: the PDP-11 memory model settings: huge,
+large, medium, models.
=item *
-vec() now tries to work with characters <= 255 when possible, but it leaves
-higher character values in place. In that case, if vec() was used to modify
-the string, it is no longer considered to be utf8-encoded.
+SOCKS support is now much more robust.
=item *
-Zero entries were missing from the Unicode classes like C<IsDigit>.
+If your file system supports symbolic links you can build Perl outside
+of the source directory by
-=back
+ mkdir /tmp/perl/build/directory
+ cd /tmp/perl/build/directory
+ sh /path/to/perl/source/Configure -Dmksymlinks ...
-=item *
+This will create in /tmp/perl/build/directory a tree of symbolic links
+pointing to files in /path/to/perl/source. The original files are left
+unaffected. After Configure has finished you can just say
-UNIVERSAL::isa no longer caches methods incorrectly. (This broke
-the Tk extension with 5.6.0.)
+ make all test
+
+and Perl will be built and tested, all in /tmp/perl/build/directory.
=back
=back
+=back
+
=head1 New or Changed Diagnostics
All regular expression compilation error messages are now hopefully
The "Unrecognized escape" warning has been extended to include C<\8>,
C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters.
+=over 4
+
+Two new debugging options have been added: if you have compiled your
+Perl with debugging, you can use the -DT and -DR options to trace
+tokenising and to add reference counts to displaying variables,
+respectively.
+
+=item *
+
+If an attempt to use a (non-blessed) reference as an array index
+is made, a warning is given.
+
+=item *
+
+C<push @a;> and C<unshift @a;> (with no values to push or unshift)
+now give a warning. This may be a problem for generated and evaled
+code.
+
+=back
+
=head1 Changed Internals
=over 4
Now xsubs can have attributes just like subs.
+=item *
+
+Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv().
+For the full list of the available APIs see L<perlapi>.
+
+=item *
+
+dTHR and djSP have been obsoleted; the former removed (because it's
+a no-op) and the latter replaced with dSP.
+
+=item *
+
+Perl now uses system malloc instead of Perl malloc on all 64-bit
+platforms, and even in some not-always-64-bit platforms like AIX,
+IRIX, and Solaris. This change breaks backward compatibility but
+Perl's malloc has problems with large address spaces and also the
+speed of vendors' malloc is generally better in large address space
+machines (Perl's malloc is mostly tuned for space).
+
+=back
+
+=head1 Security Vulnerability Closed
+
+(This change was already made in 5.7.0 but bears repeating here.)
+
+A potential security vulnerability in the optional suidperl component
+of Perl was identified in August 2000. suidperl is neither built nor
+installed by default. As of November 2001 the only known vulnerable
+platform is Linux, most likely all Linux distributions. CERT and
+various vendors and distributors have been alerted about the vulnerability.
+See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
+for more information.
+
+The problem was caused by Perl trying to report a suspected security
+exploit attempt using an external program, /bin/mail. On Linux
+platforms the /bin/mail program had an undocumented feature which
+when combined with suidperl gave access to a root shell, resulting in
+a serious compromise instead of reporting the exploit attempt. If you
+don't have /bin/mail, or if you have 'safe setuid scripts', or if
+suidperl is not installed, you are safe.
+
+The exploit attempt reporting feature has been completely removed from
+Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also
+from all the Perl 5.7 releases), so that particular vulnerability
+isn't there anymore. However, further security vulnerabilities are,
+unfortunately, always possible. The suidperl code is being reviewed
+and if deemed too risky to continue to be supported, it may be
+completely removed from future releases. 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/).
+
+=head1 Selected Bug Fixes
+
+Numerous memory leaks and uninitialized memory accesses have been hunted down.
+Most importantly anonymous subs used to leak quite a bit.
+
+=over 4
+
+=item *
+
+chop(@list) in list context returned the characters chopped in
+reverse order. This has been reversed to be in the right order.
+
+=item *
+
+The order of DESTROYs has been made more predictable.
+
+=item *
+
+mkdir() now ignores trailing slashes in the directory name,
+as mandated by POSIX.
+
+=item *
+
+Attributes (like :shared) didn't work with our().
+
+=item *
+
+The PERL5OPT environment variable (for passing command line arguments
+to Perl) didn't work for more than a single group of options.
+
+=item *
+
+The tainting behaviour of sprintf() has been rationalized. It does
+not taint the result of floating point formats anymore, making the
+behaviour consistent with that of string interpolation.
+
+=item *
+
+All but the first argument of the IO syswrite() method are now optional.
+
+=item *
+
+Tie::ARRAY SPLICE method was broken.
+
+=item *
+
+vec() now tries to work with characters <= 255 when possible, but it leaves
+higher character values in place. In that case, if vec() was used to modify
+the string, it is no longer considered to be utf8-encoded.
+
+=item *
+
+The autouse pragma didn't work for Multi::Part::Function::Names.
+
+=item *
+
+The behaviour of non-decimal but numeric string constants such as
+"0x23" was platform-dependent: in some platforms that was seen as 35,
+in some as 0, in some as a floating point number (don't ask). This
+was caused by Perl using the operating system libraries in a situation
+where the result of the string to number conversion is undefined: now
+Perl consistently handles such strings as zero in numeric contexts.
+
+=item *
+
+L<dprofpp> -R didn't work.
+
+=item *
+
+PERL5OPT with embedded spaces didn't work.
+
+=item *
+
+L<Sys::Syslog> ignored the C<LOG_AUTH> constant.
+
+=back
+
+=head2 Platform Specific Changes and Fixes
+
+=over 4
+
+=item *
+
+Some versions of glibc have a broken modfl(). This affects builds
+with C<-Duselongdouble>. This version of Perl detects this brokenness
+and has a workaround for it. The glibc release 2.2.2 is known to have
+fixed the modfl() bug.
+
+=back
+
+=head2 Platform Specific Changes and Fixes
+
+=over 4
+
+=item *
+
+Linux previously had problems related to sockaddrlen when using
+accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
+
+=item *
+
+Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
+
+=item *
+
+Windows
+
+=over 8
+
+=item *
+
+Borland C++ v5.5 is now a supported compiler that can build Perl.
+However, the generated binaries continue to be incompatible with those
+generated by the other supported compilers (GCC and 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.
+
+=item *
+
+Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
+
+=item *
+
+HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
+
+=item *
+
+The makefiles now provide a single switch to bulk-enable all the features
+enabled in ActiveState ActivePerl (a popular binary distribution).
+
+=back
+
+=head1 New Tests
+
+Several new tests have been added, especially for the F<lib> subsection.
+
+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
+to be closer to the library/extension they are testing.)
+
+=head1 New or Changed Diagnostics
+
+=over 4
+
+=item *
+
+In the regular expression diagnostics the C<E<lt>E<lt> HERE> marker
+introduced in 5.7.0 has been changed to be C<E<lt>-- HERE> since too
+many people found the C<E<lt>E<lt>> to be too similar to here-document
+starters.
+
+=item *
+
+If you try to L<perlfunc/pack> a number less than 0 or larger than 255
+using the C<"C"> format you will get an optional warning. Similarly
+for the C<"c"> format and a number less than -128 or more than 127.
+
+=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.
+
+=item *
+
+Using arrays or hashes as references (e.g. C<%foo->{bar}> has been
+deprecated for a while. Now you will get an optional warning.
+
=back
+=head1 Source Code Enhancements
+
+=head2 MAGIC constants
+
+The MAGIC constants (e.g. C<'P'>) have been macrofied
+(e.g. C<PERL_MAGIC_TIED>) for better source code readability
+and maintainability.
+
+=head2 Better commented code
+
+F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
+
+=head2 Regex pre-/post-compilation items matched up
+
+The regex compiler now maintains a structure that identifies nodes in
+the compiled bytecode with the corresponding syntactic features of the
+original regex expression. The information is attached to the new
+C<offsets> member of the C<struct regexp>. See L<perldebguts> for more
+complete information.
+
+=head2 gcc -Wall
+
+The C code has been made much more C<gcc -Wall> clean. Some warning
+messages still remain, though, so if you are compiling with gcc you
+will see some warnings about dubious practices. The warnings are
+being worked on.
+
=head1 Known Problems
-=head2 Unicode Support Still Far From Perfect
+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.
-We're working on it. Stay tuned.
+=head2 AIX
-=head2 EBCDIC Still A Lost Platform
+=over 4
-The plan is to bring them back.
+=item *
-=head2 Building Extensions Can Fail Because Of Largefiles
+In AIX 4.2 Perl extensions that use C++ functions that use statics
+may have problems in that the statics are not getting initialized.
+In newer AIX releases this has been solved by linking Perl with
+the libC_r library, but unfortunately in AIX 4.2 the said library
+has an obscure bug where the various functions related to time
+(such as time() and gettimeofday()) return broken values, and
+therefore in AIX 4.2 Perl is not linked against the libC_r.
-Certain extensions like mod_perl and BSD::Resource are known to have
-issues with `largefiles', a change brought by Perl 5.6.0 in which file
-offsets default to 64 bits wide, where supported. Modules may fail to
-compile at all or compile and work incorrectly. Currently there is no
-good solution for the problem, but Configure now provides appropriate
-non-largefile ccflags, ldflags, libswanted, and libs in the %Config
-hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
-having problems can try configuring themselves without the
-largefileness. This is admittedly not a clean solution, and the
-solution may not even work at all. One potential failure is whether
-one can (or, if one can, whether it's a good idea) link together at
-all binaries with different ideas about file offsets, all this is
-platform-dependent.
+=item *
-=head2 ftmp-security tests warn 'system possibly insecure'
+vac 5.0.0.0 May Produce Buggy Code For Perl
-Don't panic. Read INSTALL 'make test' section instead.
+The AIX C compiler vac version 5.0.0.0 may produce buggy code,
+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.
-=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
+=back
+
+=head2 Amiga Perl Invoking Mystery
+
+One cannot call Perl using the C<volume:> syntax, that is, C<perl -v>
+works, but for example C<bin:perl -v> doesn't. The exact reason is
+known but the current suspect is the F<ixemul> library.
+
+=head2 lib/ftmp-security tests warn 'system possibly insecure'
+
+Don't panic. Read INSTALL 'make test' section instead.
+
+=head2 Cygwin intermittent failures of lib/Memoize/t/expire_file 11 and 12
+
+The subtests 11 and 12 sometimes fail and sometimes work.
+
+=head2 HP-UX lib/io_multihomed Fails When LP64-Configured
+
+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).
+
+=head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
If perl is configured with -Duse64bitall, the successful result of the
subtest 10 of lib/posix may arrive before the successful result of the
subtest 9, which confuses the test harness so much that it thinks the
subtest 9 failed.
-=head2 Long Doubles Still Don't Work In Solaris
-
-The experimental long double support is still very much so in Solaris.
-(Other platforms like Linux and Tru64 are beginning to solidify in
-this area.)
-
=head2 Linux With Sfio Fails op/misc Test 48
No known fix.
-=head2 Storable tests fail in some platforms
-
-If any Storable tests fail the use of Storable is not advisable.
+=head2 OS/390
+
+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.
+
+ 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.
+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
+
+B<Note that support for 5.005-style threading remains experimental.>
+
+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
+
+=head2 UNICOS
=over 4
=item *
-Many Storable tests fail on AIX configured with 64 bit integers.
-
-So far unidentified problems break Storable in AIX if Perl is
-configured to use 64 bit integers. AIX in 32-bit mode works and
-other 64-bit platforms work with Storable.
+ext/POSIX/sigaction subtests 6 and 13 may fail.
=item *
-DOS DJGPP may hang when testing Storable.
+lib/ExtUtils may spuriously claim that subtest 28 failed,
+which is interesting since the test only has 27 tests.
=item *
-st-06compat fails in UNICOS and UNICOS/mk.
+Numerous numerical test failures
-This means that you cannot read old (pre-Storable-0.7) Storable images
-made in other platforms.
+ op/numconvert 209,210,217,218
+ op/override 7
+ ext/Time/HiRes/HiRes 9
+ lib/Math/BigInt/t/bigintpm 1145
+ lib/Math/Trig 25
-=item *
+These tests fail because of yet unresolved floating point inaccuracies.
+
+=back
+
+=head2 UTS
-st-store.t and st-retrieve may fail with Compaq C 6.2 on OpenVMS Alpha 7.2.
+There are a few known test failures, see L<perluts>.
-=head2 Threads Are Still Experimental
+=head2 VMS
-Multithreading is still an experimental feature. Some platforms
-emit the following message for lib/thr5005
+Rather many tests are failing in VMS but that 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 a KNOWN FAILURE, and one of the reasons why threading
- # is still an experimental feature. It is here to stop people
- # from deploying threads in production. ;-)
- #
+Here are the known failures from some compiler/platform combinations.
+
+DEC C V5.3-006 on OpenVMS VAX V6.2
-and another known thread-related warning is
-
- pragma/overload......Unbalanced saves: 3 more saves than restores
- panic: magic_mutexfree during global destruction.
- ok
- lib/selfloader.......Unbalanced saves: 3 more saves than restores
- panic: magic_mutexfree during global destruction.
- ok
- lib/st-dclone........Unbalanced saves: 3 more saves than restores
- panic: magic_mutexfree during global destruction.
- ok
+ [-.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.
+
+DEC C V6.0-001 on OpenVMS Alpha V7.2-1 and
+Compaq C V6.2-008 on OpenVMS Alpha V7.1
+
+ [-.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
+ Failed 4/399 tests, 92.48% okay.
+
+Compaq C V6.4-005 on OpenVMS Alpha 7.2.1
+
+ [-.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.
+
+=head2 Win32
+
+In multi-CPU boxes there are some problems with the I/O buffering:
+some output may appear twice.
+
+=head2 Localising a Tied Variable Leaks Memory
+
+ use Tie::Hash;
+ tie my %tie_hash => 'Tie::StdHash';
+
+ ...
+
+ local($tie_hash{Foo}) = 1; # leaks
+
+Code like the above is known to leak memory every time the local()
+is executed.
+
+=head2 Self-tying of Arrays and Hashes Is Forbidden
+
+Self-tying of arrays and hashes is broken in rather deep and
+hard-to-fix ways. As a stop-gap measure to avoid people from getting
+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
+`largefiles', a change brought by Perl 5.6.0 in which file offsets
+default to 64 bits wide, where supported. Modules may fail to compile
+at all or compile and work incorrectly. Currently there is no good
+solution for the problem, but Configure now provides appropriate
+non-largefile ccflags, ldflags, libswanted, and libs in the %Config
+hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
+having problems can try configuring themselves without the
+largefileness. This is admittedly not a clean solution, and the
+solution may not even work at all. One potential failure is whether
+one can (or, if one can, whether it's a good idea) link together at
+all binaries with different ideas about file offsets, all this is
+platform-dependent.
=head2 The Compiler Suite Is Still Experimental
The compiler suite is slowly getting better but is nowhere near
-working order yet. The backend part that has seen perhaps the most
-progress is the bytecode compiler.
+working order yet.
-=back
+=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
+experimental. The implementations of long doubles are not yet
+widespread and the existing implementations are not quite mature
+or standardised, therefore trying to support them is a rare
+and moving target. The gain of more precision may also be offset
+by slowdown in computations (more bits to move around, and the
+operations are more likely to be executed by less optimised
+libraries).
=head1 Reporting Bugs
=head1 HISTORY
-Written by Jarkko Hietaniemi <F<jhi@iki.fi>>, with many contributions
-from The Perl Porters and Perl Users submitting feedback and patches.
-
-Send omissions or corrections to <F<perlbug@perl.org>>.
+Written by Jarkko Hietaniemi <F<jhi@iki.fi>>.
=cut
projects / p5sagit/p5-mst-13.2.git / blobdiff