3 perldelta - what is new for perl v5.8.0
7 This document describes differences between the 5.6.0 release
10 Many of the bug fixes in 5.8.0 were already seen in the 5.6.1
11 maintenance release since the two releases were kept closely
14 If you are upgrading from Perl 5.005_03, you might also want
15 to read L<perl56delta>.
17 =head1 Highlights In 5.8.0
23 Better Unicode support
27 New Thread Implementation
35 Better Numeric Accuracy
43 More Extensive Regression Testing
47 =head1 Incompatible Changes
49 =head2 Binary Incompatibility
51 B<Perl 5.8 is not binary compatible with earlier releases of Perl.>
53 B<You have to recompile your XS modules.>
55 (Pure Perl modules should continue to work.)
57 The major reason for the discontinity is the new IO architecture
58 called PerlIO. PerlIO is the default configuration because
59 without it many new features of Perl 5.8 cannot be used. In other
60 words: you just have to recompile your modules, sorry about that.
62 In future releases of Perl, non-PerlIO aware XS modules may become
63 completely unsupported. This shouldn't be too difficult for module
64 authors, however: PerlIO has been designed as a drop-in replacement
65 (at the source code level) for the stdio interface.
67 Depending on your platform, there are also other reasons why
68 we decided to break binary compatibility, please read on.
70 =head2 64-bit platforms and malloc
72 If your pointers are 64 bits wide, the Perl malloc is no longer being
73 used because it does not work well with 8-byte pointers. Also,
74 usually the system mallocs on such platforms are much better optimized
75 for such large memory models than the Perl malloc. Some memory-hungry
76 Perl applications like the PDL don't work well with Perl's malloc.
77 Finally, other applications than Perl (like modperl) tend to prefer
78 the system malloc. Such platforms include Alpha and 64-bit HPPA,
81 =head2 AIX Dynaloading
83 The AIX dynaloading now uses in AIX releases 4.3 and newer the native
84 dlopen interface of AIX instead of the old emulated interface. This
85 change will probably break backward compatibility with compiled
86 modules. The change was made to make Perl more compliant with other
87 applications like modperl which are using the AIX native interface.
89 =head2 Attributes for C<my> variables now handled at run-time.
91 The C<my EXPR : ATTRS> syntax now applies variable attributes at
92 run-time. (Subroutine and C<our> variables still get attributes applied
93 at compile-time.) See L<attributes> for additional details. In particular,
94 however, this allows variable attributes to be useful for C<tie> interfaces,
95 which was a deficiency of earlier releases. Note that the new semantics
96 doesn't work with the Attribute::Handlers module (as of version 0.76).
98 =head2 Socket Extension Dynamic in VMS
100 The Socket extension is now dynamically loaded instead of being
101 statically built in. This may or may not be a problem with ancient
102 TCP/IP stacks of VMS: we do not know since we weren't able to test
103 Perl in such configurations.
105 =head2 IEEE-format Floating Point Default on OpenVMS Alpha
107 Perl now uses IEEE format (T_FLOAT) as the default internal floating
108 point format on OpenVMS Alpha, potentially breaking binary compatibility
109 with external libraries or existing data. G_FLOAT is still available as
110 a configuration option. The default on VAX (D_FLOAT) has not changed.
112 =head2 New Unicode Properties
114 Unicode I<scripts> are now supported. Scripts are similar to (and superior
115 to) Unicode I<blocks>. The difference between scripts and blocks is that
116 scripts are the glyphs used by a language or a group of languages, while
117 the blocks are more artificial groupings of (mostly) 256 characters based
118 on the Unicode numbering.
120 In general, scripts are more inclusive, but not universally so. For
121 example, while the script C<Latin> includes all the Latin characters and
122 their various diacritic-adorned versions, it does not include the various
123 punctuation or digits (since they are not solely C<Latin>).
125 A number of other properties are now supported, including C<\p{L&}>,
126 C<\p{Any}> C<\p{Assigned}>, C<\p{Unassigned}>, C<\p{Blank}> and
127 C<\p{SpacePerl}> (along with their C<\P{...}> versions, of course).
128 See L<perlunicode> for details, and more additions.
130 The C<In> or C<Is> prefix to names used with the C<\p{...}> and C<\P{...}>
131 are now almost always optional. The only exception is that a C<In> prefix
132 is required to signify a Unicode block when a block name conflicts with a
133 script name. For example, C<\p{Tibetan}> refers to the script, while
134 C<\p{InTibetan}> refers to the block. When there is no name conflict, you
135 can omit the C<In> from the block name (e.g. C<\p{BraillePatterns}>), but
136 to be safe, it's probably best to always use the C<In>).
138 =head2 REF(...) Instead Of SCALAR(...)
140 A reference to a reference now stringifies as "REF(0x81485ec)" instead
141 of "SCALAR(0x81485ec)" in order to be more consistent with the return
144 =head2 pack/unpack D/F recycled
146 The undocumented pack/unpack template letters D/F have been recycled
147 for better use: now they stand for long double (if supported by the
148 platform) and NV (Perl internal floating point type). (They used
149 to be aliases for d/f, but you never knew that.)
157 The semantics of bless(REF, REF) were unclear and until someone proves
158 it to make some sense, it is forbidden.
162 The obsolete chat2 library that should never have been allowed
163 to escape the laboratory has been decommissioned.
167 The builtin dump() function has probably outlived most of its
168 usefulness. The core-dumping functionality will remain in future
169 available as an explicit call to C<CORE::dump()>, but in future
170 releases the behaviour of an unqualified C<dump()> call may change.
174 The very dusty examples in the eg/ directory have been removed.
175 Suggestions for new shiny examples welcome but the main issue is that
176 the examples need to be documented, tested and (most importantly)
181 The (bogus) escape sequences \8 and \9 now give an optional warning
182 ("Unrecognized escape passed through"). There is no need to \-escape
187 The list of filenames from glob() (or <...>) is now by default sorted
188 alphabetically to be csh-compliant (which is what happened before
189 in most UNIX platforms). (bsd_glob() does still sort platform
190 natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.)
194 Spurious syntax errors generated in certain situations, when glob()
195 caused File::Glob to be loaded for the first time, have been fixed.
199 Although "you shouldn't do that", it was possible to write code that
200 depends on Perl's hashed key order (Data::Dumper does this). The new
201 algorithm "One-at-a-Time" produces a different hashed key order.
202 More details are in L</"Performance Enhancements">.
206 lstat(FILEHANDLE) now gives a warning because the operation makes no sense.
207 In future releases this may become a fatal error.
211 The C<package;> syntax (C<package> without an argument) has been
212 deprecated. Its semantics were never that clear and its
213 implementation even less so. If you have used that feature to
214 disallow all but fully qualified variables, C<use strict;> instead.
218 The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still
219 recognised but now cause fatal errors. The previous behaviour of
220 ignoring them by default and warning if requested was unacceptable
221 since it, in a way, falsely promised that the features could be used.
225 The current user-visible implementation of pseudo-hashes (the weird
226 use of the first array element) is deprecated starting from Perl 5.8.0
227 and will be removed in Perl 5.10.0, and the feature will be
228 implemented differently. Not only is the current interface rather
229 ugly, but the current implementation slows down normal array and hash
230 use quite noticeably. The C<fields> pragma interface will remain
231 available. The I<restricted hashes> interface is expected to
232 be the replacement interface (see L<Hash::Util>).
236 The syntaxes C<< @a->[...] >> and C<< %h->{...} >> have now been deprecated.
240 After years of trying the suidperl is considered to be too complex to
241 ever be considered truly secure. The suidperl functionality is likely
242 to be removed in a future release.
246 The long deprecated uppercase aliases for the string comparison
247 operators (EQ, NE, LT, LE, GE, GT) have now been removed.
251 The tr///C and tr///U features have been removed and will not return;
252 the interface was a mistake. Sorry about that. For similar
253 functionality, see pack('U0', ...) and pack('C0', ...).
257 Earlier Perls treated "sub foo (@bar)" as equivalent to "sub foo (@)".
258 The prototypes are now checked at compile-time for invalid characters.
259 An optional warning is generated ("Illegal character in prototype...")
260 but this may be upgraded to a fatal error in a future release.
264 =head1 Core Enhancements
266 =head2 PerlIO is Now The Default
272 IO is now by default done via PerlIO rather than system's "stdio".
273 PerlIO allows "layers" to be "pushed" onto a file handle to alter the
274 handle's behaviour. Layers can be specified at open time via 3-arg
277 open($fh,'>:crlf :utf8', $path) || ...
279 or on already opened handles via extended C<binmode>:
281 binmode($fh,':encoding(iso-8859-7)');
283 The built-in layers are: unix (low level read/write), stdio (as in
284 previous Perls), perlio (re-implementation of stdio buffering in a
285 portable manner), crlf (does CRLF <=> "\n" translation as on Win32,
286 but available on any platform). A mmap layer may be available if
287 platform supports it (mostly UNIXes).
289 Layers to be applied by default may be specified via the 'open' pragma.
291 See L</"Installation and Configuration Improvements"> for the effects
292 of PerlIO on your architecture name.
296 File handles can be marked as accepting Perl's internal encoding of Unicode
297 (UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" :
299 open($fh,">:utf8","Uni.txt");
301 Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named
302 for you since it's not UTF-8 what you will be getting but instead
303 UTF-EBCDIC. See L<perlunicode>, L<utf8>, and
304 http://www.unicode.org/unicode/reports/tr16/ for more information.
305 In future releases this naming may change.
309 File handles can translate character encodings from/to Perl's internal
310 Unicode form on read/write via the ":encoding()" layer.
314 File handles can be opened to "in memory" files held in Perl scalars via:
316 open($fh,'>', \$variable) || ...
320 Anonymous temporary files are available without need to
321 'use FileHandle' or other module via
323 open($fh,"+>", undef) || ...
325 That is a literal undef, not an undefined value.
329 The list form of C<open> is now implemented for pipes (at least on UNIX):
331 open($fh,"-|", 'cat', '/etc/motd')
333 creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
338 If your locale environment variables (LANGUAGE, LC_ALL, LC_CTYPE, LANG)
339 contain the strings 'UTF-8' or 'UTF8' (case-insensitive matching),
340 the default encoding of your STDIN, STDOUT, and STDERR, and of
341 B<any subsequent file open>, is UTF-8.
345 =head2 Restricted Hashes
347 A restricted hash is restricted to a certain set of keys, no keys
348 outside the set can be added. Also individual keys can be restricted
349 so that the key cannot be deleted and the value cannot be changed.
350 No new syntax is involved: the Hash::Util module is the interface.
354 Perl used to be fragile in that signals arriving at inopportune moments
355 could corrupt Perl's internal state. Now Perl postpones handling of
356 signals until it's safe (between opcodes).
358 This change may have surprising side effects because signals no longer
359 interrupt Perl instantly. Perl will now first finish whatever it was
360 doing, like finishing an internal operation (like sort()) or an
361 external operation (like an I/O operation), and only then look at any
362 arrived signals (and before starting the next operation). No more corrupt
363 internal state since the current operation is always finished first,
364 but the signal may take more time to get heard. Note that breaking
365 out from potentially blocking operations should still work, though.
367 =head2 Unicode Overhaul
369 Unicode in general should be now much more usable than in Perl 5.6.0
370 (or even in 5.6.1). Unicode can be used in hash keys, Unicode in
371 regular expressions should work now, Unicode in tr/// should work now,
372 Unicode in I/O should work now. See L<perluniintro> for introduction
373 and L<perlunicode> for details.
379 The Unicode Character Database coming with Perl has been upgraded
380 to Unicode 3.2.0. For more information, see http://www.unicode.org/ .
384 For developers interested in enhancing Perl's Unicode capabilities:
385 almost all the UCD files are included with the Perl distribution in
386 the F<lib/unicore subdirectory>. The most notable omission, for space
387 considerations, is the Unihan database.
391 The properties \p{Blank} and \p{SpacePerl} have been added. "Blank" is like
392 C isblank(), that is, it contains only "horizontal whitespace" (the space
393 character is, the newline isn't), and the "SpacePerl" is the Unicode
394 equivalent of C<\s> (\p{Space} isn't, since that includes the vertical
395 tabulator character, whereas C<\s> doesn't.)
397 See "New Unicode Properties" earlier in this document for additional
398 information on changes with Unicode properties.
402 =head2 Understanding of Numbers
404 In general a lot of fixing has happened in the area of Perl's
405 understanding of numbers, both integer and floating point. Since in
406 many systems the standard number parsing functions like C<strtoul()>
407 and C<atof()> seem to have bugs, Perl tries to work around their
408 deficiencies. This results hopefully in more accurate numbers.
410 Perl now tries internally to use integer values in numeric conversions
411 and basic arithmetics (+ - * /) if the arguments are integers, and
412 tries also to keep the results stored internally as integers.
413 This change leads to often slightly faster and always less lossy
414 arithmetics. (Previously Perl always preferred floating point numbers
417 =head2 Miscellaneous Changes
423 AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
424 to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
428 C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
429 in multiple arguments.)
433 The builtin dump() now gives an optional warning
434 C<dump() better written as CORE::dump()>,
435 meaning that by default C<dump(...)> is resolved as the builtin
436 dump() which dumps core and aborts, not as (possibly) user-defined
437 C<sub dump>. To call the latter, qualify the call as C<&dump(...)>.
438 (The whole dump() feature is to considered deprecated, and possibly
439 removed/changed in future releases.)
443 chomp() and chop() are now overridable. Note, however, that their
444 prototype (as given by C<prototype("CORE::chomp")> is undefined,
445 because it cannot be expressed and therefore one cannot really write
446 replacements to override these builtins.
450 END blocks are now run even if you exit/die in a BEGIN block.
451 Internally, the execution of END blocks is now controlled by
452 PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new
453 behaviour for Perl embedders. This will default in 5.10. See
458 Formats now support zero-padded decimal fields.
462 Lvalue subroutines can now return C<undef> in list context.
463 However, the lvalue subroutine feature still remains experimental.
467 A lost warning "Can't declare ... dereference in my" has been
468 restored (Perl had it earlier but it became lost in later releases.)
472 A new special regular expression variable has been introduced:
473 C<$^N>, which contains the most-recently closed group (submatch).
477 C<no Module;> now works even if there is no "sub unimport" in the Module.
481 The numerical comparison operators return C<undef> if either operand
482 is a NaN. Previously the behaviour was unspecified.
486 The following builtin functions are now overridable: each(), keys(),
487 pop(), push(), shift(), splice(), unshift().
491 C<pack() / unpack()> now can group template letters with C<()> and then
492 apply repetition/count modifiers on the groups.
496 C<pack() / unpack()> can now process the Perl internal numeric types:
497 IVs, UVs, NVs-- and also long doubles, if supported by the platform.
498 The template letters are C<j>, C<J>, C<F>, and C<D>.
502 C<pack('U0a*', ...)> can now be used to force a string to UTF8.
506 my __PACKAGE__ $obj now works.
510 The printf() and sprintf() now support parameter reordering using the
511 C<%\d+\$> and C<*\d+\$> syntaxes. For example
513 print "%2\$s %1\$s\n", "foo", "bar";
515 will print "bar foo\n". This feature helps in writing
516 internationalised software, and in general when the order
517 of the parameters can vary.
521 prototype(\&) is now available.
525 prototype(\[$@%&]) is now available to implicitly create references
526 (useful for example if you want to emulate the tie() interface).
530 A new command-line option, C<-t> is available. It is the
531 little brother of C<-T>: instead of dying on taint violations,
532 lexical warnings are given. B<This is only meant as a temporary
533 debugging aid while securing the code of old legacy applications.
534 This is not a substitute for -T.>
538 In other taint news, the C<exec LIST> and C<system LIST> have now been
539 considered too risky (think C<exec @ARGV>: it can start any program
540 with any arguments), and now the said forms cause a warning.
541 You should carefully launder the arguments to guarantee their
542 validity. In future releases of Perl the forms will become fatal
543 errors so consider starting laundering now.
547 If tr/// is just counting characters, it doesn't attempt to
552 untie() will now call an UNTIE() hook if it exists. See L<perltie>
557 L<utime> now supports C<utime undef, undef, @files> to change the
558 file timestamps to the current time.
562 The rules for allowing underscores (underbars) in numeric constants
563 have been relaxed and simplified: now you can have an underscore
564 simply B<between digits>.
568 Rather than relying on C's argv[0] (which may not contain a full pathname)
569 where possible $^X is now set by asking the operating system.
570 (eg by reading F</proc/self/exe> on Linux, F</proc/curproc/file> on FreeBSD)
574 A new variable, C<${^TAINT}>, indicates whether taint mode is enabled.
578 You can now override the readline() builtin, and this overrides also
579 the <FILEHANDLE> angle bracket operator.
583 The command-line options -s and -F are now recognized on the shebang
588 Use of the C</c> match modifier without an accompanying C</g> modifier
589 elicits a new warning: C<Use of /c modifier is meaningless without /g>.
591 Use of C</c> in substitutions, even with C</g>, elicits
592 C<Use of /c modifier is meaningless in s///>.
594 Use of C</g> with C<split> elicits C<Use of /g modifier is meaningless
599 =head1 Modules and Pragmata
601 =head2 New Modules and Pragmata
607 C<Attribute::Handlers> allows a class to define attribute handlers.
610 use Attribute::Handlers;
611 sub Wolf :ATTR(SCALAR) { print "howl!\n" }
613 # later, in some package using or inheriting from MyPack...
615 my MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called
617 Both variables and routines can have attribute handlers. Handlers can
618 be specific to type (SCALAR, ARRAY, HASH, or CODE), or specific to the
619 exact compilation phase (BEGIN, CHECK, INIT, or END).
623 B<B::Concise> is a new compiler backend for walking the Perl syntax
624 tree, printing concise info about ops, from Stephen McCamant. The
625 output is highly customisable. See L<B::Concise>.
629 The new bignum, bigint, and bigrat pragmas implement transparent
630 bignum support (using the Math::BigInt, Math::BigFloat, and
631 Math::BigRat backends), by Tels.
635 C<Class::ISA> for reporting the search path for a class's ISA tree,
636 by Sean Burke, has been added. See L<Class::ISA>.
640 C<Cwd> has now a split personality: if possible, an XS extension is
641 used, (this will hopefully be faster, more secure, and more robust)
642 but if not possible, the familiar Perl implementation is used.
646 C<Devel::PPPort>, originally from Kenneth Albanowski and now
647 maintained by Paul Marquess, has been added. It is primarily used
648 by C<h2xs> to enhance portability of XS modules between different
653 C<Digest>, frontend module for calculating digests (checksums), from
654 Gisle Aas, has been added. See L<Digest>.
658 C<Digest::MD5> for calculating MD5 digests (checksums) as defined in
659 RFC 1321, from Gisle Aas, has been added. See L<Digest::MD5>.
661 use Digest::MD5 'md5_hex';
663 $digest = md5_hex("Thirsty Camel");
665 print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
667 NOTE: the C<MD5> backward compatibility module is deliberately not
668 included since its further use is discouraged.
672 C<Encode>, orginally by Nick Ing-Simmons and now maintained by Dan
673 Kogai, provides a mechanism to translate between different character
674 encodings. Support for Unicode, ISO-8859-1, and ASCII are compiled in
675 to the module. Several other encodings (like the rest of the
676 ISO-8859, CP*/Win*, Mac, KOI8-R, three variants EBCDIC, Chinese,
677 Japanese, and Korean encodings) are included and can be loaded at
678 runtime. (For space considerations, the largest Chinese encodings
679 have been separated into their own CPAN module, Encode::HanExtra,
680 which Encode will use if available). See L<Encode>.
682 Any encoding supported by Encode module is also available to the
683 ":encoding()" layer if PerlIO is used.
687 C<Hash::Util> is the interface to the new I<restricted hashes>
688 feature. (Implemented by Jeffrey Friedl, Nick Ing-Simmons, and
693 C<I18N::Langinfo> can be use to query locale information.
694 See L<I18N::Langinfo>.
698 C<I18N::LangTags> has functions for dealing with RFC3066-style
699 language tags, by Sean Burke. See L<I18N::LangTags>.
703 C<ExtUtils::Constant> is a new tool for extension writers for
704 generating XS code to import C header constants, by Nicholas Clark.
705 See L<ExtUtils::Constant>.
709 C<Filter::Simple> is an easy-to-use frontend to Filter::Util::Call,
710 from Damian Conway. See L<Filter::Simple>.
716 use Filter::Simple sub {
717 while (my ($from, $to) = splice @_, 0, 2) {
726 use MyFilter qr/red/ => 'green';
728 print "red\n"; # this code is filtered, will print "green\n"
729 print "bored\n"; # this code is filtered, will print "bogreen\n"
733 print "red\n"; # this code is not filtered, will print "red\n"
737 C<File::Temp> allows one to create temporary files and directories in
738 an easy, portable, and secure way, by Tim Jenness. See L<File::Temp>.
742 C<Filter::Util::Call> provides you with the framework to write
743 I<Source Filters> in Perl, from Paul Marquess. For most uses the
744 frontend Filter::Simple is to be preferred. See L<Filter::Util::Call>.
748 C<if> is a new pragma for conditional inclusion of modules, from
753 L<libnet> is a collection of perl5 modules related to network
754 programming, from Graham Barr. See L<Net::FTP>, L<Net::NNTP>,
755 L<Net::Ping> (not part of libnet, but related), L<Net::POP3>,
756 L<Net::SMTP>, and L<Net::Time>.
758 Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure.
762 C<List::Util> is a selection of general-utility list subroutines, like
763 sum(), min(), first(), and shuffle(), by Graham Barr. See L<List::Util>.
767 C<Locale::Constants>, C<Locale::Country>, C<Locale::Currency>
768 C<Locale::Language>, and L<Locale::Script>, from Neil Bowers, have
769 been added. They provide the codes for various locale standards, such
770 as "fr" for France, "usd" for US Dollar, and "ja" for Japanese.
774 $country = code2country('jp'); # $country gets 'Japan'
775 $code = country2code('Norway'); # $code gets 'no'
777 See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>,
778 and L<Locale::Language>.
782 C<Locale::Maketext> is localization framework from Sean Burke. See
783 L<Locale::Maketext>, and L<Locale::Maketext::TPJ13>. The latter is an
784 article about software localization, originally published in The Perl
785 Journal #13, republished here with kind permission.
789 C<Math::BigRat> for big rational numbers, to accompany Math::BigInt and
790 Math::BigFloat, from Tels.
794 C<Memoize> can make your functions faster by trading space for time,
795 from Mark-Jason Dominus. See L<Memoize>.
799 C<MIME::Base64> allows you to encode data in base64, from Gisle Aas,
800 as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
805 $encoded = encode_base64('Aladdin:open sesame');
806 $decoded = decode_base64($encoded);
808 print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
814 C<MIME::QuotedPrint> allows you to encode data in quoted-printable
815 encoding, as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
816 Extensions)>, from Gisle Aas.
818 use MIME::QuotedPrint;
820 $encoded = encode_qp("Smiley in Unicode: \x{263a}");
821 $decoded = decode_qp($encoded);
823 print $encoded, "\n"; # "Smiley in Unicode: =263A"
825 MIME::QuotedPrint has been enhanced to provide the basic methods
826 necessary to use it with PerlIO::Via as in :
828 use MIME::QuotedPrint;
829 open($fh,">Via(MIME::QuotedPrint)",$path);
831 See L<MIME::QuotedPrint>.
835 C<NEXT> is pseudo-class for method redispatch, from Damian Conway.
840 C<open> is a new pragma for setting the default I/O disciplines
845 C<PerlIO::Scalar> provides the implementation of IO to "in memory"
846 Perl scalars as discussed above, from Nick Ing-Simmons. It also
847 serves as an example of a loadable PerlIO layer. Other future
848 possibilities include PerlIO::Array and PerlIO::Code.
849 See L<PerlIO::Scalar>.
853 C<PerlIO::Via> acts as a PerlIO layer and wraps PerlIO layer
854 functionality provided by a class (typically implemented in perl
855 code), from Nick Ing-Simmons.
857 use MIME::QuotedPrint;
858 open($fh,">Via(MIME::QuotedPrint)",$path);
860 This will automatically convert everything output to C<$fh>
861 to Quoted-Printable. See L<PerlIO::Via>.
865 C<Pod::ParseLink>, by Russ Allbery, has been added,
866 to parse LZ<><> links in pods as described in the new
871 C<Pod::Text::Overstrike>, by Joe Smith, has been added.
872 It converts POD data to formatted overstrike text.
873 See L<Pod::Text::Overstrike>.
877 C<Scalar::Util> is a selection of general-utility scalar subroutines,
878 like blessed(), reftype(), and tainted(). See L<Scalar::Util>.
882 C<sort> is a new pragma for controlling the behaviour of sort().
886 C<Storable> gives persistence to Perl data structures by allowing the
887 storage and retrieval of Perl data to and from files in a fast and
888 compact binary format. Because in effect Storable does serialisation
889 of Perl data structues, with it you can also clone deep, hierarchical
890 datastructures. Storable was created by Raphael Manfredi but it is
891 now maintained by the Perl development team. Storable has been
892 enhanced to understand the two new hash features, Unicode keys and
893 restricted hashes. See L<Storable>.
897 C<Switch>, from Damian Conway, has been added. Just by saying
901 you have C<switch> and C<case> available in Perl.
907 case 1 { print "number 1" }
908 case "a" { print "string a" }
909 case [1..10,42] { print "number in list" }
910 case (@array) { print "number in list" }
911 case /\w+/ { print "pattern" }
912 case qr/\w+/ { print "pattern" }
913 case (%hash) { print "entry in hash" }
914 case (\%hash) { print "entry in hash" }
915 case (\&sub) { print "arg to subroutine" }
916 else { print "previous case not true" }
923 C<Test::More> is yet another framework for writing test scripts,
924 more extensive than Test::Simple, by Michael Schwern. See L<Test::More>.
928 C<Test::Simple> has basic utilities for writing tests, by Michael
929 Schwern. See L<Test::Simple>.
933 C<Text::Balanced> has been added, for extracting delimited text
934 sequences from strings, from Damian Conway.
936 use Text::Balanced 'extract_delimited';
938 ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
940 $a will be "'never say never'", $b will be ', he never said'.
942 In addition to extract_delimited() there are also extract_bracketed(),
943 extract_quotelike(), extract_codeblock(), extract_variable(),
944 extract_tagged(), extract_multiple(), gen_delimited_pat(), and
945 gen_extract_tagged(). With these you can implement rather advanced
946 parsing algorithms. See L<Text::Balanced>.
950 C<threads> is an interface to interpreter threads, by Arthur Bergman.
951 Interpreter threads (ithreads) is the new thread model introduced in
952 Perl 5.6 but only available as an internal interface for extension
953 writers (and for Win32 Perl for C<fork()> emulation). See L<threads>.
957 C<threads::shared> allows data sharing for interpreter threads, from
958 Arthur Bergman. In the ithreads model any data sharing between
959 threads must be explicit, as opposed to the old 5.005 thread model
960 where data sharing was implicit. See L<threads::shared>.
964 C<Tie::File>, by Mark-Jason Dominus, associates a Perl array with the
969 C<Tie::Memoize>, by Ilya Zakharevich, provides on-demand loaded hashes.
973 C<Tie::RefHash::Nestable>, by Edward Avis, allows storing hash
974 references (unlike the standard Tie::RefHash) The module is contained
975 within Tie::RefHash, see L<Tie::RefHash>.
979 C<Time::HiRes> provides high resolution timing (ualarm, usleep,
980 and gettimeofday), from Douglas E. Wegscheid. See L<Time::HiRes>.
984 C<Unicode::UCD> offers a querying interface to the Unicode Character
985 Database. See L<Unicode::UCD>.
989 C<Unicode::Collate> implements the UCA (Unicode Collation Algorithm)
990 for sorting Unicode strings, by SADAHIRO Tomoyuki. See L<Unicode::Collate>.
994 C<Unicode::Normalize> implements the various Unicode normalization
995 forms, by SADAHIRO Tomoyuki. See L<Unicode::Normalize>.
999 C<XS::Typemap>, by Tim Jenness, is a test extension that exercises XS
1000 typemaps. Nothing gets installed but for extension writers the code
1005 =head2 Updated And Improved Modules and Pragmata
1011 The following independently supported modules have been updated to the
1012 newest versions from CPAN: CGI, CPAN, DB_File, File::Spec, File::Temp,
1013 Getopt::Long, Math::BigFloat, Math::BigInt, the podlators bundle
1014 (Pod::Man, Pod::Text), Pod::LaTeX, Pod::Parser, Storable,
1015 Term::ANSIColor, Test, Text-Tabs+Wrap.
1019 The attributes::reftype() now works on tied arguments.
1023 AutoLoader can now be disabled with C<no AutoLoader;>.
1027 B::Deparse has been significantly enhanced. It now can deparse almost
1028 all of the standard test suite (so that the tests still succeed).
1029 There is a make target "test.deparse" for trying this out.
1033 Class::Struct can now define the classes in compile time.
1037 Class::Struct now assigns the array/hash element if the accessor
1038 is called with an array/hash element as the B<sole> argument.
1042 Data::Dumper has now an option to sort hashes.
1046 Data::Dumper has now an option to dump code references
1051 DB_File now supports newer Berkeley DB versions, among
1056 The English module can now be used without the infamous performance
1059 use English '-no_match_vars';
1061 (Assuming, of course, that one doesn't need the troublesome variables
1062 C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
1063 C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
1067 Fcntl, Socket, and Sys::Syslog have been rewritten to use the
1068 new-style constant dispatch section (see L<ExtUtils::Constant>).
1069 This means that they will be more robust and hopefully faster.
1073 File::Find now chdir()s correctly when chasing symbolic links.
1077 File::Find now has pre- and post-processing callbacks. It also
1078 correctly changes directories when chasing symbolic links. Callbacks
1079 (naughtily) exiting with "next;" instead of "return;" now work.
1083 File::Find is now (again) reentrant. It also has been made
1088 The warnings issued by File::Find now belong to their own category.
1089 You can enable/disable them with C<use/no warnings 'File::Find';>.
1093 File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
1094 prototype mismatch with CORE::glob().
1098 File::Glob now supports C<GLOB_LIMIT> constant to limit the size of
1099 the returned list of filenames.
1103 Devel::Peek now has an interface for the Perl memory statistics
1104 (this works only if you are using perl's malloc, and if you have
1105 compiled with debugging).
1109 IPC::Open3 now allows the use of numeric file descriptors.
1113 IO::Socket has now atmark() method, which returns true if the socket
1114 is positioned at the out-of-band mark. The method is also exportable
1115 as a sockatmark() function.
1119 IO::Socket::INET has support for ReusePort option (if your platform
1120 supports it). The Reuse option now has an alias, ReuseAddr. For clarity
1121 you may want to prefer ReuseAddr.
1125 IO::Socket::INET now supports C<LocalPort> of zero (usually meaning
1126 that the operating system will make one up.)
1130 use lib now works identically to @INC. Removing directories
1131 with 'no lib' now works.
1135 ExtUtils::MakeMaker now uses File::Spec internally, which hopefully
1136 leads into better portability.
1140 Math::BigFloat and Math::BigInt have undergone a full rewrite.
1141 They are now magnitudes faster, and they support various
1142 bignum libraries such as GMP and PARI as their backends.
1146 Math::Complex handles inf, NaN etc., better.
1150 Net::Ping has been muchly enhanced: multihoming is now supported,
1151 Win32 functionality is better, there is now time measuring
1152 functionality (optionally high-resolution using Time::HiRes),
1153 and there is now "external" protocol which uses Net::Ping::External
1154 module which runs your external ping utility and parses the output.
1155 A version of Net::Ping::External is available in CPAN.
1157 Note that some of the Net::Ping tests are disabled when running
1158 under the Perl distribution since one cannot assume one or more
1159 of the following: enabled echo port at localhost, full Internet
1160 connectivity, or sympathetic firewalls. You can set the environment
1161 variable PERL_TEST_Net_Ping to "1" (one) before running the Perl test
1162 suite to enable all the Net::Ping tests.
1166 POSIX::sigaction() is now much more flexible and robust.
1167 You can now install coderef handlers, 'DEFAULT', and 'IGNORE'
1168 handlers, installing new handlers was not atomic.
1172 In Safe the C<%INC> now localised in a Safe compartment so that
1177 In SDBM_File on dosish platforms, some keys went missing because of
1178 lack of support for files with "holes". A workaround for the problem
1183 In Search::Dict one can now have a pre-processing hook for the
1184 lines being searched.
1188 The Shell module now has an OO interface.
1192 In Sys::Syslog there is now a failover mechanism that will go
1193 through alternative connection mechanisms until the message
1194 is successfully logged.
1198 The Test module has been significantly enhanced.
1202 Time::Local::timelocal() does not handle fractional seconds anymore.
1203 The rationale is that neither does localtime(), and timelocal() and
1204 localtime() are supposed to be inverses of each other.
1208 The vars pragma now supports declaring fully qualified variables.
1209 (Something that C<our()> does not and will not support.)
1213 The C<utf8::> name space (as in the pragma) provides various
1214 Perl-callable functions to provide low level access to Perl's
1215 internal Unicode representation. At the moment only length()
1216 has been implemented.
1220 =head1 Utility Changes
1226 Emacs perl mode (emacs/cperl-mode.el) has been updated to version
1231 F<emacs/e2ctags.pl> is now much faster.
1235 C<enc2xs> is a tool for people adding their own encodings to the
1240 C<h2ph> now supports C trigraphs.
1244 C<h2xs> now produces a template README.
1248 C<h2xs> now uses C<Devel::PPort> for better portability between
1249 different versions of Perl.
1253 C<h2xs> uses the new L<ExtUtils::Constant> module which will affect
1254 newly created extensions that define constants. Since the new code is
1255 more correct (if you have two constants where the first one is a
1256 prefix of the second one, the first constant B<never> gets defined),
1257 less lossy (it uses integers for integer constant, as opposed to the
1258 old code that used floating point numbers even for integer constants),
1259 and slightly faster, you might want to consider regenerating your
1260 extension code (the new scheme makes regenerating easy).
1261 L<h2xs> now also supports C trigraphs.
1265 C<libnetcfg> has been added to configure the libnet.
1269 C<perlbug> is now much more robust. It also sends the bug report to
1270 perl.org, not perl.com.
1274 C<perlcc> has been rewritten and its user interface (that is,
1275 command line) is much more like that of the UNIX C compiler, cc.
1276 (The perlbc tools has been removed. Use C<perlcc -B> instead.)
1280 C<perlivp> is a new Installation Verification Procedure utility
1281 for running any time after installing Perl.
1285 C<piconv> is an implementation of the character conversion utility
1286 C<iconv>, demonstrating the new Encode module.
1290 C<pod2html> now allows specifying a cache directory.
1294 C<pod2html> now produces XHTML 1.0.
1298 C<pod2html> now understands POD written using different line endings
1299 (PC-like CRLF versus UNIX-like LF versus MacClassic-like CR).
1303 C<s2p> has been completely rewritten in Perl. (It is in fact a full
1304 implementation of sed in Perl: you can use the sed functionality by
1305 using the C<psed> utility.)
1309 C<xsubpp> now understands POD documentation embedded in the *.xs files.
1313 C<xsubpp> now supports OUT keyword.
1317 =head1 New Documentation
1323 perl56delta details the changes between the 5.005 release and the
1328 perlclib documents the internal replacements for standard C library
1329 functions. (Interesting only for extension writers and Perl core
1334 perldebtut is a Perl debugging tutorial.
1338 perlebcdic contains considerations for running Perl on EBCDIC platforms.
1342 perlintro is a gentle introduction to Perl.
1346 perliol documents the internals of PerlIO with layers.
1350 perlmodstyle is a style guide for writing modules.
1354 perlnewmod tells about writing and submitting a new module.
1358 perlpacktut is a pack() tutorial.
1362 perlpod has been rewritten to be clearer and to record the best
1363 practices gathered over the years.
1367 perlpodspec is a more formal specification of the pod format,
1368 mainly of interest for writers of pod applications, not to
1369 people writing in pod.
1373 perlretut is a regular expression tutorial.
1377 perlrequick is a regular expressions quick-start guide.
1378 Yes, much quicker than perlretut.
1382 perltodo has been updated.
1386 perltootc has been renamed as perltooc (to not to conflict
1387 with perltoot in filesystems restricted to "8.3" names)
1391 perluniintro is an introduction to using Unicode in Perl.
1392 (perlunicode is more of a detailed reference and background
1397 perlutil explains the command line utilities packaged with the Perl
1402 The following platform-specific documents are available before
1403 the installation as README.I<platform>, and after the installation
1406 perlaix perlamiga perlapollo perlbeos perlbs2000
1407 perlce perlcygwin perldgux perldos perlepoc perlhpux
1408 perlhurd perlmachten perlmacos perlmint perlmpeix
1409 perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris
1410 perltru64 perluts perlvmesa perlvms perlvos perlwin32
1416 The documentation for the POSIX-BC platform is called "BS2000", to avoid
1417 confusion with the Perl POSIX module.
1421 The documentation for the WinCE platform is called perlce (README.ce
1422 in the source code kit), to avoid confusion with the perlwin32
1423 documentation on 8.3-restricted filesystems.
1427 =head1 Performance Enhancements
1433 map() could get pathologically slow when the result list it generates
1434 is larger than the source list. The performance has been improved for
1439 sort() has been changed to use primarily mergesort internally as
1440 opposed to the earlier quicksort. For very small lists this may
1441 result in slightly slower sorting times, but in general the speedup
1442 should be at least 20%. Additional bonuses are that the worst case
1443 behaviour of sort() is now better (in computer science terms it now
1444 runs in time O(N log N), as opposed to quicksort's Theta(N**2)
1445 worst-case run time behaviour), and that sort() is now stable
1446 (meaning that elements with identical keys will stay ordered as they
1447 were before the sort). See the C<sort> pragma for information.
1449 The story in more detail: suppose you want to serve yourself a little
1452 @digits = ( 3,1,4,1,5,9 );
1454 A numerical sort of the digits will yield (1,1,3,4,5,9), as expected.
1455 Which C<1> comes first is hard to know, since one C<1> looks pretty
1456 much like any other. You can regard this as totally trivial,
1457 or somewhat profound. However, if you just want to sort the even
1458 digits ahead of the odd ones, then what will
1460 sort { ($a % 2) <=> ($b % 2) } @digits;
1462 yield? The only even digit, C<4>, will come first. But how about
1463 the odd numbers, which all compare equal? With the quicksort algorithm
1464 used to implement Perl 5.6 and earlier, the order of ties is left up
1465 to the sort. So, as you add more and more digits of Pi, the order
1466 in which the sorted even and odd digits appear will change.
1467 and, for sufficiently large slices of Pi, the quicksort algorithm
1468 in Perl 5.8 won't return the same results even if reinvoked with the
1469 same input. The justification for this rests with quicksort's
1470 worst case behavior. If you run
1472 sort { $a <=> $b } ( 1 .. $N , 1 .. $N );
1474 (something you might approximate if you wanted to merge two sorted
1475 arrays using sort), doubling $N doesn't just double the quicksort time,
1476 it I<quadruples> it. Quicksort has a worst case run time that can
1477 grow like N**2, so-called I<quadratic> behaviour, and it can happen
1478 on patterns that may well arise in normal use. You won't notice this
1479 for small arrays, but you I<will> notice it with larger arrays,
1480 and you may not live long enough for the sort to complete on arrays
1481 of a million elements. So the 5.8 quicksort scrambles large arrays
1482 before sorting them, as a statistical defence against quadratic behaviour.
1483 But that means if you sort the same large array twice, ties may be
1484 broken in different ways.
1486 Because of the unpredictability of tie-breaking order, and the quadratic
1487 worst-case behaviour, quicksort was I<almost> replaced completely with
1488 a stable mergesort. I<Stable> means that ties are broken to preserve
1489 the original order of appearance in the input array. So
1491 sort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9);
1493 will yield (4,3,1,1,5,9), guaranteed. The even and odd numbers
1494 appear in the output in the same order they appeared in the input.
1495 Mergesort has worst case O(NlogN) behaviour, the best value
1496 attainable. And, ironically, this mergesort does particularly
1497 well where quicksort goes quadratic: mergesort sorts (1..$N, 1..$N)
1498 in O(N) time. But quicksort was rescued at the last moment because
1499 it is faster than mergesort on certain inputs and platforms.
1500 For example, if you really I<don't> care about the order of even
1501 and odd digits, quicksort will run in O(N) time; it's very good
1502 at sorting many repetitions of a small number of distinct elements.
1503 The quicksort divide and conquer strategy works well on platforms
1504 with relatively small, very fast, caches. Eventually, the problem gets
1505 whittled down to one that fits in the cache, from which point it
1506 benefits from the increased memory speed.
1508 Quicksort was rescued by implementing a sort pragma to control aspects
1509 of the sort. The B<stable> subpragma forces stable behaviour,
1510 regardless of algorithm. The B<_quicksort> and B<_mergesort>
1511 subpragmas are heavy-handed ways to select the underlying implementation.
1512 The leading C<_> is a reminder that these subpragmas may not survive
1513 beyond 5.8. More appropriate mechanisms for selecting the implementation
1514 exist, but they wouldn't have arrived in time to save quicksort.
1518 Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm
1519 ( http://burtleburtle.net/bob/hash/doobs.html ). This algorithm is
1520 reasonably fast while producing a much better spread of values than
1521 the old hashing algorithm (originally by Chris Torek, later tweaked by
1522 Ilya Zakharevich). Hash values output from the algorithm on a hash of
1523 all 3-char printable ASCII keys comes much closer to passing the
1524 DIEHARD random number generation tests. According to perlbench, this
1525 change has not affected the overall speed of Perl.
1529 unshift() should now be noticeably faster.
1533 =head1 Installation and Configuration Improvements
1535 =head2 Generic Improvements
1541 INSTALL now explains how you can configure Perl to use 64-bit
1542 integers even on non-64-bit platforms.
1546 Policy.sh policy change: if you are reusing a Policy.sh file
1547 (see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old
1548 Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of
1549 them will now be changed to the new prefix, /foo/bar. (Previously
1550 only $prefix changed.) If you do not like this new behaviour,
1551 specify prefix, siteprefix, and vendorprefix explicitly.
1555 A new optional location for Perl libraries, otherlibdirs, is available.
1556 It can be used for example for vendor add-ons without disturbing Perl's
1557 own library directories.
1561 In many platforms the vendor-supplied 'cc' is too stripped-down to
1562 build Perl (basically, 'cc' doesn't do ANSI C). If this seems
1563 to be the case and 'cc' does not seem to be the GNU C compiler
1564 'gcc', an automatic attempt is made to find and use 'gcc' instead.
1568 gcc needs to closely track the operating system release to avoid
1569 build problems. If Configure finds that gcc was built for a different
1570 operating system release than is running, it now gives a clearly visible
1571 warning that there may be trouble ahead.
1575 If binary compatibility with the 5.005 release is not wanted, Configure
1576 no longer suggests including the 5.005 modules in @INC.
1580 Configure C<-S> can now run non-interactively.
1584 Configure support for pdp11-style memory models has been removed due
1589 configure.gnu now works with options with whitespace in them.
1593 installperl now outputs everything to STDERR.
1597 $Config{byteorder} is now computed dynamically (this is more robust
1598 with "fat binaries" where an executable image contains binaries for
1599 more than one binary platform.)
1603 Because PerlIO is now the default on most platforms, "-perlio" doesn't
1604 get appended to the $Config{archname} (also known as $^O) anymore.
1605 Instead, if you explicitly choose not to use perlio (Configure command
1606 line option -Uuseperlio), you will get "-stdio" appended.
1610 Another change related to the architecture name is that "-64all"
1611 (-Duse64bitall, or "maximally 64-bit") is appended only if your
1612 pointers are 64 bits wide. (To be exact, the use64bitall is ignored.)
1616 In AFS installations one can configure the root of the AFS to be
1617 somewhere else than the default F</afs> by using the Configure
1618 parameter C<-Dafsroot=/some/where/else>.
1622 APPLLIB_EXP, a less-know configuration-time definition, has been
1623 documented. It can be used to prepend site-specific directories
1624 to Perl's default search path (@INC), see INSTALL for information.
1628 The version of Berkeley DB used when the Perl (and, presumably, the
1629 DB_File extension) was built is now available as
1630 C<@Config{qw(db_version_major db_version_minor db_version_patch)}>
1631 from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG
1632 DB_VERSION_PATCH_CFG> from C.
1636 Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
1637 has been documented in INSTALL.
1641 If you have CPAN access (either network or a local copy such as a
1642 CD-ROM) you can during specify extra modules to Configure to build and
1643 install with Perl using the -Dextras=... option. See INSTALL for
1648 In addition to config.over a new override file, config.arch, is
1649 available. That is supposed to be used by hints file writers for
1650 architecture-wide changes (as opposed to config.over which is for
1655 If your file system supports symbolic links you can build Perl outside
1656 of the source directory by
1658 mkdir /tmp/perl/build/directory
1659 cd /tmp/perl/build/directory
1660 sh /path/to/perl/source/Configure -Dmksymlinks ...
1662 This will create in /tmp/perl/build/directory a tree of symbolic links
1663 pointing to files in /path/to/perl/source. The original files are left
1664 unaffected. After Configure has finished you can just say
1668 and Perl will be built and tested, all in /tmp/perl/build/directory.
1672 For Perl developers several new make targets for profiling
1673 and debugging have been added, see L<perlhack>.
1679 Use of the F<gprof> tool to profile Perl has been documented in
1680 L<perlhack>. There is a make target called "perl.gprof" for
1681 generating a gprofiled Perl executable.
1685 If you have GCC 3, there is a make target called "perl.gcov" for
1686 creating a gcoved Perl executable for coverage analysis. See
1691 If you are on IRIX or Tru64 platforms, new profiling/debugging options
1692 have been added, see L<perlhack> for more information about pixie and
1699 Guidelines of how to construct minimal Perl installations have
1700 been added to INSTALL.
1704 The Thread extension is now not built at all under ithreads
1705 (C<Configure -Duseithreads>) because it wouldn't work anyway (the
1706 Thread extension requires being Configured with C<-Duse5005threads>).
1708 But note that the Thread.pm interface is now shared by both
1713 The Gconvert macro ($Config{d_Gconvert}) used by perl for stringifying
1714 floating-point numbers is now more picky about using sprintf %.*g
1715 rules for the conversion. Some platforms that used to use gcvt may
1716 now resort to the slower sprintf.
1720 =head2 New Or Improved Platforms
1722 For the list of platforms known to support Perl,
1723 see L<perlport/"Supported Platforms">.
1729 AIX dynamic loading should be now better supported.
1733 AIX should now work better with gcc, threads, and 64-bitness. Also the
1734 long doubles support in AIX should be better now. See L<perlaix>.
1738 After a long pause, AmigaOS has been verified to be happy with Perl.
1742 AtheOS ( http://www.atheos.cx/ ) is a new platform.
1746 BeOS has been reclaimed.
1750 DG/UX platform now supports the 5.005-style threads. See L<perldgux>.
1754 DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2.
1758 EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA)
1759 have been regained. Many test suite tests still fail and the
1760 co-existence of Unicode and EBCDIC isn't quite settled, but the
1761 situation is much better than with Perl 5.6. See L<perlos390>,
1762 L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information.
1766 Building perl with -Duseithreads or -Duse5005threads now works under
1767 HP-UX 10.20 (previously it only worked under 10.30 or later). You will
1768 need a thread library package installed. See README.hpux.
1772 MacOS Classic (MacPerl has of course been available since
1773 perl 5.004 but now the source code bases of standard Perl
1774 and MacPerl have been synchronised)
1778 MacOS X (or Darwin) should now be able to build Perl even on HFS+
1779 filesystems. (The case-insensitivity confused the Perl build process.)
1783 NCR MP-RAS is now supported.
1787 All the NetBSD specific patches (except for the installation
1788 specific ones) have been merged back to the main distribution.
1792 NetWare from Novell is now supported. See L<perlnetware>.
1796 NonStop-UX is now supported.
1800 NEC SUPER-UX is now supported.
1804 All the OpenBSD specific patches (except for the installation
1805 specific ones) have been merged back to the main distribution.
1809 Perl has been tested with the GNU pth userlevel thread package
1810 ( http://www.gnu.org/software/pth/pth.html ) . All but one thread
1811 test worked, and that one failure was because of test results arriving
1812 in unexpected order.
1816 Amdahl UTS UNIX mainframe platform is now supported.
1820 WinCE is now supported. See L<perlce>.
1824 z/OS (formerly known as OS/390, formerly known as MVS OE) has now
1825 support for dynamic loading. This is not selected by default,
1826 however, you must specify -Dusedl in the arguments of Configure.
1830 =head1 Selected Bug Fixes
1832 Numerous memory leaks and uninitialized memory accesses have been
1833 hunted down. Most importantly anonymous subs used to leak quite
1840 The autouse pragma didn't work for Multi::Part::Function::Names.
1844 caller() could cause core dumps in certain situations. Carp was sometimes
1845 affected by this problem.
1849 chop(@list) in list context returned the characters chopped in
1850 reverse order. This has been reversed to be in the right order.
1854 Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
1855 when building the Perl binary. The only exception to this is SunOS 4.x,
1860 The behaviour of non-decimal but numeric string constants such as
1861 "0x23" was platform-dependent: in some platforms that was seen as 35,
1862 in some as 0, in some as a floating point number (don't ask). This
1863 was caused by Perl using the operating system libraries in a situation
1864 where the result of the string to number conversion is undefined: now
1865 Perl consistently handles such strings as zero in numeric contexts.
1869 The order of DESTROYs has been made more predictable.
1873 Several debugger fixes: exit code now reflects the script exit code,
1874 condition C<"0"> now treated correctly, the C<d> command now checks
1875 line number, the C<$.> no longer gets corrupted, all debugger output
1876 now goes correctly to the socket if RemotePort is set.
1880 Perl 5.6.0 could emit spurious warnings about redefinition of dl_error()
1881 when statically building extensions into perl. This has been corrected.
1885 L<dprofpp> -R didn't work.
1889 C<*foo{FORMAT}> now works.
1892 Infinity is now recognized as a number.
1896 UNIVERSAL::isa no longer caches methods incorrectly. (This broke
1897 the Tk extension with 5.6.0.)
1901 Lexicals I: lexicals outside an eval "" weren't resolved
1902 correctly inside a subroutine definition inside the eval "" if they
1903 were not already referenced in the top level of the eval""ed code.
1907 Lexicals II: lexicals leaked at file scope into subroutines that
1908 were declared before the lexicals.
1912 Lexical warnings now propagating correctly between scopes
1913 and into C<eval "...">.
1917 C<use warnings qw(FATAL all)> did not work as intended. This has been
1922 warnings::enabled() now reports the state of $^W correctly if the caller
1923 isn't using lexical warnings.
1927 Line renumbering with eval and C<#line> now works.
1931 Fixed numerous memory leaks, especially in eval "".
1935 mkdir() now ignores trailing slashes in the directory name,
1936 as mandated by POSIX.
1940 Some versions of glibc have a broken modfl(). This affects builds
1941 with C<-Duselongdouble>. This version of Perl detects this brokenness
1942 and has a workaround for it. The glibc release 2.2.2 is known to have
1943 fixed the modfl() bug.
1947 Modulus of unsigned numbers now works (4063328477 % 65535 used to
1948 return 27406, instead of 27047).
1952 Some "not a number" warnings introduced in 5.6.0 eliminated to be
1953 more compatible with 5.005. Infinity is now recognised as a number.
1957 Numeric conversions did not recognize changes in the string value
1958 properly in certain circumstances.
1962 Attributes (like :shared) didn't work with our().
1966 our() variables will not cause "will not stay shared" warnings.
1970 "our" variables of the same name declared in two sibling blocks
1971 resulted in bogus warnings about "redeclaration" of the variables.
1972 The problem has been corrected.
1976 pack "Z" now correctly terminates the string with "\0".
1980 Fix password routines which in some shadow password platforms
1981 (e.g. HP-UX) caused getpwent() to return every other entry.
1985 The PERL5OPT environment variable (for passing command line arguments
1986 to Perl) didn't work for more than a single group of options.
1990 PERL5OPT with embedded spaces didn't work.
1994 printf() no longer resets the numeric locale to "C".
1998 C<qw(a\\b)> now parses correctly as C<'a\\b'>.
2002 pos() did not return the correct value within s///ge in earlier
2003 versions. This is now handled correctly.
2007 Printing quads (64-bit integers) with printf/sprintf now works
2008 without the q L ll prefixes (assuming you are on a quad-capable platform).
2012 Regular expressions on references and overloaded scalars now work.
2016 Right-hand side magic (GMAGIC) could in many cases such as string
2017 concatenation be invoked too many times.
2021 scalar() now forces scalar context even when used in void context.
2025 SOCKS support is now much more robust.
2029 sort() arguments are now compiled in the right wantarray context
2030 (they were accidentally using the context of the sort() itself).
2031 The comparison block is now run in scalar context, and the arguments
2032 to be sorted are always provided list context.
2036 Changed the POSIX character class C<[[:space:]]> to include the (very
2037 rarely used) vertical tab character. Added a new POSIX-ish character
2038 class C<[[:blank:]]> which stands for horizontal whitespace
2039 (currently, the space and the tab).
2043 The tainting behaviour of sprintf() has been rationalized. It does
2044 not taint the result of floating point formats anymore, making the
2045 behaviour consistent with that of string interpolation.
2049 Some cases of inconsistent taint propagation (such as within hash
2050 values) have been fixed.
2054 The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds
2055 of simple pattern matches. These are now handled better.
2059 Regular expression debug output (whether through C<use re 'debug'>
2060 or via C<-Dr>) now looks better.
2064 Multi-line matches like C<"a\nxb\n" =~ /(?!\A)x/m> were flawed. The
2069 Use of $& could trigger a core dump under some situations. This
2074 The regular expression captured submatches ($1, $2, ...) are now
2075 more consistently unset if the match fails, instead of leaving false
2076 data lying around in them.
2080 readline() on files opened in "slurp" mode could return an extra "" at
2081 the end in certain situations. This has been corrected.
2085 Autovivification of symbolic references of special variables described
2086 in L<perlvar> (as in C<${$num}>) was accidentally disabled. This works
2091 Sys::Syslog ignored the C<LOG_AUTH> constant.
2095 All but the first argument of the IO syswrite() method are now optional.
2099 $AUTOLOAD, sort(), lock(), and spawning subprocesses
2100 in multiple threads simultaneously are now thread-safe.
2104 Tie::ARRAY SPLICE method was broken.
2108 Allow read-only string on left hand side of non-modifying tr///.
2112 If C<STDERR> is tied, warnings caused by C<warn> and C<die> now
2113 correctly pass to it.
2117 Several Unicode fixes.
2123 BOMs (byte order marks) in the beginning of Perl files
2124 (scripts, modules) should now be transparently skipped.
2125 UTF-16 (UCS-2) encoded Perl files should now be read correctly.
2129 The character tables have been updated to Unicode 3.2.0.
2133 Comparing with utf8 data does not magically upgrade non-utf8 data
2134 into utf8. (This was a problem for example if you were mixing data
2135 from I/O and Unicode data: your output might have got magically encoded
2140 Generating illegal Unicode code points like U+FFFE, or the UTF-16
2141 surrogates, now also generates an optional warning.
2145 C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
2149 Concatenation with the C<.> operator or via variable interpolation,
2150 C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
2151 substitution with C<s///>, single-quoted UTF8, should now work.
2155 The C<tr///> operator now works. Note that the C<tr///CU>
2156 functionality has been removed (but see pack('U0', ...)).
2160 C<eval "v200"> now works.
2164 Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious warnings.
2165 This has been corrected.
2169 Zero entries were missing from the Unicode classes like C<IsDigit>.
2175 Large unsigned numbers (those above 2**31) could sometimes lose their
2176 unsignedness, causing bogus results in arithmetic operations.
2180 =head2 Platform Specific Changes and Fixes
2188 Perl now works on post-4.0 BSD/OSes.
2194 Setting C<$0> now works (as much as possible; see L<perlvar> for details).
2200 Numerous updates; currently synchronised with Cygwin 1.3.10.
2204 Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
2210 EPOC update after Perl 5.6.0. See README.epoc.
2216 Perl now works on post-3.0 FreeBSDs.
2222 README.hpux updated; C<Configure -Duse64bitall> now works.
2228 Numerous compilation flag and hint enhancements; accidental mixing
2229 of 32-bit and 64-bit libraries (a doomed attempt) made much harder.
2239 Long doubles should now work (see INSTALL).
2243 Linux previously had problems related to sockaddrlen when using
2244 accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
2252 Compilation of the standard Perl distribution in MacOS Classic should
2253 now work if you have the Metrowerks development environment and
2254 the missing Mac-specific toolkit bits. Contact the macperl mailing
2261 MPE/iX update after Perl 5.6.0. See README.mpeix.
2265 NetBSD/threads: try installing the GNU pth (should be in the
2266 packages collection, or http://www.gnu.org/software/pth/),
2267 and Configure with -Duseithreads.
2273 Perl now works on NetBSD/sparc.
2279 Now works with usethreads (see INSTALL).
2285 64-bitness using the Sun Workshop compiler now works.
2289 Tru64 (aka Digital UNIX, aka DEC OSF/1)
2291 The operating system version letter now recorded in $Config{osvers}.
2292 Allow compiling with gcc (previously explicitly forbidden). Compiling
2293 with gcc still not recommended because buggy code results, even with
2300 Fixed various alignment problems that lead into core dumps either
2301 during build or later; no longer dies on math errors at runtime;
2302 now using full quad integers (64 bits), previously was using
2303 only 46 bit integers for speed.
2309 chdir() now works better despite a CRT bug; now works with MULTIPLICITY
2310 (see INSTALL); now works with Perl's malloc.
2312 The tainting of C<%ENV> elements via C<keys> or C<values> was previously
2313 unimplemented. It now works as documented.
2315 The C<waitpid> emulation has been improved. The worst bug (now fixed)
2316 was that a pid of -1 would cause a wildcard search of all processes on
2317 the system. The most significant enhancement is that we can now
2318 usually get the completion status of a terminated process.
2320 POSIX-style signals are now emulated much better on VMS versions prior
2323 The C<system> function and backticks operator have improved
2324 functionality and better error handling.
2326 File access tests now use current process privileges rather than the
2327 user's default privileges, which could sometimes result in a mismatch
2328 between reported access and actual access.
2338 accept() no longer leaks memory.
2342 Borland C++ v5.5 is now a supported compiler that can build Perl.
2343 However, the generated binaries continue to be incompatible with those
2344 generated by the other supported compilers (GCC and Visual C++).
2348 Better chdir() return value for a non-existent directory.
2352 Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
2356 New %ENV entries now propagate to subprocesses.
2360 Current directory entries in %ENV are now correctly propagated to child
2365 $ENV{LIB} now used to search for libs under Visual C.
2369 fork() emulation has been improved in various ways, but still continues
2370 to be experimental. See L<perlfork> for known bugs and caveats.
2374 A failed (pseudo)fork now returns undef and sets errno to EAGAIN.
2378 Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
2379 Other bugs in chdir() and Cwd::cwd() have also been fixed.
2383 HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
2387 The makefiles now provide a single switch to bulk-enable all the features
2388 enabled in ActiveState ActivePerl (a popular Win32 binary distribution).
2392 Allow REG_EXPAND_SZ keys in the registry.
2396 Can now send() from all threads, not just the first one.
2400 Fake signal handling reenabled, bugs and all.
2404 %SIG has been enabled under USE_ITHREADS, but its use is completely
2405 unsupported under all configurations.
2409 Less stack reserved per thread so that more threads can run
2410 concurrently. (Still 16M per thread.)
2414 C<File::Spec->tmpdir()> now prefers C:/temp over /tmp
2415 (works better when perl is running as service).
2419 Better UNC path handling under ithreads.
2423 wait(), waitpid() and backticks now return the correct exit status under
2428 winsock handle leak fixed.
2432 The Perl parser has been stress tested using both random input and
2433 Markov chain input and the few found crashes and lockups have been
2440 =head1 New or Changed Diagnostics
2446 The lexical warnings category "deprecated" is no longer a sub-category
2447 of the "syntax" category. It is now a top-level category in its own
2452 All regular expression compilation error messages are now hopefully
2453 easier to understand both because the error message now comes before
2454 the failed regex and because the point of failure is now clearly
2455 marked by a C<E<lt>-- HERE> marker.
2459 The various "opened only for", "on closed", "never opened" warnings
2460 drop the C<main::> prefix for filehandles in the C<main> package,
2461 for example C<STDIN> instead of C<main::STDIN>.
2465 The "Unrecognized escape" warning has been extended to include C<\8>,
2466 C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters.
2470 Two new debugging options have been added: if you have compiled your
2471 Perl with debugging, you can use the -DT and -DR options to trace
2472 tokenising and to add reference counts to displaying variables,
2477 The debugger (perl5db.pl) has been modified to present a more
2478 consistent commands interface, via (CommandSet=580). perl5db.t was
2479 also added to test the changes, and as a placeholder for further tests.
2485 The debugger has a new C<dumpDepth> option to control the maximum
2486 depth to which nested structures are dumped. The C<x> command has
2487 been extended so that C<x N EXPR> dumps out the value of I<EXPR> to a
2488 depth of at most I<N> levels.
2492 The debugger can now show lexical variables if you have the CPAN
2493 module PadWalker installed.
2497 If an attempt to use a (non-blessed) reference as an array index
2498 is made, a warning is given.
2502 C<push @a;> and C<unshift @a;> (with no values to push or unshift)
2503 now give a warning. This may be a problem for generated and evaled
2508 If you try to L<perlfunc/pack> a number less than 0 or larger than 255
2509 using the C<"C"> format you will get an optional warning. Similarly
2510 for the C<"c"> format and a number less than -128 or more than 127.
2514 Certain regex modifiers such as C<(?o)> make sense only if applied to
2515 the entire regex. You will get an optional warning if you try to do
2520 Using arrays or hashes as references (e.g. C<< %foo->{bar} >>
2521 has been deprecated for a while. Now you will get an optional warning.
2525 Using C<sort> in scalar context now issues an optional warning.
2526 This didn't do anything useful, as the sort was not performed.
2530 =head1 Changed Internals
2536 perlapi.pod (a companion to perlguts) now attempts to document the
2541 You can now build a really minimal perl called microperl.
2542 Building microperl does not require even running Configure;
2543 C<make -f Makefile.micro> should be enough. Beware: microperl makes
2544 many assumptions, some of which may be too bold; the resulting
2545 executable may crash or otherwise misbehave in wondrous ways.
2546 For careful hackers only.
2550 Added rsignal(), whichsig(), do_join(), op_clear, op_null,
2551 ptr_table_clear(), ptr_table_free(), sv_setref_uv(), and several UTF-8
2552 interfaces to the publicised API. For the full list of the available
2553 APIs see L<perlapi>.
2557 Made possible to propagate customised exceptions via croak()ing.
2561 Now xsubs can have attributes just like subs. (Well, at least the
2562 built-in attributes.)
2566 dTHR and djSP have been obsoleted; the former removed (because it's
2567 a no-op) and the latter replaced with dSP.
2571 PERL_OBJECT has been completely removed.
2575 The MAGIC constants (e.g. C<'P'>) have been macrofied
2576 (e.g. C<PERL_MAGIC_TIED>) for better source code readability
2577 and maintainability.
2581 The regex compiler now maintains a structure that identifies nodes in
2582 the compiled bytecode with the corresponding syntactic features of the
2583 original regex expression. The information is attached to the new
2584 C<offsets> member of the C<struct regexp>. See L<perldebguts> for more
2585 complete information.
2589 The C code has been made much more C<gcc -Wall> clean. Some warning
2590 messages still remain in some platforms, so if you are compiling with
2591 gcc you may see some warnings about dubious practices. The warnings
2592 are being worked on.
2596 F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
2600 Documentation on how to use the Perl source repository has been added
2601 to F<Porting/repository.pod>.
2605 There are now several profiling make targets.
2609 =head1 Security Vulnerability Closed
2611 (This change was already made in 5.7.0 but bears repeating here.)
2613 A potential security vulnerability in the optional suidperl component
2614 of Perl was identified in August 2000. suidperl is neither built nor
2615 installed by default. As of November 2001 the only known vulnerable
2616 platform is Linux, most likely all Linux distributions. CERT and
2617 various vendors and distributors have been alerted about the vulnerability.
2618 See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
2619 for more information.
2621 The problem was caused by Perl trying to report a suspected security
2622 exploit attempt using an external program, /bin/mail. On Linux
2623 platforms the /bin/mail program had an undocumented feature which
2624 when combined with suidperl gave access to a root shell, resulting in
2625 a serious compromise instead of reporting the exploit attempt. If you
2626 don't have /bin/mail, or if you have 'safe setuid scripts', or if
2627 suidperl is not installed, you are safe.
2629 The exploit attempt reporting feature has been completely removed from
2630 Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also
2631 from all the Perl 5.7 releases), so that particular vulnerability
2632 isn't there anymore. However, further security vulnerabilities are,
2633 unfortunately, always possible. The suidperl functionality is most
2634 probably going to be removed in Perl 5.10. In any case, suidperl
2635 should only be used by security experts who know exactly what they are
2636 doing and why they are using suidperl instead of some other solution
2637 such as sudo ( see http://www.courtesan.com/sudo/ ).
2641 Several new tests have been added, especially for the F<lib>
2642 subsection. There are now about 56 000 individual tests (spread over
2643 about 620 test scripts), in the regression suite (5.6.1 has about
2644 11700 tests, in 258 test scripts) Many of the new tests are introduced
2645 by the new modules, but still in general Perl is now more thoroughly
2648 Because of the large number of tests, running the regression suite
2649 will take considerably longer time than it used to: expect the suite
2650 to take up to 4-5 times longer to run than in perl 5.6. In a really
2651 fast machine you can hope to finish the suite in about 6-8 minutes
2654 The tests are now reported in a different order than in earlier Perls.
2655 (This happens because the test scripts from under t/lib have been moved
2656 to be closer to the library/extension they are testing.)
2658 =head1 Known Problems
2666 In AIX 4.2 Perl extensions that use C++ functions that use statics
2667 may have problems in that the statics are not getting initialized.
2668 In newer AIX releases this has been solved by linking Perl with
2669 the libC_r library, but unfortunately in AIX 4.2 the said library
2670 has an obscure bug where the various functions related to time
2671 (such as time() and gettimeofday()) return broken values, and
2672 therefore in AIX 4.2 Perl is not linked against the libC_r.
2676 vac 5.0.0.0 May Produce Buggy Code For Perl
2678 The AIX C compiler vac version 5.0.0.0 may produce buggy code,
2679 resulting in few random tests failing, but when the failing tests
2680 are run by hand, they succeed. We suggest upgrading to at least
2681 vac version 5.0.1.0, that has been known to compile Perl correctly.
2682 "lslpp -L|grep vac.C" will tell you the vac version. See README.aix.
2686 If building threaded Perl, you may get compilation warning from pp_sys.c:
2688 "pp_sys.c", line 4651.39: 1506-280 (W) Function argument assignment between types "unsigned char*" and "const void*" is not allowed.
2690 This is harmless; it is caused by the getnetbyaddr() and getnetbyaddr_r()
2691 having slightly different types for their first argument.
2695 =head2 Amiga Perl Invoking Mystery
2697 One cannot call Perl using the C<volume:> syntax, that is, C<perl -v>
2698 works, but for example C<bin:perl -v> doesn't. The exact reason isn't
2699 known but the current suspect is the F<ixemul> library.
2701 =head2 FreeBSD Failing locale Test 117 For ISO8859-15 Locales
2703 The ISO8859-15 locales may fail the locale test 117 in FreeBSD.
2704 This is caused by the characters \xFF (y with diaeresis) and \xBE
2705 (Y with diaeresis) not behaving correctly when being matched
2708 =head2 mod_perl 1.26 Doesn't Build With Threaded Perl
2710 Use mod_perl 1.27 or higher.
2712 =head2 lib/ftmp-security tests warn 'system possibly insecure'
2714 Don't panic. Read INSTALL 'make test' section instead.
2716 =head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
2718 If perl is configured with -Duse64bitall, the successful result of the
2719 subtest 10 of lib/posix may arrive before the successful result of the
2720 subtest 9, which confuses the test harness so much that it thinks the
2723 =head2 Linux With Sfio Fails op/misc Test 48
2729 Please remember to set your environment variable LC_ALL to "C"
2730 (setenv LC_ALL C) before running "make test" to avoid a lot of
2731 warnings about the broken locales of Mac OS X.
2733 The following tests are known to fail:
2735 Failed Test Stat Wstat Total Fail Failed List of Failed
2736 -------------------------------------------------------------------------
2737 ../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ??
2738 ../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65
2739 ../ext/POSIX/t/posix.t 31 1 3.23% 10
2741 If you are building on a UFS partition, you will also probably see
2742 t/op/stat.t subtest #9 fail. This is caused by Darwin's UFS not
2743 supporting inode change time.
2745 =head2 op/sprintf tests 91, 129, and 130
2747 The op/sprintf tests 91, 129, and 130 are known to fail on some platforms.
2748 Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
2750 The test 91 is known to fail at QNX6 (nto), because C<sprintf '%e',0>
2751 incorrectly produces C<0.000000e+0> instead of C<0.000000e+00>.
2753 For the tests 129 and 130 the failing platforms do not comply with
2754 the ANSI C Standard, line 19ff on page 134 of ANSI X3.159 1989 to
2755 be exact. (They produce something other than "1" and "-1" when
2756 formatting 0.6 and -0.6 using the printf format "%.0f", most often
2757 they produce "0" and "-0".)
2761 In case you are still using Solaris 2.5 (aka SunOS 5.5), you may
2762 experience failures (the test core dumping) in lib/locale.t.
2763 The suggested cure is to upgrade your Solaris.
2765 =head2 Failure of Thread (5.005-style) tests
2767 B<Note that support for 5.005-style threading remains experimental
2768 and practically unsupported.>
2770 The following tests are known to fail due to fundamental problems in
2771 the 5.005 threading implementation. These are not new failures--Perl
2772 5.005_0x has the same bugs, but didn't have these tests.
2774 ../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7
2775 ../lib/English.t 2 512 54 2 3.70% 2-3
2776 ../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3
2777 ../lib/Filter/Simple/t/filter_onl 9 3 33.33% 1-2 5
2778 ../lib/autouse.t 10 1 10.00% 4
2779 op/flip.t 15 1 6.67% 15
2781 These failures are unlikely to get fixed as the 5.005-style
2782 threads are considered fundamentally broken.
2786 Failed Test Stat Wstat Total Fail Failed List of Failed
2787 -------------------------------------------------------------------------
2788 ../ext/Socket/socketpair.t 1 256 45 1 2.22% 12
2789 ../lib/Math/Trig.t 26 1 3.85% 25
2790 ../lib/warnings.t 460 1 0.22% 425
2791 io/fs.t 36 1 2.78% 31
2792 op/numconvert.t 1440 13 0.90% 208 509-510
2793 657-658 665-666 829-830 989-990 1149-1150
2801 During Configure the test
2803 Guessing which symbols your C compiler and preprocessor define...
2805 will probably fail with error messages like
2807 CC-20 cc: ERROR File = try.c, Line = 3
2808 The identifier "bad" is undefined.
2810 bad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K
2813 CC-65 cc: ERROR File = try.c, Line = 3
2814 A semicolon is expected at this point.
2816 This is caused by a bug in awk utility of UNICOS/mk. You can ignore
2817 the error, but it does cause a slight problem: you cannot fully
2818 benefit from the h2ph utility (see L<h2ph>) that can be used to
2819 convert C headers to Perl libraries, mainly used to be able to access
2820 from Perl the constants defined using C preprocessor, cpp. Because of
2821 the above error parts of the converted headers will be invisible.
2822 Luckily, these days the need for h2ph is rare.
2826 If building Perl with the interpreter threads (ithreads), the
2827 getgrent(), getgrnam(), and getgrgid() functions cannot return the
2828 list of the group members due to a bug in the multithreaded support of
2829 UNICOS/mk. What this means that in list context the functions will
2830 return only three values, not four.
2836 There are a few known test failures, see L<perluts>.
2840 There should be no reported test failures with a default configuration,
2841 though there are a number of tests marked TODO that point to areas
2842 needing further debugging and/or porting work.
2846 In multi-CPU boxes there are some problems with the I/O buffering:
2847 some output may appear twice.
2849 =head2 XML::Parser not working
2851 Use XML::Parser 2.31 or later.
2853 =head2 Localising a Tied Variable Leaks Memory
2856 tie my %tie_hash => 'Tie::StdHash';
2860 local($tie_hash{Foo}) = 1; # leaks
2862 Code like the above is known to leak memory every time the local()
2865 =head2 z/OS (OS/390)
2867 z/OS has rather many test failures but the situation is actually
2868 better than it was in 5.6.0, it's just that so many new modules and
2869 tests have been added.
2871 Failed Test Stat Wstat Total Fail Failed List of Failed
2872 -------------------------------------------------------------------------------
2873 ../ext/Data/Dumper/t/dumper.t 339 8 2.36% 311 314 325 327
2875 ../ext/IO/lib/IO/t/io_unix.t 5 4 80.00% 2-5
2876 ../ext/Storable/t/utf8hash.t 10 2560 148 10 6.76% 1 5 72 76 143-148
2877 ../lib/utf8.t 94 13 13.83% 27 30-31 43 46 73
2880 ../lib/ExtUtils/t/Constant.t 121 30976 48 48 100.00% 1-48
2881 ../lib/ExtUtils/t/Embed.t 9 9 100.00% 1-9
2882 op/pat.t 900 9 1.00% 242-243 665 776
2884 op/sprintf.t 224 3 1.34% 98 100 136
2885 op/tr.t 97 5 5.15% 63 71-74
2886 run/fresh_perl.t 94 3 3.19% 92-94
2887 uni/fold.t 780 6 0.77% 61 169 196 661
2890 =head2 Localising Tied Arrays and Hashes Is Broken
2894 doesn't work as one would expect: the old value is restored
2897 =head2 Self-tying of Arrays and Hashes Is Forbidden
2899 Self-tying of arrays and hashes is broken in rather deep and
2900 hard-to-fix ways. As a stop-gap measure to avoid people from getting
2901 frustrated at the mysterious results (core dumps, most often) it is
2902 for now forbidden (you will get a fatal error even from an attempt).
2904 =head2 Building Extensions Can Fail Because Of Largefiles
2906 Some extensions like mod_perl are known to have issues with
2907 `largefiles', a change brought by Perl 5.6.0 in which file offsets
2908 default to 64 bits wide, where supported. Modules may fail to compile
2909 at all or compile and work incorrectly. Currently there is no good
2910 solution for the problem, but Configure now provides appropriate
2911 non-largefile ccflags, ldflags, libswanted, and libs in the %Config
2912 hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
2913 having problems can try configuring themselves without the
2914 largefileness. This is admittedly not a clean solution, and the
2915 solution may not even work at all. One potential failure is whether
2916 one can (or, if one can, whether it's a good idea) link together at
2917 all binaries with different ideas about file offsets, all this is
2920 =head2 Unicode Support on EBCDIC Still Spotty
2922 Though mostly working, Unicode support still has problem spots on
2923 EBCDIC platforms. One such known spot are the C<\p{}> and C<\P{}>
2924 regular expression constructs for code points less than 256: the
2925 pP are testing for Unicode code points, not knowing about EBCDIC.
2927 =head2 The Compiler Suite Is Still Experimental
2929 The compiler suite is slowly getting better but it continues to be
2930 highly experimental. Use in production environments is discouraged.
2932 =head2 The Long Double Support Is Still Experimental
2934 The ability to configure Perl's numbers to use "long doubles",
2935 floating point numbers of hopefully better accuracy, is still
2936 experimental. The implementations of long doubles are not yet
2937 widespread and the existing implementations are not quite mature
2938 or standardised, therefore trying to support them is a rare
2939 and moving target. The gain of more precision may also be offset
2940 by slowdown in computations (more bits to move around, and the
2941 operations are more likely to be executed by less optimised
2944 =head2 Seen In Perl 5.7 But Gone Now
2946 C<Time::Piece> (previously known as C<Time::Object>) was removed
2947 because it was felt that it didn't have enough value in it to be a
2948 core module. It is still a useful module, though, and is available
2951 =head1 Reporting Bugs
2953 If you find what you think is a bug, you might check the articles
2954 recently posted to the comp.lang.perl.misc newsgroup and the perl
2955 bug database at http://bugs.perl.org/ There may also be
2956 information at http://www.perl.com/ , the Perl Home Page.
2958 If you believe you have an unreported bug, please run the B<perlbug>
2959 program included with your release. Be sure to trim your bug down
2960 to a tiny but sufficient test case. Your bug report, along with the
2961 output of C<perl -V>, will be sent off to perlbug@perl.org to be
2962 analysed by the Perl porting team.
2966 The F<Changes> file for exhaustive details on what changed.
2968 The F<INSTALL> file for how to build Perl.
2970 The F<README> file for general stuff.
2972 The F<Artistic> and F<Copying> files for copyright information.
2976 Written by Jarkko Hietaniemi <F<jhi@iki.fi>>.