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 Tied hash interfaces are now required to have the EXISTS and DELETE
548 methods (either own or inherited).
552 If tr/// is just counting characters, it doesn't attempt to
557 untie() will now call an UNTIE() hook if it exists. See L<perltie>
562 L<utime> now supports C<utime undef, undef, @files> to change the
563 file timestamps to the current time.
567 The rules for allowing underscores (underbars) in numeric constants
568 have been relaxed and simplified: now you can have an underscore
569 simply B<between digits>.
573 Rather than relying on C's argv[0] (which may not contain a full pathname)
574 where possible $^X is now set by asking the operating system.
575 (eg by reading F</proc/self/exe> on Linux, F</proc/curproc/file> on FreeBSD)
579 A new variable, C<${^TAINT}>, indicates whether taint mode is enabled.
583 You can now override the readline() builtin, and this overrides also
584 the <FILEHANDLE> angle bracket operator.
588 The command-line options -s and -F are now recognized on the shebang
593 Use of the C</c> match modifier without an accompanying C</g> modifier
594 elicits a new warning: C<Use of /c modifier is meaningless without /g>.
596 Use of C</c> in substitutions, even with C</g>, elicits
597 C<Use of /c modifier is meaningless in s///>.
599 Use of C</g> with C<split> elicits C<Use of /g modifier is meaningless
604 =head1 Modules and Pragmata
606 =head2 New Modules and Pragmata
612 C<Attribute::Handlers> allows a class to define attribute handlers.
615 use Attribute::Handlers;
616 sub Wolf :ATTR(SCALAR) { print "howl!\n" }
618 # later, in some package using or inheriting from MyPack...
620 my MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called
622 Both variables and routines can have attribute handlers. Handlers can
623 be specific to type (SCALAR, ARRAY, HASH, or CODE), or specific to the
624 exact compilation phase (BEGIN, CHECK, INIT, or END).
628 B<B::Concise> is a new compiler backend for walking the Perl syntax
629 tree, printing concise info about ops, from Stephen McCamant. The
630 output is highly customisable. See L<B::Concise>.
634 The new bignum, bigint, and bigrat pragmas implement transparent
635 bignum support (using the Math::BigInt, Math::BigFloat, and
636 Math::BigRat backends), by Tels.
640 C<Class::ISA> for reporting the search path for a class's ISA tree,
641 by Sean Burke, has been added. See L<Class::ISA>.
645 C<Cwd> has now a split personality: if possible, an XS extension is
646 used, (this will hopefully be faster, more secure, and more robust)
647 but if not possible, the familiar Perl implementation is used.
651 C<Devel::PPPort>, originally from Kenneth Albanowski and now
652 maintained by Paul Marquess, has been added. It is primarily used
653 by C<h2xs> to enhance portability of XS modules between different
658 C<Digest>, frontend module for calculating digests (checksums), from
659 Gisle Aas, has been added. See L<Digest>.
663 C<Digest::MD5> for calculating MD5 digests (checksums) as defined in
664 RFC 1321, from Gisle Aas, has been added. See L<Digest::MD5>.
666 use Digest::MD5 'md5_hex';
668 $digest = md5_hex("Thirsty Camel");
670 print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
672 NOTE: the C<MD5> backward compatibility module is deliberately not
673 included since its further use is discouraged.
677 C<Encode>, orginally by Nick Ing-Simmons and now maintained by Dan
678 Kogai, provides a mechanism to translate between different character
679 encodings. Support for Unicode, ISO-8859-1, and ASCII are compiled in
680 to the module. Several other encodings (like the rest of the
681 ISO-8859, CP*/Win*, Mac, KOI8-R, three variants EBCDIC, Chinese,
682 Japanese, and Korean encodings) are included and can be loaded at
683 runtime. (For space considerations, the largest Chinese encodings
684 have been separated into their own CPAN module, Encode::HanExtra,
685 which Encode will use if available). See L<Encode>.
687 Any encoding supported by Encode module is also available to the
688 ":encoding()" layer if PerlIO is used.
692 C<Hash::Util> is the interface to the new I<restricted hashes>
693 feature. (Implemented by Jeffrey Friedl, Nick Ing-Simmons, and
698 C<I18N::Langinfo> can be use to query locale information.
699 See L<I18N::Langinfo>.
703 C<I18N::LangTags> has functions for dealing with RFC3066-style
704 language tags, by Sean Burke. See L<I18N::LangTags>.
708 C<ExtUtils::Constant> is a new tool for extension writers for
709 generating XS code to import C header constants, by Nicholas Clark.
710 See L<ExtUtils::Constant>.
714 C<Filter::Simple> is an easy-to-use frontend to Filter::Util::Call,
715 from Damian Conway. See L<Filter::Simple>.
721 use Filter::Simple sub {
722 while (my ($from, $to) = splice @_, 0, 2) {
731 use MyFilter qr/red/ => 'green';
733 print "red\n"; # this code is filtered, will print "green\n"
734 print "bored\n"; # this code is filtered, will print "bogreen\n"
738 print "red\n"; # this code is not filtered, will print "red\n"
742 C<File::Temp> allows one to create temporary files and directories in
743 an easy, portable, and secure way, by Tim Jenness. See L<File::Temp>.
747 C<Filter::Util::Call> provides you with the framework to write
748 I<Source Filters> in Perl, from Paul Marquess. For most uses the
749 frontend Filter::Simple is to be preferred. See L<Filter::Util::Call>.
753 C<if> is a new pragma for conditional inclusion of modules, from
758 L<libnet> is a collection of perl5 modules related to network
759 programming, from Graham Barr. See L<Net::FTP>, L<Net::NNTP>,
760 L<Net::Ping> (not part of libnet, but related), L<Net::POP3>,
761 L<Net::SMTP>, and L<Net::Time>.
763 Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure.
767 C<List::Util> is a selection of general-utility list subroutines, like
768 sum(), min(), first(), and shuffle(), by Graham Barr. See L<List::Util>.
772 C<Locale::Constants>, C<Locale::Country>, C<Locale::Currency>
773 C<Locale::Language>, and L<Locale::Script>, from Neil Bowers, have
774 been added. They provide the codes for various locale standards, such
775 as "fr" for France, "usd" for US Dollar, and "ja" for Japanese.
779 $country = code2country('jp'); # $country gets 'Japan'
780 $code = country2code('Norway'); # $code gets 'no'
782 See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>,
783 and L<Locale::Language>.
787 C<Locale::Maketext> is localization framework from Sean Burke. See
788 L<Locale::Maketext>, and L<Locale::Maketext::TPJ13>. The latter is an
789 article about software localization, originally published in The Perl
790 Journal #13, republished here with kind permission.
794 C<Math::BigRat> for big rational numbers, to accompany Math::BigInt and
795 Math::BigFloat, from Tels.
799 C<Memoize> can make your functions faster by trading space for time,
800 from Mark-Jason Dominus. See L<Memoize>.
804 C<MIME::Base64> allows you to encode data in base64, from Gisle Aas,
805 as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
810 $encoded = encode_base64('Aladdin:open sesame');
811 $decoded = decode_base64($encoded);
813 print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
819 C<MIME::QuotedPrint> allows you to encode data in quoted-printable
820 encoding, as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
821 Extensions)>, from Gisle Aas.
823 use MIME::QuotedPrint;
825 $encoded = encode_qp("Smiley in Unicode: \x{263a}");
826 $decoded = decode_qp($encoded);
828 print $encoded, "\n"; # "Smiley in Unicode: =263A"
830 MIME::QuotedPrint has been enhanced to provide the basic methods
831 necessary to use it with PerlIO::Via as in :
833 use MIME::QuotedPrint;
834 open($fh,">Via(MIME::QuotedPrint)",$path);
836 See L<MIME::QuotedPrint>.
840 C<NEXT> is pseudo-class for method redispatch, from Damian Conway.
845 C<open> is a new pragma for setting the default I/O disciplines
850 C<PerlIO::Scalar> provides the implementation of IO to "in memory"
851 Perl scalars as discussed above, from Nick Ing-Simmons. It also
852 serves as an example of a loadable PerlIO layer. Other future
853 possibilities include PerlIO::Array and PerlIO::Code.
854 See L<PerlIO::Scalar>.
858 C<PerlIO::Via> acts as a PerlIO layer and wraps PerlIO layer
859 functionality provided by a class (typically implemented in perl
860 code), from Nick Ing-Simmons.
862 use MIME::QuotedPrint;
863 open($fh,">Via(MIME::QuotedPrint)",$path);
865 This will automatically convert everything output to C<$fh>
866 to Quoted-Printable. See L<PerlIO::Via>.
870 C<Pod::ParseLink>, by Russ Allbery, has been added,
871 to parse LZ<><> links in pods as described in the new
876 C<Pod::Text::Overstrike>, by Joe Smith, has been added.
877 It converts POD data to formatted overstrike text.
878 See L<Pod::Text::Overstrike>.
882 C<Scalar::Util> is a selection of general-utility scalar subroutines,
883 like blessed(), reftype(), and tainted(). See L<Scalar::Util>.
887 C<sort> is a new pragma for controlling the behaviour of sort().
891 C<Storable> gives persistence to Perl data structures by allowing the
892 storage and retrieval of Perl data to and from files in a fast and
893 compact binary format. Because in effect Storable does serialisation
894 of Perl data structues, with it you can also clone deep, hierarchical
895 datastructures. Storable was created by Raphael Manfredi but it is
896 now maintained by the Perl development team. Storable has been
897 enhanced to understand the two new hash features, Unicode keys and
898 restricted hashes. See L<Storable>.
902 C<Switch>, from Damian Conway, has been added. Just by saying
906 you have C<switch> and C<case> available in Perl.
912 case 1 { print "number 1" }
913 case "a" { print "string a" }
914 case [1..10,42] { print "number in list" }
915 case (@array) { print "number in list" }
916 case /\w+/ { print "pattern" }
917 case qr/\w+/ { print "pattern" }
918 case (%hash) { print "entry in hash" }
919 case (\%hash) { print "entry in hash" }
920 case (\&sub) { print "arg to subroutine" }
921 else { print "previous case not true" }
928 C<Test::More> is yet another framework for writing test scripts,
929 more extensive than Test::Simple, by Michael Schwern. See L<Test::More>.
933 C<Test::Simple> has basic utilities for writing tests, by Michael
934 Schwern. See L<Test::Simple>.
938 C<Text::Balanced> has been added, for extracting delimited text
939 sequences from strings, from Damian Conway.
941 use Text::Balanced 'extract_delimited';
943 ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
945 $a will be "'never say never'", $b will be ', he never said'.
947 In addition to extract_delimited() there are also extract_bracketed(),
948 extract_quotelike(), extract_codeblock(), extract_variable(),
949 extract_tagged(), extract_multiple(), gen_delimited_pat(), and
950 gen_extract_tagged(). With these you can implement rather advanced
951 parsing algorithms. See L<Text::Balanced>.
955 C<threads> is an interface to interpreter threads, by Arthur Bergman.
956 Interpreter threads (ithreads) is the new thread model introduced in
957 Perl 5.6 but only available as an internal interface for extension
958 writers (and for Win32 Perl for C<fork()> emulation). See L<threads>.
962 C<threads::shared> allows data sharing for interpreter threads, from
963 Arthur Bergman. In the ithreads model any data sharing between
964 threads must be explicit, as opposed to the old 5.005 thread model
965 where data sharing was implicit. See L<threads::shared>.
969 C<Tie::File>, by Mark-Jason Dominus, associates a Perl array with the
974 C<Tie::Memoize>, by Ilya Zakharevich, provides on-demand loaded hashes.
978 C<Tie::RefHash::Nestable>, by Edward Avis, allows storing hash
979 references (unlike the standard Tie::RefHash) The module is contained
980 within Tie::RefHash, see L<Tie::RefHash>.
984 C<Time::HiRes> provides high resolution timing (ualarm, usleep,
985 and gettimeofday), from Douglas E. Wegscheid. See L<Time::HiRes>.
989 C<Unicode::UCD> offers a querying interface to the Unicode Character
990 Database. See L<Unicode::UCD>.
994 C<Unicode::Collate> implements the UCA (Unicode Collation Algorithm)
995 for sorting Unicode strings, by SADAHIRO Tomoyuki. See L<Unicode::Collate>.
999 C<Unicode::Normalize> implements the various Unicode normalization
1000 forms, by SADAHIRO Tomoyuki. See L<Unicode::Normalize>.
1004 C<XS::Typemap>, by Tim Jenness, is a test extension that exercises XS
1005 typemaps. Nothing gets installed but for extension writers the code
1010 =head2 Updated And Improved Modules and Pragmata
1016 The following independently supported modules have been updated to the
1017 newest versions from CPAN: CGI, CPAN, DB_File, File::Spec, File::Temp,
1018 Getopt::Long, Math::BigFloat, Math::BigInt, the podlators bundle
1019 (Pod::Man, Pod::Text), Pod::LaTeX, Pod::Parser, Storable,
1020 Term::ANSIColor, Test, Text-Tabs+Wrap.
1024 The attributes::reftype() now works on tied arguments.
1028 AutoLoader can now be disabled with C<no AutoLoader;>.
1032 B::Deparse has been significantly enhanced. It now can deparse almost
1033 all of the standard test suite (so that the tests still succeed).
1034 There is a make target "test.deparse" for trying this out.
1038 Class::Struct can now define the classes in compile time.
1042 Class::Struct now assigns the array/hash element if the accessor
1043 is called with an array/hash element as the B<sole> argument.
1047 Data::Dumper has now an option to sort hashes.
1051 Data::Dumper has now an option to dump code references
1056 DB_File now supports newer Berkeley DB versions, among
1061 The English module can now be used without the infamous performance
1064 use English '-no_match_vars';
1066 (Assuming, of course, that one doesn't need the troublesome variables
1067 C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
1068 C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
1072 Fcntl, Socket, and Sys::Syslog have been rewritten to use the
1073 new-style constant dispatch section (see L<ExtUtils::Constant>).
1074 This means that they will be more robust and hopefully faster.
1078 File::Find now chdir()s correctly when chasing symbolic links.
1082 File::Find now has pre- and post-processing callbacks. It also
1083 correctly changes directories when chasing symbolic links. Callbacks
1084 (naughtily) exiting with "next;" instead of "return;" now work.
1088 File::Find is now (again) reentrant. It also has been made
1093 The warnings issued by File::Find now belong to their own category.
1094 You can enable/disable them with C<use/no warnings 'File::Find';>.
1098 File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
1099 prototype mismatch with CORE::glob().
1103 File::Glob now supports C<GLOB_LIMIT> constant to limit the size of
1104 the returned list of filenames.
1108 Devel::Peek now has an interface for the Perl memory statistics
1109 (this works only if you are using perl's malloc, and if you have
1110 compiled with debugging).
1114 IPC::Open3 now allows the use of numeric file descriptors.
1118 IO::Socket has now atmark() method, which returns true if the socket
1119 is positioned at the out-of-band mark. The method is also exportable
1120 as a sockatmark() function.
1124 IO::Socket::INET has support for ReusePort option (if your platform
1125 supports it). The Reuse option now has an alias, ReuseAddr. For clarity
1126 you may want to prefer ReuseAddr.
1130 IO::Socket::INET now supports C<LocalPort> of zero (usually meaning
1131 that the operating system will make one up.)
1135 use lib now works identically to @INC. Removing directories
1136 with 'no lib' now works.
1140 ExtUtils::MakeMaker now uses File::Spec internally, which hopefully
1141 leads into better portability.
1145 Math::BigFloat and Math::BigInt have undergone a full rewrite.
1146 They are now magnitudes faster, and they support various
1147 bignum libraries such as GMP and PARI as their backends.
1151 Math::Complex handles inf, NaN etc., better.
1155 Net::Ping has been muchly enhanced: multihoming is now supported,
1156 Win32 functionality is better, there is now time measuring
1157 functionality (optionally high-resolution using Time::HiRes),
1158 and there is now "external" protocol which uses Net::Ping::External
1159 module which runs your external ping utility and parses the output.
1160 A version of Net::Ping::External is available in CPAN.
1162 Note that some of the Net::Ping tests are disabled when running
1163 under the Perl distribution since one cannot assume one or more
1164 of the following: enabled echo port at localhost, full Internet
1165 connectivity, or sympathetic firewalls. You can set the environment
1166 variable PERL_TEST_Net_Ping to "1" (one) before running the Perl test
1167 suite to enable all the Net::Ping tests.
1171 POSIX::sigaction() is now much more flexible and robust.
1172 You can now install coderef handlers, 'DEFAULT', and 'IGNORE'
1173 handlers, installing new handlers was not atomic.
1177 In Safe the C<%INC> now localised in a Safe compartment so that
1182 In SDBM_File on dosish platforms, some keys went missing because of
1183 lack of support for files with "holes". A workaround for the problem
1188 In Search::Dict one can now have a pre-processing hook for the
1189 lines being searched.
1193 The Shell module now has an OO interface.
1197 In Sys::Syslog there is now a failover mechanism that will go
1198 through alternative connection mechanisms until the message
1199 is successfully logged.
1203 The Test module has been significantly enhanced.
1207 Time::Local::timelocal() does not handle fractional seconds anymore.
1208 The rationale is that neither does localtime(), and timelocal() and
1209 localtime() are supposed to be inverses of each other.
1213 The vars pragma now supports declaring fully qualified variables.
1214 (Something that C<our()> does not and will not support.)
1218 The C<utf8::> name space (as in the pragma) provides various
1219 Perl-callable functions to provide low level access to Perl's
1220 internal Unicode representation. At the moment only length()
1221 has been implemented.
1225 =head1 Utility Changes
1231 Emacs perl mode (emacs/cperl-mode.el) has been updated to version
1236 F<emacs/e2ctags.pl> is now much faster.
1240 C<enc2xs> is a tool for people adding their own encodings to the
1245 C<h2ph> now supports C trigraphs.
1249 C<h2xs> now produces a template README.
1253 C<h2xs> now uses C<Devel::PPort> for better portability between
1254 different versions of Perl.
1258 C<h2xs> uses the new L<ExtUtils::Constant> module which will affect
1259 newly created extensions that define constants. Since the new code is
1260 more correct (if you have two constants where the first one is a
1261 prefix of the second one, the first constant B<never> gets defined),
1262 less lossy (it uses integers for integer constant, as opposed to the
1263 old code that used floating point numbers even for integer constants),
1264 and slightly faster, you might want to consider regenerating your
1265 extension code (the new scheme makes regenerating easy).
1266 L<h2xs> now also supports C trigraphs.
1270 C<libnetcfg> has been added to configure the libnet.
1274 C<perlbug> is now much more robust. It also sends the bug report to
1275 perl.org, not perl.com.
1279 C<perlcc> has been rewritten and its user interface (that is,
1280 command line) is much more like that of the UNIX C compiler, cc.
1281 (The perlbc tools has been removed. Use C<perlcc -B> instead.)
1285 C<perlivp> is a new Installation Verification Procedure utility
1286 for running any time after installing Perl.
1290 C<piconv> is an implementation of the character conversion utility
1291 C<iconv>, demonstrating the new Encode module.
1295 C<pod2html> now allows specifying a cache directory.
1299 C<pod2html> now produces XHTML 1.0.
1303 C<pod2html> now understands POD written using different line endings
1304 (PC-like CRLF versus UNIX-like LF versus MacClassic-like CR).
1308 C<s2p> has been completely rewritten in Perl. (It is in fact a full
1309 implementation of sed in Perl: you can use the sed functionality by
1310 using the C<psed> utility.)
1314 C<xsubpp> now understands POD documentation embedded in the *.xs files.
1318 C<xsubpp> now supports OUT keyword.
1322 =head1 New Documentation
1328 perl56delta details the changes between the 5.005 release and the
1333 perlclib documents the internal replacements for standard C library
1334 functions. (Interesting only for extension writers and Perl core
1339 perldebtut is a Perl debugging tutorial.
1343 perlebcdic contains considerations for running Perl on EBCDIC platforms.
1347 perlintro is a gentle introduction to Perl.
1351 perliol documents the internals of PerlIO with layers.
1355 perlmodstyle is a style guide for writing modules.
1359 perlnewmod tells about writing and submitting a new module.
1363 perlpacktut is a pack() tutorial.
1367 perlpod has been rewritten to be clearer and to record the best
1368 practices gathered over the years.
1372 perlpodspec is a more formal specification of the pod format,
1373 mainly of interest for writers of pod applications, not to
1374 people writing in pod.
1378 perlretut is a regular expression tutorial.
1382 perlrequick is a regular expressions quick-start guide.
1383 Yes, much quicker than perlretut.
1387 perltodo has been updated.
1391 perltootc has been renamed as perltooc (to not to conflict
1392 with perltoot in filesystems restricted to "8.3" names)
1396 perluniintro is an introduction to using Unicode in Perl.
1397 (perlunicode is more of a detailed reference and background
1402 perlutil explains the command line utilities packaged with the Perl
1407 The following platform-specific documents are available before
1408 the installation as README.I<platform>, and after the installation
1411 perlaix perlamiga perlapollo perlbeos perlbs2000
1412 perlce perlcygwin perldgux perldos perlepoc perlhpux
1413 perlhurd perlmachten perlmacos perlmint perlmpeix
1414 perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris
1415 perltru64 perluts perlvmesa perlvms perlvos perlwin32
1421 The documentation for the POSIX-BC platform is called "BS2000", to avoid
1422 confusion with the Perl POSIX module.
1426 The documentation for the WinCE platform is called perlce (README.ce
1427 in the source code kit), to avoid confusion with the perlwin32
1428 documentation on 8.3-restricted filesystems.
1432 =head1 Performance Enhancements
1438 map() could get pathologically slow when the result list it generates
1439 is larger than the source list. The performance has been improved for
1444 sort() has been changed to use primarily mergesort internally as
1445 opposed to the earlier quicksort. For very small lists this may
1446 result in slightly slower sorting times, but in general the speedup
1447 should be at least 20%. Additional bonuses are that the worst case
1448 behaviour of sort() is now better (in computer science terms it now
1449 runs in time O(N log N), as opposed to quicksort's Theta(N**2)
1450 worst-case run time behaviour), and that sort() is now stable
1451 (meaning that elements with identical keys will stay ordered as they
1452 were before the sort). See the C<sort> pragma for information.
1454 The story in more detail: suppose you want to serve yourself a little
1457 @digits = ( 3,1,4,1,5,9 );
1459 A numerical sort of the digits will yield (1,1,3,4,5,9), as expected.
1460 Which C<1> comes first is hard to know, since one C<1> looks pretty
1461 much like any other. You can regard this as totally trivial,
1462 or somewhat profound. However, if you just want to sort the even
1463 digits ahead of the odd ones, then what will
1465 sort { ($a % 2) <=> ($b % 2) } @digits;
1467 yield? The only even digit, C<4>, will come first. But how about
1468 the odd numbers, which all compare equal? With the quicksort algorithm
1469 used to implement Perl 5.6 and earlier, the order of ties is left up
1470 to the sort. So, as you add more and more digits of Pi, the order
1471 in which the sorted even and odd digits appear will change.
1472 and, for sufficiently large slices of Pi, the quicksort algorithm
1473 in Perl 5.8 won't return the same results even if reinvoked with the
1474 same input. The justification for this rests with quicksort's
1475 worst case behavior. If you run
1477 sort { $a <=> $b } ( 1 .. $N , 1 .. $N );
1479 (something you might approximate if you wanted to merge two sorted
1480 arrays using sort), doubling $N doesn't just double the quicksort time,
1481 it I<quadruples> it. Quicksort has a worst case run time that can
1482 grow like N**2, so-called I<quadratic> behaviour, and it can happen
1483 on patterns that may well arise in normal use. You won't notice this
1484 for small arrays, but you I<will> notice it with larger arrays,
1485 and you may not live long enough for the sort to complete on arrays
1486 of a million elements. So the 5.8 quicksort scrambles large arrays
1487 before sorting them, as a statistical defence against quadratic behaviour.
1488 But that means if you sort the same large array twice, ties may be
1489 broken in different ways.
1491 Because of the unpredictability of tie-breaking order, and the quadratic
1492 worst-case behaviour, quicksort was I<almost> replaced completely with
1493 a stable mergesort. I<Stable> means that ties are broken to preserve
1494 the original order of appearance in the input array. So
1496 sort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9);
1498 will yield (4,3,1,1,5,9), guaranteed. The even and odd numbers
1499 appear in the output in the same order they appeared in the input.
1500 Mergesort has worst case O(NlogN) behaviour, the best value
1501 attainable. And, ironically, this mergesort does particularly
1502 well where quicksort goes quadratic: mergesort sorts (1..$N, 1..$N)
1503 in O(N) time. But quicksort was rescued at the last moment because
1504 it is faster than mergesort on certain inputs and platforms.
1505 For example, if you really I<don't> care about the order of even
1506 and odd digits, quicksort will run in O(N) time; it's very good
1507 at sorting many repetitions of a small number of distinct elements.
1508 The quicksort divide and conquer strategy works well on platforms
1509 with relatively small, very fast, caches. Eventually, the problem gets
1510 whittled down to one that fits in the cache, from which point it
1511 benefits from the increased memory speed.
1513 Quicksort was rescued by implementing a sort pragma to control aspects
1514 of the sort. The B<stable> subpragma forces stable behaviour,
1515 regardless of algorithm. The B<_quicksort> and B<_mergesort>
1516 subpragmas are heavy-handed ways to select the underlying implementation.
1517 The leading C<_> is a reminder that these subpragmas may not survive
1518 beyond 5.8. More appropriate mechanisms for selecting the implementation
1519 exist, but they wouldn't have arrived in time to save quicksort.
1523 Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm
1524 ( http://burtleburtle.net/bob/hash/doobs.html ). This algorithm is
1525 reasonably fast while producing a much better spread of values than
1526 the old hashing algorithm (originally by Chris Torek, later tweaked by
1527 Ilya Zakharevich). Hash values output from the algorithm on a hash of
1528 all 3-char printable ASCII keys comes much closer to passing the
1529 DIEHARD random number generation tests. According to perlbench, this
1530 change has not affected the overall speed of Perl.
1534 unshift() should now be noticeably faster.
1538 =head1 Installation and Configuration Improvements
1540 =head2 Generic Improvements
1546 INSTALL now explains how you can configure Perl to use 64-bit
1547 integers even on non-64-bit platforms.
1551 Policy.sh policy change: if you are reusing a Policy.sh file
1552 (see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old
1553 Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of
1554 them will now be changed to the new prefix, /foo/bar. (Previously
1555 only $prefix changed.) If you do not like this new behaviour,
1556 specify prefix, siteprefix, and vendorprefix explicitly.
1560 A new optional location for Perl libraries, otherlibdirs, is available.
1561 It can be used for example for vendor add-ons without disturbing Perl's
1562 own library directories.
1566 In many platforms the vendor-supplied 'cc' is too stripped-down to
1567 build Perl (basically, 'cc' doesn't do ANSI C). If this seems
1568 to be the case and 'cc' does not seem to be the GNU C compiler
1569 'gcc', an automatic attempt is made to find and use 'gcc' instead.
1573 gcc needs to closely track the operating system release to avoid
1574 build problems. If Configure finds that gcc was built for a different
1575 operating system release than is running, it now gives a clearly visible
1576 warning that there may be trouble ahead.
1580 If binary compatibility with the 5.005 release is not wanted, Configure
1581 no longer suggests including the 5.005 modules in @INC.
1585 Configure C<-S> can now run non-interactively.
1589 Configure support for pdp11-style memory models has been removed due
1594 configure.gnu now works with options with whitespace in them.
1598 installperl now outputs everything to STDERR.
1602 $Config{byteorder} is now computed dynamically (this is more robust
1603 with "fat binaries" where an executable image contains binaries for
1604 more than one binary platform.)
1608 Because PerlIO is now the default on most platforms, "-perlio" doesn't
1609 get appended to the $Config{archname} (also known as $^O) anymore.
1610 Instead, if you explicitly choose not to use perlio (Configure command
1611 line option -Uuseperlio), you will get "-stdio" appended.
1615 Another change related to the architecture name is that "-64all"
1616 (-Duse64bitall, or "maximally 64-bit") is appended only if your
1617 pointers are 64 bits wide. (To be exact, the use64bitall is ignored.)
1621 In AFS installations one can configure the root of the AFS to be
1622 somewhere else than the default F</afs> by using the Configure
1623 parameter C<-Dafsroot=/some/where/else>.
1627 APPLLIB_EXP, a less-know configuration-time definition, has been
1628 documented. It can be used to prepend site-specific directories
1629 to Perl's default search path (@INC), see INSTALL for information.
1633 The version of Berkeley DB used when the Perl (and, presumably, the
1634 DB_File extension) was built is now available as
1635 C<@Config{qw(db_version_major db_version_minor db_version_patch)}>
1636 from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG
1637 DB_VERSION_PATCH_CFG> from C.
1641 Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
1642 has been documented in INSTALL.
1646 If you have CPAN access (either network or a local copy such as a
1647 CD-ROM) you can during specify extra modules to Configure to build and
1648 install with Perl using the -Dextras=... option. See INSTALL for
1653 In addition to config.over a new override file, config.arch, is
1654 available. That is supposed to be used by hints file writers for
1655 architecture-wide changes (as opposed to config.over which is for
1660 If your file system supports symbolic links you can build Perl outside
1661 of the source directory by
1663 mkdir /tmp/perl/build/directory
1664 cd /tmp/perl/build/directory
1665 sh /path/to/perl/source/Configure -Dmksymlinks ...
1667 This will create in /tmp/perl/build/directory a tree of symbolic links
1668 pointing to files in /path/to/perl/source. The original files are left
1669 unaffected. After Configure has finished you can just say
1673 and Perl will be built and tested, all in /tmp/perl/build/directory.
1677 For Perl developers several new make targets for profiling
1678 and debugging have been added, see L<perlhack>.
1684 Use of the F<gprof> tool to profile Perl has been documented in
1685 L<perlhack>. There is a make target called "perl.gprof" for
1686 generating a gprofiled Perl executable.
1690 If you have GCC 3, there is a make target called "perl.gcov" for
1691 creating a gcoved Perl executable for coverage analysis. See
1696 If you are on IRIX or Tru64 platforms, new profiling/debugging options
1697 have been added, see L<perlhack> for more information about pixie and
1704 Guidelines of how to construct minimal Perl installations have
1705 been added to INSTALL.
1709 The Thread extension is now not built at all under ithreads
1710 (C<Configure -Duseithreads>) because it wouldn't work anyway (the
1711 Thread extension requires being Configured with C<-Duse5005threads>).
1713 But note that the Thread.pm interface is now shared by both
1718 The Gconvert macro ($Config{d_Gconvert}) used by perl for stringifying
1719 floating-point numbers is now more picky about using sprintf %.*g
1720 rules for the conversion. Some platforms that used to use gcvt may
1721 now resort to the slower sprintf.
1725 =head2 New Or Improved Platforms
1727 For the list of platforms known to support Perl,
1728 see L<perlport/"Supported Platforms">.
1734 AIX dynamic loading should be now better supported.
1738 AIX should now work better with gcc, threads, and 64-bitness. Also the
1739 long doubles support in AIX should be better now. See L<perlaix>.
1743 AtheOS ( http://www.atheos.cx/ ) is a new platform.
1747 BeOS has been reclaimed.
1751 DG/UX platform now supports the 5.005-style threads. See L<perldgux>.
1755 DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2.
1759 EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA)
1760 have been regained. Many test suite tests still fail and the
1761 co-existence of Unicode and EBCDIC isn't quite settled, but the
1762 situation is much better than with Perl 5.6. See L<perlos390>,
1763 L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information.
1767 Building perl with -Duseithreads or -Duse5005threads now works under
1768 HP-UX 10.20 (previously it only worked under 10.30 or later). You will
1769 need a thread library package installed. See README.hpux.
1773 MacOS Classic (MacPerl has of course been available since
1774 perl 5.004 but now the source code bases of standard Perl
1775 and MacPerl have been synchronised)
1779 MacOS X (or Darwin) should now be able to build Perl even on HFS+
1780 filesystems. (The case-insensitivity confused the Perl build process.)
1784 NCR MP-RAS is now supported.
1788 All the NetBSD specific patches (except for the installation
1789 specific ones) have been merged back to the main distribution.
1793 NetWare from Novell is now supported. See L<perlnetware>.
1797 NonStop-UX is now supported.
1801 NEC SUPER-UX is now supported.
1805 All the OpenBSD specific patches (except for the installation
1806 specific ones) have been merged back to the main distribution.
1810 Perl has been tested with the GNU pth userlevel thread package
1811 ( http://www.gnu.org/software/pth/pth.html ) . All but one thread
1812 test worked, and that one failure was because of test results arriving
1813 in unexpected order.
1817 Amdahl UTS UNIX mainframe platform is now supported.
1821 WinCE is now supported. See L<perlce>.
1825 z/OS (formerly known as OS/390, formerly known as MVS OE) has now
1826 support for dynamic loading. This is not selected by default,
1827 however, you must specify -Dusedl in the arguments of Configure.
1831 =head1 Selected Bug Fixes
1833 Numerous memory leaks and uninitialized memory accesses have been
1834 hunted down. Most importantly anonymous subs used to leak quite
1841 The autouse pragma didn't work for Multi::Part::Function::Names.
1845 caller() could cause core dumps in certain situations. Carp was sometimes
1846 affected by this problem.
1850 chop(@list) in list context returned the characters chopped in
1851 reverse order. This has been reversed to be in the right order.
1855 Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
1856 when building the Perl binary. The only exception to this is SunOS 4.x,
1861 The behaviour of non-decimal but numeric string constants such as
1862 "0x23" was platform-dependent: in some platforms that was seen as 35,
1863 in some as 0, in some as a floating point number (don't ask). This
1864 was caused by Perl using the operating system libraries in a situation
1865 where the result of the string to number conversion is undefined: now
1866 Perl consistently handles such strings as zero in numeric contexts.
1870 The order of DESTROYs has been made more predictable.
1874 Several debugger fixes: exit code now reflects the script exit code,
1875 condition C<"0"> now treated correctly, the C<d> command now checks
1876 line number, the C<$.> no longer gets corrupted, all debugger output
1877 now goes correctly to the socket if RemotePort is set.
1881 Perl 5.6.0 could emit spurious warnings about redefinition of dl_error()
1882 when statically building extensions into perl. This has been corrected.
1886 L<dprofpp> -R didn't work.
1890 C<*foo{FORMAT}> now works.
1893 Infinity is now recognized as a number.
1897 UNIVERSAL::isa no longer caches methods incorrectly. (This broke
1898 the Tk extension with 5.6.0.)
1902 Lexicals I: lexicals outside an eval "" weren't resolved
1903 correctly inside a subroutine definition inside the eval "" if they
1904 were not already referenced in the top level of the eval""ed code.
1908 Lexicals II: lexicals leaked at file scope into subroutines that
1909 were declared before the lexicals.
1913 Lexical warnings now propagating correctly between scopes
1914 and into C<eval "...">.
1918 C<use warnings qw(FATAL all)> did not work as intended. This has been
1923 warnings::enabled() now reports the state of $^W correctly if the caller
1924 isn't using lexical warnings.
1928 Line renumbering with eval and C<#line> now works.
1932 Fixed numerous memory leaks, especially in eval "".
1936 Localised tied variables no more leak memory
1939 tie my %tied_hash => 'Tie::StdHash';
1943 # Used to leak memory every time local() was called,
1944 # in a loop this added up.
1945 local($tied_hash{Foo}) = 1;
1949 Localised hash elements (and %ENV) are correctly unlocalised to not to
1950 exist, if that's what they were.
1954 tie my %tied_hash => 'Tie::StdHash';
1958 # Nothing has set the FOO element so far
1960 { local $tied_hash{FOO} = 'Bar' }
1962 # Here the FOO element would have been C<undef>,
1965 As a side effect of this fix, tied hash interfaces B<must> define
1966 the EXISTS and DELETE methods.
1970 mkdir() now ignores trailing slashes in the directory name,
1971 as mandated by POSIX.
1975 Some versions of glibc have a broken modfl(). This affects builds
1976 with C<-Duselongdouble>. This version of Perl detects this brokenness
1977 and has a workaround for it. The glibc release 2.2.2 is known to have
1978 fixed the modfl() bug.
1982 Modulus of unsigned numbers now works (4063328477 % 65535 used to
1983 return 27406, instead of 27047).
1987 Some "not a number" warnings introduced in 5.6.0 eliminated to be
1988 more compatible with 5.005. Infinity is now recognised as a number.
1992 Numeric conversions did not recognize changes in the string value
1993 properly in certain circumstances.
1997 Attributes (like :shared) didn't work with our().
2001 our() variables will not cause "will not stay shared" warnings.
2005 "our" variables of the same name declared in two sibling blocks
2006 resulted in bogus warnings about "redeclaration" of the variables.
2007 The problem has been corrected.
2011 pack "Z" now correctly terminates the string with "\0".
2015 Fix password routines which in some shadow password platforms
2016 (e.g. HP-UX) caused getpwent() to return every other entry.
2020 The PERL5OPT environment variable (for passing command line arguments
2021 to Perl) didn't work for more than a single group of options.
2025 PERL5OPT with embedded spaces didn't work.
2029 printf() no longer resets the numeric locale to "C".
2033 C<qw(a\\b)> now parses correctly as C<'a\\b'>.
2037 pos() did not return the correct value within s///ge in earlier
2038 versions. This is now handled correctly.
2042 Printing quads (64-bit integers) with printf/sprintf now works
2043 without the q L ll prefixes (assuming you are on a quad-capable platform).
2047 Regular expressions on references and overloaded scalars now work.
2051 Right-hand side magic (GMAGIC) could in many cases such as string
2052 concatenation be invoked too many times.
2056 scalar() now forces scalar context even when used in void context.
2060 SOCKS support is now much more robust.
2064 sort() arguments are now compiled in the right wantarray context
2065 (they were accidentally using the context of the sort() itself).
2066 The comparison block is now run in scalar context, and the arguments
2067 to be sorted are always provided list context.
2071 Changed the POSIX character class C<[[:space:]]> to include the (very
2072 rarely used) vertical tab character. Added a new POSIX-ish character
2073 class C<[[:blank:]]> which stands for horizontal whitespace
2074 (currently, the space and the tab).
2078 The tainting behaviour of sprintf() has been rationalized. It does
2079 not taint the result of floating point formats anymore, making the
2080 behaviour consistent with that of string interpolation.
2084 Some cases of inconsistent taint propagation (such as within hash
2085 values) have been fixed.
2089 The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds
2090 of simple pattern matches. These are now handled better.
2094 Regular expression debug output (whether through C<use re 'debug'>
2095 or via C<-Dr>) now looks better.
2099 Multi-line matches like C<"a\nxb\n" =~ /(?!\A)x/m> were flawed. The
2104 Use of $& could trigger a core dump under some situations. This
2109 The regular expression captured submatches ($1, $2, ...) are now
2110 more consistently unset if the match fails, instead of leaving false
2111 data lying around in them.
2115 readline() on files opened in "slurp" mode could return an extra "" at
2116 the end in certain situations. This has been corrected.
2120 Autovivification of symbolic references of special variables described
2121 in L<perlvar> (as in C<${$num}>) was accidentally disabled. This works
2126 Sys::Syslog ignored the C<LOG_AUTH> constant.
2130 All but the first argument of the IO syswrite() method are now optional.
2134 $AUTOLOAD, sort(), lock(), and spawning subprocesses
2135 in multiple threads simultaneously are now thread-safe.
2139 Tie::ARRAY SPLICE method was broken.
2143 Allow read-only string on left hand side of non-modifying tr///.
2147 If C<STDERR> is tied, warnings caused by C<warn> and C<die> now
2148 correctly pass to it.
2152 Several Unicode fixes.
2158 BOMs (byte order marks) in the beginning of Perl files
2159 (scripts, modules) should now be transparently skipped.
2160 UTF-16 (UCS-2) encoded Perl files should now be read correctly.
2164 The character tables have been updated to Unicode 3.2.0.
2168 Comparing with utf8 data does not magically upgrade non-utf8 data
2169 into utf8. (This was a problem for example if you were mixing data
2170 from I/O and Unicode data: your output might have got magically encoded
2175 Generating illegal Unicode code points like U+FFFE, or the UTF-16
2176 surrogates, now also generates an optional warning.
2180 C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
2184 Concatenation with the C<.> operator or via variable interpolation,
2185 C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
2186 substitution with C<s///>, single-quoted UTF8, should now work.
2190 The C<tr///> operator now works. Note that the C<tr///CU>
2191 functionality has been removed (but see pack('U0', ...)).
2195 C<eval "v200"> now works.
2199 Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious warnings.
2200 This has been corrected.
2204 Zero entries were missing from the Unicode classes like C<IsDigit>.
2210 Large unsigned numbers (those above 2**31) could sometimes lose their
2211 unsignedness, causing bogus results in arithmetic operations.
2215 =head2 Platform Specific Changes and Fixes
2223 Perl now works on post-4.0 BSD/OSes.
2229 Setting C<$0> now works (as much as possible; see L<perlvar> for details).
2235 Numerous updates; currently synchronised with Cygwin 1.3.10.
2239 Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
2245 EPOC update after Perl 5.6.0. See README.epoc.
2251 Perl now works on post-3.0 FreeBSDs.
2257 README.hpux updated; C<Configure -Duse64bitall> now works.
2263 Numerous compilation flag and hint enhancements; accidental mixing
2264 of 32-bit and 64-bit libraries (a doomed attempt) made much harder.
2274 Long doubles should now work (see INSTALL).
2278 Linux previously had problems related to sockaddrlen when using
2279 accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
2287 Compilation of the standard Perl distribution in MacOS Classic should
2288 now work if you have the Metrowerks development environment and
2289 the missing Mac-specific toolkit bits. Contact the macperl mailing
2296 MPE/iX update after Perl 5.6.0. See README.mpeix.
2300 NetBSD/threads: try installing the GNU pth (should be in the
2301 packages collection, or http://www.gnu.org/software/pth/),
2302 and Configure with -Duseithreads.
2308 Perl now works on NetBSD/sparc.
2314 Now works with usethreads (see INSTALL).
2320 64-bitness using the Sun Workshop compiler now works.
2324 Tru64 (aka Digital UNIX, aka DEC OSF/1)
2326 The operating system version letter now recorded in $Config{osvers}.
2327 Allow compiling with gcc (previously explicitly forbidden). Compiling
2328 with gcc still not recommended because buggy code results, even with
2335 Fixed various alignment problems that lead into core dumps either
2336 during build or later; no longer dies on math errors at runtime;
2337 now using full quad integers (64 bits), previously was using
2338 only 46 bit integers for speed.
2344 chdir() now works better despite a CRT bug; now works with MULTIPLICITY
2345 (see INSTALL); now works with Perl's malloc.
2347 The tainting of C<%ENV> elements via C<keys> or C<values> was previously
2348 unimplemented. It now works as documented.
2350 The C<waitpid> emulation has been improved. The worst bug (now fixed)
2351 was that a pid of -1 would cause a wildcard search of all processes on
2352 the system. The most significant enhancement is that we can now
2353 usually get the completion status of a terminated process.
2355 POSIX-style signals are now emulated much better on VMS versions prior
2358 The C<system> function and backticks operator have improved
2359 functionality and better error handling.
2361 File access tests now use current process privileges rather than the
2362 user's default privileges, which could sometimes result in a mismatch
2363 between reported access and actual access.
2373 accept() no longer leaks memory.
2377 Borland C++ v5.5 is now a supported compiler that can build Perl.
2378 However, the generated binaries continue to be incompatible with those
2379 generated by the other supported compilers (GCC and Visual C++).
2383 Better chdir() return value for a non-existent directory.
2387 Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
2391 New %ENV entries now propagate to subprocesses.
2395 Current directory entries in %ENV are now correctly propagated to child
2400 $ENV{LIB} now used to search for libs under Visual C.
2404 fork() emulation has been improved in various ways, but still continues
2405 to be experimental. See L<perlfork> for known bugs and caveats.
2409 A failed (pseudo)fork now returns undef and sets errno to EAGAIN.
2413 Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
2414 Other bugs in chdir() and Cwd::cwd() have also been fixed.
2418 HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
2422 The makefiles now provide a single switch to bulk-enable all the features
2423 enabled in ActiveState ActivePerl (a popular Win32 binary distribution).
2427 Allow REG_EXPAND_SZ keys in the registry.
2431 Can now send() from all threads, not just the first one.
2435 Fake signal handling reenabled, bugs and all.
2439 %SIG has been enabled under USE_ITHREADS, but its use is completely
2440 unsupported under all configurations.
2444 Less stack reserved per thread so that more threads can run
2445 concurrently. (Still 16M per thread.)
2449 C<File::Spec->tmpdir()> now prefers C:/temp over /tmp
2450 (works better when perl is running as service).
2454 Better UNC path handling under ithreads.
2458 wait(), waitpid() and backticks now return the correct exit status under
2463 winsock handle leak fixed.
2467 The Perl parser has been stress tested using both random input and
2468 Markov chain input and the few found crashes and lockups have been
2475 =head1 New or Changed Diagnostics
2481 The lexical warnings category "deprecated" is no longer a sub-category
2482 of the "syntax" category. It is now a top-level category in its own
2487 All regular expression compilation error messages are now hopefully
2488 easier to understand both because the error message now comes before
2489 the failed regex and because the point of failure is now clearly
2490 marked by a C<E<lt>-- HERE> marker.
2494 The various "opened only for", "on closed", "never opened" warnings
2495 drop the C<main::> prefix for filehandles in the C<main> package,
2496 for example C<STDIN> instead of C<main::STDIN>.
2500 The "Unrecognized escape" warning has been extended to include C<\8>,
2501 C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters.
2505 Two new debugging options have been added: if you have compiled your
2506 Perl with debugging, you can use the -DT and -DR options to trace
2507 tokenising and to add reference counts to displaying variables,
2512 The debugger (perl5db.pl) has been modified to present a more
2513 consistent commands interface, via (CommandSet=580). perl5db.t was
2514 also added to test the changes, and as a placeholder for further tests.
2520 The debugger has a new C<dumpDepth> option to control the maximum
2521 depth to which nested structures are dumped. The C<x> command has
2522 been extended so that C<x N EXPR> dumps out the value of I<EXPR> to a
2523 depth of at most I<N> levels.
2527 The debugger can now show lexical variables if you have the CPAN
2528 module PadWalker installed.
2532 If an attempt to use a (non-blessed) reference as an array index
2533 is made, a warning is given.
2537 C<push @a;> and C<unshift @a;> (with no values to push or unshift)
2538 now give a warning. This may be a problem for generated and evaled
2543 If you try to L<perlfunc/pack> a number less than 0 or larger than 255
2544 using the C<"C"> format you will get an optional warning. Similarly
2545 for the C<"c"> format and a number less than -128 or more than 127.
2549 Certain regex modifiers such as C<(?o)> make sense only if applied to
2550 the entire regex. You will get an optional warning if you try to do
2555 Using arrays or hashes as references (e.g. C<< %foo->{bar} >>
2556 has been deprecated for a while. Now you will get an optional warning.
2560 Using C<sort> in scalar context now issues an optional warning.
2561 This didn't do anything useful, as the sort was not performed.
2565 =head1 Changed Internals
2571 perlapi.pod (a companion to perlguts) now attempts to document the
2576 You can now build a really minimal perl called microperl.
2577 Building microperl does not require even running Configure;
2578 C<make -f Makefile.micro> should be enough. Beware: microperl makes
2579 many assumptions, some of which may be too bold; the resulting
2580 executable may crash or otherwise misbehave in wondrous ways.
2581 For careful hackers only.
2585 Added rsignal(), whichsig(), do_join(), op_clear, op_null,
2586 ptr_table_clear(), ptr_table_free(), sv_setref_uv(), and several UTF-8
2587 interfaces to the publicised API. For the full list of the available
2588 APIs see L<perlapi>.
2592 Made possible to propagate customised exceptions via croak()ing.
2596 Now xsubs can have attributes just like subs. (Well, at least the
2597 built-in attributes.)
2601 dTHR and djSP have been obsoleted; the former removed (because it's
2602 a no-op) and the latter replaced with dSP.
2606 PERL_OBJECT has been completely removed.
2610 The MAGIC constants (e.g. C<'P'>) have been macrofied
2611 (e.g. C<PERL_MAGIC_TIED>) for better source code readability
2612 and maintainability.
2616 The regex compiler now maintains a structure that identifies nodes in
2617 the compiled bytecode with the corresponding syntactic features of the
2618 original regex expression. The information is attached to the new
2619 C<offsets> member of the C<struct regexp>. See L<perldebguts> for more
2620 complete information.
2624 The C code has been made much more C<gcc -Wall> clean. Some warning
2625 messages still remain in some platforms, so if you are compiling with
2626 gcc you may see some warnings about dubious practices. The warnings
2627 are being worked on.
2631 F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
2635 Documentation on how to use the Perl source repository has been added
2636 to F<Porting/repository.pod>.
2640 There are now several profiling make targets.
2644 =head1 Security Vulnerability Closed
2646 (This change was already made in 5.7.0 but bears repeating here.)
2648 A potential security vulnerability in the optional suidperl component
2649 of Perl was identified in August 2000. suidperl is neither built nor
2650 installed by default. As of November 2001 the only known vulnerable
2651 platform is Linux, most likely all Linux distributions. CERT and
2652 various vendors and distributors have been alerted about the vulnerability.
2653 See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
2654 for more information.
2656 The problem was caused by Perl trying to report a suspected security
2657 exploit attempt using an external program, /bin/mail. On Linux
2658 platforms the /bin/mail program had an undocumented feature which
2659 when combined with suidperl gave access to a root shell, resulting in
2660 a serious compromise instead of reporting the exploit attempt. If you
2661 don't have /bin/mail, or if you have 'safe setuid scripts', or if
2662 suidperl is not installed, you are safe.
2664 The exploit attempt reporting feature has been completely removed from
2665 Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also
2666 from all the Perl 5.7 releases), so that particular vulnerability
2667 isn't there anymore. However, further security vulnerabilities are,
2668 unfortunately, always possible. The suidperl functionality is most
2669 probably going to be removed in Perl 5.10. In any case, suidperl
2670 should only be used by security experts who know exactly what they are
2671 doing and why they are using suidperl instead of some other solution
2672 such as sudo ( see http://www.courtesan.com/sudo/ ).
2676 Several new tests have been added, especially for the F<lib>
2677 subsection. There are now about 56 000 individual tests (spread over
2678 about 620 test scripts), in the regression suite (5.6.1 has about
2679 11700 tests, in 258 test scripts) Many of the new tests are introduced
2680 by the new modules, but still in general Perl is now more thoroughly
2683 Because of the large number of tests, running the regression suite
2684 will take considerably longer time than it used to: expect the suite
2685 to take up to 4-5 times longer to run than in perl 5.6. In a really
2686 fast machine you can hope to finish the suite in about 6-8 minutes
2689 The tests are now reported in a different order than in earlier Perls.
2690 (This happens because the test scripts from under t/lib have been moved
2691 to be closer to the library/extension they are testing.)
2693 =head1 Known Problems
2701 In AIX 4.2 Perl extensions that use C++ functions that use statics
2702 may have problems in that the statics are not getting initialized.
2703 In newer AIX releases this has been solved by linking Perl with
2704 the libC_r library, but unfortunately in AIX 4.2 the said library
2705 has an obscure bug where the various functions related to time
2706 (such as time() and gettimeofday()) return broken values, and
2707 therefore in AIX 4.2 Perl is not linked against the libC_r.
2711 vac 5.0.0.0 May Produce Buggy Code For Perl
2713 The AIX C compiler vac version 5.0.0.0 may produce buggy code,
2714 resulting in few random tests failing, but when the failing tests
2715 are run by hand, they succeed. We suggest upgrading to at least
2716 vac version 5.0.1.0, that has been known to compile Perl correctly.
2717 "lslpp -L|grep vac.C" will tell you the vac version. See README.aix.
2721 If building threaded Perl, you may get compilation warning from pp_sys.c:
2723 "pp_sys.c", line 4651.39: 1506-280 (W) Function argument assignment between types "unsigned char*" and "const void*" is not allowed.
2725 This is harmless; it is caused by the getnetbyaddr() and getnetbyaddr_r()
2726 having slightly different types for their first argument.
2730 =head2 Amiga Perl Invoking Mystery
2732 One cannot call Perl using the C<volume:> syntax, that is, C<perl -v>
2733 works, but for example C<bin:perl -v> doesn't. The exact reason isn't
2734 known but the current suspect is the F<ixemul> library.
2736 =head2 FreeBSD Failing locale Test 117 For ISO8859-15 Locales
2738 The ISO8859-15 locales may fail the locale test 117 in FreeBSD.
2739 This is caused by the characters \xFF (y with diaeresis) and \xBE
2740 (Y with diaeresis) not behaving correctly when being matched
2743 =head2 mod_perl 1.26 Doesn't Build With Threaded Perl
2745 Use mod_perl 1.27 or higher.
2747 =head2 lib/ftmp-security tests warn 'system possibly insecure'
2749 Don't panic. Read INSTALL 'make test' section instead.
2751 =head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
2753 If perl is configured with -Duse64bitall, the successful result of the
2754 subtest 10 of lib/posix may arrive before the successful result of the
2755 subtest 9, which confuses the test harness so much that it thinks the
2758 =head2 Linux With Sfio Fails op/misc Test 48
2764 Please remember to set your environment variable LC_ALL to "C"
2765 (setenv LC_ALL C) before running "make test" to avoid a lot of
2766 warnings about the broken locales of Mac OS X.
2768 The following tests are known to fail:
2770 Failed Test Stat Wstat Total Fail Failed List of Failed
2771 -------------------------------------------------------------------------
2772 ../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ??
2773 ../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65
2774 ../ext/POSIX/t/posix.t 31 1 3.23% 10
2776 If you are building on a UFS partition, you will also probably see
2777 t/op/stat.t subtest #9 fail. This is caused by Darwin's UFS not
2778 supporting inode change time.
2780 =head2 op/sprintf tests 91, 129, and 130
2782 The op/sprintf tests 91, 129, and 130 are known to fail on some platforms.
2783 Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
2785 The test 91 is known to fail at QNX6 (nto), because C<sprintf '%e',0>
2786 incorrectly produces C<0.000000e+0> instead of C<0.000000e+00>.
2788 For the tests 129 and 130 the failing platforms do not comply with
2789 the ANSI C Standard, line 19ff on page 134 of ANSI X3.159 1989 to
2790 be exact. (They produce something other than "1" and "-1" when
2791 formatting 0.6 and -0.6 using the printf format "%.0f", most often
2792 they produce "0" and "-0".)
2796 In case you are still using Solaris 2.5 (aka SunOS 5.5), you may
2797 experience failures (the test core dumping) in lib/locale.t.
2798 The suggested cure is to upgrade your Solaris.
2800 =head2 Failure of Thread (5.005-style) tests
2802 B<Note that support for 5.005-style threading remains experimental
2803 and practically unsupported.>
2805 The following tests are known to fail due to fundamental problems in
2806 the 5.005 threading implementation. These are not new failures--Perl
2807 5.005_0x has the same bugs, but didn't have these tests.
2809 ../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7
2810 ../lib/English.t 2 512 54 2 3.70% 2-3
2811 ../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3
2812 ../lib/Filter/Simple/t/filter_onl 9 3 33.33% 1-2 5
2813 ../lib/autouse.t 10 1 10.00% 4
2814 op/flip.t 15 1 6.67% 15
2816 These failures are unlikely to get fixed as the 5.005-style
2817 threads are considered fundamentally broken.
2821 Failed Test Stat Wstat Total Fail Failed List of Failed
2822 -------------------------------------------------------------------------
2823 ../ext/Socket/socketpair.t 1 256 45 1 2.22% 12
2824 ../lib/Math/Trig.t 26 1 3.85% 25
2825 ../lib/warnings.t 460 1 0.22% 425
2826 io/fs.t 36 1 2.78% 31
2827 op/numconvert.t 1440 13 0.90% 208 509-510
2828 657-658 665-666 829-830 989-990 1149-1150
2836 During Configure the test
2838 Guessing which symbols your C compiler and preprocessor define...
2840 will probably fail with error messages like
2842 CC-20 cc: ERROR File = try.c, Line = 3
2843 The identifier "bad" is undefined.
2845 bad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K
2848 CC-65 cc: ERROR File = try.c, Line = 3
2849 A semicolon is expected at this point.
2851 This is caused by a bug in awk utility of UNICOS/mk. You can ignore
2852 the error, but it does cause a slight problem: you cannot fully
2853 benefit from the h2ph utility (see L<h2ph>) that can be used to
2854 convert C headers to Perl libraries, mainly used to be able to access
2855 from Perl the constants defined using C preprocessor, cpp. Because of
2856 the above error parts of the converted headers will be invisible.
2857 Luckily, these days the need for h2ph is rare.
2861 If building Perl with the interpreter threads (ithreads), the
2862 getgrent(), getgrnam(), and getgrgid() functions cannot return the
2863 list of the group members due to a bug in the multithreaded support of
2864 UNICOS/mk. What this means that in list context the functions will
2865 return only three values, not four.
2871 There are a few known test failures, see L<perluts>.
2875 There should be no reported test failures with a default configuration,
2876 though there are a number of tests marked TODO that point to areas
2877 needing further debugging and/or porting work.
2881 In multi-CPU boxes there are some problems with the I/O buffering:
2882 some output may appear twice.
2884 =head2 XML::Parser not working
2886 Use XML::Parser 2.31 or later.
2888 =head2 z/OS (OS/390)
2890 z/OS has rather many test failures but the situation is actually
2891 better than it was in 5.6.0, it's just that so many new modules and
2892 tests have been added.
2894 Failed Test Stat Wstat Total Fail Failed List of Failed
2895 -------------------------------------------------------------------------------
2896 ../ext/Data/Dumper/t/dumper.t 339 8 2.36% 311 314 325 327
2898 ../ext/IO/lib/IO/t/io_unix.t 5 4 80.00% 2-5
2899 ../ext/Storable/t/utf8hash.t 10 2560 148 10 6.76% 1 5 72 76 143-148
2900 ../lib/utf8.t 94 13 13.83% 27 30-31 43 46 73
2903 ../lib/ExtUtils/t/Constant.t 121 30976 48 48 100.00% 1-48
2904 ../lib/ExtUtils/t/Embed.t 9 9 100.00% 1-9
2905 op/pat.t 900 9 1.00% 242-243 665 776
2907 op/sprintf.t 224 3 1.34% 98 100 136
2908 op/tr.t 97 5 5.15% 63 71-74
2909 run/fresh_perl.t 94 3 3.19% 92-94
2910 uni/fold.t 780 6 0.77% 61 169 196 661
2913 =head2 Localising Tied Arrays and Hashes Is Broken
2917 doesn't work as one would expect: the old value is restored
2920 =head2 Self-tying of Arrays and Hashes Is Forbidden
2922 Self-tying of arrays and hashes is broken in rather deep and
2923 hard-to-fix ways. As a stop-gap measure to avoid people from getting
2924 frustrated at the mysterious results (core dumps, most often) it is
2925 for now forbidden (you will get a fatal error even from an attempt).
2927 =head2 Building Extensions Can Fail Because Of Largefiles
2929 Some extensions like mod_perl are known to have issues with
2930 `largefiles', a change brought by Perl 5.6.0 in which file offsets
2931 default to 64 bits wide, where supported. Modules may fail to compile
2932 at all or compile and work incorrectly. Currently there is no good
2933 solution for the problem, but Configure now provides appropriate
2934 non-largefile ccflags, ldflags, libswanted, and libs in the %Config
2935 hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
2936 having problems can try configuring themselves without the
2937 largefileness. This is admittedly not a clean solution, and the
2938 solution may not even work at all. One potential failure is whether
2939 one can (or, if one can, whether it's a good idea) link together at
2940 all binaries with different ideas about file offsets, all this is
2943 =head2 Unicode Support on EBCDIC Still Spotty
2945 Though mostly working, Unicode support still has problem spots on
2946 EBCDIC platforms. One such known spot are the C<\p{}> and C<\P{}>
2947 regular expression constructs for code points less than 256: the
2948 pP are testing for Unicode code points, not knowing about EBCDIC.
2950 =head2 The Compiler Suite Is Still Experimental
2952 The compiler suite is slowly getting better but it continues to be
2953 highly experimental. Use in production environments is discouraged.
2955 =head2 The Long Double Support Is Still Experimental
2957 The ability to configure Perl's numbers to use "long doubles",
2958 floating point numbers of hopefully better accuracy, is still
2959 experimental. The implementations of long doubles are not yet
2960 widespread and the existing implementations are not quite mature
2961 or standardised, therefore trying to support them is a rare
2962 and moving target. The gain of more precision may also be offset
2963 by slowdown in computations (more bits to move around, and the
2964 operations are more likely to be executed by less optimised
2967 =head2 Seen In Perl 5.7 But Gone Now
2969 C<Time::Piece> (previously known as C<Time::Object>) was removed
2970 because it was felt that it didn't have enough value in it to be a
2971 core module. It is still a useful module, though, and is available
2974 =head1 Reporting Bugs
2976 If you find what you think is a bug, you might check the articles
2977 recently posted to the comp.lang.perl.misc newsgroup and the perl
2978 bug database at http://bugs.perl.org/ There may also be
2979 information at http://www.perl.com/ , the Perl Home Page.
2981 If you believe you have an unreported bug, please run the B<perlbug>
2982 program included with your release. Be sure to trim your bug down
2983 to a tiny but sufficient test case. Your bug report, along with the
2984 output of C<perl -V>, will be sent off to perlbug@perl.org to be
2985 analysed by the Perl porting team.
2989 The F<Changes> file for exhaustive details on what changed.
2991 The F<INSTALL> file for how to build Perl.
2993 The F<README> file for general stuff.
2995 The F<Artistic> and F<Copying> files for copyright information.
2999 Written by Jarkko Hietaniemi <F<jhi@iki.fi>>.