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1=head1 NAME
2
f39f21d8 3perldelta - what is new for perl v5.8.0
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4
5=head1 DESCRIPTION
6
f39f21d8
JH
7This document describes differences between the 5.6.0 release and the
85.8.0 release.
9
10=head1 Security Vulnerability Closed
11
12A potential security vulnerability in the optional suidperl component
13of Perl has been identified. suidperl is neither built nor installed
14by default. As of September the 2nd, 2000, the only known vulnerable
15platform is Linux, most likely all Linux distributions. CERT and
16various vendors have been alerted about the vulnerability.
17
18The problem was caused by Perl trying to report a suspected security
19exploit attempt using an external program, /bin/mail. On Linux
20platforms the /bin/mail program had an undocumented feature which
21when combined with suidperl gave access to a root shell, resulting in
22a serious compromise instead of reporting the exploit attempt. If you
23don't have /bin/mail, or if you have 'safe setuid scripts', or if
24suidperl is not installed, you are safe.
25
26The exploit attempt reporting feature has been completely removed from
27the Perl 5.7.0 release, so that particular vulnerability isn't there
28anymore. However, further security vulnerabilities are,
29unfortunately, always possible. The suidperl code is being reviewed
30and if deemed too risky to continue to be supported, it may be
31completely removed from future releases. In any case, suidperl should
32only be used by security experts who know exactly what they are doing
33and why they are using suidperl instead of some other solution such as
34sudo (see http://www.courtesan.com/sudo/).
35
36=head1 Incompatible Changes
37
38=over 4
39
40=item *
41
42Arrays now always interpolate into double-quoted strings:
43constructs like "foo@bar" now always assume C<@bar> is an array,
44whether or not the compiler has seen use of C<@bar>.
45
46=item *
47
48The semantics of bless(REF, REF) were unclear and until someone proves
49it to make some sense, it is forbidden.
50
51=item *
52
53A reference to a reference now stringify as "REF(0x81485ec)" instead
54of "SCALAR(0x81485ec)" in order to be more consistent with the return
55value of ref().
56
57=item *
58
59The very dusty examples in the eg/ directory have been removed.
60Suggestions for new shiny examples welcome but the main issue is that
61the examples need to be documented, tested and (most importantly)
62maintained.
63
64=item *
65
66The obsolete chat2 library that should never have been allowed
67to escape the laboratory has been decommissioned.
68
69=item *
70
71The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still
72recognised but now cause fatal errors. The previous behaviour of
73ignoring them by default and warning if requested was unacceptable
74since it, in a way, falsely promised that the features could be used.
75
76=item *
77
78The (bogus) escape sequences \8 and \9 now give an optional warning
79("Unrecognized escape passed through"). There is no need to \-escape
80any C<\w> character.
81
82=item *
83
84lstat(FILEHANDLE) now gives a warning because the operation makes no sense.
85In future releases this may become a fatal error.
86
87=item *
88
89The long deprecated uppercase aliases for the string comparison
90operators (EQ, NE, LT, LE, GE, GT) have now been removed.
91
92=item *
93
94The regular expression captured submatches ($1, $2, ...) are now
95more consistently unset if the match fails, instead of leaving false
96data lying around in them.
97
98=item *
99
100The tr///C and tr///U features have been removed and will not return;
101the interface was a mistake. Sorry about that. For similar
102functionality, see pack('U0', ...) and pack('C0', ...).
103
104=back
105
106=head1 Core Enhancements
107
108=over 4
109
110=item *
111
112C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
113in multiple arguments.)
114
115=item *
116
117my __PACKAGE__ $obj now works.
118
119=item *
120
121C<no Module;> now works even if there is no "sub unimport" in the Module.
122
123=item *
124
125The numerical comparison operators return C<undef> if either operand
126is a NaN. Previously the behaviour was unspecified.
127
128=item *
129
130C<pack('U0a*', ...)> can now be used to force a string to UTF8.
131
132=item *
133
134prototype(\&) is now available.
135
136=item *
137
138There is now an UNTIE method.
139
140=back
141
142=head1 Modules and Pragmata
143
144=head2 New Modules
145
146=over 4
147
148=item *
149
150File::Temp allows one to create temporary files and directories in an
151easy, portable, and secure way.
152
153=item *
154
155Storable gives persistence to Perl data structures by allowing the
156storage and retrieval of Perl data to and from files in a fast and
157compact binary format.
158
159=back
160
161=head2 Updated And Improved Modules and Pragmata
162
163=over 4
164
165=item *
166
167The following independently supported modules have been updated to
168newer versions from CPAN: CGI, CPAN, DB_File, File::Spec, Getopt::Long,
169the podlators bundle, Pod::LaTeX, Pod::Parser, Term::ANSIColor, Test.
170
171=item *
172
173Bug fixes and minor enhancements have been applied to B::Deparse,
174Data::Dumper, IO::Poll, IO::Socket::INET, Math::BigFloat,
175Math::Complex, Math::Trig, Net::protoent, the re pragma, SelfLoader,
176Sys::SysLog, Test::Harness, Text::Wrap, UNIVERSAL, and the warnings
177pragma.
178
179=item *
180
181The attributes::reftype() now works on tied arguments.
182
183=item *
184
185AutoLoader can now be disabled with C<no AutoLoader;>,
186
187=item *
188
189The English module can now be used without the infamous performance
190hit by saying
191
192 use English '-no_performance_hit';
193
194(Assuming, of course, that one doesn't need the troublesome variables
195C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
196C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
197
198=item *
199
200File::Find now has pre- and post-processing callbacks. It also
201correctly changes directories when chasing symbolic links. Callbacks
202(naughtily) exiting with "next;" instead of "return;" now work.
203
204=item *
205
206File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
207prototype mismatch with CORE::glob().
208
209=item *
210
211IPC::Open3 now allows the use of numeric file descriptors.
212
213=item *
214
215use lib now works identically to @INC. Removing directories
216with 'no lib' now works.
217
218=item *
219
220C<%INC> now localised in a Safe compartment so that use/require work.
221
222=item *
223
224The Shell module now has an OO interface.
225
226=back
227
228=head1 Utility Changes
229
230=over 4
231
232=item *
233
234The Emacs perl mode (emacs/cperl-mode.el) has been updated to version
2354.31.
236
237=item *
238
239Perlbug is now much more robust. It also sends the bug report to
240perl.org, not perl.com.
241
242=item *
243
244The perlcc utility has been rewritten and its user interface (that is,
245command line) is much more like that of the UNIX C compiler, cc.
246
247=item *
248
249The xsubpp utility for extension writers now understands POD
250documentation embedded in the *.xs files.
251
252=back
253
254=head1 New Documentation
255
256=over 4
257
258=item *
259
260perl56delta details the changes between the 5.005 release and the
2615.6.0 release.
262
263=item *
264
265perldebtut is a Perl debugging tutorial.
266
267=item *
268
269perlebcdic contains considerations for running Perl on EBCDIC platforms.
270Note that unfortunately EBCDIC platforms that used to supported back in
271Perl 5.005 are still unsupported by Perl 5.7.0; the plan, however, is to
272bring them back to the fold.
273
274=item *
275
276perlnewmod tells about writing and submitting a new module.
277
278=item *
279
280perlposix-bc explains using Perl on the POSIX-BC platform
281(an EBCDIC mainframe platform).
282
283=item *
284
285perlretut is a regular expression tutorial.
286
287=item *
288
289perlrequick is a regular expressions quick-start guide.
290Yes, much quicker than perlretut.
291
292=item *
293
294perlutil explains the command line utilities packaged with the Perl
295distribution.
296
297=back
298
299=head1 Performance Enhancements
300
301=over 4
302
303=item *
304
305map() that changes the size of the list should now work faster.
306
307=item *
308
309sort() has been changed to use mergesort internally as opposed to the
310earlier quicksort. For very small lists this may result in slightly
311slower sorting times, but in general the speedup should be at least
31220%. Additional bonuses are that the worst case behaviour of sort()
313is now better (in computer science terms it now runs in time O(N log N),
314as opposed to quicksort's Theta(N**2) worst-case run time behaviour),
315and that sort() is now stable (meaning that elements with identical
316keys will stay ordered as they were before the sort).
317
318=back
319
320=head1 Installation and Configuration Improvements
321
322=head2 Generic Improvements
323
324=over 4
325
326=item *
327
328INSTALL now explains how you can configure Perl to use 64-bit
329integers even on non-64-bit platforms.
330
331=item *
332
333Policy.sh policy change: if you are reusing a Policy.sh file
334(see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old
335Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of
336them will now be changed to the new prefix, /foo/bar. (Previously
337only $prefix changed.) If you do not like this new behaviour,
338specify prefix, siteprefix, and vendorprefix explicitly.
339
340=item *
341
342A new optional location for Perl libraries, otherlibdirs, is available.
343It can be used for example for vendor add-ons without disturbing Perl's
344own library directories.
345
346=item *
347
348In many platforms the vendor-supplied 'cc' is too stripped-down to
349build Perl (basically, 'cc' doesn't do ANSI C). If this seems
350to be the case and 'cc' does not seem to be the GNU C compiler
351'gcc', an automatic attempt is made to find and use 'gcc' instead.
352
353=item *
354
355gcc needs to closely track the operating system release to avoid
356build problems. If Configure finds that gcc was built for a different
357operating system release than is running, it now gives a clearly visible
358warning that there may be trouble ahead.
359
360=item *
361
362If binary compatibility with the 5.005 release is not wanted, Configure
363no longer suggests including the 5.005 modules in @INC.
364
365=item *
366
367Configure C<-S> can now run non-interactively.
368
369=item *
370
371configure.gnu now works with options with whitespace in them.
372
373=item *
374
375installperl now outputs everything to STDERR.
376
377=item *
378
379$Config{byteorder} is now computed dynamically (this is more robust
380with "fat binaries" where an executable image contains binaries for
381more than one binary platform.)
382
383=back
384
385=head1 Selected Bug Fixes
386
387=over 4
388
389=item *
390
391Several debugger fixes: exit code now reflects the script exit code,
392condition C<"0"> now treated correctly, the C<d> command now checks
393line number, the C<$.> no longer gets corrupted, all debugger output now
394goes correctly to the socket if RemotePort is set.
395
396=item *
397
398C<*foo{FORMAT}> now works.
399
400=item *
401
402Lexical warnings now propagating correctly between scopes.
403
404=item *
405
406Line renumbering with eval and C<#line> now works.
407
408=item *
409
410Fixed numerous memory leaks, especially in eval "".
411
412=item *
413
414Modulus of unsigned numbers now works (4063328477 % 65535 used to
415return 27406, instead of 27047).
416
417=item *
418
419Some "not a number" warnings introduced in 5.6.0 eliminated to be
420more compatible with 5.005. Infinity is now recognised as a number.
421
422=item *
423
424our() variables will not cause "will not stay shared" warnings.
425
426=item *
427
428pack "Z" now correctly terminates the string with "\0".
429
430=item *
431
432Fix password routines which in some shadow password platforms
433(e.g. HP-UX) caused getpwent() to return every other entry.
434
435=item *
436
437printf() no longer resets the numeric locale to "C".
438
439=item *
440
441C<q(a\\b)> now parses correctly as C<'a\\b'>.
442
443=item *
444
445Printing quads (64-bit integers) with printf/sprintf now works
446without the q L ll prefixes (assuming you are on a quad-capable platform).
447
448=item *
449
450Regular expressions on references and overloaded scalars now work.
451
452=item *
453
454scalar() now forces scalar context even when used in void context.
455
456=item *
457
458sort() arguments are now compiled in the right wantarray context
459(they were accidentally using the context of the sort() itself).
460
461=item *
462
463Changed the POSIX character class C<[[:space:]]> to include the (very
464rare) vertical tab character. Added a new POSIX-ish character class
465C<[[:blank:]]> which stands for horizontal whitespace (currently,
466the space and the tab).
467
468=item *
469
470$AUTOLOAD, sort(), lock(), and spawning subprocesses
471in multiple threads simultaneously are now thread-safe.
472
473=item *
474
475Allow read-only string on left hand side of non-modifying tr///.
476
477=item *
478
479Several Unicode fixes (but still not perfect).
480
481=over 8
482
483=item *
484
485BOMs (byte order marks) in the beginning of Perl files
486(scripts, modules) should now be transparently skipped.
487UTF-16 (UCS-2) encoded Perl files should now be read correctly.
488
489=item *
490
491The character tables have been updated to Unicode 3.0.1.
492
493=item *
494
495chr() for values greater than 127 now create utf8 when under use
496utf8.
497
498=item *
499
500Comparing with utf8 data does not magically upgrade non-utf8 data into
501utf8.
502
503=item *
504
505C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
506
507=item *
508
509Concatenation with the C<.> operator or via variable interpolation,
510C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
511substitution with C<s///>, single-quoted UTF8, should now work--in
512theory.
513
514=item *
515
516The C<tr///> operator now works I<slightly> better but is still rather
517broken. Note that the C<tr///CU> functionality has been removed (but
518see pack('U0', ...)).
519
520=item *
521
522vec() now refuses to deal with characters >255.
523
524=item *
525
526Zero entries were missing from the Unicode classes like C<IsDigit>.
527
528=back
529
530=item *
531
532UNIVERSAL::isa no longer caches methods incorrectly. (This broke
533the Tk extension with 5.6.0.)
534
535=back
536
537=head2 Platform Specific Changes and Fixes
538
539=over 4
540
541=item *
542
543BSDI 4.*
544
545Perl now works on post-4.0 BSD/OSes.
546
547=item *
548
549All BSDs
550
551Setting C<$0> now works (as much as possible; see perlvar for details).
552
553=item *
554
555Cygwin
556
557Numerous updates; currently synchronised with Cygwin 1.1.4.
558
559=item *
560
561EPOC
562
563EPOC update after Perl 5.6.0. See README.epoc.
564
565=item *
566
567FreeBSD 3.*
568
569Perl now works on post-3.0 FreeBSDs.
570
571=item *
572
573HP-UX
574
575README.hpux updated; C<Configure -Duse64bitall> now almost works.
576
577=item *
578
579IRIX
580
581Numerous compilation flag and hint enhancements; accidental mixing
582of 32-bit and 64-bit libraries (a doomed attempt) made much harder.
583
584=item *
585
586Linux
587
588Long doubles should now work (see INSTALL).
589
590=item *
591
592MacOS Classic
593
594Compilation of the standard Perl distribution in MacOS Classic should
595now work if you have the Metrowerks development environment and
596the missing Mac-specific toolkit bits. Contact the macperl mailing
597list for details.
598
599=item *
600
601MPE/iX
602
603MPE/iX update after Perl 5.6.0. See README.mpeix.
604
605=item *
606
607NetBSD/sparc
608
609Perl now works on NetBSD/sparc.
610
611=item *
612
613OS/2
614
615Now works with usethreads (see INSTALL).
616
617=item *
618
619Solaris
620
62164-bitness using the Sun Workshop compiler now works.
622
623=item *
624
625Tru64 (aka Digital UNIX, aka DEC OSF/1)
626
627The operating system version letter now recorded in $Config{osvers}.
628Allow compiling with gcc (previously explicitly forbidden). Compiling
629with gcc still not recommended because buggy code results, even with
630gcc 2.95.2.
631
632=item *
633
634Unicos
635
636Fixed various alignment problems that lead into core dumps either
637during build or later; no longer dies on math errors at runtime;
638now using full quad integers (64 bits), previously was using
639only 46 bit integers for speed.
640
641=item *
642
643VMS
644
645chdir() now works better despite a CRT bug; now works with MULTIPLICITY
646(see INSTALL); now works with Perl's malloc.
647
648=item *
649
650Windows
651
652=over 8
653
654=item *
655
656accept() no longer leaks memory.
657
658=item *
659
660Better chdir() return value for a non-existent directory.
661
662=item *
663
664New %ENV entries now propagate to subprocesses.
665
666=item *
667
668$ENV{LIB} now used to search for libs under Visual C.
669
670=item *
671
672A failed (pseudo)fork now returns undef and sets errno to EAGAIN.
673
674=item *
675
676Allow REG_EXPAND_SZ keys in the registry.
677
678=item *
679
680Can now send() from all threads, not just the first one.
681
682=item *
683
684Fake signal handling reenabled, bugs and all.
685
686=item *
687
688Less stack reserved per thread so that more threads can run
689concurrently. (Still 16M per thread.)
690
691=item *
692
693C<File::Spec->tmpdir()> now prefers C:/temp over /tmp
694(works better when perl is running as service).
695
696=item *
697
698Better UNC path handling under ithreads.
699
700=item *
701
702wait() and waitpid() now work much better.
703
704=item *
705
706winsock handle leak fixed.
707
708=back
709
710=back
711
712=head1 New or Changed Diagnostics
713
714All regular expression compilation error messages are now hopefully
715easier to understand both because the error message now comes before
716the failed regex and because the point of failure is now clearly
717marked.
718
719The various "opened only for", "on closed", "never opened" warnings
720drop the C<main::> prefix for filehandles in the C<main> package,
721for example C<STDIN> instead of <main::STDIN>.
722
723The "Unrecognized escape" warning has been extended to include C<\8>,
724C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters.
725
726=head1 Changed Internals
727
728=over 4
729
730=item *
731
732perlapi.pod (a companion to perlguts) now attempts to document the
733internal API.
734
735=item *
736
737You can now build a really minimal perl called microperl.
738Building microperl does not require even running Configure;
739C<make -f Makefile.micro> should be enough. Beware: microperl makes
740many assumptions, some of which may be too bold; the resulting
741executable may crash or otherwise misbehave in wondrous ways.
742For careful hackers only.
743
744=item *
745
746Added rsignal(), whichsig(), do_join() to the publicised API.
747
748=item *
749
750Made possible to propagate customised exceptions via croak()ing.
751
752=item *
753
754Added is_utf8_char(), is_utf8_string(), bytes_to_utf8(), and utf8_to_bytes().
755
756=item *
757
758Now xsubs can have attributes just like subs.
759
760=back
761
762=head1 Known Problems
763
764=head2 Unicode Support Still Far From Perfect
765
766We're working on it. Stay tuned.
767
768=head2 EBCDIC Still A Lost Platform
769
770The plan is to bring them back.
771
772=head2 Building Extensions Can Fail Because Of Largefiles
773
774Certain extensions like mod_perl and BSD::Resource are known to have
775issues with `largefiles', a change brought by Perl 5.6.0 in which file
776offsets default to 64 bits wide, where supported. Modules may fail to
777compile at all or compile and work incorrectly. Currently there is no
778good solution for the problem, but Configure now provides appropriate
779non-largefile ccflags, ldflags, libswanted, and libs in the %Config
780hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
781having problems can try configuring themselves without the
782largefileness. This is admittedly not a clean solution, and the
783solution may not even work at all. One potential failure is whether
784one can (or, if one can, whether it's a good idea) link together at
785all binaries with different ideas about file offsets, all this is
786platform-dependent.
787
788=head2 ftmp-security tests warn 'system possibly insecure'
789
790Don't panic. Read INSTALL 'make test' section instead.
791
792=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
793
794If perl is configured with -Duse64bitall, the successful result of the
795subtest 10 of lib/posix may arrive before the successful result of the
796subtest 9, which confuses the test harness so much that it thinks the
797subtest 9 failed.
798
799=head2 Long Doubles Still Don't Work In Solaris
800
801The experimental long double support is still very much so in Solaris.
802(Other platforms like Linux and Tru64 are beginning to solidify in
803this area.)
804
805=head2 Linux With Sfio Fails op/misc Test 48
806
807No known fix.
808
809=head2 Storable tests fail in some platforms
810
811If any Storable tests fail the use of Storable is not advisable.
812
813=over 4
814
815=item *
816
817Many Storable tests fail on AIX configured with 64 bit integers.
818
819So far unidentified problems break Storable in AIX if Perl is
820configured to use 64 bit integers. AIX in 32-bit mode works and
821other 64-bit platforms work with Storable.
822
823=item *
824
825DOS DJGPP may hang when testing Storable.
826
827=item *
828
829st-06compat fails in UNICOS and UNICOS/mk.
830
831This means that you cannot read old (pre-Storable-0.7) Storable images
832made in other platforms.
833
834=item *
835
836st-store.t and st-retrieve may fail with Compaq C 6.2 on OpenVMS Alpha 7.2.
837
838=back
839
840=head2 Threads Are Still Experimental
841
842Multithreading is still an experimental feature. Some platforms
843emit the following message for lib/thr5005
844
845 #
846 # This is a KNOWN FAILURE, and one of the reasons why threading
847 # is still an experimental feature. It is here to stop people
848 # from deploying threads in production. ;-)
849 #
850
851and another known thread-related warning is
852
853 pragma/overload......Unbalanced saves: 3 more saves than restores
854 panic: magic_mutexfree during global destruction.
855 ok
856 lib/selfloader.......Unbalanced saves: 3 more saves than restores
857 panic: magic_mutexfree during global destruction.
858 ok
859 lib/st-dclone........Unbalanced saves: 3 more saves than restores
860 panic: magic_mutexfree during global destruction.
861 ok
862
863=head2 The Compiler Suite Is Still Experimental
864
865The compiler suite is slowly getting better but is nowhere near
866working order yet. The backend part that has seen perhaps the most
867progress is the bytecode compiler.
868
869=head1 Security Vulnerability Closed
870
871(This change was already made in 5.7.0 but bears repeating here.)
872
873A potential security vulnerability in the optional suidperl component
874of Perl was identified in August 2000. suidperl is neither built nor
875installed by default. As of April 2001 the only known vulnerable
876platform is Linux, most likely all Linux distributions. CERT and
877various vendors and distributors have been alerted about the vulnerability.
878See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
879for more information.
880
881The problem was caused by Perl trying to report a suspected security
882exploit attempt using an external program, /bin/mail. On Linux
883platforms the /bin/mail program had an undocumented feature which
884when combined with suidperl gave access to a root shell, resulting in
885a serious compromise instead of reporting the exploit attempt. If you
886don't have /bin/mail, or if you have 'safe setuid scripts', or if
887suidperl is not installed, you are safe.
888
889The exploit attempt reporting feature has been completely removed from
890all the Perl 5.7 releases (and will be gone also from the maintenance
891release 5.6.1), so that particular vulnerability isn't there anymore.
892However, further security vulnerabilities are, unfortunately, always
893possible. The suidperl code is being reviewed and if deemed too risky
894to continue to be supported, it may be completely removed from future
895releases. In any case, suidperl should only be used by security
896experts who know exactly what they are doing and why they are using
897suidperl instead of some other solution such as sudo (see
898http://www.courtesan.com/sudo/).
899
900=head1 Incompatible Changes
901
902=over 4
903
904=item *
905
906Although "you shouldn't do that", it was possible to write code that
907depends on Perl's hashed key order (Data::Dumper does this). The new
908algorithm "One-at-a-Time" produces a different hashed key order.
909More details are in L</"Performance Enhancements">.
910
911=item *
912
913The list of filenames from glob() (or <...>) is now by default sorted
914alphabetically to be csh-compliant. (bsd_glob() does still sort platform
915natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.)
916
917=back
918
919=head1 Core Enhancements
920
921=head2 AUTOLOAD Is Now Lvaluable
922
923AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
924to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
925
926=head2 PerlIO is Now The Default
927
928=over 4
929
930=item *
931
932IO is now by default done via PerlIO rather than system's "stdio".
933PerlIO allows "layers" to be "pushed" onto a file handle to alter the
934handle's behaviour. Layers can be specified at open time via 3-arg
935form of open:
936
937 open($fh,'>:crlf :utf8', $path) || ...
938
939or on already opened handles via extended C<binmode>:
940
941 binmode($fh,':encoding(iso-8859-7)');
942
943The built-in layers are: unix (low level read/write), stdio (as in
944previous Perls), perlio (re-implementation of stdio buffering in a
945portable manner), crlf (does CRLF <=> "\n" translation as on Win32,
946but available on any platform). A mmap layer may be available if
947platform supports it (mostly UNIXes).
948
949Layers to be applied by default may be specified via the 'open' pragma.
950
951See L</"Installation and Configuration Improvements"> for the effects
952of PerlIO on your architecture name.
953
954=item *
955
956File handles can be marked as accepting Perl's internal encoding of Unicode
957(UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" :
958
959 open($fh,">:utf8","Uni.txt");
960
961Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named
962for you since it's not UTF-8 what you will be getting but instead
963UTF-EBCDIC. See L<perlunicode>, L<utf8>, and
964http://www.unicode.org/unicode/reports/tr16/ for more information.
965In future releases this naming may change.
966
967=item *
968
969File handles can translate character encodings from/to Perl's internal
970Unicode form on read/write via the ":encoding()" layer.
971
972=item *
973
974File handles can be opened to "in memory" files held in Perl scalars via:
975
976 open($fh,'>', \$variable) || ...
977
978=item *
979
980Anonymous temporary files are available without need to
981'use FileHandle' or other module via
982
983 open($fh,"+>", undef) || ...
984
985That is a literal undef, not an undefined value.
986
987=item *
988
989The list form of C<open> is now implemented for pipes (at least on UNIX):
990
991 open($fh,"-|", 'cat', '/etc/motd')
992
993creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
994the child process.
995
996=item *
997
998The following builtin functions are now overridable: chop(), chomp(),
999each(), keys(), pop(), push(), shift(), splice(), unshift().
1000
1001=item *
1002
1003Formats now support zero-padded decimal fields.
1004
1005=item *
1006
1007Perl now tries internally to use integer values in numeric conversions
1008and basic arithmetics (+ - * /) if the arguments are integers, and
1009tries also to keep the results stored internally as integers.
1010This change leads into often slightly faster and always less lossy
1011arithmetics. (Previously Perl always preferred floating point numbers
1012in its math.)
1013
1014=item *
1015
1016The printf() and sprintf() now support parameter reordering using the
1017C<%\d+\$> and C<*\d+\$> syntaxes. For example
1018
1019 print "%2\$s %1\$s\n", "foo", "bar";
1020
1021will print "bar foo\n"; This feature helps in writing
1022internationalised software.
1023
1024=item *
1025
1026Unicode in general should be now much more usable. Unicode can be
1027used in hash keys, Unicode in regular expressions should work now,
1028Unicode in tr/// should work now (though tr/// seems to be a
1029particularly tricky to get right, so you have been warned)
1030
1031=item *
1032
1033The Unicode Character Database coming with Perl has been upgraded
1034to Unicode 3.1. For more information, see http://www.unicode.org/,
1035and http://www.unicode.org/unicode/reports/tr27/
1036
1037For developers interested in enhancing Perl's Unicode capabilities:
1038almost all the UCD files are included with the Perl distribution in
1039the lib/unicode subdirectory. The most notable omission, for space
1040considerations, is the Unihan database.
1041
1042=item *
1043
1044The Unicode character classes \p{Blank} and \p{SpacePerl} have been
1045added. "Blank" is like C isblank(), that is, it contains only
1046"horizontal whitespace" (the space character is, the newline isn't),
1047and the "SpacePerl" is the Unicode equivalent of C<\s> (\p{Space}
1048isn't, since that includes the vertical tabulator character, whereas
1049C<\s> doesn't.)
1050
1051=back
1052
1053=head2 Signals Are Now Safe
1054
1055Perl used to be fragile in that signals arriving at inopportune moments
1056could corrupt Perl's internal state.
1057
1058=head1 Modules and Pragmata
1059
1060=head2 New Modules
1061
1062=over 4
1063
1064=item *
1065
1066B::Concise, by Stephen McCamant, is a new compiler backend for
1067walking the Perl syntax tree, printing concise info about ops.
1068The output is highly customisable.
1069
1070See L<B::Concise> for more information.
1071
1072=item *
1073
1074Class::ISA, by Sean Burke, for reporting the search path for a
1075class's ISA tree, has been added.
1076
1077See L<Class::ISA> for more information.
1078
1079=item *
1080
1081Cwd has now a split personality: if possible, an extension is used,
1082(this will hopefully be both faster and more secure and robust) but
1083if not possible, the familiar Perl library implementation is used.
1084
1085=item *
1086
1087Digest, a frontend module for calculating digests (checksums),
1088from Gisle Aas, has been added.
1089
1090See L<Digest> for more information.
1091
1092=item *
1093
1094Digest::MD5 for calculating MD5 digests (checksums), by Gisle Aas,
1095has been added.
1096
1097 use Digest::MD5 'md5_hex';
1098
1099 $digest = md5_hex("Thirsty Camel");
1100
1101 print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
1102
1103NOTE: the MD5 backward compatibility module is deliberately not
1104included since its use is discouraged.
1105
1106See L<Digest::MD5> for more information.
1107
1108=item *
1109
1110Encode, by Nick Ing-Simmons, provides a mechanism to translate
1111between different character encodings. Support for Unicode,
1112ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
1113compiled in to the module. Several other encodings (like Japanese,
1114Chinese, and MacIntosh encodings) are included and will be loaded at
1115runtime.
1116
1117Any encoding supported by Encode module is also available to the
1118":encoding()" layer if PerlIO is used.
1119
1120See L<Encode> for more information.
1121
1122=item *
1123
1124Filter::Simple is an easy-to-use frontend to Filter::Util::Call,
1125from Damian Conway.
1126
1127 # in MyFilter.pm:
1128
1129 package MyFilter;
1130
1131 use Filter::Simple sub {
1132 while (my ($from, $to) = splice @_, 0, 2) {
1133 s/$from/$to/g;
1134 }
1135 };
1136
1137 1;
1138
1139 # in user's code:
1140
1141 use MyFilter qr/red/ => 'green';
1142
1143 print "red\n"; # this code is filtered, will print "green\n"
1144 print "bored\n"; # this code is filtered, will print "bogreen\n"
1145
1146 no MyFilter;
1147
1148 print "red\n"; # this code is not filtered, will print "red\n"
1149
1150See L<Filter::Simple> for more information.
1151
1152=item *
1153
1154Filter::Util::Call, by Paul Marquess, provides you with the
1155framework to write I<Source Filters> in Perl. For most uses
1156the frontend Filter::Simple is to be preferred.
1157See L<Filter::Util::Call> for more information.
1158
1159=item *
1160
1161Locale::Constants, Locale::Country, Locale::Currency, and Locale::Language,
1162from Neil Bowers, have been added. They provide the codes for various
1163locale standards, such as "fr" for France, "usd" for US Dollar, and
1164"jp" for Japanese.
1165
1166 use Locale::Country;
1167
1168 $country = code2country('jp'); # $country gets 'Japan'
1169 $code = country2code('Norway'); # $code gets 'no'
1170
1171See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>,
1172and L<Locale::Language> for more information.
1173
1174=item *
1175
1176MIME::Base64, by Gisle Aas, allows you to encode data in base64.
1177
1178 use MIME::Base64;
1179
1180 $encoded = encode_base64('Aladdin:open sesame');
1181 $decoded = decode_base64($encoded);
1182
1183 print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
1184
1185See L<MIME::Base64> for more information.
1186
1187=item *
1188
1189MIME::QuotedPrint, by Gisle Aas, allows you to encode data in
1190quoted-printable encoding.
1191
1192 use MIME::QuotedPrint;
1193
1194 $encoded = encode_qp("Smiley in Unicode: \x{263a}");
1195 $decoded = decode_qp($encoded);
1196
1197 print $encoded, "\n"; # "Smiley in Unicode: =263A"
1198
1199MIME::QuotedPrint has been enhanced to provide the basic methods
1200necessary to use it with PerlIO::Via as in :
1201
1202 use MIME::QuotedPrint;
1203 open($fh,">Via(MIME::QuotedPrint)",$path)
1204
1205See L<MIME::QuotedPrint> for more information.
1206
1207=item *
1208
1209PerlIO::Scalar, by Nick Ing-Simmons, provides the implementation of
1210IO to "in memory" Perl scalars as discussed above. It also serves as
1211an example of a loadable layer. Other future possibilities include
1212PerlIO::Array and PerlIO::Code. See L<PerlIO::Scalar> for more
1213information.
1214
1215=item *
1216
1217PerlIO::Via, by Nick Ing-Simmons, acts as a PerlIO layer and wraps
1218PerlIO layer functionality provided by a class (typically implemented
1219in perl code).
1220
1221 use MIME::QuotedPrint;
1222 open($fh,">Via(MIME::QuotedPrint)",$path)
1223
1224This will automatically convert everything output to C<$fh>
1225to Quoted-Printable. See L<PerlIO::Via> for more information.
1226
1227=item *
1228
1229Pod::Text::Overstrike, by Joe Smith, has been added.
1230It converts POD data to formatted overstrike text.
1231See L<Pod::Text::Overstrike> for more information.
1232
1233=item *
1234
1235Switch from Damian Conway has been added. Just by saying
1236
1237 use Switch;
1238
1239you have C<switch> and C<case> available in Perl.
1240
1241 use Switch;
1242
1243 switch ($val) {
1244
1245 case 1 { print "number 1" }
1246 case "a" { print "string a" }
1247 case [1..10,42] { print "number in list" }
1248 case (@array) { print "number in list" }
1249 case /\w+/ { print "pattern" }
1250 case qr/\w+/ { print "pattern" }
1251 case (%hash) { print "entry in hash" }
1252 case (\%hash) { print "entry in hash" }
1253 case (\&sub) { print "arg to subroutine" }
1254 else { print "previous case not true" }
1255 }
1256
1257See L<Switch> for more information.
1258
1259=item *
1260
1261Text::Balanced from Damian Conway has been added, for
1262extracting delimited text sequences from strings.
1263
1264 use Text::Balanced 'extract_delimited';
1265
1266 ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
1267
1268$a will be "'never say never'", $b will be ', he never said'.
1269
1270In addition to extract_delimited() there are also extract_bracketed(),
1271extract_quotelike(), extract_codeblock(), extract_variable(),
1272extract_tagged(), extract_multiple(), gen_delimited_pat(), and
1273gen_extract_tagged(). With these you can implement rather advanced
1274parsing algorithms. See L<Text::Balanced> for more information.
1275
1276=item *
1277
1278Tie::RefHash::Nestable, by Edward Avis, allows storing hash references
1279(unlike the standard Tie::RefHash) The module is contained within
1280Tie::RefHash.
1281
1282=item *
1283
1284XS::Typemap, by Tim Jenness, is a test extension that exercises XS
1285typemaps. Nothing gets installed but for extension writers the code
1286is worth studying.
1287
1288=back
1289
1290=head2 Updated And Improved Modules and Pragmata
1291
1292=over 4
1293
1294=item *
1295
1296B::Deparse should be now more robust. It still far from providing a full
1297round trip for any random piece of Perl code, though, and is under active
1298development: expect more robustness in 5.7.2.
1299
1300=item *
1301
1302Class::Struct can now define the classes in compile time.
1303
1304=item *
1305
1306Math::BigFloat has undergone much fixing, and in addition the fmod()
1307function now supports modulus operations.
1308
1309(The fixed Math::BigFloat module is also available in CPAN for those
1310who can't upgrade their Perl: http://www.cpan.org/authors/id/J/JP/JPEACOCK/)
1311
1312=item *
1313
1314Devel::Peek now has an interface for the Perl memory statistics
1315(this works only if you are using perl's malloc, and if you have
1316compiled with debugging).
1317
1318=item *
1319
1320IO::Socket has now atmark() method, which returns true if the socket
1321is positioned at the out-of-band mark. The method is also exportable
1322as a sockatmark() function.
1323
1324=item *
1325
1326IO::Socket::INET has support for ReusePort option (if your platform
1327supports it). The Reuse option now has an alias, ReuseAddr. For clarity
1328you may want to prefer ReuseAddr.
1329
1330=item *
1331
1332Net::Ping has been enhanced. There is now "external" protocol which
1333uses Net::Ping::External module which runs external ping(1) and parses
1334the output. An alpha version of Net::Ping::External is available in
1335CPAN and in 5.7.2 the Net::Ping::External may be integrated to Perl.
1336
1337=item *
1338
1339The C<open> pragma allows layers other than ":raw" and ":crlf" when
1340using PerlIO.
1341
1342=item *
1343
1344POSIX::sigaction() is now much more flexible and robust.
1345You can now install coderef handlers, 'DEFAULT', and 'IGNORE'
1346handlers, installing new handlers was not atomic.
1347
1348=item *
1349
1350The Test module has been significantly enhanced. Its use is
1351greatly recommended for module writers.
1352
1353=item *
1354
1355The utf8:: name space (as in the pragma) provides various
1356Perl-callable functions to provide low level access to Perl's
1357internal Unicode representation. At the moment only length()
1358has been implemented.
1359
1360=back
1361
1362The following modules have been upgraded from the versions at CPAN:
1363CPAN, CGI, DB_File, File::Temp, Getopt::Long, Pod::Man, Pod::Text,
1364Storable, Text-Tabs+Wrap.
1365
1366=head1 Performance Enhancements
1367
1368=over 4
1369
1370=item *
1371
1372Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm
1373(http://burtleburtle.net/bob/hash/doobs.html). This algorithm is
1374reasonably fast while producing a much better spread of values than
1375the old hashing algorithm (originally by Chris Torek, later tweaked by
1376Ilya Zakharevich). Hash values output from the algorithm on a hash of
1377all 3-char printable ASCII keys comes much closer to passing the
1378DIEHARD random number generation tests. According to perlbench, this
1379change has not affected the overall speed of Perl.
1380
1381=item *
1382
1383unshift() should now be noticeably faster.
1384
1385=back
1386
1387=head1 Utility Changes
1388
1389=over 4
1390
1391=item *
1392
1393h2xs now produces template README.
1394
1395=item *
1396
1397s2p has been completely rewritten in Perl. (It is in fact a full
1398implementation of sed in Perl.)
1399
1400=item *
1401
1402xsubpp now supports OUT keyword.
1403
1404=back
1405
1406=head1 New Documentation
1407
1408=head2 perlclib
1409
1410Internal replacements for standard C library functions.
1411(Interesting only for extension writers and Perl core hackers.)
1412
1413=head2 perliol
1414
1415Internals of PerlIO with layers.
1416
1417=head2 README.aix
1418
1419Documentation on compiling Perl on AIX has been added. AIX has
1420several different C compilers and getting the right patch level
1421is essential. On install README.aix will be installed as L<perlaix>.
1422
1423=head2 README.bs2000
1424
1425Documentation on compiling Perl on the POSIX-BC platform (an EBCDIC
1426mainframe environment) has been added.
1427
1428This was formerly known as README.posix-bc but the name was considered
1429to be too confusing (it has nothing to do with the POSIX module or the
1430POSIX standard). On install README.bs2000 will be installed as L<perlbs2000>.
1431
1432=head2 README.macos
1433
1434In perl 5.7.1 (and in the 5.6.1) the MacPerl sources have been
1435synchronised with the standard Perl sources. To compile MacPerl
1436some additional steps are required, and this file documents those
1437steps. On install README.macos will be installed as L<perlmacos>.
1438
1439=head2 README.mpeix
1440
1441The README.mpeix has been podified, which means that this information
1442about compiling and using Perl on the MPE/iX miniframe platform will
1443be installed as L<perlmpeix>.
1444
1445=head2 README.solaris
1446
1447README.solaris has been created and Solaris wisdom from elsewhere
1448in the Perl documentation has been collected there. On install
1449README.solaris will be installed as L<perlsolaris>.
1450
1451=head2 README.vos
1452
1453The README.vos has been podified, which means that this information
1454about compiling and using Perl on the Stratus VOS miniframe platform
1455will be installed as L<perlvos>.
1456
1457=head2 Porting/repository.pod
1458
1459Documentation on how to use the Perl source repository has been added.
1460
1461=head1 Installation and Configuration Improvements
1462
1463=over 4
1464
1465=item *
1466
1467Because PerlIO is now the default on most platforms, "-perlio" doesn't
1468get appended to the $Config{archname} (also known as $^O) anymore.
1469Instead, if you explicitly choose not to use perlio (Configure command
1470line option -Uuseperlio), you will get "-stdio" appended.
1471
1472=item *
1473
1474Another change related to the architecture name is that "-64all"
1475(-Duse64bitall, or "maximally 64-bit") is appended only if your
1476pointers are 64 bits wide. (To be exact, the use64bitall is ignored.)
1477
1478=item *
1479
1480APPLLIB_EXP, a less-know configuration-time definition, has been
1481documented. It can be used to prepend site-specific directories
1482to Perl's default search path (@INC), see INSTALL for information.
1483
1484=item *
1485
1486Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
1487has been documented in INSTALL.
1488
1489=item *
1490
1491If you are on IRIX or Tru64 platforms, new profiling/debugging options
1492have been added, see L<perlhack> for more information about pixie and
1493Third Degree.
1494
1495=back
1496
1497=head2 New Or Improved Platforms
1498
1499For the list of platforms known to support Perl,
1500see L<perlport/"Supported Platforms">.
1501
1502=over 4
1503
1504=item *
1505
1506AIX dynamic loading should be now better supported.
1507
1508=item *
1509
1510After a long pause, AmigaOS has been verified to be happy with Perl.
1511
1512=item *
1513
1514EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA)
1515have been regained. Many test suite tests still fail and the
1516co-existence of Unicode and EBCDIC isn't quite settled, but the
1517situation is much better than with Perl 5.6. See L<perlos390>,
1518L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information.
1519
1520=item *
1521
1522Building perl with -Duseithreads or -Duse5005threads now works under
1523HP-UX 10.20 (previously it only worked under 10.30 or later). You will
1524need a thread library package installed. See README.hpux.
1525
1526=item *
1527
1528MacOS Classic (MacPerl has of course been available since
1529perl 5.004 but now the source code bases of standard Perl
1530and MacPerl have been synchronised)
1531
1532=item *
1533
1534NCR MP-RAS is now supported.
1535
1536=item *
1537
1538NonStop-UX is now supported.
1539
1540=item *
1541
1542Amdahl UTS is now supported.
1543
1544=item *
1545
1546z/OS (formerly known as OS/390, formerly known as MVS OE) has now
1547support for dynamic loading. This is not selected by default,
1548however, you must specify -Dusedl in the arguments of Configure.
1549
1550=back
1551
1552=head2 Generic Improvements
1553
1554=over 4
1555
1556=item *
1557
1558Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
1559when building the Perl binary. The only exception to this is SunOS 4.x,
1560which needs them.
1561
1562=item *
1563
1564Some new Configure symbols, useful for extension writers:
1565
1566=over 8
1567
1568=item d_cmsghdr
1569
1570For struct cmsghdr.
1571
1572=item d_fcntl_can_lock
1573
1574Whether fcntl() can be used for file locking.
1575
1576=item d_fsync
1577
1578=item d_getitimer
1579
1580=item d_getpagsz
1581
1582For getpagesize(), though you should prefer POSIX::sysconf(_SC_PAGE_SIZE))
1583
1584=item d_msghdr_s
1585
1586For struct msghdr.
1587
1588=item need_va_copy
1589
1590Whether one needs to use Perl_va_copy() to copy varargs.
1591
1592=item d_readv
1593
1594=item d_recvmsg
1595
1596=item d_sendmsg
1597
1598=item sig_size
1599
1600The number of elements in an array needed to hold all the available signals.
1601
1602=item d_sockatmark
1603
1604=item d_strtoq
1605
1606=item d_u32align
1607
1608Whether one needs to access character data aligned by U32 sized pointers.
1609
1610=item d_ualarm
1611
1612=item d_usleep
1613
1614=back
1615
1616=item *
1617
1618Removed Configure symbols: the PDP-11 memory model settings: huge,
1619large, medium, models.
1620
1621=item *
1622
1623SOCKS support is now much more robust.
1624
1625=item *
1626
1627If your file system supports symbolic links you can build Perl outside
1628of the source directory by
1629
1630 mkdir /tmp/perl/build/directory
1631 cd /tmp/perl/build/directory
1632 sh /path/to/perl/source/Configure -Dmksymlinks ...
1633
1634This will create in /tmp/perl/build/directory a tree of symbolic links
1635pointing to files in /path/to/perl/source. The original files are left
1636unaffected. After Configure has finished you can just say
1637
1638 make all test
1639
1640and Perl will be built and tested, all in /tmp/perl/build/directory.
1641
1642=back
1643
1644=head1 Selected Bug Fixes
1645
1646Numerous memory leaks and uninitialized memory accesses have been hunted down.
1647Most importantly anonymous subs used to leak quite a bit.
1648
1649=over 4
1650
1651=item *
1652
1653chop(@list) in list context returned the characters chopped in
1654reverse order. This has been reversed to be in the right order.
1655
1656=item *
1657
1658The order of DESTROYs has been made more predictable.
1659
1660=item *
1661
1662mkdir() now ignores trailing slashes in the directory name,
1663as mandated by POSIX.
1664
1665=item *
1666
1667Attributes (like :shared) didn't work with our().
1668
1669=item *
1670
1671The PERL5OPT environment variable (for passing command line arguments
1672to Perl) didn't work for more than a single group of options.
1673
1674=item *
1675
1676The tainting behaviour of sprintf() has been rationalized. It does
1677not taint the result of floating point formats anymore, making the
1678behaviour consistent with that of string interpolation.
1679
1680=item *
1681
1682All but the first argument of the IO syswrite() method are now optional.
1683
1684=item *
1685
1686Tie::ARRAY SPLICE method was broken.
1687
1688=item *
1689
1690vec() now tries to work with characters <= 255 when possible, but it leaves
1691higher character values in place. In that case, if vec() was used to modify
1692the string, it is no longer considered to be utf8-encoded.
1693
1694=back
1695
1696=head2 Platform Specific Changes and Fixes
1697
1698=over 4
1699
1700=item *
1701
1702Linux previously had problems related to sockaddrlen when using
1703accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
1704
1705=item *
1706
1707Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
1708
1709=item *
1710
1711Windows
1712
1713=over 8
1714
1715=item *
1716
1717Borland C++ v5.5 is now a supported compiler that can build Perl.
1718However, the generated binaries continue to be incompatible with those
1719generated by the other supported compilers (GCC and Visual C++).
1720
1721=item *
1722
1723Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
1724Other bugs in chdir() and Cwd::cwd() have also been fixed.
1725
1726=item *
1727
1728Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
1729
1730=item *
1731
1732HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
1733
1734=item *
1735
1736The makefiles now provide a single switch to bulk-enable all the features
1737enabled in ActiveState ActivePerl (a popular binary distribution).
1738
1739=back
1740
1741=back
1742
1743=head1 New or Changed Diagnostics
1744
1745Two new debugging options have been added: if you have compiled your
1746Perl with debugging, you can use the -DT and -DR options to trace
1747tokenising and to add reference counts to displaying variables,
1748respectively.
1749
1750=over 4
1751
1752=item *
1753
1754If an attempt to use a (non-blessed) reference as an array index
1755is made, a warning is given.
1756
1757=item *
1758
1759C<push @a;> and C<unshift @a;> (with no values to push or unshift)
1760now give a warning. This may be a problem for generated and evaled
1761code.
1762
1763=back
1764
1765=head1 Changed Internals
1766
1767=over 4
1768
1769=item *
1770
1771Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv().
1772For the full list of the available APIs see L<perlapi>.
1773
1774=item *
1775
1776dTHR and djSP have been obsoleted; the former removed (because it's
1777a no-op) and the latter replaced with dSP.
1778
1779=item *
1780
1781Perl now uses system malloc instead of Perl malloc on all 64-bit
1782platforms, and even in some not-always-64-bit platforms like AIX,
1783IRIX, and Solaris. This change breaks backward compatibility but
1784Perl's malloc has problems with large address spaces and also the
1785speed of vendors' malloc is generally better in large address space
1786machines (Perl's malloc is mostly tuned for space).
1787
1788=back
1789
1790=head1 New Tests
1791
1792Many new tests have been added. The most notable is probably the
1793lib/1_compile: it is very notable because running it takes quite a
1794long time -- it test compiles all the Perl modules in the distribution.
1795Please be patient.
1796
1797=head1 Known Problems
1798
1799Note that unlike other sections in this document (which describe
1800changes since 5.7.0) this section is cumulative containing known
1801problems for all the 5.7 releases.
1802
1803=head2 AIX vac 5.0.0.0 May Produce Buggy Code For Perl
1804
1805The AIX C compiler vac version 5.0.0.0 may produce buggy code,
1806resulting in few random tests failing, but when the failing tests
1807are run by hand, they succeed. We suggest upgrading to at least
1808vac version 5.0.1.0, that has been known to compile Perl correctly.
1809"lslpp -L|grep vac.C" will tell you the vac version.
1810
1811=head2 lib/ftmp-security tests warn 'system possibly insecure'
1812
1813Don't panic. Read INSTALL 'make test' section instead.
1814
1815=head2 lib/io_multihomed Fails In LP64-Configured HP-UX
1816
1817The lib/io_multihomed test may hang in HP-UX if Perl has been
1818configured to be 64-bit. Because other 64-bit platforms do not hang in
1819this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The
1820test attempts to create and connect to "multihomed" sockets (sockets
1821which have multiple IP addresses).
1822
1823=head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX
1824
1825If perl is configured with -Duse64bitall, the successful result of the
1826subtest 10 of lib/posix may arrive before the successful result of the
1827subtest 9, which confuses the test harness so much that it thinks the
1828subtest 9 failed.
1829
1830=head2 lib/b test 19
1831
1832The test fails on various platforms (PA64 and IA64 are known), but the
1833exact cause is still being investigated.
1834
1835=head2 Linux With Sfio Fails op/misc Test 48
1836
1837No known fix.
1838
1839=head2 sigaction test 13 in VMS
1840
1841The test is known to fail; whether it's because of VMS of because
1842of faulty test is not known.
1843
1844=head2 sprintf tests 129 and 130
1845
1846The op/sprintf tests 129 and 130 are known to fail on some platforms.
1847Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
1848The failing platforms do not comply with the ANSI C Standard, line
184919ff on page 134 of ANSI X3.159 1989 to be exact. (They produce
1850something else than "1" and "-1" when formatting 0.6 and -0.6 using
1851the printf format "%.0f", most often they produce "0" and "-0".)
1852
1853=head2 Failure of Thread tests
1854
1855The subtests 19 and 20 of lib/thr5005.t test are known to fail due to
1856fundamental problems in the 5.005 threading implementation. These are
1857not new failures--Perl 5.005_0x has the same bugs, but didn't have
1858these tests. (Note that support for 5.005-style threading remains
1859experimental.)
1860
1861=head2 Localising a Tied Variable Leaks Memory
1862
1863 use Tie::Hash;
1864 tie my %tie_hash => 'Tie::StdHash';
1865
1866 ...
1867
1868 local($tie_hash{Foo}) = 1; # leaks
1869
1870Code like the above is known to leak memory every time the local()
1871is executed.
1872
1873=head2 Self-tying of Arrays and Hashes Is Forbidden
1874
1875Self-tying of arrays and hashes is broken in rather deep and
1876hard-to-fix ways. As a stop-gap measure to avoid people from getting
1877frustrated at the mysterious results (core dumps, most often) it is
1878for now forbidden (you will get a fatal error even from an attempt).
1879
1880=head2 Building Extensions Can Fail Because Of Largefiles
1881
1882Some extensions like mod_perl are known to have issues with
1883`largefiles', a change brought by Perl 5.6.0 in which file offsets
1884default to 64 bits wide, where supported. Modules may fail to compile
1885at all or compile and work incorrectly. Currently there is no good
1886solution for the problem, but Configure now provides appropriate
1887non-largefile ccflags, ldflags, libswanted, and libs in the %Config
1888hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
1889having problems can try configuring themselves without the
1890largefileness. This is admittedly not a clean solution, and the
1891solution may not even work at all. One potential failure is whether
1892one can (or, if one can, whether it's a good idea) link together at
1893all binaries with different ideas about file offsets, all this is
1894platform-dependent.
1895
1896=head2 The Compiler Suite Is Still Experimental
1897
1898The compiler suite is slowly getting better but is nowhere near
1899working order yet.
1900
1901=head1 Security Vulnerability Closed
1902
1903(This change was already made in 5.7.0 but bears repeating here.)
1904
1905A security vulnerability affecting all Perl versions prior to 5.6.1
1906was found in August 2000. The vulnerability does not affect default
1907installations and as far as is known affects only the Linux platform.
1908
1909You should upgrade your Perl to 5.6.1 as soon as possible. Patches
1910for earlier releases exist but using the patches require full
1911recompilation from the source code anyway, so 5.6.1 is your best
1912choice.
1913
1914See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
1915for more information.
1916
1917=head1 Incompatible Changes
1918
1919=head2 64-bit platforms and malloc
1920
1921If your pointers are 64 bits wide, the Perl malloc is no more being
1922used because it simply does not work with 8-byte pointers. Also,
1923usually the system malloc on such platforms are much better optimized
1924for such large memory models than the Perl malloc.
1925
1926=head2 AIX Dynaloading
1927
1928The AIX dynaloading now uses in AIX releases 4.3 and newer the native
1929dlopen interface of AIX instead of the old emulated interface. This
1930change will probably break backward compatibility with compiled
1931modules. The change was made to make Perl more compliant with other
1932applications like modperl which are using the AIX native interface.
1933
1934=head2 Socket Extension Dynamic in VMS
1935
1936The Socket extension is now dynamically loaded instead of being
1937statically built in. This may or may not be a problem with ancient
1938TCP/IP stacks of VMS: we do not know since we weren't able to test
1939Perl in such configurations.
1940
1941=head2 Different Definition of the Unicode Character Classes \p{In...}
1942
1943As suggested by the Unicode consortium, the Unicode character classes
1944now prefer I<scripts> as opposed to I<blocks> (as defined by Unicode);
1945in Perl, when the C<\p{In....}> and the C<\p{In....}> regular expression
1946constructs are used. This has changed the definition of some of those
1947character classes.
1948
1949The difference between scripts and blocks is that scripts are the
1950glyphs used by a language or a group of languages, while the blocks
1951are more artificial groupings of 256 characters based on the Unicode
1952numbering.
1953
1954In general this change results in more inclusive Unicode character
1955classes, but changes to the other direction also do take place:
1956for example while the script C<Latin> includes all the Latin
1957characters and their various diacritic-adorned versions, it
1958does not include the various punctuation or digits (since they
1959are not solely C<Latin>).
1960
1961Changes in the character class semantics may have happened if a script
1962and a block happen to have the same name, for example C<Hebrew>.
1963In such cases the script wins and C<\p{InHebrew}> now means the script
1964definition of Hebrew. The block definition in still available,
1965though, by appending C<Block> to the name: C<\p{InHebrewBlock}> means
1966what C<\p{InHebrew}> meant in perl 5.6.0. For the full list
1967of affected character classes, see L<perlunicode/Blocks>.
1968
1969=head2 Deprecations
1970
1971The current user-visible implementation of pseudo-hashes (the weird
1972use of the first array element) is deprecated starting from Perl 5.8.0
1973and will be removed in Perl 5.10.0, and the feature will be
1974implemented differently. Not only is the current interface rather
1975ugly, but the current implementation slows down normal array and hash
1976use quite noticeably. The C<fields> pragma interface will remain
1977available.
1978
1979The syntaxes C<@a->[...]> and C<@h->{...}> have now been deprecated.
1980
1981The suidperl is also considered to be too much a risk to continue
1982maintaining and the suidperl code is likely to be removed in a future
1983release.
1984
1985The C<package;> syntax (C<package> without an argument has been
1986deprecated. Its semantics were never that clear and its
1987implementation even less so. If you have used that feature to
1988disallow all but fully qualified variables, C<use strict;> instead.
1989
1990The chdir(undef) and chdir('') behaviors to match chdir() has been
1991deprecated. In future versions, chdir(undef) and chdir('') will
1992simply fail.
1993
1994=head1 Core Enhancements
1995
1996In general a lot of fixing has happened in the area of Perl's
1997understanding of numbers, both integer and floating point. Since in
1998many systems the standard number parsing functions like C<strtoul()>
1999and C<atof()> seem to have bugs, Perl tries to work around their
2000deficiencies. This results hopefully in more accurate numbers.
2001
2002=over 4
2003
2004=item *
2005
2006The rules for allowing underscores (underbars) in numeric constants
2007have been relaxed and simplified: now you can have an underscore
2008B<between digits>.
2009
2010=item *
2011
2012GMAGIC (right-hand side magic) could in many cases such as string
2013concatenation be invoked too many times.
2014
2015=item *
2016
2017Lexicals I: lexicals outside an eval "" weren't resolved
2018correctly inside a subroutine definition inside the eval "" if they
2019were not already referenced in the top level of the eval""ed code.
2020
2021=item *
2022
2023Lexicals II: lexicals leaked at file scope into subroutines that
2024were declared before the lexicals.
2025
2026=item *
2027
2028Lvalue subroutines can now return C<undef> in list context.
2029
2030=item *
2031
2032The C<op_clear> and C<op_null> are now exported.
2033
2034=item *
2035
2036A new special regular expression variable has been introduced:
2037C<$^N>, which contains the most-recently closed group (submatch).
2038
2039=item *
2040
2041L<utime> now supports C<utime undef, undef, @files> to change the
2042file timestamps to the current time.
2043
2044=item *
2045
2046The Perl parser has been stress tested using both random input and
2047Markov chain input.
2048
2049=item *
2050
2051C<eval "v200"> now works.
2052
2053=item *
2054
2055VMS now works under PerlIO.
2056
2057=item *
2058
2059END blocks are now run even if you exit/die in a BEGIN block.
2060The execution of END blocks is now controlled by
2061PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new
2062behaviour for perl embedders. This will default in 5.10. See
2063L<perlembed>.
2064
2065=back
2066
2067=head1 Modules and Pragmata
2068
2069=head2 New Modules and Distributions
2070
2071=over 4
2072
2073=item *
2074
2075L<Attribute::Handlers> - Simpler definition of attribute handlers
2076
2077=item *
2078
2079L<ExtUtils::Constant> - generate XS code to import C header constants
2080
2081=item *
2082
2083L<I18N::Langinfo> - query locale information
2084
2085=item *
2086
2087L<I18N::LangTags> - functions for dealing with RFC3066-style language tags
2088
2089=item *
2090
2091L<libnet> - a collection of perl5 modules related to network programming
2092
2093Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure.
2094
2095=item *
2096
2097L<List::Util> - selection of general-utility list subroutines
2098
2099=item *
2100
2101L<Locale::Maketext> - framework for localization
2102
2103=item *
2104
2105L<Memoize> - Make your functions faster by trading space for time
2106
2107=item *
2108
2109L<NEXT> - pseudo-class for method redispatch
2110
2111=item *
2112
2113L<Scalar::Util> - selection of general-utility scalar subroutines
2114
2115=item *
2116
2117L<Test::More> - yet another framework for writing test scripts
2118
2119=item *
2120
2121L<Test::Simple> - Basic utilities for writing tests
2122
2123=item *
2124
2125L<Time::HiRes> - high resolution ualarm, usleep, and gettimeofday
2126
2127=item *
2128
2129L<Time::Piece> - Object Oriented time objects
2130
2131(Previously known as L<Time::Object>.)
2132
2133=item *
2134
2135L<Time::Seconds> - a simple API to convert seconds to other date values
2136
2137=item *
2138
2139L<UnicodeCD> - Unicode Character Database
2140
2141=back
2142
2143=head2 Updated And Improved Modules and Pragmata
2144
2145=over 4
2146
2147=item *
2148
2149L<B::Deparse> module has been significantly enhanced. It now
2150can deparse almost all of the standard test suite (so that the
2151tests still succeed). There is a make target "test.deparse"
2152for trying this out.
2153
2154=item *
2155
2156L<Class::Struct> now assigns the array/hash element if the accessor
2157is called with an array/hash element as the B<sole> argument.
2158
2159=item *
2160
2161L<Cwd> extension is now (even) faster.
2162
2163=item *
2164
2165L<DB_File> extension has been updated to version 1.77.
2166
2167=item *
2168
2169L<Fcntl>, L<Socket>, and L<Sys::Syslog> have been rewritten to use the
2170new-style constant dispatch section (see L<ExtUtils::Constant>).
2171
2172=item *
2173
2174L<File::Find> is now (again) reentrant. It also has been made
2175more portable.
2176
2177=item *
2178
2179L<File::Glob> now supports C<GLOB_LIMIT> constant to limit the
2180size of the returned list of filenames.
2181
2182=item *
2183
2184L<IO::Socket::INET> now supports C<LocalPort> of zero (usually meaning
2185that the operating system will make one up.)
2186
2187=item *
2188
2189The L<vars> pragma now supports declaring fully qualified variables.
2190(Something that C<our()> does not and will not support.)
2191
2192=back
2193
2194=head1 Utility Changes
2195
2196=over 4
2197
2198=item *
2199
2200The F<emacs/e2ctags.pl> is now much faster.
2201
2202=item *
2203
2204L<h2ph> now supports C trigraphs.
2205
2206=item *
2207
2208L<h2xs> uses the new L<ExtUtils::Constant> module which will affect
2209newly created extensions that define constants. Since the new code is
2210more correct (if you have two constants where the first one is a
2211prefix of the second one, the first constant B<never> gets defined),
2212less lossy (it uses integers for integer constant, as opposed to the
2213old code that used floating point numbers even for integer constants),
2214and slightly faster, you might want to consider regenerating your
2215extension code (the new scheme makes regenerating easy).
2216L<h2xs> now also supports C trigraphs.
2217
2218=item *
2219
2220L<libnetcfg> has been added to configure the libnet.
2221
2222=item *
2223
2224The F<Pod::Html> (and thusly L<pod2html>) now allows specifying
2225a cache directory.
2226
2227=back
2228
2229=head1 New Documentation
2230
2231=over 4
2232
2233=item *
2234
2235L<Locale::Maketext::TPJ13> is an article about software localization,
2236originally published in The Perl Journal #13, republished here with
2237kind permission.
2238
2239=item *
2240
2241More README.$PLATFORM files have been converted into pod, which also
2242means that they also be installed as perl$PLATFORM documentation
2243files. The new files are L<perlapollo>, L<perlbeos>, L<perldgux>,
2244L<perlhurd>, L<perlmint>, L<perlnetware>, L<perlplan9>, L<perlqnx>,
2245and L<perltru64>.
2246
2247=item *
2248
2249The F<Todo> and F<Todo-5.6> files have been merged into L<perltodo>.
2250
2251=item *
2252
2253Use of the F<gprof> tool to profile Perl has been documented in
2254L<perlhack>. There is a make target "perl.gprof" for generating a
2255gprofiled Perl executable.
2256
2257=back
2258
2259=head1 Installation and Configuration Improvements
2260
2261=head2 New Or Improved Platforms
2262
2263=over 4
2264
2265=item *
2266
2267AIX should now work better with gcc, threads, and 64-bitness. Also the
2268long doubles support in AIX should be better now. See L<perlaix>.
2269
2270=item *
2271
2272AtheOS (http://www.atheos.cx/) is a new platform.
2273
2274=item *
2275
2276DG/UX platform now supports the 5.005-style threads. See L<perldgux>.
2277
2278=item *
2279
2280DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2.
2281
2282=item *
2283
2284Several MacOS (Classic) portability patches have been applied. We
2285hope to get a fully working port by 5.8.0. (The remaining problems
2286relate to the changed IO model of Perl.) See L<perlmacos>.
2287
2288=item *
2289
2290MacOS X (or Darwin) should now be able to build Perl even on HFS+
2291filesystems. (The case-insensitivity confused the Perl build process.)
2292
2293=item *
2294
2295NetWare from Novell is now supported. See L<perlnetware>.
2296
2297=item *
2298
2299The Amdahl UTS UNIX mainframe platform is now supported.
2300
2301=back
2302
2303=head2 Generic Improvements
2304
2305=over 4
2306
2307=item *
2308
2309In AFS installations one can configure the root of the AFS to be
2310somewhere else than the default F</afs> by using the Configure
2311parameter C<-Dafsroot=/some/where/else>.
2312
2313=item *
2314
2315The version of Berkeley DB used when the Perl (and, presumably, the
2316DB_File extension) was built is now available as
2317C<@Config{qw(db_version_major db_version_minor db_version_patch)}>
2318from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG
2319DB_VERSION_PATCH_CFG> from C.
2320
2321=item *
2322
2323The Thread extension is now not built at all under ithreads
2324(C<Configure -Duseithreads>) because it wouldn't work anyway (the
2325Thread extension requires being Configured with C<-Duse5005threads>).
2326
2327=item *
2328
2329The C<B::Deparse> compiler backend has been so significantly improved
2330that almost the whole Perl test suite passes after being deparsed. A
2331make target has been added to help in further testing: C<make test.deparse>.
2332
2333=back
2334
2335=head1 Selected Bug Fixes
2336
2337=over 5
2338
2339=item *
2340
2341The autouse pragma didn't work for Multi::Part::Function::Names.
2342
2343=item *
2344
2345The behaviour of non-decimal but numeric string constants such as
2346"0x23" was platform-dependent: in some platforms that was seen as 35,
2347in some as 0, in some as a floating point number (don't ask). This
2348was caused by Perl using the operating system libraries in a situation
2349where the result of the string to number conversion is undefined: now
2350Perl consistently handles such strings as zero in numeric contexts.
2351
2352=item *
2353
2354L<dprofpp> -R didn't work.
2355
2356=item *
2357
2358PERL5OPT with embedded spaces didn't work.
2359
2360=item *
2361
2362L<Sys::Syslog> ignored the C<LOG_AUTH> constant.
2363
2364=back
2365
2366=head2 Platform Specific Changes and Fixes
2367
2368=over 4
2369
2370=item *
2371
2372Some versions of glibc have a broken modfl(). This affects builds
2373with C<-Duselongdouble>. This version of Perl detects this brokenness
2374and has a workaround for it. The glibc release 2.2.2 is known to have
2375fixed the modfl() bug.
2376
2377=back
2378
2379=head1 New or Changed Diagnostics
2380
2381=over 4
2382
2383=item *
2384
2385In the regular expression diagnostics the C<E<lt>E<lt> HERE> marker
2386introduced in 5.7.0 has been changed to be C<E<lt>-- HERE> since too
2387many people found the C<E<lt>E<lt>> to be too similar to here-document
2388starters.
2389
2390=item *
2391
2392If you try to L<perlfunc/pack> a number less than 0 or larger than 255
2393using the C<"C"> format you will get an optional warning. Similarly
2394for the C<"c"> format and a number less than -128 or more than 127.
2395
2396=item *
2397
2398Certain regex modifiers such as C<(?o)> make sense only if applied to
2399the entire regex. You will an optional warning if you try to do otherwise.
2400
2401=item *
2402
2403Using arrays or hashes as references (e.g. C<%foo->{bar}> has been
2404deprecated for a while. Now you will get an optional warning.
2405
2406=back
2407
2408=head1 Source Code Enhancements
2409
2410=head2 MAGIC constants
2411
2412The MAGIC constants (e.g. C<'P'>) have been macrofied
2413(e.g. C<PERL_MAGIC_TIED>) for better source code readability
2414and maintainability.
2415
2416=head2 Better commented code
2417
2418F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
2419
2420=head2 Regex pre-/post-compilation items matched up
2421
2422The regex compiler now maintains a structure that identifies nodes in
2423the compiled bytecode with the corresponding syntactic features of the
2424original regex expression. The information is attached to the new
2425C<offsets> member of the C<struct regexp>. See L<perldebguts> for more
2426complete information.
2427
2428=head2 gcc -Wall
2429
2430The C code has been made much more C<gcc -Wall> clean. Some warning
2431messages still remain, though, so if you are compiling with gcc you
2432will see some warnings about dubious practices. The warnings are
2433being worked on.
2434
2435=head1 New Tests
2436
2437Several new tests have been added, especially for the F<lib> subsection.
2438
2439The tests are now reported in a different order than in earlier Perls.
2440(This happens because the test scripts from under t/lib have been moved
2441to be closer to the library/extension they are testing.)
2442
2443=head1 Known Problems
2444
2445Note that unlike other sections in this document (which describe
2446changes since 5.7.0) this section is cumulative containing known
2447problems for all the 5.7 releases.
2448
2449=head2 AIX
2450
2451=over 4
2452
2453=item *
2454
2455In AIX 4.2 Perl extensions that use C++ functions that use statics
2456may have problems in that the statics are not getting initialized.
2457In newer AIX releases this has been solved by linking Perl with
2458the libC_r library, but unfortunately in AIX 4.2 the said library
2459has an obscure bug where the various functions related to time
2460(such as time() and gettimeofday()) return broken values, and
2461therefore in AIX 4.2 Perl is not linked against the libC_r.
2462
2463=item *
2464
2465vac 5.0.0.0 May Produce Buggy Code For Perl
2466
2467The AIX C compiler vac version 5.0.0.0 may produce buggy code,
2468resulting in few random tests failing, but when the failing tests
2469are run by hand, they succeed. We suggest upgrading to at least
2470vac version 5.0.1.0, that has been known to compile Perl correctly.
2471"lslpp -L|grep vac.C" will tell you the vac version.
2472
2473=back
2474
2475=head2 Amiga Perl Invoking Mystery
2476
2477One cannot call Perl using the C<volume:> syntax, that is, C<perl -v>
2478works, but for example C<bin:perl -v> doesn't. The exact reason is
2479known but the current suspect is the F<ixemul> library.
2480
2481=head2 lib/ftmp-security tests warn 'system possibly insecure'
2482
2483Don't panic. Read INSTALL 'make test' section instead.
2484
2485=head2 Cygwin intermittent failures of lib/Memoize/t/expire_file 11 and 12
2486
2487The subtests 11 and 12 sometimes fail and sometimes work.
2488
2489=head2 HP-UX lib/io_multihomed Fails When LP64-Configured
2490
2491The lib/io_multihomed test may hang in HP-UX if Perl has been
2492configured to be 64-bit. Because other 64-bit platforms do not hang in
2493this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The
2494test attempts to create and connect to "multihomed" sockets (sockets
2495which have multiple IP addresses).
2496
2497=head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
2498
2499If perl is configured with -Duse64bitall, the successful result of the
2500subtest 10 of lib/posix may arrive before the successful result of the
2501subtest 9, which confuses the test harness so much that it thinks the
2502subtest 9 failed.
2503
2504=head2 Linux With Sfio Fails op/misc Test 48
2505
2506No known fix.
2507
2508=head2 OS/390
2509
2510OS/390 has rather many test failures but the situation is actually
2511better than it was in 5.6.0, it's just that so many new modules and
2512tests have been added.
2513
2514 Failed Test Stat Wstat Total Fail Failed List of Failed
2515 -----------------------------------------------------------------------------
2516 ../ext/B/Deparse.t 14 1 7.14% 14
2517 ../ext/B/Showlex.t 1 1 100.00% 1
2518 ../ext/Encode/Encode/Tcl.t 610 13 2.13% 592 594 596 598
2519 600 602 604-610
2520 ../ext/IO/lib/IO/t/io_unix.t 113 28928 5 3 60.00% 3-5
2521 ../ext/POSIX/POSIX.t 29 1 3.45% 14
2522 ../ext/Storable/t/lock.t 255 65280 5 3 60.00% 3-5
2523 ../lib/locale.t 129 33024 117 19 16.24% 99-117
2524 ../lib/warnings.t 434 1 0.23% 75
2525 ../lib/ExtUtils.t 27 1 3.70% 25
2526 ../lib/Math/BigInt/t/bigintpm.t 1190 1 0.08% 1145
2527 ../lib/Unicode/UCD.t 81 48 59.26% 1-16 49-64 66-81
2528 ../lib/User/pwent.t 9 1 11.11% 4
2529 op/pat.t 660 6 0.91% 242-243 424-425
2530 626-627
2531 op/split.t 0 9 ?? ?? % ??
2532 op/taint.t 174 3 1.72% 156 162 168
2533 op/tr.t 70 3 4.29% 50 58-59
2534 Failed 16/422 test scripts, 96.21% okay. 105/23251 subtests failed, 99.55% okay.
2535
2536=head2 op/sprintf tests 129 and 130
2537
2538The op/sprintf tests 129 and 130 are known to fail on some platforms.
2539Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
2540The failing platforms do not comply with the ANSI C Standard, line
254119ff on page 134 of ANSI X3.159 1989 to be exact. (They produce
2542something other than "1" and "-1" when formatting 0.6 and -0.6 using
2543the printf format "%.0f", most often they produce "0" and "-0".)
2544
2545=head2 Failure of Thread tests
2546
2547B<Note that support for 5.005-style threading remains experimental.>
2548
2549The following tests are known to fail due to fundamental problems in
2550the 5.005 threading implementation. These are not new failures--Perl
25515.005_0x has the same bugs, but didn't have these tests.
2552
2553 lib/autouse.t 4
2554 t/lib/thr5005.t 19-20
2555
2556=head2 UNICOS
2557
2558=over 4
2559
2560=item *
2561
2562ext/POSIX/sigaction subtests 6 and 13 may fail.
2563
2564=item *
2565
2566lib/ExtUtils may spuriously claim that subtest 28 failed,
2567which is interesting since the test only has 27 tests.
2568
2569=item *
2570
2571Numerous numerical test failures
2572
2573 op/numconvert 209,210,217,218
2574 op/override 7
2575 ext/Time/HiRes/HiRes 9
2576 lib/Math/BigInt/t/bigintpm 1145
2577 lib/Math/Trig 25
2578
2579These tests fail because of yet unresolved floating point inaccuracies.
2580
2581=back
2582
2583=head2 UTS
2584
2585There are a few known test failures, see L<perluts>.
2586
2587=head2 VMS
2588
2589Rather many tests are failing in VMS but that actually more tests
2590succeed in VMS than they used to, it's just that there are many,
2591many more tests than there used to be.
2592
2593Here are the known failures from some compiler/platform combinations.
2594
2595DEC C V5.3-006 on OpenVMS VAX V6.2
2596
2597 [-.ext.list.util.t]tainted..............FAILED on test 3
2598 [-.ext.posix]sigaction..................FAILED on test 7
2599 [-.ext.time.hires]hires.................FAILED on test 14
2600 [-.lib.file.find]taint..................FAILED on test 17
2601 [-.lib.math.bigint.t]bigintpm...........FAILED on test 1183
2602 [-.lib.test.simple.t]exit...............FAILED on test 1
2603 [.lib]vmsish............................FAILED on test 13
2604 [.op]sprintf............................FAILED on test 12
2605 Failed 8/399 tests, 91.23% okay.
2606
2607DEC C V6.0-001 on OpenVMS Alpha V7.2-1 and
2608Compaq C V6.2-008 on OpenVMS Alpha V7.1
2609
2610 [-.ext.list.util.t]tainted..............FAILED on test 3
2611 [-.lib.file.find]taint..................FAILED on test 17
2612 [-.lib.test.simple.t]exit...............FAILED on test 1
2613 [.lib]vmsish............................FAILED on test 13
2614 Failed 4/399 tests, 92.48% okay.
2615
2616Compaq C V6.4-005 on OpenVMS Alpha 7.2.1
2617
2618 [-.ext.b]showlex........................FAILED on test 1
2619 [-.ext.list.util.t]tainted..............FAILED on test 3
2620 [-.lib.file.find]taint..................FAILED on test 17
2621 [-.lib.test.simple.t]exit...............FAILED on test 1
2622 [.lib]vmsish............................FAILED on test 13
2623 [.op]misc...............................FAILED on test 49
2624 Failed 6/401 tests, 92.77% okay.
2625
2626=head2 Win32
2627
2628In multi-CPU boxes there are some problems with the I/O buffering:
2629some output may appear twice.
2630
2631=head2 Localising a Tied Variable Leaks Memory
2632
2633 use Tie::Hash;
2634 tie my %tie_hash => 'Tie::StdHash';
2635
2636 ...
2637
2638 local($tie_hash{Foo}) = 1; # leaks
2639
2640Code like the above is known to leak memory every time the local()
2641is executed.
2642
2643=head2 Self-tying of Arrays and Hashes Is Forbidden
2644
2645Self-tying of arrays and hashes is broken in rather deep and
2646hard-to-fix ways. As a stop-gap measure to avoid people from getting
2647frustrated at the mysterious results (core dumps, most often) it is
2648for now forbidden (you will get a fatal error even from an attempt).
2649
2650=head2 Variable Attributes are not Currently Usable for Tieing
2651
2652This limitation will hopefully be fixed in future. (Subroutine
2653attributes work fine for tieing, see L<Attribute::Handlers>).
2654
2655=head2 Building Extensions Can Fail Because Of Largefiles
2656
2657Some extensions like mod_perl are known to have issues with
2658`largefiles', a change brought by Perl 5.6.0 in which file offsets
2659default to 64 bits wide, where supported. Modules may fail to compile
2660at all or compile and work incorrectly. Currently there is no good
2661solution for the problem, but Configure now provides appropriate
2662non-largefile ccflags, ldflags, libswanted, and libs in the %Config
2663hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
2664having problems can try configuring themselves without the
2665largefileness. This is admittedly not a clean solution, and the
2666solution may not even work at all. One potential failure is whether
2667one can (or, if one can, whether it's a good idea) link together at
2668all binaries with different ideas about file offsets, all this is
2669platform-dependent.
2670
2671=head2 The Compiler Suite Is Still Experimental
2672
2673The compiler suite is slowly getting better but is nowhere near
2674working order yet.
2675
2676=head2 The Long Double Support is Still Experimental
2677
2678The ability to configure Perl's numbers to use "long doubles",
2679floating point numbers of hopefully better accuracy, is still
2680experimental. The implementations of long doubles are not yet
2681widespread and the existing implementations are not quite mature
2682or standardised, therefore trying to support them is a rare
2683and moving target. The gain of more precision may also be offset
2684by slowdown in computations (more bits to move around, and the
2685operations are more likely to be executed by less optimised
2686libraries).
33a87e58 2687
cc0fca54
GS
2688=head1 Reporting Bugs
2689
d4ad863d
JH
2690If you find what you think is a bug, you might check the articles
2691recently posted to the comp.lang.perl.misc newsgroup and the perl
2692bug database at http://bugs.perl.org. There may also be
2693information at http://www.perl.com/perl/, the Perl Home Page.
cc0fca54
GS
2694
2695If you believe you have an unreported bug, please run the B<perlbug>
2696program included with your release. Be sure to trim your bug down
2697to a tiny but sufficient test case. Your bug report, along with the
d4ad863d 2698output of C<perl -V>, will be sent off to perlbug@perl.org to be
cc0fca54
GS
2699analysed by the Perl porting team.
2700
2701=head1 SEE ALSO
2702
2703The F<Changes> file for exhaustive details on what changed.
2704
2705The F<INSTALL> file for how to build Perl.
2706
2707The F<README> file for general stuff.
2708
2709The F<Artistic> and F<Copying> files for copyright information.
2710
2711=head1 HISTORY
2712
d468ca04 2713Written by Jarkko Hietaniemi <F<jhi@iki.fi>>.
cc0fca54
GS
2714
2715=cut