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ba370e9b 1=head1 NAME
cc0fca54 2
f39f21d8 3perldelta - what is new for perl v5.8.0
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4
5=head1 DESCRIPTION
6
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7This document describes differences between the 5.6.0 release and the
85.8.0 release.
9
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10=head1 Incompatible Changes
11
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12=head2 64-bit platforms and malloc
13
14If your pointers are 64 bits wide, the Perl malloc is no more being
15used because it simply does not work with 8-byte pointers. Also,
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16usually the system mallocs on such platforms are much better optimized
17for such large memory models than the Perl malloc. Such platforms
18include 64-bit Alpha, MIPS, HPPA, PPC, and Sparc.
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19
20=head2 AIX Dynaloading
21
22The AIX dynaloading now uses in AIX releases 4.3 and newer the native
23dlopen interface of AIX instead of the old emulated interface. This
24change will probably break backward compatibility with compiled
25modules. The change was made to make Perl more compliant with other
26applications like modperl which are using the AIX native interface.
27
28=head2 Socket Extension Dynamic in VMS
29
30The Socket extension is now dynamically loaded instead of being
31statically built in. This may or may not be a problem with ancient
32TCP/IP stacks of VMS: we do not know since we weren't able to test
33Perl in such configurations.
34
35=head2 Different Definition of the Unicode Character Classes \p{In...}
36
37As suggested by the Unicode consortium, the Unicode character classes
38now prefer I<scripts> as opposed to I<blocks> (as defined by Unicode);
39in Perl, when the C<\p{In....}> and the C<\p{In....}> regular expression
40constructs are used. This has changed the definition of some of those
41character classes.
42
43The difference between scripts and blocks is that scripts are the
44glyphs used by a language or a group of languages, while the blocks
45are more artificial groupings of 256 characters based on the Unicode
46numbering.
47
48In general this change results in more inclusive Unicode character
49classes, but changes to the other direction also do take place:
50for example while the script C<Latin> includes all the Latin
51characters and their various diacritic-adorned versions, it
52does not include the various punctuation or digits (since they
53are not solely C<Latin>).
54
55Changes in the character class semantics may have happened if a script
56and a block happen to have the same name, for example C<Hebrew>.
57In such cases the script wins and C<\p{InHebrew}> now means the script
58definition of Hebrew. The block definition in still available,
59though, by appending C<Block> to the name: C<\p{InHebrewBlock}> means
60what C<\p{InHebrew}> meant in perl 5.6.0. For the full list
61of affected character classes, see L<perlunicode/Blocks>.
62
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63=head2 Perl Parser Stress Tested
64
65The Perl parser has been stress tested using both random input and
66Markov chain input and the few found crashes and lockups have been
67fixed.
68
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69=head2 Deprecations
70
71The current user-visible implementation of pseudo-hashes (the weird
72use of the first array element) is deprecated starting from Perl 5.8.0
73and will be removed in Perl 5.10.0, and the feature will be
74implemented differently. Not only is the current interface rather
75ugly, but the current implementation slows down normal array and hash
76use quite noticeably. The C<fields> pragma interface will remain
77available.
78
79The syntaxes C<@a->[...]> and C<@h->{...}> have now been deprecated.
80
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81After years of trying the suidperl is considered to be too complex to
82ever be considered truly secure. The suidperl functionality is likely
83to be removed in a future release.
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84
85The C<package;> syntax (C<package> without an argument has been
86deprecated. Its semantics were never that clear and its
87implementation even less so. If you have used that feature to
88disallow all but fully qualified variables, C<use strict;> instead.
89
61947107 90=over 4
77c8cf41 91
61947107 92=item *
f39f21d8 93
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94The semantics of bless(REF, REF) were unclear and until someone proves
95it to make some sense, it is forbidden.
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96
97=item *
98
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99A reference to a reference now stringify as "REF(0x81485ec)" instead
100of "SCALAR(0x81485ec)" in order to be more consistent with the return
101value of ref().
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102
103=item *
104
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105The very dusty examples in the eg/ directory have been removed.
106Suggestions for new shiny examples welcome but the main issue is that
107the examples need to be documented, tested and (most importantly)
108maintained.
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109
110=item *
111
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112The obsolete chat2 library that should never have been allowed
113to escape the laboratory has been decommissioned.
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114
115=item *
116
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117The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still
118recognised but now cause fatal errors. The previous behaviour of
119ignoring them by default and warning if requested was unacceptable
120since it, in a way, falsely promised that the features could be used.
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121
122=item *
123
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124The (bogus) escape sequences \8 and \9 now give an optional warning
125("Unrecognized escape passed through"). There is no need to \-escape
126any C<\w> character.
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127
128=item *
129
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130lstat(FILEHANDLE) now gives a warning because the operation makes no sense.
131In future releases this may become a fatal error.
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132
133=item *
134
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135The long deprecated uppercase aliases for the string comparison
136operators (EQ, NE, LT, LE, GE, GT) have now been removed.
137
138=item *
139
140The regular expression captured submatches ($1, $2, ...) are now
141more consistently unset if the match fails, instead of leaving false
142data lying around in them.
143
144=item *
145
146The tr///C and tr///U features have been removed and will not return;
147the interface was a mistake. Sorry about that. For similar
148functionality, see pack('U0', ...) and pack('C0', ...).
149
150=item *
151
152Although "you shouldn't do that", it was possible to write code that
153depends on Perl's hashed key order (Data::Dumper does this). The new
154algorithm "One-at-a-Time" produces a different hashed key order.
155More details are in L</"Performance Enhancements">.
156
157=item *
158
159The list of filenames from glob() (or <...>) is now by default sorted
160alphabetically to be csh-compliant. (bsd_glob() does still sort platform
161natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.)
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162
163=back
164
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165=head1 Core Enhancements
166
77c8cf41 167=head2 AUTOLOAD Is Now Lvaluable
f39f21d8 168
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169AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
170to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
171
172=head2 PerlIO is Now The Default
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173
174=over 4
175
176=item *
177
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178IO is now by default done via PerlIO rather than system's "stdio".
179PerlIO allows "layers" to be "pushed" onto a file handle to alter the
180handle's behaviour. Layers can be specified at open time via 3-arg
181form of open:
f39f21d8 182
77c8cf41 183 open($fh,'>:crlf :utf8', $path) || ...
f39f21d8 184
77c8cf41 185or on already opened handles via extended C<binmode>:
f39f21d8 186
77c8cf41 187 binmode($fh,':encoding(iso-8859-7)');
f39f21d8 188
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189The built-in layers are: unix (low level read/write), stdio (as in
190previous Perls), perlio (re-implementation of stdio buffering in a
191portable manner), crlf (does CRLF <=> "\n" translation as on Win32,
192but available on any platform). A mmap layer may be available if
193platform supports it (mostly UNIXes).
f39f21d8 194
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195Layers to be applied by default may be specified via the 'open' pragma.
196
197See L</"Installation and Configuration Improvements"> for the effects
198of PerlIO on your architecture name.
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199
200=item *
201
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202File handles can be marked as accepting Perl's internal encoding of Unicode
203(UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" :
f39f21d8 204
77c8cf41 205 open($fh,">:utf8","Uni.txt");
f39f21d8 206
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207Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named
208for you since it's not UTF-8 what you will be getting but instead
209UTF-EBCDIC. See L<perlunicode>, L<utf8>, and
210http://www.unicode.org/unicode/reports/tr16/ for more information.
211In future releases this naming may change.
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212
213=item *
214
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215File handles can translate character encodings from/to Perl's internal
216Unicode form on read/write via the ":encoding()" layer.
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217
218=item *
219
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220File handles can be opened to "in memory" files held in Perl scalars via:
221
222 open($fh,'>', \$variable) || ...
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223
224=item *
225
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226Anonymous temporary files are available without need to
227'use FileHandle' or other module via
f39f21d8 228
77c8cf41 229 open($fh,"+>", undef) || ...
f39f21d8 230
77c8cf41 231That is a literal undef, not an undefined value.
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232
233=item *
234
77c8cf41 235The list form of C<open> is now implemented for pipes (at least on UNIX):
f39f21d8 236
77c8cf41 237 open($fh,"-|", 'cat', '/etc/motd')
f39f21d8 238
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239creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
240the child process.
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241
242=item *
243
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244The following builtin functions are now overridable: chop(), chomp(),
245each(), keys(), pop(), push(), shift(), splice(), unshift().
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246
247=item *
248
77c8cf41 249Formats now support zero-padded decimal fields.
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250
251=item *
252
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253Perl now tries internally to use integer values in numeric conversions
254and basic arithmetics (+ - * /) if the arguments are integers, and
255tries also to keep the results stored internally as integers.
256This change leads into often slightly faster and always less lossy
257arithmetics. (Previously Perl always preferred floating point numbers
258in its math.)
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259
260=item *
261
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262The printf() and sprintf() now support parameter reordering using the
263C<%\d+\$> and C<*\d+\$> syntaxes. For example
f39f21d8 264
77c8cf41 265 print "%2\$s %1\$s\n", "foo", "bar";
f39f21d8 266
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267will print "bar foo\n"; This feature helps in writing
268internationalised software.
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269
270=item *
271
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272Unicode in general should be now much more usable. Unicode can be
273used in hash keys, Unicode in regular expressions should work now,
274Unicode in tr/// should work now (though tr/// seems to be a
275particularly tricky to get right, so you have been warned)
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276
277=item *
278
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279The Unicode Character Database coming with Perl has been upgraded
280to Unicode 3.1. For more information, see http://www.unicode.org/,
281and http://www.unicode.org/unicode/reports/tr27/
f39f21d8 282
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283For developers interested in enhancing Perl's Unicode capabilities:
284almost all the UCD files are included with the Perl distribution in
285the lib/unicode subdirectory. The most notable omission, for space
286considerations, is the Unihan database.
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287
288=item *
289
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290The Unicode character classes \p{Blank} and \p{SpacePerl} have been
291added. "Blank" is like C isblank(), that is, it contains only
292"horizontal whitespace" (the space character is, the newline isn't),
293and the "SpacePerl" is the Unicode equivalent of C<\s> (\p{Space}
294isn't, since that includes the vertical tabulator character, whereas
295C<\s> doesn't.)
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296
297=back
298
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299=head2 Signals Are Now Safe
300
301Perl used to be fragile in that signals arriving at inopportune moments
302could corrupt Perl's internal state.
303
304=head2 Understanding of Numbers
305
306In general a lot of fixing has happened in the area of Perl's
307understanding of numbers, both integer and floating point. Since in
308many systems the standard number parsing functions like C<strtoul()>
309and C<atof()> seem to have bugs, Perl tries to work around their
310deficiencies. This results hopefully in more accurate numbers.
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311
312=over 4
313
314=item *
315
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316C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
317in multiple arguments.)
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318
319=item *
320
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321END blocks are now run even if you exit/die in a BEGIN block.
322Internally, the execution of END blocks is now controlled by
323PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new
324behaviour for Perl embedders. This will default in 5.10. See
325L<perlembed>.
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326
327=item *
328
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329Lexicals I: lexicals outside an eval "" weren't resolved
330correctly inside a subroutine definition inside the eval "" if they
331were not already referenced in the top level of the eval""ed code.
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332
333=item *
334
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335Lexicals II: lexicals leaked at file scope into subroutines that
336were declared before the lexicals.
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337
338=item *
339
77c8cf41 340Lvalue subroutines can now return C<undef> in list context.
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341
342=item *
343
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344A new special regular expression variable has been introduced:
345C<$^N>, which contains the most-recently closed group (submatch).
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346
347=item *
348
61947107 349C<no Module;> now works even if there is no "sub unimport" in the Module.
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350
351=item *
352
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353The numerical comparison operators return C<undef> if either operand
354is a NaN. Previously the behaviour was unspecified.
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355
356=item *
357
61947107 358C<pack('U0a*', ...)> can now be used to force a string to UTF8.
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359
360=item *
361
61947107 362my __PACKAGE__ $obj now works.
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363
364=item *
365
61947107 366prototype(\&) is now available.
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367
368=item *
369
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370Right-hand side magic (GMAGIC) could in many cases such as string
371concatenation be invoked too many times.
372
373=item *
374
375The rules for allowing underscores (underbars) in numeric constants
376have been relaxed and simplified: now you can have an underscore
377simply B<between digits>.
378
379=item *
380
381An UNTIE method is now available.
382
383=item *
384
385L<utime> now supports C<utime undef, undef, @files> to change the
386file timestamps to the current time.
387
388=item *
389
390C<eval "v200"> now works.
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391
392=back
393
77c8cf41 394=head1 Modules and Pragmata
f39f21d8 395
1e13d81f 396=head2 New Modules and Pragmata
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397
398=over 4
399
400=item *
401
61947107 402C<Attribute::Handlers> allows a class to define attribute handlers.
f39f21d8 403
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404 package MyPack;
405 use Attribute::Handlers;
406 sub Wolf :ATTR(SCALAR) { print "howl!\n" }
f39f21d8 407
61947107 408 # later, in some package using or inheriting from MyPack...
f39f21d8 409
61947107 410 my MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called
ba370e9b 411
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412Both variables and routines can have attribute handlers. Handlers can
413be specific to type (SCALAR, ARRAY, HASH, or CODE), or specific to the
414exact compilation phase (BEGIN, CHECK, INIT, or END).
f39f21d8 415
61947107 416=item *
f39f21d8 417
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418B<B::Concise> is a new compiler backend for walking the Perl syntax
419tree, printing concise info about ops, from Stephen McCamant. The
420output is highly customisable. See L<B::Concise>.
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421
422=item *
423
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424C<Class::ISA> for reporting the search path for a class's ISA tree,
425by Sean Burke, has been added. See L<Class::ISA>.
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426
427=item *
428
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429C<Cwd> has now a split personality: if possible, an XS extension is
430used, (this will hopefully be faster, more secure, and more robust)
431but if not possible, the familiar Perl implementation is used.
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432
433=item *
434
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435C<Devel::PPPort>, from Kenneth Albanowski, has been added. It is
436primarily used by C<h2xs> to enhance portability of of XS modules
437between different versions of Perl.
438
439=item *
440
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441C<Digest>, frontend module for calculating digests (checksums), from
442Gisle Aas, has been added. See L<Digest>.
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443
444=item *
445
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446C<Digest::MD5> for calculating MD5 digests (checksums) as defined in
447RFC 1321, from Gisle Aas, has been added. See L<Digest::MD5>.
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448
449 use Digest::MD5 'md5_hex';
450
451 $digest = md5_hex("Thirsty Camel");
452
453 print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
454
61947107 455NOTE: the C<MD5> backward compatibility module is deliberately not
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456included since its use is discouraged.
457
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458=item *
459
61947107 460C<Encode>, by Nick Ing-Simmons, provides a mechanism to translate
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461between different character encodings. Support for Unicode,
462ISO-8859-*, ASCII, CP*, KOI8-R, and three variants of EBCDIC are
463compiled in to the module. Several other encodings (like Japanese,
464Chinese, and MacIntosh encodings) are included and will be loaded at
61947107 465runtime. See L<Encode>.
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466
467Any encoding supported by Encode module is also available to the
468":encoding()" layer if PerlIO is used.
469
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470=item *
471
472C<I18N::Langinfo> can be use to query locale information.
473See L<I18N::Langinfo>.
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474
475=item *
476
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477C<I18N::LangTags> has functions for dealing with RFC3066-style
478language tags, by Sean Burke. See <I18N::LangTags>.
479
480=item *
481
482C<ExtUtils::Constant> is a new tool for extension writers for
483generating XS code to import C header constants, by Nicholas Clark.
484See L<ExtUtils::Constant>.
485
486=item *
487
488C<Filter::Simple> is an easy-to-use frontend to Filter::Util::Call,
489from Damian Conway. See L<Filter::Simple>.
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490
491 # in MyFilter.pm:
492
493 package MyFilter;
494
495 use Filter::Simple sub {
496 while (my ($from, $to) = splice @_, 0, 2) {
497 s/$from/$to/g;
498 }
499 };
500
501 1;
502
503 # in user's code:
504
505 use MyFilter qr/red/ => 'green';
506
507 print "red\n"; # this code is filtered, will print "green\n"
508 print "bored\n"; # this code is filtered, will print "bogreen\n"
509
510 no MyFilter;
511
512 print "red\n"; # this code is not filtered, will print "red\n"
513
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514=item *
515
516C<File::Temp> allows one to create temporary files and directories in
517an easy, portable, and secure way, by Tim Jenness. See L<File::Temp>.
518
519=item *
520
521C<Filter::Util::Call> provides you with the framework to write
522I<Source Filters> in Perl, from Paul Marquess. For most uses the
523frontend Filter::Simple is to be preferred. See L<Filter::Util::Call>.
524
525=item *
526
527L<libnet> is a collection of perl5 modules related to network
528programming, from Graham Barr. See L<Net::FTP>, L<Net::NNTP>,
529L<Net::Ping>, L<Net::POP3>, L<Net::SMTP>, and L<Net::Time>.
530
531Perl installation leaves libnet unconfigured, use F<libnetcfg> to configure.
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532
533=item *
534
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535C<List::Util> is a selection of general-utility list subroutines, like
536sum(), min(), first(), and shuffle(), by Graham barr. See L<List::Util>.
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537
538=item *
539
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540C<Locale::Constants>, C<Locale::Country>, C<Locale::Currency>, and
541C<Locale::Language>, from Neil Bowers, have been added. They provide the
542codes for various locale standards, such as "fr" for France, "usd" for
543US Dollar, and "jp" for Japanese.
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544
545 use Locale::Country;
546
547 $country = code2country('jp'); # $country gets 'Japan'
548 $code = country2code('Norway'); # $code gets 'no'
549
550See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>,
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551and L<Locale::Language>.
552
553=item *
554
555C<Locale::Maketext> is localization framework from Sean Burke. See
556L<Locale::Maketext>, and L<Locale::Maketext::TPJ13>. The latter is an
557article about software localization, originally published in The Perl
558Journal #13, republished here with kind permission.
559
560=item *
561
562C<Memoize> can make your functions faster by trading space for time,
563from Mark-Jason Dominus. See L<Memoize>.
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564
565=item *
566
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567C<MIME::Base64> allows you to encode data in base64, from Gisle Aas,
568as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
569Extensions)>.
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570
571 use MIME::Base64;
572
573 $encoded = encode_base64('Aladdin:open sesame');
574 $decoded = decode_base64($encoded);
575
576 print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
577
61947107 578See L<MIME::Base64>.
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579
580=item *
581
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582C<MIME::QuotedPrint> allows you to encode data in quoted-printable
583encoding, as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail
584Extensions)>, from Gisle Aas.
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585
586 use MIME::QuotedPrint;
587
588 $encoded = encode_qp("Smiley in Unicode: \x{263a}");
589 $decoded = decode_qp($encoded);
590
591 print $encoded, "\n"; # "Smiley in Unicode: =263A"
592
593MIME::QuotedPrint has been enhanced to provide the basic methods
594necessary to use it with PerlIO::Via as in :
595
596 use MIME::QuotedPrint;
597 open($fh,">Via(MIME::QuotedPrint)",$path)
598
61947107 599See L<MIME::QuotedPrint>.
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600
601=item *
602
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603C<NEXT> is pseudo-class for method redispatch, from Damian Conway.
604See L<NEXT>.
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605
606=item *
607
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608C<open> is a new pragma for setting the default I/O disciplines
609for open().
610
611=item *
612
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613C<PerlIO::Scalar> provides the implementation of IO to "in memory"
614Perl scalars as discussed above, from Nick Ing-Simmons. It also
615serves as an example of a loadable PerlIO layer. Other future
616possibilities include PerlIO::Array and PerlIO::Code.
617See L<PerlIO::Scalar>.
618
619=item *
620
621C<PerlIO::Via> acts as a PerlIO layer and wraps PerlIO layer
622functionality provided by a class (typically implemented in perl
623code), from Nick Ing-Simmons.
f39f21d8
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624
625 use MIME::QuotedPrint;
626 open($fh,">Via(MIME::QuotedPrint)",$path)
627
628This will automatically convert everything output to C<$fh>
61947107 629to Quoted-Printable. See L<PerlIO::Via>.
f39f21d8
JH
630
631=item *
632
1e13d81f
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633C<Pod::ParseLink>, by Russ Allbery, has been added,
634to parse L<> links in pods as described in the new
635perlpodspec.
636
637=item *
638
61947107 639C<Pod::Text::Overstrike>, by Joe Smith, has been added.
f39f21d8 640It converts POD data to formatted overstrike text.
61947107 641See L<Pod::Text::Overstrike>.
f39f21d8
JH
642
643=item *
644
61947107
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645C<Scalar::Util> is a selection of general-utility scalar subroutines,
646like blessed(), reftype(), and tainted(). See L<Scalar::Util>.
647
648=item *
649
1e13d81f
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650C<sort> is a new pragma for controlling the behaviour of sort().
651
652=item *
653
61947107
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654C<Storable> gives persistence to Perl data structures by allowing the
655storage and retrieval of Perl data to and from files in a fast and
656compact binary format, from Raphael Manfredi. See L<Storable>.
657
658=item *
659
660C<Switch>, from Damian Conway, has been added. Just by saying
f39f21d8
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661
662 use Switch;
663
664you have C<switch> and C<case> available in Perl.
665
666 use Switch;
667
668 switch ($val) {
669
670 case 1 { print "number 1" }
671 case "a" { print "string a" }
672 case [1..10,42] { print "number in list" }
673 case (@array) { print "number in list" }
674 case /\w+/ { print "pattern" }
675 case qr/\w+/ { print "pattern" }
676 case (%hash) { print "entry in hash" }
677 case (\%hash) { print "entry in hash" }
678 case (\&sub) { print "arg to subroutine" }
679 else { print "previous case not true" }
680 }
681
61947107
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682See L<Switch>.
683
684=item *
685
686C<Test::More> is yet another framework for writing test scripts,
687more extensive than Test::Simple, by Michael Schwern. See L<Test::More>.
688
689=item *
690
691C<Test::Simple> has the- basic utilities for writing tests, by Michael
692Schwern. See L<Test::Simple>.
77c8cf41
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693
694=item *
695
61947107
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696C<Text::Balanced> has been added, for extracting delimited text
697sequences from strings, from Damian Conway.
77c8cf41
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698
699 use Text::Balanced 'extract_delimited';
700
701 ($a, $b) = extract_delimited("'never say never', he never said", "'", '');
702
703$a will be "'never say never'", $b will be ', he never said'.
704
705In addition to extract_delimited() there are also extract_bracketed(),
706extract_quotelike(), extract_codeblock(), extract_variable(),
707extract_tagged(), extract_multiple(), gen_delimited_pat(), and
708gen_extract_tagged(). With these you can implement rather advanced
61947107 709parsing algorithms. See L<Text::Balanced>.
77c8cf41
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710
711=item *
712
61947107
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713C<threads> is an interface interpreter threads, by Arthur Bergman.
714Interpreter threads (ithreads) is the new thread model introduced in
715Perl 5.6 but then available only as an internal interface for
716extension writers. See L<threads>.
77c8cf41
JH
717
718=item *
719
61947107
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720C<threads::shared> allows data sharing for interpreter threads, from
721Arthur Bergman. In the ithreads model any data sharing between
722threads must be explicit, as opposed to the old 5.005 thread model
723where data sharing was implicit. See L<threads::shared>.
77c8cf41
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724
725=item *
726
61947107 727C<Tie::RefHash::Nestable>, by Edward Avis, allows storing hash
ba370e9b
JH
728references (unlike the standard Tie::RefHash) The module is contained
729within Tie::RefHash, see L<Tie::RefHash>.
77c8cf41
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730
731=item *
732
61947107
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733C<Time::HiRes> provides high resolution timing (ualarm, usleep,
734and gettimeofday), from Douglas E. Wegscheid. See L<Time::HiRes>.
77c8cf41
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735
736=item *
737
61947107
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738C<Unicode::UCD> offers a querying interface to the Unicode Character
739Database. See L<Unicode::UCD>.
77c8cf41
JH
740
741=item *
742
61947107
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743C<Unicode::Collate> implements the UCA (Unicode Collation Algorithm)
744for sorting Unicode strings, by SADAHIRO Tomoyuki. See L<Unicode::Collate>.
77c8cf41
JH
745
746=item *
747
61947107
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748C<Unicode::Normalize> implements the various Unicode normalization
749forms, by SADAHIRO Tomoyuki. See L<Unicode::Normalize>.
77c8cf41
JH
750
751=item *
752
61947107
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753C<XS::Typemap>, by Tim Jenness, is a test extension that exercises XS
754typemaps. Nothing gets installed but for extension writers the code
755is worth studying.
77c8cf41
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756
757=back
758
759=head2 Updated And Improved Modules and Pragmata
760
761=over 4
762
763=item *
764
61947107
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765The following independently supported modules have been updated to the
766newest versions from CPAN: CGI, CPAN, DB_File, File::Spec, File::Temp,
767Getopt::Long, Math::BigFloat, Math::BigInt, the podlators bundle
768(Pod::Man, Pod::Text), Pod::LaTeX, Pod::Parser, Storable,
769Term::ANSIColor, Test, Text-Tabs+Wrap.
77c8cf41
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770
771=item *
772
61947107 773The attributes::reftype() now works on tied arguments.
77c8cf41
JH
774
775=item *
776
61947107 777AutoLoader can now be disabled with C<no AutoLoader;>,
77c8cf41
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778
779=item *
780
1e13d81f
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781B::Deparse has been significantly enhanced. It now can deparse almost
782all of the standard test suite (so that the tests still succeed).
783There is a make target "test.deparse" for trying this out.
77c8cf41
JH
784
785=item *
786
1e13d81f 787Class::Struct can now define the classes in compile time.
77c8cf41
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788
789=item *
790
1e13d81f
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791Class::Struct now assigns the array/hash element if the accessor
792is called with an array/hash element as the B<sole> argument.
77c8cf41
JH
793
794=item *
795
1e13d81f 796Data::Dumper has now an option to sort hashes.
77c8cf41
JH
797
798=item *
799
1e13d81f
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800Data::Dumper has now an option to dump code references
801using B::Deparse.
77c8cf41
JH
802
803=item *
804
1e13d81f
JH
805The English module can now be used without the infamous performance
806hit by saying
77c8cf41 807
1e13d81f 808 use English '-no_performance_hit';
77c8cf41 809
1e13d81f
JH
810(Assuming, of course, that one doesn't need the troublesome variables
811C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
812C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
77c8cf41
JH
813
814=item *
815
1e13d81f
JH
816Fcntl, Socket, and Sys::Syslog have been rewritten to use the
817new-style constant dispatch section (see L<ExtUtils::Constant>).
818This means that they will be more robust and hopefully faster.
77c8cf41
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819
820=item *
821
1e13d81f
JH
822File::Find now has pre- and post-processing callbacks. It also
823correctly changes directories when chasing symbolic links. Callbacks
824(naughtily) exiting with "next;" instead of "return;" now work.
61947107
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825
826=item *
827
1e13d81f
JH
828File::Find is now (again) reentrant. It also has been made
829more portable.
77c8cf41 830
61947107
JH
831=item *
832
1e13d81f
JH
833File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
834prototype mismatch with CORE::glob().
61947107
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835
836=item *
837
838File::Glob now supports C<GLOB_LIMIT> constant to limit the size of
839the returned list of filenames.
77c8cf41
JH
840
841=item *
842
843Devel::Peek now has an interface for the Perl memory statistics
844(this works only if you are using perl's malloc, and if you have
845compiled with debugging).
846
847=item *
848
1e13d81f
JH
849IPC::Open3 now allows the use of numeric file descriptors.
850
851=item *
852
77c8cf41
JH
853IO::Socket has now atmark() method, which returns true if the socket
854is positioned at the out-of-band mark. The method is also exportable
855as a sockatmark() function.
856
857=item *
858
859IO::Socket::INET has support for ReusePort option (if your platform
860supports it). The Reuse option now has an alias, ReuseAddr. For clarity
861you may want to prefer ReuseAddr.
862
863=item *
864
61947107
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865IO::Socket::INET now supports C<LocalPort> of zero (usually meaning
866that the operating system will make one up.)
77c8cf41
JH
867
868=item *
869
1e13d81f
JH
870use lib now works identically to @INC. Removing directories
871with 'no lib' now works.
872
873=item *
874
875Math::BigFloat and Math::BigInt have undergone a full rewrite.
876They are now magnitudes faster, and they support various
61947107 877bignum libraries such as GMP and PARI as their backends.
f39f21d8
JH
878
879=item *
880
61947107
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881Net::Ping has been enhanced. There is now "external" protocol which
882uses Net::Ping::External module which runs external ping(1) and parses
883the output. An alpha version of Net::Ping::External is available in
884CPAN and in 5.7.2 the Net::Ping::External may be integrated to Perl.
f39f21d8 885
77c8cf41 886=item *
f39f21d8 887
61947107
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888POSIX::sigaction() is now much more flexible and robust.
889You can now install coderef handlers, 'DEFAULT', and 'IGNORE'
890handlers, installing new handlers was not atomic.
f39f21d8
JH
891
892=item *
893
1e13d81f
JH
894C<%INC> now localised in a Safe compartment so that use/require work.
895
896=item *
897
898The Shell module now has an OO interface.
899
900=item *
901
61947107 902The Test module has been significantly enhanced.
f39f21d8
JH
903
904=item *
905
61947107 906The C<vars> pragma now supports declaring fully qualified variables.
77c8cf41 907(Something that C<our()> does not and will not support.)
f39f21d8 908
888aee59
JH
909=item *
910
61947107
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911The utf8:: name space (as in the pragma) provides various
912Perl-callable functions to provide low level access to Perl's
913internal Unicode representation. At the moment only length()
914has been implemented.
888aee59 915
f39f21d8
JH
916=back
917
77c8cf41 918=head1 Utility Changes
f39f21d8
JH
919
920=over 4
921
922=item *
923
61947107 924Emacs perl mode (emacs/cperl-mode.el) has been updated to version
77c8cf41 9254.31.
f39f21d8
JH
926
927=item *
928
61947107 929F<emacs/e2ctags.pl> is now much faster.
f39f21d8
JH
930
931=item *
932
1e13d81f
JH
933C<h2ph> now supports C trigraphs.
934
935=item *
936
937C<h2xs> now produces a template README.
f39f21d8 938
77c8cf41
JH
939=item *
940
1e13d81f
JH
941C<h2xs> now uses C<Devel::PPort> for better portability between
942different versions of Perl.
f39f21d8
JH
943
944=item *
945
1e13d81f 946C<h2xs> uses the new L<ExtUtils::Constant> module which will affect
61947107
JH
947newly created extensions that define constants. Since the new code is
948more correct (if you have two constants where the first one is a
949prefix of the second one, the first constant B<never> gets defined),
950less lossy (it uses integers for integer constant, as opposed to the
951old code that used floating point numbers even for integer constants),
952and slightly faster, you might want to consider regenerating your
953extension code (the new scheme makes regenerating easy).
954L<h2xs> now also supports C trigraphs.
f39f21d8
JH
955
956=item *
957
1e13d81f 958C<libnetcfg> has been added to configure the libnet.
f39f21d8
JH
959
960=item *
961
1e13d81f 962C<perlbug> is now much more robust. It also sends the bug report to
61947107 963perl.org, not perl.com.
f39f21d8
JH
964
965=item *
966
1e13d81f 967C<perlcc> has been rewritten and its user interface (that is,
61947107 968command line) is much more like that of the UNIX C compiler, cc.
f39f21d8
JH
969
970=item *
971
1e13d81f 972C<perlivp> is a new utility for doing Installation Verification
61947107 973Procedure after installing Perl.
f39f21d8
JH
974
975=item *
976
1e13d81f 977C<pod2html> now allows specifying a cache directory.
f39f21d8
JH
978
979=item *
980
1e13d81f
JH
981C<s2p> has been completely rewritten in Perl. (It is in fact a full
982implementation of sed in Perl: you can use the sed functionality by
983using the C<psed> utility.)
61947107
JH
984
985=item *
986
1e13d81f 987C<xsubpp> now understands POD documentation embedded in the *.xs files.
f39f21d8
JH
988
989=item *
990
1e13d81f 991C<xsubpp> now supports OUT keyword.
f39f21d8
JH
992
993=back
994
77c8cf41 995=head1 New Documentation
f39f21d8
JH
996
997=over 4
998
999=item *
1000
77c8cf41
JH
1001perl56delta details the changes between the 5.005 release and the
10025.6.0 release.
f39f21d8
JH
1003
1004=item *
1005
61947107
JH
1006perlclib documents the internal replacements for standard C library
1007functions. (Interesting only for extension writers and Perl core
1008hackers.)
1009
1010=item *
1011
77c8cf41 1012perldebtut is a Perl debugging tutorial.
f39f21d8 1013
77c8cf41 1014=item *
f39f21d8 1015
77c8cf41
JH
1016perlebcdic contains considerations for running Perl on EBCDIC platforms.
1017Note that unfortunately EBCDIC platforms that used to supported back in
1018Perl 5.005 are still unsupported by Perl 5.7.0; the plan, however, is to
1019bring them back to the fold.
f39f21d8 1020
77c8cf41
JH
1021=item *
1022
888aee59
JH
1023perlintro is a gentle introduction to Perl.
1024
1025=item *
1026
61947107
JH
1027perliol documents the internals of PerlIO with layers.
1028
1029=item *
1030
888aee59
JH
1031perlmodstyle is a style guide for writing modules.
1032
1033=item *
1034
77c8cf41 1035perlnewmod tells about writing and submitting a new module.
f39f21d8
JH
1036
1037=item *
1038
888aee59
JH
1039perlpod has been rewritten to be clearer and to record the best
1040practices gathered over the years.
1041
1042=item *
1043
1044perlpodstyle is a more formal specification of the pod format,
1045mainly of interest for writers of pod applications, not to
1046people writing in pod.
1047
1048=item *
1049
77c8cf41
JH
1050perlposix-bc explains using Perl on the POSIX-BC platform
1051(an EBCDIC mainframe platform).
f39f21d8
JH
1052
1053=item *
1054
77c8cf41 1055perlretut is a regular expression tutorial.
f39f21d8
JH
1056
1057=item *
1058
77c8cf41
JH
1059perlrequick is a regular expressions quick-start guide.
1060Yes, much quicker than perlretut.
f39f21d8 1061
77c8cf41 1062=item *
f39f21d8 1063
61947107
JH
1064perltodo has been updated.
1065
1066=item *
1067
888aee59 1068perltootc has been renamed as perltooc (to not to conflict
61947107 1069with perltoot in filesystems restricted to "8.3" names)
888aee59
JH
1070
1071=item *
1072
1073perluniintro is an introduction to using Unicode in Perl
1074(perlunicode is more of a reference)
1075
1076=item *
1077
77c8cf41
JH
1078perlutil explains the command line utilities packaged with the Perl
1079distribution.
1080
1081=back
f39f21d8 1082
61947107
JH
1083The following platform-specific documents are available before
1084the installation as README.I<platform>, and after the installation
1085as perlI<platform>:
f39f21d8 1086
61947107
JH
1087 perlaix perlamiga perlapollo perlbeos perlbs2000
1088 perlce perlcygwin perldgux perldos perlepoc perlhpux
1089 perlhurd perlmachten perlmacos perlmint perlmpeix
1090 perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris
1091 perltru64 perluts perlvmesa perlvms perlvos perlwin32
77c8cf41
JH
1092
1093=over 4
1094
1095=item *
1096
61947107
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1097The documentation for the POSIX-BC platform is called "BS2000", to avoid
1098confusion with the Perl POSIX module.
77c8cf41
JH
1099
1100=item *
1101
61947107
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1102The documentation for the WinCE platform is called "CE", to avoid
1103confusion with the perlwin32 documentation on 8.3-restricted filesystems.
77c8cf41
JH
1104
1105=back
1106
1107=head1 Performance Enhancements
1108
1109=over 4
1110
1111=item *
1112
1113map() that changes the size of the list should now work faster.
1114
1115=item *
1116
1117sort() has been changed to use mergesort internally as opposed to the
1118earlier quicksort. For very small lists this may result in slightly
1119slower sorting times, but in general the speedup should be at least
112020%. Additional bonuses are that the worst case behaviour of sort()
1121is now better (in computer science terms it now runs in time O(N log N),
1122as opposed to quicksort's Theta(N**2) worst-case run time behaviour),
1123and that sort() is now stable (meaning that elements with identical
1124keys will stay ordered as they were before the sort).
1125
1126=item *
1127
1128Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm
1129(http://burtleburtle.net/bob/hash/doobs.html). This algorithm is
1130reasonably fast while producing a much better spread of values than
1131the old hashing algorithm (originally by Chris Torek, later tweaked by
1132Ilya Zakharevich). Hash values output from the algorithm on a hash of
1133all 3-char printable ASCII keys comes much closer to passing the
1134DIEHARD random number generation tests. According to perlbench, this
1135change has not affected the overall speed of Perl.
1136
1137=item *
1138
1139unshift() should now be noticeably faster.
1140
1141=back
1142
1143=head1 Installation and Configuration Improvements
1144
1145=head2 Generic Improvements
1146
1147=over 4
1148
1149=item *
1150
1151INSTALL now explains how you can configure Perl to use 64-bit
1152integers even on non-64-bit platforms.
1153
1154=item *
1155
1156Policy.sh policy change: if you are reusing a Policy.sh file
1157(see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old
1158Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of
1159them will now be changed to the new prefix, /foo/bar. (Previously
1160only $prefix changed.) If you do not like this new behaviour,
1161specify prefix, siteprefix, and vendorprefix explicitly.
1162
1163=item *
1164
1165A new optional location for Perl libraries, otherlibdirs, is available.
1166It can be used for example for vendor add-ons without disturbing Perl's
1167own library directories.
1168
1169=item *
1170
1171In many platforms the vendor-supplied 'cc' is too stripped-down to
1172build Perl (basically, 'cc' doesn't do ANSI C). If this seems
1173to be the case and 'cc' does not seem to be the GNU C compiler
1174'gcc', an automatic attempt is made to find and use 'gcc' instead.
1175
1176=item *
1177
1178gcc needs to closely track the operating system release to avoid
1179build problems. If Configure finds that gcc was built for a different
1180operating system release than is running, it now gives a clearly visible
1181warning that there may be trouble ahead.
1182
1183=item *
1184
1185If binary compatibility with the 5.005 release is not wanted, Configure
1186no longer suggests including the 5.005 modules in @INC.
1187
1188=item *
1189
1190Configure C<-S> can now run non-interactively.
1191
1192=item *
1193
1194configure.gnu now works with options with whitespace in them.
f39f21d8 1195
77c8cf41 1196=item *
f39f21d8 1197
77c8cf41 1198installperl now outputs everything to STDERR.
f39f21d8 1199
77c8cf41
JH
1200=item *
1201
1202$Config{byteorder} is now computed dynamically (this is more robust
1203with "fat binaries" where an executable image contains binaries for
1204more than one binary platform.)
f39f21d8
JH
1205
1206=item *
1207
1208Because PerlIO is now the default on most platforms, "-perlio" doesn't
1209get appended to the $Config{archname} (also known as $^O) anymore.
1210Instead, if you explicitly choose not to use perlio (Configure command
1211line option -Uuseperlio), you will get "-stdio" appended.
1212
1213=item *
1214
1215Another change related to the architecture name is that "-64all"
1216(-Duse64bitall, or "maximally 64-bit") is appended only if your
1217pointers are 64 bits wide. (To be exact, the use64bitall is ignored.)
1218
1219=item *
1220
77c8cf41
JH
1221In AFS installations one can configure the root of the AFS to be
1222somewhere else than the default F</afs> by using the Configure
1223parameter C<-Dafsroot=/some/where/else>.
1224
1225=item *
1226
61947107
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1227APPLLIB_EXP, a less-know configuration-time definition, has been
1228documented. It can be used to prepend site-specific directories
1229to Perl's default search path (@INC), see INSTALL for information.
1230
1231=item *
1232
77c8cf41
JH
1233The version of Berkeley DB used when the Perl (and, presumably, the
1234DB_File extension) was built is now available as
1235C<@Config{qw(db_version_major db_version_minor db_version_patch)}>
1236from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG
1237DB_VERSION_PATCH_CFG> from C.
1238
1239=item *
1240
61947107
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1241Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM
1242has been documented in INSTALL.
77c8cf41
JH
1243
1244=item *
1245
61947107
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1246If you have CPAN access (either network or a local copy such as a
1247CD-ROM) you can during specify extra modules to Configure to build and
1248install with Perl using the -Dextras=... option. See INSTALL for
1249more details.
f39f21d8 1250
61947107 1251=item *
f39f21d8 1252
61947107
JH
1253In addition to config.over a new override file, config.arch, is
1254available. That is supposed to be used by hints file writers for
1255architecture-wide changes (as opposed to config.over which is for
1256site-wide changes).
f39f21d8
JH
1257
1258=item *
1259
61947107
JH
1260For Perl developers several new make targets for profiling
1261and debugging have been added, see L<perlhack>.
1262
1263=over 8
f39f21d8
JH
1264
1265=item *
1266
61947107
JH
1267Use of the F<gprof> tool to profile Perl has been documented in
1268L<perlhack>. There is a make target called "perl.gprof" for
1269generating a gprofiled Perl executable.
f39f21d8
JH
1270
1271=item *
1272
61947107
JH
1273If you have GCC 3, there is a make target called "perl.gcov" for
1274creating a gcoved Perl executable for coverage analysis. See
1275L<perlhack>.
f39f21d8
JH
1276
1277=item *
1278
61947107
JH
1279If you are on IRIX or Tru64 platforms, new profiling/debugging options
1280have been added, see L<perlhack> for more information about pixie and
1281Third Degree.
1282
1283=back
f39f21d8
JH
1284
1285=item *
1286
61947107
JH
1287Guidelines of how to construct minimal Perl installations have
1288been added to INSTALL.
f39f21d8
JH
1289
1290=item *
1291
61947107
JH
1292The Thread extension is now not built at all under ithreads
1293(C<Configure -Duseithreads>) because it wouldn't work anyway (the
1294Thread extension requires being Configured with C<-Duse5005threads>).
f39f21d8 1295
61947107
JH
1296But note that the Thread.pm interface is now shared by both
1297thread models.
f39f21d8 1298
61947107 1299=back
f39f21d8 1300
61947107 1301=head2 New Or Improved Platforms
f39f21d8 1302
61947107
JH
1303For the list of platforms known to support Perl,
1304see L<perlport/"Supported Platforms">.
1305
1306=over 4
f39f21d8
JH
1307
1308=item *
1309
61947107 1310AIX dynamic loading should be now better supported.
f39f21d8 1311
f39f21d8
JH
1312=item *
1313
77c8cf41
JH
1314AIX should now work better with gcc, threads, and 64-bitness. Also the
1315long doubles support in AIX should be better now. See L<perlaix>.
f39f21d8
JH
1316
1317=item *
1318
61947107
JH
1319After a long pause, AmigaOS has been verified to be happy with Perl.
1320
1321=item *
1322
77c8cf41 1323AtheOS (http://www.atheos.cx/) is a new platform.
f39f21d8 1324
77c8cf41 1325=item *
f39f21d8 1326
77c8cf41 1327DG/UX platform now supports the 5.005-style threads. See L<perldgux>.
f39f21d8
JH
1328
1329=item *
1330
77c8cf41 1331DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2.
f39f21d8
JH
1332
1333=item *
1334
61947107
JH
1335EBCDIC platforms (z/OS, also known as OS/390, POSIX-BC, and VM/ESA)
1336have been regained. Many test suite tests still fail and the
1337co-existence of Unicode and EBCDIC isn't quite settled, but the
1338situation is much better than with Perl 5.6. See L<perlos390>,
1339L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information.
f39f21d8
JH
1340
1341=item *
1342
61947107
JH
1343Building perl with -Duseithreads or -Duse5005threads now works under
1344HP-UX 10.20 (previously it only worked under 10.30 or later). You will
1345need a thread library package installed. See README.hpux.
f39f21d8 1346
77c8cf41 1347=item *
f39f21d8 1348
61947107
JH
1349MacOS Classic (MacPerl has of course been available since
1350perl 5.004 but now the source code bases of standard Perl
1351and MacPerl have been synchronised)
f39f21d8 1352
77c8cf41 1353=item *
f39f21d8 1354
61947107
JH
1355MacOS X (or Darwin) should now be able to build Perl even on HFS+
1356filesystems. (The case-insensitivity confused the Perl build process.)
f39f21d8 1357
888aee59
JH
1358=item *
1359
61947107 1360NCR MP-RAS is now supported.
888aee59
JH
1361
1362=item *
1363
61947107 1364NetWare from Novell is now supported. See L<perlnetware>.
888aee59
JH
1365
1366=item *
1367
61947107 1368NonStop-UX is now supported.
888aee59
JH
1369
1370=item *
1371
61947107 1372Amdahl UTS UNIX mainframe platform is now supported.
888aee59
JH
1373
1374=item *
1375
61947107
JH
1376WinCE is now supported. See L<perlce>.
1377
1378=item *
1379
1380z/OS (formerly known as OS/390, formerly known as MVS OE) has now
1381support for dynamic loading. This is not selected by default,
1382however, you must specify -Dusedl in the arguments of Configure.
888aee59 1383
f39f21d8
JH
1384=back
1385
1386=head1 Selected Bug Fixes
1387
ba370e9b
JH
1388Numerous memory leaks and uninitialized memory accesses have been hunted down.
1389Most importantly anonymous subs used to leak quite a bit.
1390
f39f21d8
JH
1391=over 4
1392
1393=item *
1394
77c8cf41
JH
1395Several debugger fixes: exit code now reflects the script exit code,
1396condition C<"0"> now treated correctly, the C<d> command now checks
1397line number, the C<$.> no longer gets corrupted, all debugger output now
1398goes correctly to the socket if RemotePort is set.
f39f21d8
JH
1399
1400=item *
1401
77c8cf41 1402C<*foo{FORMAT}> now works.
f39f21d8
JH
1403
1404=item *
1405
77c8cf41 1406Lexical warnings now propagating correctly between scopes.
f39f21d8
JH
1407
1408=item *
1409
77c8cf41 1410Line renumbering with eval and C<#line> now works.
f39f21d8
JH
1411
1412=item *
1413
77c8cf41 1414Fixed numerous memory leaks, especially in eval "".
f39f21d8
JH
1415
1416=item *
1417
77c8cf41
JH
1418Modulus of unsigned numbers now works (4063328477 % 65535 used to
1419return 27406, instead of 27047).
f39f21d8
JH
1420
1421=item *
1422
77c8cf41
JH
1423Some "not a number" warnings introduced in 5.6.0 eliminated to be
1424more compatible with 5.005. Infinity is now recognised as a number.
f39f21d8
JH
1425
1426=item *
1427
77c8cf41 1428our() variables will not cause "will not stay shared" warnings.
f39f21d8
JH
1429
1430=item *
1431
77c8cf41 1432pack "Z" now correctly terminates the string with "\0".
f39f21d8
JH
1433
1434=item *
1435
77c8cf41
JH
1436Fix password routines which in some shadow password platforms
1437(e.g. HP-UX) caused getpwent() to return every other entry.
f39f21d8
JH
1438
1439=item *
1440
77c8cf41 1441printf() no longer resets the numeric locale to "C".
f39f21d8
JH
1442
1443=item *
1444
77c8cf41 1445C<q(a\\b)> now parses correctly as C<'a\\b'>.
f39f21d8
JH
1446
1447=item *
1448
77c8cf41
JH
1449Printing quads (64-bit integers) with printf/sprintf now works
1450without the q L ll prefixes (assuming you are on a quad-capable platform).
f39f21d8
JH
1451
1452=item *
1453
77c8cf41 1454Regular expressions on references and overloaded scalars now work.
f39f21d8
JH
1455
1456=item *
1457
77c8cf41 1458scalar() now forces scalar context even when used in void context.
f39f21d8
JH
1459
1460=item *
1461
77c8cf41
JH
1462sort() arguments are now compiled in the right wantarray context
1463(they were accidentally using the context of the sort() itself).
f39f21d8
JH
1464
1465=item *
1466
77c8cf41
JH
1467Changed the POSIX character class C<[[:space:]]> to include the (very
1468rare) vertical tab character. Added a new POSIX-ish character class
1469C<[[:blank:]]> which stands for horizontal whitespace (currently,
1470the space and the tab).
f39f21d8
JH
1471
1472=item *
1473
77c8cf41
JH
1474$AUTOLOAD, sort(), lock(), and spawning subprocesses
1475in multiple threads simultaneously are now thread-safe.
f39f21d8
JH
1476
1477=item *
1478
77c8cf41 1479Allow read-only string on left hand side of non-modifying tr///.
f39f21d8 1480
77c8cf41 1481=item *
f39f21d8 1482
77c8cf41 1483Several Unicode fixes (but still not perfect).
f39f21d8 1484
77c8cf41 1485=over 8
f39f21d8
JH
1486
1487=item *
1488
77c8cf41
JH
1489BOMs (byte order marks) in the beginning of Perl files
1490(scripts, modules) should now be transparently skipped.
1491UTF-16 (UCS-2) encoded Perl files should now be read correctly.
f39f21d8
JH
1492
1493=item *
1494
77c8cf41 1495The character tables have been updated to Unicode 3.0.1.
f39f21d8
JH
1496
1497=item *
1498
77c8cf41
JH
1499chr() for values greater than 127 now create utf8 when under use
1500utf8.
f39f21d8 1501
77c8cf41 1502=item *
f39f21d8 1503
77c8cf41
JH
1504Comparing with utf8 data does not magically upgrade non-utf8 data into
1505utf8.
f39f21d8 1506
77c8cf41 1507=item *
f39f21d8 1508
77c8cf41 1509C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
f39f21d8 1510
77c8cf41 1511=item *
f39f21d8 1512
77c8cf41
JH
1513Concatenation with the C<.> operator or via variable interpolation,
1514C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
1515substitution with C<s///>, single-quoted UTF8, should now work--in
1516theory.
f39f21d8 1517
77c8cf41 1518=item *
f39f21d8 1519
77c8cf41
JH
1520The C<tr///> operator now works I<slightly> better but is still rather
1521broken. Note that the C<tr///CU> functionality has been removed (but
1522see pack('U0', ...)).
f39f21d8 1523
77c8cf41 1524=item *
f39f21d8 1525
77c8cf41 1526vec() now refuses to deal with characters >255.
f39f21d8 1527
77c8cf41 1528=item *
f39f21d8 1529
77c8cf41 1530Zero entries were missing from the Unicode classes like C<IsDigit>.
f39f21d8 1531
ba370e9b
JH
1532=item *
1533
1534chop(@list) in list context returned the characters chopped in
1535reverse order. This has been reversed to be in the right order.
1536
1537=item *
1538
1539The order of DESTROYs has been made more predictable.
1540
1541=item *
1542
1543mkdir() now ignores trailing slashes in the directory name,
1544as mandated by POSIX.
1545
1546=item *
1547
1548Attributes (like :shared) didn't work with our().
1549
1550=item *
1551
1552The PERL5OPT environment variable (for passing command line arguments
1553to Perl) didn't work for more than a single group of options.
1554
1555=item *
1556
1557The tainting behaviour of sprintf() has been rationalized. It does
1558not taint the result of floating point formats anymore, making the
1559behaviour consistent with that of string interpolation.
1560
1561=item *
1562
1563All but the first argument of the IO syswrite() method are now optional.
1564
1565=item *
1566
1567Tie::ARRAY SPLICE method was broken.
1568
1569=item *
1570
1571vec() now tries to work with characters <= 255 when possible, but it leaves
1572higher character values in place. In that case, if vec() was used to modify
1573the string, it is no longer considered to be utf8-encoded.
1574
1575=item *
1576
1577The autouse pragma didn't work for Multi::Part::Function::Names.
1578
1579=item *
1580
1581The behaviour of non-decimal but numeric string constants such as
1582"0x23" was platform-dependent: in some platforms that was seen as 35,
1583in some as 0, in some as a floating point number (don't ask). This
1584was caused by Perl using the operating system libraries in a situation
1585where the result of the string to number conversion is undefined: now
1586Perl consistently handles such strings as zero in numeric contexts.
1587
1588=item *
1589
1590L<dprofpp> -R didn't work.
1591
1592=item *
1593
1594PERL5OPT with embedded spaces didn't work.
1595
1596=item *
1597
1598L<Sys::Syslog> ignored the C<LOG_AUTH> constant.
1599
1600=item *
1601
1602Some versions of glibc have a broken modfl(). This affects builds
1603with C<-Duselongdouble>. This version of Perl detects this brokenness
1604and has a workaround for it. The glibc release 2.2.2 is known to have
1605fixed the modfl() bug.
1606
1607=item *
1608
1609Linux previously had problems related to sockaddrlen when using
1610accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
1611
1612=item *
1613
1614Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
1615
1616=item *
1617
1618Windows
1619
1620=over 8
1621
1622=item *
1623
1624Borland C++ v5.5 is now a supported compiler that can build Perl.
1625However, the generated binaries continue to be incompatible with those
1626generated by the other supported compilers (GCC and Visual C++).
1627
1628=item *
1629
1630Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
1631Other bugs in chdir() and Cwd::cwd() have also been fixed.
1632
1633=item *
1634
1635Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
1636
1637=item *
1638
1639HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
1640
1641=item *
1642
1643The makefiles now provide a single switch to bulk-enable all the features
1644enabled in ActiveState ActivePerl (a popular Win32 binary distribution).
1645
1646=back
1647
77c8cf41 1648=back
f39f21d8 1649
77c8cf41 1650=item *
f39f21d8 1651
77c8cf41
JH
1652UNIVERSAL::isa no longer caches methods incorrectly. (This broke
1653the Tk extension with 5.6.0.)
f39f21d8 1654
77c8cf41 1655=item *
f39f21d8 1656
77c8cf41
JH
1657Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
1658when building the Perl binary. The only exception to this is SunOS 4.x,
1659which needs them.
f39f21d8 1660
77c8cf41 1661=item *
f39f21d8 1662
77c8cf41 1663SOCKS support is now much more robust.
f39f21d8 1664
77c8cf41 1665=item *
f39f21d8 1666
77c8cf41
JH
1667If your file system supports symbolic links you can build Perl outside
1668of the source directory by
f39f21d8 1669
77c8cf41
JH
1670 mkdir /tmp/perl/build/directory
1671 cd /tmp/perl/build/directory
1672 sh /path/to/perl/source/Configure -Dmksymlinks ...
f39f21d8 1673
77c8cf41
JH
1674This will create in /tmp/perl/build/directory a tree of symbolic links
1675pointing to files in /path/to/perl/source. The original files are left
1676unaffected. After Configure has finished you can just say
f39f21d8 1677
77c8cf41 1678 make all test
f39f21d8 1679
77c8cf41 1680and Perl will be built and tested, all in /tmp/perl/build/directory.
f39f21d8 1681
77c8cf41 1682=back
f39f21d8 1683
77c8cf41 1684=head2 Platform Specific Changes and Fixes
f39f21d8
JH
1685
1686=over 4
1687
1688=item *
1689
77c8cf41 1690BSDI 4.*
f39f21d8 1691
77c8cf41 1692Perl now works on post-4.0 BSD/OSes.
f39f21d8
JH
1693
1694=item *
1695
77c8cf41 1696All BSDs
f39f21d8 1697
77c8cf41 1698Setting C<$0> now works (as much as possible; see perlvar for details).
f39f21d8
JH
1699
1700=item *
1701
77c8cf41 1702Cygwin
f39f21d8 1703
77c8cf41 1704Numerous updates; currently synchronised with Cygwin 1.1.4.
f39f21d8
JH
1705
1706=item *
1707
77c8cf41 1708EPOC
f39f21d8 1709
77c8cf41 1710EPOC update after Perl 5.6.0. See README.epoc.
f39f21d8
JH
1711
1712=item *
1713
77c8cf41 1714FreeBSD 3.*
f39f21d8 1715
77c8cf41 1716Perl now works on post-3.0 FreeBSDs.
f39f21d8
JH
1717
1718=item *
1719
77c8cf41
JH
1720HP-UX
1721
1722README.hpux updated; C<Configure -Duse64bitall> now almost works.
f39f21d8
JH
1723
1724=item *
1725
77c8cf41 1726IRIX
f39f21d8 1727
77c8cf41
JH
1728Numerous compilation flag and hint enhancements; accidental mixing
1729of 32-bit and 64-bit libraries (a doomed attempt) made much harder.
f39f21d8 1730
77c8cf41 1731=item *
f39f21d8 1732
77c8cf41 1733Linux
f39f21d8 1734
77c8cf41 1735Long doubles should now work (see INSTALL).
f39f21d8
JH
1736
1737=item *
1738
77c8cf41 1739MacOS Classic
f39f21d8 1740
77c8cf41
JH
1741Compilation of the standard Perl distribution in MacOS Classic should
1742now work if you have the Metrowerks development environment and
1743the missing Mac-specific toolkit bits. Contact the macperl mailing
1744list for details.
f39f21d8
JH
1745
1746=item *
1747
77c8cf41 1748MPE/iX
f39f21d8 1749
77c8cf41 1750MPE/iX update after Perl 5.6.0. See README.mpeix.
f39f21d8
JH
1751
1752=item *
1753
77c8cf41 1754NetBSD/sparc
f39f21d8 1755
77c8cf41 1756Perl now works on NetBSD/sparc.
f39f21d8
JH
1757
1758=item *
1759
77c8cf41 1760OS/2
f39f21d8 1761
77c8cf41 1762Now works with usethreads (see INSTALL).
f39f21d8
JH
1763
1764=item *
1765
77c8cf41 1766Solaris
f39f21d8 1767
77c8cf41 176864-bitness using the Sun Workshop compiler now works.
f39f21d8
JH
1769
1770=item *
1771
77c8cf41 1772Tru64 (aka Digital UNIX, aka DEC OSF/1)
f39f21d8 1773
77c8cf41
JH
1774The operating system version letter now recorded in $Config{osvers}.
1775Allow compiling with gcc (previously explicitly forbidden). Compiling
1776with gcc still not recommended because buggy code results, even with
1777gcc 2.95.2.
f39f21d8
JH
1778
1779=item *
1780
77c8cf41
JH
1781Unicos
1782
1783Fixed various alignment problems that lead into core dumps either
1784during build or later; no longer dies on math errors at runtime;
1785now using full quad integers (64 bits), previously was using
1786only 46 bit integers for speed.
f39f21d8
JH
1787
1788=item *
1789
77c8cf41
JH
1790VMS
1791
1792chdir() now works better despite a CRT bug; now works with MULTIPLICITY
1793(see INSTALL); now works with Perl's malloc.
f39f21d8
JH
1794
1795=item *
1796
77c8cf41 1797Windows
f39f21d8 1798
77c8cf41 1799=over 8
f39f21d8
JH
1800
1801=item *
1802
77c8cf41 1803accept() no longer leaks memory.
f39f21d8
JH
1804
1805=item *
1806
77c8cf41 1807Better chdir() return value for a non-existent directory.
f39f21d8 1808
77c8cf41 1809=item *
f39f21d8 1810
77c8cf41 1811New %ENV entries now propagate to subprocesses.
f39f21d8
JH
1812
1813=item *
1814
77c8cf41
JH
1815$ENV{LIB} now used to search for libs under Visual C.
1816
1817=item *
1818
1819A failed (pseudo)fork now returns undef and sets errno to EAGAIN.
f39f21d8
JH
1820
1821=item *
1822
77c8cf41 1823Allow REG_EXPAND_SZ keys in the registry.
f39f21d8
JH
1824
1825=item *
1826
77c8cf41 1827Can now send() from all threads, not just the first one.
f39f21d8
JH
1828
1829=item *
1830
77c8cf41 1831Fake signal handling reenabled, bugs and all.
f39f21d8
JH
1832
1833=item *
1834
77c8cf41
JH
1835Less stack reserved per thread so that more threads can run
1836concurrently. (Still 16M per thread.)
f39f21d8
JH
1837
1838=item *
1839
77c8cf41
JH
1840C<File::Spec->tmpdir()> now prefers C:/temp over /tmp
1841(works better when perl is running as service).
f39f21d8
JH
1842
1843=item *
1844
77c8cf41 1845Better UNC path handling under ithreads.
f39f21d8
JH
1846
1847=item *
1848
77c8cf41 1849wait() and waitpid() now work much better.
f39f21d8
JH
1850
1851=item *
1852
77c8cf41 1853winsock handle leak fixed.
f39f21d8
JH
1854
1855=back
1856
77c8cf41 1857=back
f39f21d8 1858
77c8cf41 1859=head1 New or Changed Diagnostics
f39f21d8 1860
ba370e9b
JH
1861=over 4
1862
1863=item *
1864
77c8cf41
JH
1865All regular expression compilation error messages are now hopefully
1866easier to understand both because the error message now comes before
1867the failed regex and because the point of failure is now clearly
ba370e9b
JH
1868marked by a C<E<lt>-- HERE> marker.
1869
1870=item *
f39f21d8 1871
77c8cf41
JH
1872The various "opened only for", "on closed", "never opened" warnings
1873drop the C<main::> prefix for filehandles in the C<main> package,
1874for example C<STDIN> instead of <main::STDIN>.
f39f21d8 1875
ba370e9b
JH
1876=item *
1877
77c8cf41
JH
1878The "Unrecognized escape" warning has been extended to include C<\8>,
1879C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters.
f39f21d8 1880
ba370e9b 1881=item *
f39f21d8 1882
77c8cf41
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1883Two new debugging options have been added: if you have compiled your
1884Perl with debugging, you can use the -DT and -DR options to trace
1885tokenising and to add reference counts to displaying variables,
1886respectively.
f39f21d8
JH
1887
1888=item *
1889
77c8cf41
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1890If an attempt to use a (non-blessed) reference as an array index
1891is made, a warning is given.
f39f21d8
JH
1892
1893=item *
1894
77c8cf41
JH
1895C<push @a;> and C<unshift @a;> (with no values to push or unshift)
1896now give a warning. This may be a problem for generated and evaled
1897code.
f39f21d8 1898
ba370e9b
JH
1899=item *
1900
1901If you try to L<perlfunc/pack> a number less than 0 or larger than 255
1902using the C<"C"> format you will get an optional warning. Similarly
1903for the C<"c"> format and a number less than -128 or more than 127.
1904
1905=item *
1906
1907Certain regex modifiers such as C<(?o)> make sense only if applied to
1908the entire regex. You will an optional warning if you try to do otherwise.
1909
1910=item *
1911
1912Using arrays or hashes as references (e.g. C<%foo->{bar}> has been
1913deprecated for a while. Now you will get an optional warning.
1914
f39f21d8
JH
1915=back
1916
77c8cf41 1917=head1 Changed Internals
f39f21d8
JH
1918
1919=over 4
1920
1921=item *
1922
77c8cf41
JH
1923perlapi.pod (a companion to perlguts) now attempts to document the
1924internal API.
f39f21d8
JH
1925
1926=item *
1927
77c8cf41
JH
1928You can now build a really minimal perl called microperl.
1929Building microperl does not require even running Configure;
1930C<make -f Makefile.micro> should be enough. Beware: microperl makes
1931many assumptions, some of which may be too bold; the resulting
1932executable may crash or otherwise misbehave in wondrous ways.
1933For careful hackers only.
f39f21d8
JH
1934
1935=item *
1936
77c8cf41 1937Added rsignal(), whichsig(), do_join() to the publicised API.
f39f21d8
JH
1938
1939=item *
1940
77c8cf41 1941Made possible to propagate customised exceptions via croak()ing.
f39f21d8 1942
77c8cf41 1943=item *
f39f21d8 1944
77c8cf41 1945Added is_utf8_char(), is_utf8_string(), bytes_to_utf8(), and utf8_to_bytes().
f39f21d8 1946
77c8cf41 1947=item *
f39f21d8 1948
77c8cf41 1949Now xsubs can have attributes just like subs.
f39f21d8
JH
1950
1951=item *
1952
77c8cf41
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1953Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv().
1954For the full list of the available APIs see L<perlapi>.
f39f21d8
JH
1955
1956=item *
1957
77c8cf41
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1958dTHR and djSP have been obsoleted; the former removed (because it's
1959a no-op) and the latter replaced with dSP.
f39f21d8
JH
1960
1961=item *
1962
61947107
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1963PERL_OBJECT has been completely removed.
1964
1965=item *
1966
ba370e9b
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1967The MAGIC constants (e.g. C<'P'>) have been macrofied
1968(e.g. C<PERL_MAGIC_TIED>) for better source code readability
1969and maintainability.
1970
1971=item *
1972
1973The regex compiler now maintains a structure that identifies nodes in
1974the compiled bytecode with the corresponding syntactic features of the
1975original regex expression. The information is attached to the new
1976C<offsets> member of the C<struct regexp>. See L<perldebguts> for more
1977complete information.
1978
1979=item *
1980
1981The C code has been made much more C<gcc -Wall> clean. Some warning
1982messages still remain in some platforms, so if you are compiling with
1983gcc you may see some warnings about dubious practices. The warnings
1984are being worked on.
1985
1986=item *
1987
1988F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented.
1989
1990=item *
1991
61947107
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1992Documentation on how to use the Perl source repository has been added
1993to F<Porting/repository.pod>.
f39f21d8 1994
888aee59
JH
1995=item *
1996
61947107
JH
1997There are now several profiling make targets
1998
1999=item *
2000
2001The C<op_clear> and C<op_null> are now exported.
888aee59 2002
77c8cf41 2003=back
f39f21d8 2004
77c8cf41 2005=head1 Security Vulnerability Closed
f39f21d8 2006
77c8cf41 2007(This change was already made in 5.7.0 but bears repeating here.)
f39f21d8 2008
77c8cf41
JH
2009A potential security vulnerability in the optional suidperl component
2010of Perl was identified in August 2000. suidperl is neither built nor
2011installed by default. As of November 2001 the only known vulnerable
2012platform is Linux, most likely all Linux distributions. CERT and
2013various vendors and distributors have been alerted about the vulnerability.
2014See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt
2015for more information.
f39f21d8 2016
77c8cf41
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2017The problem was caused by Perl trying to report a suspected security
2018exploit attempt using an external program, /bin/mail. On Linux
2019platforms the /bin/mail program had an undocumented feature which
2020when combined with suidperl gave access to a root shell, resulting in
2021a serious compromise instead of reporting the exploit attempt. If you
2022don't have /bin/mail, or if you have 'safe setuid scripts', or if
2023suidperl is not installed, you are safe.
f39f21d8 2024
77c8cf41
JH
2025The exploit attempt reporting feature has been completely removed from
2026Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also
2027from all the Perl 5.7 releases), so that particular vulnerability
2028isn't there anymore. However, further security vulnerabilities are,
ba370e9b
JH
2029unfortunately, always possible. The suidperl functionality is most
2030probably going to be removed in Perl 5.10. In any case, suidperl
2031should only be used by security experts who know exactly what they are
2032doing and why they are using suidperl instead of some other solution
2033such as sudo (see http://www.courtesan.com/sudo/).
77c8cf41
JH
2034
2035=head1 New Tests
2036
2037Several new tests have been added, especially for the F<lib> subsection.
2038
2039The tests are now reported in a different order than in earlier Perls.
2040(This happens because the test scripts from under t/lib have been moved
2041to be closer to the library/extension they are testing.)
2042
f39f21d8
JH
2043=head1 Known Problems
2044
2045Note that unlike other sections in this document (which describe
2046changes since 5.7.0) this section is cumulative containing known
2047problems for all the 5.7 releases.
2048
2049=head2 AIX
2050
2051=over 4
2052
2053=item *
2054
2055In AIX 4.2 Perl extensions that use C++ functions that use statics
2056may have problems in that the statics are not getting initialized.
2057In newer AIX releases this has been solved by linking Perl with
2058the libC_r library, but unfortunately in AIX 4.2 the said library
2059has an obscure bug where the various functions related to time
2060(such as time() and gettimeofday()) return broken values, and
2061therefore in AIX 4.2 Perl is not linked against the libC_r.
2062
2063=item *
2064
2065vac 5.0.0.0 May Produce Buggy Code For Perl
2066
2067The AIX C compiler vac version 5.0.0.0 may produce buggy code,
2068resulting in few random tests failing, but when the failing tests
2069are run by hand, they succeed. We suggest upgrading to at least
2070vac version 5.0.1.0, that has been known to compile Perl correctly.
2071"lslpp -L|grep vac.C" will tell you the vac version.
2072
2073=back
2074
2075=head2 Amiga Perl Invoking Mystery
2076
2077One cannot call Perl using the C<volume:> syntax, that is, C<perl -v>
2078works, but for example C<bin:perl -v> doesn't. The exact reason is
2079known but the current suspect is the F<ixemul> library.
2080
2081=head2 lib/ftmp-security tests warn 'system possibly insecure'
2082
2083Don't panic. Read INSTALL 'make test' section instead.
2084
2085=head2 Cygwin intermittent failures of lib/Memoize/t/expire_file 11 and 12
2086
2087The subtests 11 and 12 sometimes fail and sometimes work.
2088
2089=head2 HP-UX lib/io_multihomed Fails When LP64-Configured
2090
2091The lib/io_multihomed test may hang in HP-UX if Perl has been
2092configured to be 64-bit. Because other 64-bit platforms do not hang in
2093this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The
2094test attempts to create and connect to "multihomed" sockets (sockets
2095which have multiple IP addresses).
2096
2097=head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
2098
2099If perl is configured with -Duse64bitall, the successful result of the
2100subtest 10 of lib/posix may arrive before the successful result of the
2101subtest 9, which confuses the test harness so much that it thinks the
2102subtest 9 failed.
2103
2104=head2 Linux With Sfio Fails op/misc Test 48
2105
2106No known fix.
2107
2108=head2 OS/390
2109
2110OS/390 has rather many test failures but the situation is actually
2111better than it was in 5.6.0, it's just that so many new modules and
2112tests have been added.
2113
2114 Failed Test Stat Wstat Total Fail Failed List of Failed
2115 -----------------------------------------------------------------------------
2116 ../ext/B/Deparse.t 14 1 7.14% 14
2117 ../ext/B/Showlex.t 1 1 100.00% 1
2118 ../ext/Encode/Encode/Tcl.t 610 13 2.13% 592 594 596 598
2119 600 602 604-610
2120 ../ext/IO/lib/IO/t/io_unix.t 113 28928 5 3 60.00% 3-5
2121 ../ext/POSIX/POSIX.t 29 1 3.45% 14
2122 ../ext/Storable/t/lock.t 255 65280 5 3 60.00% 3-5
2123 ../lib/locale.t 129 33024 117 19 16.24% 99-117
2124 ../lib/warnings.t 434 1 0.23% 75
2125 ../lib/ExtUtils.t 27 1 3.70% 25
2126 ../lib/Math/BigInt/t/bigintpm.t 1190 1 0.08% 1145
2127 ../lib/Unicode/UCD.t 81 48 59.26% 1-16 49-64 66-81
2128 ../lib/User/pwent.t 9 1 11.11% 4
2129 op/pat.t 660 6 0.91% 242-243 424-425
2130 626-627
2131 op/split.t 0 9 ?? ?? % ??
2132 op/taint.t 174 3 1.72% 156 162 168
2133 op/tr.t 70 3 4.29% 50 58-59
2134 Failed 16/422 test scripts, 96.21% okay. 105/23251 subtests failed, 99.55% okay.
2135
2136=head2 op/sprintf tests 129 and 130
2137
2138The op/sprintf tests 129 and 130 are known to fail on some platforms.
2139Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX.
2140The failing platforms do not comply with the ANSI C Standard, line
214119ff on page 134 of ANSI X3.159 1989 to be exact. (They produce
2142something other than "1" and "-1" when formatting 0.6 and -0.6 using
2143the printf format "%.0f", most often they produce "0" and "-0".)
2144
2145=head2 Failure of Thread tests
2146
2147B<Note that support for 5.005-style threading remains experimental.>
2148
2149The following tests are known to fail due to fundamental problems in
2150the 5.005 threading implementation. These are not new failures--Perl
21515.005_0x has the same bugs, but didn't have these tests.
2152
2153 lib/autouse.t 4
2154 t/lib/thr5005.t 19-20
2155
2156=head2 UNICOS
2157
2158=over 4
2159
2160=item *
2161
2162ext/POSIX/sigaction subtests 6 and 13 may fail.
2163
2164=item *
2165
2166lib/ExtUtils may spuriously claim that subtest 28 failed,
2167which is interesting since the test only has 27 tests.
2168
2169=item *
2170
2171Numerous numerical test failures
2172
2173 op/numconvert 209,210,217,218
2174 op/override 7
2175 ext/Time/HiRes/HiRes 9
2176 lib/Math/BigInt/t/bigintpm 1145
2177 lib/Math/Trig 25
2178
2179These tests fail because of yet unresolved floating point inaccuracies.
2180
2181=back
2182
2183=head2 UTS
2184
2185There are a few known test failures, see L<perluts>.
2186
2187=head2 VMS
2188
2189Rather many tests are failing in VMS but that actually more tests
2190succeed in VMS than they used to, it's just that there are many,
2191many more tests than there used to be.
2192
2193Here are the known failures from some compiler/platform combinations.
2194
2195DEC C V5.3-006 on OpenVMS VAX V6.2
ba370e9b 2196
f39f21d8
JH
2197 [-.ext.list.util.t]tainted..............FAILED on test 3
2198 [-.ext.posix]sigaction..................FAILED on test 7
2199 [-.ext.time.hires]hires.................FAILED on test 14
2200 [-.lib.file.find]taint..................FAILED on test 17
2201 [-.lib.math.bigint.t]bigintpm...........FAILED on test 1183
2202 [-.lib.test.simple.t]exit...............FAILED on test 1
2203 [.lib]vmsish............................FAILED on test 13
2204 [.op]sprintf............................FAILED on test 12
2205 Failed 8/399 tests, 91.23% okay.
2206
2207DEC C V6.0-001 on OpenVMS Alpha V7.2-1 and
2208Compaq C V6.2-008 on OpenVMS Alpha V7.1
2209
2210 [-.ext.list.util.t]tainted..............FAILED on test 3
2211 [-.lib.file.find]taint..................FAILED on test 17
2212 [-.lib.test.simple.t]exit...............FAILED on test 1
2213 [.lib]vmsish............................FAILED on test 13
2214 Failed 4/399 tests, 92.48% okay.
2215
2216Compaq C V6.4-005 on OpenVMS Alpha 7.2.1
2217
2218 [-.ext.b]showlex........................FAILED on test 1
2219 [-.ext.list.util.t]tainted..............FAILED on test 3
2220 [-.lib.file.find]taint..................FAILED on test 17
2221 [-.lib.test.simple.t]exit...............FAILED on test 1
2222 [.lib]vmsish............................FAILED on test 13
2223 [.op]misc...............................FAILED on test 49
2224 Failed 6/401 tests, 92.77% okay.
2225
2226=head2 Win32
2227
2228In multi-CPU boxes there are some problems with the I/O buffering:
2229some output may appear twice.
2230
2231=head2 Localising a Tied Variable Leaks Memory
2232
2233 use Tie::Hash;
2234 tie my %tie_hash => 'Tie::StdHash';
2235
2236 ...
2237
2238 local($tie_hash{Foo}) = 1; # leaks
2239
2240Code like the above is known to leak memory every time the local()
2241is executed.
2242
2243=head2 Self-tying of Arrays and Hashes Is Forbidden
2244
2245Self-tying of arrays and hashes is broken in rather deep and
2246hard-to-fix ways. As a stop-gap measure to avoid people from getting
2247frustrated at the mysterious results (core dumps, most often) it is
2248for now forbidden (you will get a fatal error even from an attempt).
2249
2250=head2 Variable Attributes are not Currently Usable for Tieing
2251
2252This limitation will hopefully be fixed in future. (Subroutine
2253attributes work fine for tieing, see L<Attribute::Handlers>).
2254
2255=head2 Building Extensions Can Fail Because Of Largefiles
2256
2257Some extensions like mod_perl are known to have issues with
2258`largefiles', a change brought by Perl 5.6.0 in which file offsets
2259default to 64 bits wide, where supported. Modules may fail to compile
2260at all or compile and work incorrectly. Currently there is no good
2261solution for the problem, but Configure now provides appropriate
2262non-largefile ccflags, ldflags, libswanted, and libs in the %Config
2263hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are
2264having problems can try configuring themselves without the
2265largefileness. This is admittedly not a clean solution, and the
2266solution may not even work at all. One potential failure is whether
2267one can (or, if one can, whether it's a good idea) link together at
2268all binaries with different ideas about file offsets, all this is
2269platform-dependent.
2270
2271=head2 The Compiler Suite Is Still Experimental
2272
2273The compiler suite is slowly getting better but is nowhere near
2274working order yet.
2275
2276=head2 The Long Double Support is Still Experimental
2277
2278The ability to configure Perl's numbers to use "long doubles",
2279floating point numbers of hopefully better accuracy, is still
2280experimental. The implementations of long doubles are not yet
2281widespread and the existing implementations are not quite mature
2282or standardised, therefore trying to support them is a rare
2283and moving target. The gain of more precision may also be offset
2284by slowdown in computations (more bits to move around, and the
2285operations are more likely to be executed by less optimised
2286libraries).
33a87e58 2287
cc0fca54
GS
2288=head1 Reporting Bugs
2289
d4ad863d
JH
2290If you find what you think is a bug, you might check the articles
2291recently posted to the comp.lang.perl.misc newsgroup and the perl
2292bug database at http://bugs.perl.org. There may also be
2293information at http://www.perl.com/perl/, the Perl Home Page.
cc0fca54
GS
2294
2295If you believe you have an unreported bug, please run the B<perlbug>
2296program included with your release. Be sure to trim your bug down
2297to a tiny but sufficient test case. Your bug report, along with the
d4ad863d 2298output of C<perl -V>, will be sent off to perlbug@perl.org to be
cc0fca54
GS
2299analysed by the Perl porting team.
2300
2301=head1 SEE ALSO
2302
2303The F<Changes> file for exhaustive details on what changed.
2304
2305The F<INSTALL> file for how to build Perl.
2306
2307The F<README> file for general stuff.
2308
2309The F<Artistic> and F<Copying> files for copyright information.
2310
2311=head1 HISTORY
2312
d468ca04 2313Written by Jarkko Hietaniemi <F<jhi@iki.fi>>.
cc0fca54
GS
2314
2315=cut