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1 | =head1 NAME |
2 | ||
3 | perldelta - what is new for perl v5.8.0 | |
4 | ||
5 | =head1 DESCRIPTION | |
6 | ||
7 | This document describes differences between the 5.6.0 release and | |
8 | the 5.8.0 release. | |
9 | ||
10 | Many of the bug fixes in 5.8.0 were already seen in the 5.6.1 | |
11 | maintenance release since the two releases were kept closely | |
12 | coordinated (while 5.8.0 was still called 5.7.something). | |
13 | ||
14 | Changes that were integrated into the 5.6.1 release are marked C<[561]>. | |
15 | Many of these changes have been further developed since 5.6.1 was released, | |
16 | those are marked C<[561+]>. | |
17 | ||
18 | You can see the list of changes in the 5.6.1 release (both from the | |
19 | 5.005_03 release and the 5.6.0 release) by reading L<perl561delta>. | |
20 | ||
21 | =head1 Highlights In 5.8.0 | |
22 | ||
23 | =over 4 | |
24 | ||
25 | =item * | |
26 | ||
27 | Better Unicode support | |
28 | ||
29 | =item * | |
30 | ||
31 | New IO Implementation | |
32 | ||
33 | =item * | |
34 | ||
35 | New Thread Implementation | |
36 | ||
37 | =item * | |
38 | ||
39 | Better Numeric Accuracy | |
40 | ||
41 | =item * | |
42 | ||
43 | Safe Signals | |
44 | ||
45 | =item * | |
46 | ||
47 | Many New Modules | |
48 | ||
49 | =item * | |
50 | ||
51 | More Extensive Regression Testing | |
52 | ||
53 | =back | |
54 | ||
55 | =head1 Incompatible Changes | |
56 | ||
57 | =head2 Binary Incompatibility | |
58 | ||
59 | B<Perl 5.8 is not binary compatible with earlier releases of Perl.> | |
60 | ||
61 | B<You have to recompile your XS modules.> | |
62 | ||
63 | (Pure Perl modules should continue to work.) | |
64 | ||
65 | The major reason for the discontinuity is the new IO architecture | |
66 | called PerlIO. PerlIO is the default configuration because without | |
67 | it many new features of Perl 5.8 cannot be used. In other words: | |
68 | you just have to recompile your modules containing XS code, sorry | |
69 | about that. | |
70 | ||
71 | In future releases of Perl, non-PerlIO aware XS modules may become | |
72 | completely unsupported. This shouldn't be too difficult for module | |
73 | authors, however: PerlIO has been designed as a drop-in replacement | |
74 | (at the source code level) for the stdio interface. | |
75 | ||
76 | Depending on your platform, there are also other reasons why | |
77 | we decided to break binary compatibility, please read on. | |
78 | ||
79 | =head2 64-bit platforms and malloc | |
80 | ||
81 | If your pointers are 64 bits wide, the Perl malloc is no longer being | |
82 | used because it does not work well with 8-byte pointers. Also, | |
83 | usually the system mallocs on such platforms are much better optimized | |
84 | for such large memory models than the Perl malloc. Some memory-hungry | |
85 | Perl applications like the PDL don't work well with Perl's malloc. | |
86 | Finally, other applications than Perl (such as mod_perl) tend to prefer | |
87 | the system malloc. Such platforms include Alpha and 64-bit HPPA, | |
88 | MIPS, PPC, and Sparc. | |
89 | ||
90 | =head2 AIX Dynaloading | |
91 | ||
92 | The AIX dynaloading now uses in AIX releases 4.3 and newer the native | |
93 | dlopen interface of AIX instead of the old emulated interface. This | |
94 | change will probably break backward compatibility with compiled | |
95 | modules. The change was made to make Perl more compliant with other | |
96 | applications like mod_perl which are using the AIX native interface. | |
97 | ||
98 | =head2 Attributes for C<my> variables now handled at run-time | |
99 | ||
100 | The C<my EXPR : ATTRS> syntax now applies variable attributes at | |
101 | run-time. (Subroutine and C<our> variables still get attributes applied | |
102 | at compile-time.) See L<attributes> for additional details. In particular, | |
103 | however, this allows variable attributes to be useful for C<tie> interfaces, | |
104 | which was a deficiency of earlier releases. Note that the new semantics | |
105 | doesn't work with the Attribute::Handlers module (as of version 0.76). | |
106 | ||
107 | =head2 Socket Extension Dynamic in VMS | |
108 | ||
109 | The Socket extension is now dynamically loaded instead of being | |
110 | statically built in. This may or may not be a problem with ancient | |
111 | TCP/IP stacks of VMS: we do not know since we weren't able to test | |
112 | Perl in such configurations. | |
113 | ||
114 | =head2 IEEE-format Floating Point Default on OpenVMS Alpha | |
115 | ||
116 | Perl now uses IEEE format (T_FLOAT) as the default internal floating | |
117 | point format on OpenVMS Alpha, potentially breaking binary compatibility | |
118 | with external libraries or existing data. G_FLOAT is still available as | |
119 | a configuration option. The default on VAX (D_FLOAT) has not changed. | |
120 | ||
121 | =head2 New Unicode Semantics (no more C<use utf8>, almost) | |
122 | ||
123 | Previously in Perl 5.6 to use Unicode one would say "use utf8" and | |
124 | then the operations (like string concatenation) were Unicode-aware | |
125 | in that lexical scope. | |
126 | ||
127 | This was found to be an inconvenient interface, and in Perl 5.8 the | |
128 | Unicode model has completely changed: now the "Unicodeness" is bound | |
129 | to the data itself, and for most of the time "use utf8" is not needed | |
130 | at all. The only remaining use of "use utf8" is when the Perl script | |
131 | itself has been written in the UTF-8 encoding of Unicode. (UTF-8 has | |
132 | not been made the default since there are many Perl scripts out there | |
133 | that are using various national eight-bit character sets, which would | |
134 | be illegal in UTF-8.) | |
135 | ||
136 | See L<perluniintro> for the explanation of the current model, | |
137 | and L<utf8> for the current use of the utf8 pragma. | |
138 | ||
139 | =head2 New Unicode Properties | |
140 | ||
141 | Unicode I<scripts> are now supported. Scripts are similar to (and superior | |
142 | to) Unicode I<blocks>. The difference between scripts and blocks is that | |
143 | scripts are the glyphs used by a language or a group of languages, while | |
144 | the blocks are more artificial groupings of (mostly) 256 characters based | |
145 | on the Unicode numbering. | |
146 | ||
147 | In general, scripts are more inclusive, but not universally so. For | |
148 | example, while the script C<Latin> includes all the Latin characters and | |
149 | their various diacritic-adorned versions, it does not include the various | |
150 | punctuation or digits (since they are not solely C<Latin>). | |
151 | ||
152 | A number of other properties are now supported, including C<\p{L&}>, | |
153 | C<\p{Any}> C<\p{Assigned}>, C<\p{Unassigned}>, C<\p{Blank}> [561] and | |
154 | C<\p{SpacePerl}> [561] (along with their C<\P{...}> versions, of course). | |
155 | See L<perlunicode> for details, and more additions. | |
156 | ||
157 | The C<In> or C<Is> prefix to names used with the C<\p{...}> and C<\P{...}> | |
158 | are now almost always optional. The only exception is that a C<In> prefix | |
159 | is required to signify a Unicode block when a block name conflicts with a | |
160 | script name. For example, C<\p{Tibetan}> refers to the script, while | |
161 | C<\p{InTibetan}> refers to the block. When there is no name conflict, you | |
162 | can omit the C<In> from the block name (e.g. C<\p{BraillePatterns}>), but | |
163 | to be safe, it's probably best to always use the C<In>). | |
164 | ||
165 | =head2 REF(...) Instead Of SCALAR(...) | |
166 | ||
167 | A reference to a reference now stringifies as "REF(0x81485ec)" instead | |
168 | of "SCALAR(0x81485ec)" in order to be more consistent with the return | |
169 | value of ref(). | |
170 | ||
171 | =head2 pack/unpack D/F recycled | |
172 | ||
173 | The undocumented pack/unpack template letters D/F have been recycled | |
174 | for better use: now they stand for long double (if supported by the | |
175 | platform) and NV (Perl internal floating point type). (They used | |
176 | to be aliases for d/f, but you never knew that.) | |
177 | ||
178 | =head2 glob() now returns filenames in alphabetical order | |
179 | ||
180 | The list of filenames from glob() (or <...>) is now by default sorted | |
181 | alphabetically to be csh-compliant (which is what happened before | |
182 | in most UNIX platforms). (bsd_glob() does still sort platform | |
183 | natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.) [561] | |
184 | ||
185 | =head2 Deprecations | |
186 | ||
187 | =over 4 | |
188 | ||
189 | =item * | |
190 | ||
191 | The semantics of bless(REF, REF) were unclear and until someone proves | |
192 | it to make some sense, it is forbidden. | |
193 | ||
194 | =item * | |
195 | ||
196 | The obsolete chat2 library that should never have been allowed | |
197 | to escape the laboratory has been decommissioned. | |
198 | ||
199 | =item * | |
200 | ||
201 | Using chdir("") or chdir(undef) instead of explicit chdir() is | |
202 | doubtful. A failure (think chdir(some_function()) can lead into | |
203 | unintended chdir() to the home directory, therefore this behaviour | |
204 | is deprecated. | |
205 | ||
206 | =item * | |
207 | ||
208 | The builtin dump() function has probably outlived most of its | |
209 | usefulness. The core-dumping functionality will remain in future | |
210 | available as an explicit call to C<CORE::dump()>, but in future | |
211 | releases the behaviour of an unqualified C<dump()> call may change. | |
212 | ||
213 | =item * | |
214 | ||
215 | The very dusty examples in the eg/ directory have been removed. | |
216 | Suggestions for new shiny examples welcome but the main issue is that | |
217 | the examples need to be documented, tested and (most importantly) | |
218 | maintained. | |
219 | ||
220 | =item * | |
221 | ||
222 | The (bogus) escape sequences \8 and \9 now give an optional warning | |
223 | ("Unrecognized escape passed through"). There is no need to \-escape | |
224 | any C<\w> character. | |
225 | ||
226 | =item * | |
227 | ||
228 | The *glob{FILEHANDLE} is deprecated, use *glob{IO} instead. | |
229 | ||
230 | =item * | |
231 | ||
232 | The C<package;> syntax (C<package> without an argument) has been | |
233 | deprecated. Its semantics were never that clear and its | |
234 | implementation even less so. If you have used that feature to | |
235 | disallow all but fully qualified variables, C<use strict;> instead. | |
236 | ||
237 | =item * | |
238 | ||
239 | The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still | |
240 | recognised but now cause fatal errors. The previous behaviour of | |
241 | ignoring them by default and warning if requested was unacceptable | |
242 | since it, in a way, falsely promised that the features could be used. | |
243 | ||
244 | =item * | |
245 | ||
246 | In future releases, non-PerlIO aware XS modules may become completely | |
247 | unsupported. Since PerlIO is a drop-in replacement for stdio at the | |
248 | source code level, this shouldn't be that drastic a change. | |
249 | ||
250 | =item * | |
251 | ||
252 | Previous versions of perl and some readings of some sections of Camel | |
253 | III implied that the C<:raw> "discipline" was the inverse of C<:crlf>. | |
254 | Turning off "clrfness" is no longer enough to make a stream truly | |
255 | binary. So the PerlIO C<:raw> layer (or "discipline", to use the Camel | |
256 | book's older terminology) is now formally defined as being equivalent | |
257 | to binmode(FH) - which is in turn defined as doing whatever is | |
258 | necessary to pass each byte as-is without any translation. In | |
259 | particular binmode(FH) - and hence C<:raw> - will now turn off both | |
260 | CRLF and UTF-8 translation and remove other layers (e.g. :encoding()) | |
261 | which would modify byte stream. | |
262 | ||
263 | =item * | |
264 | ||
265 | The current user-visible implementation of pseudo-hashes (the weird | |
266 | use of the first array element) is deprecated starting from Perl 5.8.0 | |
267 | and will be removed in Perl 5.10.0, and the feature will be | |
268 | implemented differently. Not only is the current interface rather | |
269 | ugly, but the current implementation slows down normal array and hash | |
270 | use quite noticeably. The C<fields> pragma interface will remain | |
271 | available. The I<restricted hashes> interface is expected to | |
272 | be the replacement interface (see L<Hash::Util>). If your existing | |
273 | programs depends on the underlying implementation, consider using | |
274 | L<Class::PseudoHash> from CPAN. | |
275 | ||
276 | =item * | |
277 | ||
278 | The syntaxes C<< @a->[...] >> and C<< %h->{...} >> have now been deprecated. | |
279 | ||
280 | =item * | |
281 | ||
282 | After years of trying, suidperl is considered to be too complex to | |
283 | ever be considered truly secure. The suidperl functionality is likely | |
284 | to be removed in a future release. | |
285 | ||
286 | =item * | |
287 | ||
288 | The 5.005 threads model (module C<Thread>) is deprecated and expected | |
289 | to be removed in Perl 5.10. Multithreaded code should be migrated to | |
290 | the new ithreads model (see L<threads>, L<threads::shared> and | |
291 | L<perlthrtut>). | |
292 | ||
293 | =item * | |
294 | ||
295 | The long deprecated uppercase aliases for the string comparison | |
296 | operators (EQ, NE, LT, LE, GE, GT) have now been removed. | |
297 | ||
298 | =item * | |
299 | ||
300 | The tr///C and tr///U features have been removed and will not return; | |
301 | the interface was a mistake. Sorry about that. For similar | |
302 | functionality, see pack('U0', ...) and pack('C0', ...). [561] | |
303 | ||
304 | =item * | |
305 | ||
306 | Earlier Perls treated "sub foo (@bar)" as equivalent to "sub foo (@)". | |
307 | The prototypes are now checked better at compile-time for invalid | |
308 | syntax. An optional warning is generated ("Illegal character in | |
309 | prototype...") but this may be upgraded to a fatal error in a future | |
310 | release. | |
311 | ||
312 | =item * | |
313 | ||
314 | The C<exec LIST> and C<system LIST> operations now produce warnings on | |
315 | tainted data and in some future release they will produce fatal errors. | |
316 | ||
317 | =item * | |
318 | ||
319 | The existing behaviour when localising tied arrays and hashes is wrong, | |
320 | and will be changed in a future release, so do not rely on the existing | |
321 | behaviour. See L<"Localising Tied Arrays and Hashes Is Broken">. | |
322 | ||
323 | =back | |
324 | ||
325 | =head1 Core Enhancements | |
326 | ||
327 | =head2 Unicode Overhaul | |
328 | ||
329 | Unicode in general should be now much more usable than in Perl 5.6.0 | |
330 | (or even in 5.6.1). Unicode can be used in hash keys, Unicode in | |
331 | regular expressions should work now, Unicode in tr/// should work now, | |
332 | Unicode in I/O should work now. See L<perluniintro> for introduction | |
333 | and L<perlunicode> for details. | |
334 | ||
335 | =over 4 | |
336 | ||
337 | =item * | |
338 | ||
339 | The Unicode Character Database coming with Perl has been upgraded | |
340 | to Unicode 3.2.0. For more information, see http://www.unicode.org/ . | |
341 | [561+] (5.6.1 has UCD 3.0.1.) | |
342 | ||
343 | =item * | |
344 | ||
345 | For developers interested in enhancing Perl's Unicode capabilities: | |
346 | almost all the UCD files are included with the Perl distribution in | |
347 | the F<lib/unicore> subdirectory. The most notable omission, for space | |
348 | considerations, is the Unihan database. | |
349 | ||
350 | =item * | |
351 | ||
352 | The properties \p{Blank} and \p{SpacePerl} have been added. "Blank" is like | |
353 | C isblank(), that is, it contains only "horizontal whitespace" (the space | |
354 | character is, the newline isn't), and the "SpacePerl" is the Unicode | |
355 | equivalent of C<\s> (\p{Space} isn't, since that includes the vertical | |
356 | tabulator character, whereas C<\s> doesn't.) | |
357 | ||
358 | See "New Unicode Properties" earlier in this document for additional | |
359 | information on changes with Unicode properties. | |
360 | ||
361 | =back | |
362 | ||
363 | =head2 PerlIO is Now The Default | |
364 | ||
365 | =over 4 | |
366 | ||
367 | =item * | |
368 | ||
369 | IO is now by default done via PerlIO rather than system's "stdio". | |
370 | PerlIO allows "layers" to be "pushed" onto a file handle to alter the | |
371 | handle's behaviour. Layers can be specified at open time via 3-arg | |
372 | form of open: | |
373 | ||
374 | open($fh,'>:crlf :utf8', $path) || ... | |
375 | ||
376 | or on already opened handles via extended C<binmode>: | |
377 | ||
378 | binmode($fh,':encoding(iso-8859-7)'); | |
379 | ||
380 | The built-in layers are: unix (low level read/write), stdio (as in | |
381 | previous Perls), perlio (re-implementation of stdio buffering in a | |
382 | portable manner), crlf (does CRLF <=> "\n" translation as on Win32, | |
383 | but available on any platform). A mmap layer may be available if | |
384 | platform supports it (mostly UNIXes). | |
385 | ||
386 | Layers to be applied by default may be specified via the 'open' pragma. | |
387 | ||
388 | See L</"Installation and Configuration Improvements"> for the effects | |
389 | of PerlIO on your architecture name. | |
390 | ||
391 | =item * | |
392 | ||
393 | If your platform supports fork(), you can use the list form of C<open> | |
394 | for pipes. For example: | |
395 | ||
396 | open KID_PS, "-|", "ps", "aux" or die $!; | |
397 | ||
398 | forks the ps(1) command (without spawning a shell, as there are more | |
399 | than three arguments to open()), and reads its standard output via the | |
400 | C<KID_PS> filehandle. See L<perlipc>. | |
401 | ||
402 | =item * | |
403 | ||
404 | File handles can be marked as accepting Perl's internal encoding of Unicode | |
405 | (UTF-8 or UTF-EBCDIC depending on platform) by a pseudo layer ":utf8" : | |
406 | ||
407 | open($fh,">:utf8","Uni.txt"); | |
408 | ||
409 | Note for EBCDIC users: the pseudo layer ":utf8" is erroneously named | |
410 | for you since it's not UTF-8 what you will be getting but instead | |
411 | UTF-EBCDIC. See L<perlunicode>, L<utf8>, and | |
412 | http://www.unicode.org/unicode/reports/tr16/ for more information. | |
413 | In future releases this naming may change. See L<perluniintro> | |
414 | for more information about UTF-8. | |
415 | ||
416 | =item * | |
417 | ||
418 | If your environment variables (LC_ALL, LC_CTYPE, LANG, LANGUAGE) look | |
419 | like you want to use UTF-8 (any of the the variables match C</utf-?8/i>), | |
420 | your STDIN, STDOUT, STDERR handles and the default open layer | |
421 | (see L<open>) are marked as UTF-8. (This feature, like other new | |
422 | features that combine Unicode and I/O, work only if you are using | |
423 | PerlIO, but that's the default.) | |
424 | ||
425 | Note that after this Perl really does assume that everything is UTF-8: | |
426 | for example if some input handle is not, Perl will probably very soon | |
427 | complain about the input data like this "Malformed UTF-8 ..." since | |
428 | any old eight-bit data is not legal UTF-8. | |
429 | ||
430 | Note for code authors: if you want to enable your users to use UTF-8 | |
431 | as their default encoding but in your code still have eight-bit I/O streams | |
432 | (such as images or zip files), you need to explicitly open() or binmode() | |
433 | with C<:bytes> (see L<perlfunc/open> and L<perlfunc/binmode>), or you | |
434 | can just use C<binmode(FH)> (nice for pre-5.8.0 backward compatibility). | |
435 | ||
436 | =item * | |
437 | ||
438 | File handles can translate character encodings from/to Perl's internal | |
439 | Unicode form on read/write via the ":encoding()" layer. | |
440 | ||
441 | =item * | |
442 | ||
443 | File handles can be opened to "in memory" files held in Perl scalars via: | |
444 | ||
445 | open($fh,'>', \$variable) || ... | |
446 | ||
447 | =item * | |
448 | ||
449 | Anonymous temporary files are available without need to | |
450 | 'use FileHandle' or other module via | |
451 | ||
452 | open($fh,"+>", undef) || ... | |
453 | ||
454 | That is a literal undef, not an undefined value. | |
455 | ||
456 | =back | |
457 | ||
458 | =head2 ithreads | |
459 | ||
460 | The new interpreter threads ("ithreads" for short) implementation of | |
461 | multithreading, by Arthur Bergman, replaces the old "5.005 threads" | |
462 | implementation. In the ithreads model any data sharing between | |
463 | threads must be explicit, as opposed to the model where data sharing | |
464 | was implicit. See L<threads> and L<threads::shared>, and | |
465 | L<perlthrtut>. | |
466 | ||
467 | As a part of the ithreads implementation Perl will also use | |
468 | any necessary and detectable reentrant libc interfaces. | |
469 | ||
470 | =head2 Restricted Hashes | |
471 | ||
472 | A restricted hash is restricted to a certain set of keys, no keys | |
473 | outside the set can be added. Also individual keys can be restricted | |
474 | so that the key cannot be deleted and the value cannot be changed. | |
475 | No new syntax is involved: the Hash::Util module is the interface. | |
476 | ||
477 | =head2 Safe Signals | |
478 | ||
479 | Perl used to be fragile in that signals arriving at inopportune moments | |
480 | could corrupt Perl's internal state. Now Perl postpones handling of | |
481 | signals until it's safe (between opcodes). | |
482 | ||
483 | This change may have surprising side effects because signals no longer | |
484 | interrupt Perl instantly. Perl will now first finish whatever it was | |
485 | doing, like finishing an internal operation (like sort()) or an | |
486 | external operation (like an I/O operation), and only then look at any | |
487 | arrived signals (and before starting the next operation). No more corrupt | |
488 | internal state since the current operation is always finished first, | |
489 | but the signal may take more time to get heard. Note that breaking | |
490 | out from potentially blocking operations should still work, though. | |
491 | ||
492 | =head2 Understanding of Numbers | |
493 | ||
494 | In general a lot of fixing has happened in the area of Perl's | |
495 | understanding of numbers, both integer and floating point. Since in | |
496 | many systems the standard number parsing functions like C<strtoul()> | |
497 | and C<atof()> seem to have bugs, Perl tries to work around their | |
498 | deficiencies. This results hopefully in more accurate numbers. | |
499 | ||
500 | Perl now tries internally to use integer values in numeric conversions | |
501 | and basic arithmetics (+ - * /) if the arguments are integers, and | |
502 | tries also to keep the results stored internally as integers. | |
503 | This change leads to often slightly faster and always less lossy | |
504 | arithmetics. (Previously Perl always preferred floating point numbers | |
505 | in its math.) | |
506 | ||
507 | =head2 Arrays now always interpolate into double-quoted strings [561] | |
508 | ||
509 | In double-quoted strings, arrays now interpolate, no matter what. The | |
510 | behavior in earlier versions of perl 5 was that arrays would interpolate | |
511 | into strings if the array had been mentioned before the string was | |
512 | compiled, and otherwise Perl would raise a fatal compile-time error. | |
513 | In versions 5.000 through 5.003, the error was | |
514 | ||
515 | Literal @example now requires backslash | |
516 | ||
517 | In versions 5.004_01 through 5.6.0, the error was | |
518 | ||
519 | In string, @example now must be written as \@example | |
520 | ||
521 | The idea here was to get people into the habit of writing | |
522 | C<"fred\@example.com"> when they wanted a literal C<@> sign, just as | |
523 | they have always written C<"Give me back my \$5"> when they wanted a | |
524 | literal C<$> sign. | |
525 | ||
526 | Starting with 5.6.1, when Perl now sees an C<@> sign in a | |
527 | double-quoted string, it I<always> attempts to interpolate an array, | |
528 | regardless of whether or not the array has been used or declared | |
529 | already. The fatal error has been downgraded to an optional warning: | |
530 | ||
531 | Possible unintended interpolation of @example in string | |
532 | ||
533 | This warns you that C<"fred@example.com"> is going to turn into | |
534 | C<fred.com> if you don't backslash the C<@>. | |
535 | See http://www.plover.com/~mjd/perl/at-error.html for more details | |
536 | about the history here. | |
537 | ||
538 | =head2 Miscellaneous Changes | |
539 | ||
540 | =over 4 | |
541 | ||
542 | =item * | |
543 | ||
544 | AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute | |
545 | to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value. | |
546 | ||
547 | =item * | |
548 | ||
549 | The $Config{byteorder} (and corresponding BYTEORDER in config.h) was | |
550 | previously wrong in platforms if sizeof(long) was 4, but sizeof(IV) | |
551 | was 8. The byteorder was only sizeof(long) bytes long (1234 or 4321), | |
552 | but now it is correctly sizeof(IV) bytes long, (12345678 or 87654321). | |
553 | (This problem didn't affect Windows platforms.) | |
554 | ||
555 | Also, $Config{byteorder} is now computed dynamically--this is more | |
556 | robust with "fat binaries" where an executable image contains binaries | |
557 | for more than one binary platform, and when cross-compiling. | |
558 | ||
559 | =item * | |
560 | ||
561 | C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass | |
562 | in multiple arguments.) | |
563 | ||
564 | =item * | |
565 | ||
566 | C<do> followed by a bareword now ensures that this bareword isn't | |
567 | a keyword (to avoid a bug where C<do q(foo.pl)> tried to call a | |
568 | subroutine called C<q>). This means that for example instead of | |
569 | C<do format()> you must write C<do &format()>. | |
570 | ||
571 | =item * | |
572 | ||
573 | The builtin dump() now gives an optional warning | |
574 | C<dump() better written as CORE::dump()>, | |
575 | meaning that by default C<dump(...)> is resolved as the builtin | |
576 | dump() which dumps core and aborts, not as (possibly) user-defined | |
577 | C<sub dump>. To call the latter, qualify the call as C<&dump(...)>. | |
578 | (The whole dump() feature is to considered deprecated, and possibly | |
579 | removed/changed in future releases.) | |
580 | ||
581 | =item * | |
582 | ||
583 | chomp() and chop() are now overridable. Note, however, that their | |
584 | prototype (as given by C<prototype("CORE::chomp")> is undefined, | |
585 | because it cannot be expressed and therefore one cannot really write | |
586 | replacements to override these builtins. | |
587 | ||
588 | =item * | |
589 | ||
590 | END blocks are now run even if you exit/die in a BEGIN block. | |
591 | Internally, the execution of END blocks is now controlled by | |
592 | PL_exit_flags & PERL_EXIT_DESTRUCT_END. This enables the new | |
593 | behaviour for Perl embedders. This will default in 5.10. See | |
594 | L<perlembed>. | |
595 | ||
596 | =item * | |
597 | ||
598 | Formats now support zero-padded decimal fields. | |
599 | ||
600 | =item * | |
601 | ||
602 | Although "you shouldn't do that", it was possible to write code that | |
603 | depends on Perl's hashed key order (Data::Dumper does this). The new | |
604 | algorithm "One-at-a-Time" produces a different hashed key order. | |
605 | More details are in L</"Performance Enhancements">. | |
606 | ||
607 | =item * | |
608 | ||
609 | lstat(FILEHANDLE) now gives a warning because the operation makes no sense. | |
610 | In future releases this may become a fatal error. | |
611 | ||
612 | =item * | |
613 | ||
614 | Spurious syntax errors generated in certain situations, when glob() | |
615 | caused File::Glob to be loaded for the first time, have been fixed. [561] | |
616 | ||
617 | =item * | |
618 | ||
619 | Lvalue subroutines can now return C<undef> in list context. However, | |
620 | the lvalue subroutine feature still remains experimental. [561+] | |
621 | ||
622 | =item * | |
623 | ||
624 | A lost warning "Can't declare ... dereference in my" has been | |
625 | restored (Perl had it earlier but it became lost in later releases.) | |
626 | ||
627 | =item * | |
628 | ||
629 | A new special regular expression variable has been introduced: | |
630 | C<$^N>, which contains the most-recently closed group (submatch). | |
631 | ||
632 | =item * | |
633 | ||
634 | C<no Module;> does not produce an error even if Module does not have an | |
635 | unimport() method. This parallels the behavior of C<use> vis-a-vis | |
636 | C<import>. [561] | |
637 | ||
638 | =item * | |
639 | ||
640 | The numerical comparison operators return C<undef> if either operand | |
641 | is a NaN. Previously the behaviour was unspecified. | |
642 | ||
643 | =item * | |
644 | ||
645 | C<our> can now have an experimental optional attribute C<unique> that | |
646 | affects how global variables are shared among multiple interpreters, | |
647 | see L<perlfunc/our>. | |
648 | ||
649 | =item * | |
650 | ||
651 | The following builtin functions are now overridable: each(), keys(), | |
652 | pop(), push(), shift(), splice(), unshift(). [561] | |
653 | ||
654 | =item * | |
655 | ||
656 | C<pack() / unpack()> can now group template letters with C<()> and then | |
657 | apply repetition/count modifiers on the groups. | |
658 | ||
659 | =item * | |
660 | ||
661 | C<pack() / unpack()> can now process the Perl internal numeric types: | |
662 | IVs, UVs, NVs-- and also long doubles, if supported by the platform. | |
663 | The template letters are C<j>, C<J>, C<F>, and C<D>. | |
664 | ||
665 | =item * | |
666 | ||
667 | C<pack('U0a*', ...)> can now be used to force a string to UTF8. | |
668 | ||
669 | =item * | |
670 | ||
671 | my __PACKAGE__ $obj now works. [561] | |
672 | ||
673 | =item * | |
674 | ||
675 | POSIX::sleep() now returns the number of I<unslept> seconds | |
676 | (as the POSIX standard says), as opposed to CORE::sleep() which | |
677 | returns the number of slept seconds. | |
678 | ||
679 | =item * | |
680 | ||
681 | The printf() and sprintf() now support parameter reordering using the | |
682 | C<%\d+\$> and C<*\d+\$> syntaxes. For example | |
683 | ||
684 | print "%2\$s %1\$s\n", "foo", "bar"; | |
685 | ||
686 | will print "bar foo\n". This feature helps in writing | |
687 | internationalised software, and in general when the order | |
688 | of the parameters can vary. | |
689 | ||
690 | =item * | |
691 | ||
692 | The (\&) prototype now works properly. [561] | |
693 | ||
694 | =item * | |
695 | ||
696 | prototype(\[$@%&]) is now available to implicitly create references | |
697 | (useful for example if you want to emulate the tie() interface). | |
698 | ||
699 | =item * | |
700 | ||
701 | A new command-line option, C<-t> is available. It is the | |
702 | little brother of C<-T>: instead of dying on taint violations, | |
703 | lexical warnings are given. B<This is only meant as a temporary | |
704 | debugging aid while securing the code of old legacy applications. | |
705 | This is not a substitute for -T.> | |
706 | ||
707 | =item * | |
708 | ||
709 | In other taint news, the C<exec LIST> and C<system LIST> have now been | |
710 | considered too risky (think C<exec @ARGV>: it can start any program | |
711 | with any arguments), and now the said forms cause a warning under | |
712 | lexical warnings. You should carefully launder the arguments to | |
713 | guarantee their validity. In future releases of Perl the forms will | |
714 | become fatal errors so consider starting laundering now. | |
715 | ||
716 | =item * | |
717 | ||
718 | Tied hash interfaces are now required to have the EXISTS and DELETE | |
719 | methods (either own or inherited). | |
720 | ||
721 | =item * | |
722 | ||
723 | If tr/// is just counting characters, it doesn't attempt to | |
724 | modify its target. | |
725 | ||
726 | =item * | |
727 | ||
728 | untie() will now call an UNTIE() hook if it exists. See L<perltie> | |
729 | for details. [561] | |
730 | ||
731 | =item * | |
732 | ||
733 | L<utime> now supports C<utime undef, undef, @files> to change the | |
734 | file timestamps to the current time. | |
735 | ||
736 | =item * | |
737 | ||
738 | The rules for allowing underscores (underbars) in numeric constants | |
739 | have been relaxed and simplified: now you can have an underscore | |
740 | simply B<between digits>. | |
741 | ||
742 | =item * | |
743 | ||
744 | Rather than relying on C's argv[0] (which may not contain a full pathname) | |
745 | where possible $^X is now set by asking the operating system. | |
746 | (eg by reading F</proc/self/exe> on Linux, F</proc/curproc/file> on FreeBSD) | |
747 | ||
748 | =item * | |
749 | ||
750 | A new variable, C<${^TAINT}>, indicates whether taint mode is enabled. | |
751 | ||
752 | =item * | |
753 | ||
754 | You can now override the readline() builtin, and this overrides also | |
755 | the <FILEHANDLE> angle bracket operator. | |
756 | ||
757 | =item * | |
758 | ||
759 | The command-line options -s and -F are now recognized on the shebang | |
760 | (#!) line. | |
761 | ||
762 | =item * | |
763 | ||
764 | Use of the C</c> match modifier without an accompanying C</g> modifier | |
765 | elicits a new warning: C<Use of /c modifier is meaningless without /g>. | |
766 | ||
767 | Use of C</c> in substitutions, even with C</g>, elicits | |
768 | C<Use of /c modifier is meaningless in s///>. | |
769 | ||
770 | Use of C</g> with C<split> elicits C<Use of /g modifier is meaningless | |
771 | in split>. | |
772 | ||
773 | =item * | |
774 | ||
775 | Support for the C<CLONE> special subroutine had been added. | |
776 | With ithreads, when a new thread is created, all Perl data is cloned, | |
777 | however non-Perl data cannot be cloned automatically. In C<CLONE> you | |
778 | can do whatever you need to do, like for example handle the cloning of | |
779 | non-Perl data, if necessary. C<CLONE> will be executed once for every | |
780 | package that has it defined or inherited. It will be called in the | |
781 | context of the new thread, so all modifications are made in the new area. | |
782 | ||
783 | See L<perlmod> | |
784 | ||
785 | =back | |
786 | ||
787 | =head1 Modules and Pragmata | |
788 | ||
789 | =head2 New Modules and Pragmata | |
790 | ||
791 | =over 4 | |
792 | ||
793 | =item * | |
794 | ||
795 | C<Attribute::Handlers>, originally by Damian Conway and now maintained | |
796 | by Arthur Bergman, allows a class to define attribute handlers. | |
797 | ||
798 | package MyPack; | |
799 | use Attribute::Handlers; | |
800 | sub Wolf :ATTR(SCALAR) { print "howl!\n" } | |
801 | ||
802 | # later, in some package using or inheriting from MyPack... | |
803 | ||
804 | my MyPack $Fluffy : Wolf; # the attribute handler Wolf will be called | |
805 | ||
806 | Both variables and routines can have attribute handlers. Handlers can | |
807 | be specific to type (SCALAR, ARRAY, HASH, or CODE), or specific to the | |
808 | exact compilation phase (BEGIN, CHECK, INIT, or END). | |
809 | See L<Attribute::Handlers>. | |
810 | ||
811 | =item * | |
812 | ||
813 | C<B::Concise>, by Stephen McCamant, is a new compiler backend for | |
814 | walking the Perl syntax tree, printing concise info about ops. | |
815 | The output is highly customisable. See L<B::Concise>. [561+] | |
816 | ||
817 | =item * | |
818 | ||
819 | The new bignum, bigint, and bigrat pragmas, by Tels, implement | |
820 | transparent bignum support (using the Math::BigInt, Math::BigFloat, | |
821 | and Math::BigRat backends). | |
822 | ||
823 | =item * | |
824 | ||
825 | C<Class::ISA>, by Sean Burke, is a module for reporting the search | |
826 | path for a class's ISA tree. See L<Class::ISA>. | |
827 | ||
828 | =item * | |
829 | ||
830 | C<Cwd> now has a split personality: if possible, an XS extension is | |
831 | used, (this will hopefully be faster, more secure, and more robust) | |
832 | but if not possible, the familiar Perl implementation is used. | |
833 | ||
834 | =item * | |
835 | ||
836 | C<Devel::PPPort>, originally by Kenneth Albanowski and now | |
837 | maintained by Paul Marquess, has been added. It is primarily used | |
838 | by C<h2xs> to enhance portability of XS modules between different | |
839 | versions of Perl. See L<Devel::PPPort>. | |
840 | ||
841 | =item * | |
842 | ||
843 | C<Digest>, frontend module for calculating digests (checksums), from | |
844 | Gisle Aas, has been added. See L<Digest>. | |
845 | ||
846 | =item * | |
847 | ||
848 | C<Digest::MD5> for calculating MD5 digests (checksums) as defined in | |
849 | RFC 1321, from Gisle Aas, has been added. See L<Digest::MD5>. | |
850 | ||
851 | use Digest::MD5 'md5_hex'; | |
852 | ||
853 | $digest = md5_hex("Thirsty Camel"); | |
854 | ||
855 | print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1 | |
856 | ||
857 | NOTE: the C<MD5> backward compatibility module is deliberately not | |
858 | included since its further use is discouraged. | |
859 | ||
860 | See also L<PerlIO::via::QuotedPrint>. | |
861 | ||
862 | =item * | |
863 | ||
864 | C<Encode>, originally by Nick Ing-Simmons and now maintained by Dan | |
865 | Kogai, provides a mechanism to translate between different character | |
866 | encodings. Support for Unicode, ISO-8859-1, and ASCII are compiled in | |
867 | to the module. Several other encodings (like the rest of the | |
868 | ISO-8859, CP*/Win*, Mac, KOI8-R, three variants EBCDIC, Chinese, | |
869 | Japanese, and Korean encodings) are included and can be loaded at | |
870 | runtime. (For space considerations, the largest Chinese encodings | |
871 | have been separated into their own CPAN module, Encode::HanExtra, | |
872 | which Encode will use if available). See L<Encode>. | |
873 | ||
874 | Any encoding supported by Encode module is also available to the | |
875 | ":encoding()" layer if PerlIO is used. | |
876 | ||
877 | =item * | |
878 | ||
879 | C<Hash::Util> is the interface to the new I<restricted hashes> | |
880 | feature. (Implemented by Jeffrey Friedl, Nick Ing-Simmons, and | |
881 | Michael Schwern.) See L<Hash::Util>. | |
882 | ||
883 | =item * | |
884 | ||
885 | C<I18N::Langinfo> can be used to query locale information. | |
886 | See L<I18N::Langinfo>. | |
887 | ||
888 | =item * | |
889 | ||
890 | C<I18N::LangTags>, by Sean Burke, has functions for dealing with | |
891 | RFC3066-style language tags. See L<I18N::LangTags>. | |
892 | ||
893 | =item * | |
894 | ||
895 | C<ExtUtils::Constant>, by Nicholas Clark, is a new tool for extension | |
896 | writers for generating XS code to import C header constants. | |
897 | See L<ExtUtils::Constant>. | |
898 | ||
899 | =item * | |
900 | ||
901 | C<Filter::Simple>, by Damian Conway, is an easy-to-use frontend to | |
902 | Filter::Util::Call. See L<Filter::Simple>. | |
903 | ||
904 | # in MyFilter.pm: | |
905 | ||
906 | package MyFilter; | |
907 | ||
908 | use Filter::Simple sub { | |
909 | while (my ($from, $to) = splice @_, 0, 2) { | |
910 | s/$from/$to/g; | |
911 | } | |
912 | }; | |
913 | ||
914 | 1; | |
915 | ||
916 | # in user's code: | |
917 | ||
918 | use MyFilter qr/red/ => 'green'; | |
919 | ||
920 | print "red\n"; # this code is filtered, will print "green\n" | |
921 | print "bored\n"; # this code is filtered, will print "bogreen\n" | |
922 | ||
923 | no MyFilter; | |
924 | ||
925 | print "red\n"; # this code is not filtered, will print "red\n" | |
926 | ||
927 | =item * | |
928 | ||
929 | C<File::Temp>, by Tim Jenness, allows one to create temporary files | |
930 | and directories in an easy, portable, and secure way. See L<File::Temp>. | |
931 | [561+] | |
932 | ||
933 | =item * | |
934 | ||
935 | C<Filter::Util::Call>, by Paul Marquess, provides you with the | |
936 | framework to write I<source filters> in Perl. For most uses, the | |
937 | frontend Filter::Simple is to be preferred. See L<Filter::Util::Call>. | |
938 | ||
939 | =item * | |
940 | ||
941 | C<if>, by Ilya Zakharevich, is a new pragma for conditional inclusion | |
942 | of modules. | |
943 | ||
944 | =item * | |
945 | ||
946 | L<libnet>, by Graham Barr, is a collection of perl5 modules related | |
947 | to network programming. See L<Net::FTP>, L<Net::NNTP>, L<Net::Ping> | |
948 | (not part of libnet, but related), L<Net::POP3>, L<Net::SMTP>, | |
949 | and L<Net::Time>. | |
950 | ||
951 | Perl installation leaves libnet unconfigured; use F<libnetcfg> | |
952 | to configure it. | |
953 | ||
954 | =item * | |
955 | ||
956 | C<List::Util>, by Graham Barr, is a selection of general-utility | |
957 | list subroutines, such as sum(), min(), first(), and shuffle(). | |
958 | See L<List::Util>. | |
959 | ||
960 | =item * | |
961 | ||
962 | C<Locale::Constants>, C<Locale::Country>, C<Locale::Currency> | |
963 | C<Locale::Language>, and L<Locale::Script>, by Neil Bowers, have | |
964 | been added. They provide the codes for various locale standards, such | |
965 | as "fr" for France, "usd" for US Dollar, and "ja" for Japanese. | |
966 | ||
967 | use Locale::Country; | |
968 | ||
969 | $country = code2country('jp'); # $country gets 'Japan' | |
970 | $code = country2code('Norway'); # $code gets 'no' | |
971 | ||
972 | See L<Locale::Constants>, L<Locale::Country>, L<Locale::Currency>, | |
973 | and L<Locale::Language>. | |
974 | ||
975 | =item * | |
976 | ||
977 | C<Locale::Maketext>, by Sean Burke, is a localization framework. See | |
978 | L<Locale::Maketext>, and L<Locale::Maketext::TPJ13>. The latter is an | |
979 | article about software localization, originally published in The Perl | |
980 | Journal #13, and republished here with kind permission. | |
981 | ||
982 | =item * | |
983 | ||
984 | C<Math::BigRat> for big rational numbers, to accompany Math::BigInt and | |
985 | Math::BigFloat, from Tels. See L<Math::BigRat>. | |
986 | ||
987 | =item * | |
988 | ||
989 | C<Memoize> can make your functions faster by trading space for time, | |
990 | from Mark-Jason Dominus. See L<Memoize>. | |
991 | ||
992 | =item * | |
993 | ||
994 | C<MIME::Base64>, by Gisle Aas, allows you to encode data in base64, | |
995 | as defined in RFC 2045 - I<MIME (Multipurpose Internet Mail | |
996 | Extensions)>. | |
997 | ||
998 | use MIME::Base64; | |
999 | ||
1000 | $encoded = encode_base64('Aladdin:open sesame'); | |
1001 | $decoded = decode_base64($encoded); | |
1002 | ||
1003 | print $encoded, "\n"; # "QWxhZGRpbjpvcGVuIHNlc2FtZQ==" | |
1004 | ||
1005 | See L<MIME::Base64>. | |
1006 | ||
1007 | =item * | |
1008 | ||
1009 | C<MIME::QuotedPrint>, by Gisle Aas, allows you to encode data | |
1010 | in quoted-printable encoding, as defined in RFC 2045 - I<MIME | |
1011 | (Multipurpose Internet Mail Extensions)>. | |
1012 | ||
1013 | use MIME::QuotedPrint; | |
1014 | ||
f467b3b7 | 1015 | $encoded = encode_qp("\xDE\xAD\xBE\xEF"); |
55e8fca7 JH |
1016 | $decoded = decode_qp($encoded); |
1017 | ||
f467b3b7 HS |
1018 | print $encoded, "\n"; # "=DE=AD=BE=EF\n" |
1019 | print $decoded, "\n"; # "\xDE\xAD\xBE\xEF\n" | |
55e8fca7 JH |
1020 | |
1021 | See also L<PerlIO::via::QuotedPrint>. | |
1022 | ||
1023 | =item * | |
1024 | ||
1025 | C<NEXT>, by Damian Conway, is a pseudo-class for method redispatch. | |
1026 | See L<NEXT>. | |
1027 | ||
1028 | =item * | |
1029 | ||
1030 | C<open> is a new pragma for setting the default I/O layers | |
1031 | for open(). | |
1032 | ||
1033 | =item * | |
1034 | ||
1035 | C<PerlIO::scalar>, by Nick Ing-Simmons, provides the implementation | |
1036 | of IO to "in memory" Perl scalars as discussed above. It also serves | |
1037 | as an example of a loadable PerlIO layer. Other future possibilities | |
1038 | include PerlIO::Array and PerlIO::Code. See L<PerlIO::scalar>. | |
1039 | ||
1040 | =item * | |
1041 | ||
1042 | C<PerlIO::via>, by Nick Ing-Simmons, acts as a PerlIO layer and wraps | |
1043 | PerlIO layer functionality provided by a class (typically implemented | |
1044 | in Perl code). | |
1045 | ||
1046 | =item * | |
1047 | ||
1048 | C<PerlIO::via::QuotedPrint>, by Elizabeth Mattijsen, is an example | |
1049 | of a C<PerlIO::via> class: | |
1050 | ||
1051 | use PerlIO::via::QuotedPrint; | |
1052 | open($fh,">:via(QuotedPrint)",$path); | |
1053 | ||
1054 | This will automatically convert everything output to C<$fh> to | |
1055 | Quoted-Printable. See L<PerlIO::via> and L<PerlIO::via::QuotedPrint>. | |
1056 | ||
1057 | =item * | |
1058 | ||
1059 | C<Pod::ParseLink>, by Russ Allbery, has been added, | |
1060 | to parse LZ<><> links in pods as described in the new | |
1061 | perlpodspec. | |
1062 | ||
1063 | =item * | |
1064 | ||
1065 | C<Pod::Text::Overstrike>, by Joe Smith, has been added. | |
1066 | It converts POD data to formatted overstrike text. | |
1067 | See L<Pod::Text::Overstrike>. [561+] | |
1068 | ||
1069 | =item * | |
1070 | ||
1071 | C<Scalar::Util> is a selection of general-utility scalar subroutines, | |
1072 | such as blessed(), reftype(), and tainted(). See L<Scalar::Util>. | |
1073 | ||
1074 | =item * | |
1075 | ||
1076 | C<sort> is a new pragma for controlling the behaviour of sort(). | |
1077 | ||
1078 | =item * | |
1079 | ||
1080 | C<Storable> gives persistence to Perl data structures by allowing the | |
1081 | storage and retrieval of Perl data to and from files in a fast and | |
1082 | compact binary format. Because in effect Storable does serialisation | |
1083 | of Perl data structures, with it you can also clone deep, hierarchical | |
1084 | datastructures. Storable was originally created by Raphael Manfredi, | |
1085 | but it is now maintained by Abhijit Menon-Sen. Storable has been | |
1086 | enhanced to understand the two new hash features, Unicode keys and | |
1087 | restricted hashes. See L<Storable>. | |
1088 | ||
1089 | =item * | |
1090 | ||
1091 | C<Switch>, by Damian Conway, has been added. Just by saying | |
1092 | ||
1093 | use Switch; | |
1094 | ||
1095 | you have C<switch> and C<case> available in Perl. | |
1096 | ||
1097 | use Switch; | |
1098 | ||
1099 | switch ($val) { | |
1100 | ||
1101 | case 1 { print "number 1" } | |
1102 | case "a" { print "string a" } | |
1103 | case [1..10,42] { print "number in list" } | |
1104 | case (@array) { print "number in list" } | |
1105 | case /\w+/ { print "pattern" } | |
1106 | case qr/\w+/ { print "pattern" } | |
1107 | case (%hash) { print "entry in hash" } | |
1108 | case (\%hash) { print "entry in hash" } | |
1109 | case (\&sub) { print "arg to subroutine" } | |
1110 | else { print "previous case not true" } | |
1111 | } | |
1112 | ||
1113 | See L<Switch>. | |
1114 | ||
1115 | =item * | |
1116 | ||
1117 | C<Test::More>, by Michael Schwern, is yet another framework for writing | |
1118 | test scripts, more extensive than Test::Simple. See L<Test::More>. | |
1119 | ||
1120 | =item * | |
1121 | ||
1122 | C<Test::Simple>, by Michael Schwern, has basic utilities for writing | |
1123 | tests. See L<Test::Simple>. | |
1124 | ||
1125 | =item * | |
1126 | ||
1127 | C<Text::Balanced>, by Damian Conway, has been added, for extracting | |
1128 | delimited text sequences from strings. | |
1129 | ||
1130 | use Text::Balanced 'extract_delimited'; | |
1131 | ||
1132 | ($a, $b) = extract_delimited("'never say never', he never said", "'", ''); | |
1133 | ||
1134 | $a will be "'never say never'", $b will be ', he never said'. | |
1135 | ||
1136 | In addition to extract_delimited(), there are also extract_bracketed(), | |
1137 | extract_quotelike(), extract_codeblock(), extract_variable(), | |
1138 | extract_tagged(), extract_multiple(), gen_delimited_pat(), and | |
1139 | gen_extract_tagged(). With these, you can implement rather advanced | |
1140 | parsing algorithms. See L<Text::Balanced>. | |
1141 | ||
1142 | =item * | |
1143 | ||
1144 | C<threads>, by Arthur Bergman, is an interface to interpreter threads. | |
1145 | Interpreter threads (ithreads) is the new thread model introduced in | |
1146 | Perl 5.6 but only available as an internal interface for extension | |
1147 | writers (and for Win32 Perl for C<fork()> emulation). See L<threads>, | |
1148 | L<threads::shared>, and L<perlthrtut>. | |
1149 | ||
1150 | =item * | |
1151 | ||
1152 | C<threads::shared>, by Arthur Bergman, allows data sharing for | |
1153 | interpreter threads. See L<threads::shared>. | |
1154 | ||
1155 | =item * | |
1156 | ||
1157 | C<Tie::File>, by Mark-Jason Dominus, associates a Perl array with the | |
1158 | lines of a file. See L<Tie::File>. | |
1159 | ||
1160 | =item * | |
1161 | ||
1162 | C<Tie::Memoize>, by Ilya Zakharevich, provides on-demand loaded hashes. | |
1163 | See L<Tie::Memoize>. | |
1164 | ||
1165 | =item * | |
1166 | ||
1167 | C<Tie::RefHash::Nestable>, by Edward Avis, allows storing hash | |
1168 | references (unlike the standard Tie::RefHash) The module is contained | |
1169 | within Tie::RefHash. See L<Tie::RefHash>. | |
1170 | ||
1171 | =item * | |
1172 | ||
1173 | C<Time::HiRes>, by Douglas E. Wegscheid, provides high resolution | |
1174 | timing (ualarm, usleep, and gettimeofday). See L<Time::HiRes>. | |
1175 | ||
1176 | =item * | |
1177 | ||
1178 | C<Unicode::UCD> offers a querying interface to the Unicode Character | |
1179 | Database. See L<Unicode::UCD>. | |
1180 | ||
1181 | =item * | |
1182 | ||
1183 | C<Unicode::Collate>, by SADAHIRO Tomoyuki, implements the UCA | |
1184 | (Unicode Collation Algorithm) for sorting Unicode strings. | |
1185 | See L<Unicode::Collate>. | |
1186 | ||
1187 | =item * | |
1188 | ||
1189 | C<Unicode::Normalize>, by SADAHIRO Tomoyuki, implements the various | |
1190 | Unicode normalization forms. See L<Unicode::Normalize>. | |
1191 | ||
1192 | =item * | |
1193 | ||
1194 | C<XS::APItest>, by Tim Jenness, is a test extension that exercises XS | |
1195 | APIs. Currently only C<printf()> is tested: how to output various | |
1196 | basic data types from XS. | |
1197 | ||
1198 | =item * | |
1199 | ||
1200 | C<XS::Typemap>, by Tim Jenness, is a test extension that exercises | |
1201 | XS typemaps. Nothing gets installed, but the code is worth studying | |
1202 | for extension writers. | |
1203 | ||
1204 | =back | |
1205 | ||
1206 | =head2 Updated And Improved Modules and Pragmata | |
1207 | ||
1208 | =over 4 | |
1209 | ||
1210 | =item * | |
1211 | ||
1212 | The following independently supported modules have been updated to the | |
1213 | newest versions from CPAN: CGI, CPAN, DB_File, File::Spec, File::Temp, | |
1214 | Getopt::Long, Math::BigFloat, Math::BigInt, the podlators bundle | |
1215 | (Pod::Man, Pod::Text), Pod::LaTeX [561+], Pod::Parser, Storable, | |
1216 | Term::ANSIColor, Test, Text-Tabs+Wrap. | |
1217 | ||
1218 | =item * | |
1219 | ||
1220 | attributes::reftype() now works on tied arguments. | |
1221 | ||
1222 | =item * | |
1223 | ||
1224 | AutoLoader can now be disabled with C<no AutoLoader;>. | |
1225 | ||
1226 | =item * | |
1227 | ||
1228 | B::Deparse has been significantly enhanced by Robin Houston. It can | |
1229 | now deparse almost all of the standard test suite (so that the tests | |
1230 | still succeed). There is a make target "test.deparse" for trying this | |
1231 | out. | |
1232 | ||
1233 | =item * | |
1234 | ||
1235 | Carp now has better interface documentation, and the @CARP_NOT | |
1236 | interface has been added to get optional control over where errors | |
1237 | are reported independently of @ISA, by Ben Tilly. | |
1238 | ||
1239 | =item * | |
1240 | ||
1241 | Class::Struct can now define the classes in compile time. | |
1242 | ||
1243 | =item * | |
1244 | ||
1245 | Class::Struct now assigns the array/hash element if the accessor | |
1246 | is called with an array/hash element as the B<sole> argument. | |
1247 | ||
1248 | =item * | |
1249 | ||
1250 | The return value of Cwd::fastcwd() is now tainted. | |
1251 | ||
1252 | =item * | |
1253 | ||
1254 | Data::Dumper now has an option to sort hashes. | |
1255 | ||
1256 | =item * | |
1257 | ||
1258 | Data::Dumper now has an option to dump code references | |
1259 | using B::Deparse. | |
1260 | ||
1261 | =item * | |
1262 | ||
1263 | DB_File now supports newer Berkeley DB versions, among | |
1264 | other improvements. | |
1265 | ||
1266 | =item * | |
1267 | ||
1268 | Devel::Peek now has an interface for the Perl memory statistics | |
1269 | (this works only if you are using perl's malloc, and if you have | |
1270 | compiled with debugging). | |
1271 | ||
1272 | =item * | |
1273 | ||
1274 | The English module can now be used without the infamous performance | |
1275 | hit by saying | |
1276 | ||
1277 | use English '-no_match_vars'; | |
1278 | ||
1279 | (Assuming, of course, that you don't need the troublesome variables | |
1280 | C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and | |
1281 | C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>. | |
1282 | ||
1283 | =item * | |
1284 | ||
1285 | ExtUtils::MakeMaker has been significantly cleaned up and fixed. | |
1286 | The enhanced version has also been backported to earlier releases | |
1287 | of Perl and submitted to CPAN so that the earlier releases can | |
1288 | enjoy the fixes. | |
1289 | ||
1290 | =item * | |
1291 | ||
1292 | The arguments of WriteMakefile() in Makefile.PL are now checked | |
1293 | for sanity much more carefully than before. This may cause new | |
1294 | warnings when modules are being installed. See L<ExtUtils::MakeMaker> | |
1295 | for more details. | |
1296 | ||
1297 | =item * | |
1298 | ||
1299 | ExtUtils::MakeMaker now uses File::Spec internally, which hopefully | |
1300 | leads to better portability. | |
1301 | ||
1302 | =item * | |
1303 | ||
1304 | Fcntl, Socket, and Sys::Syslog have been rewritten by Nicholas Clark | |
1305 | to use the new-style constant dispatch section (see L<ExtUtils::Constant>). | |
1306 | This means that they will be more robust and hopefully faster. | |
1307 | ||
1308 | =item * | |
1309 | ||
1310 | File::Find now chdir()s correctly when chasing symbolic links. [561] | |
1311 | ||
1312 | =item * | |
1313 | ||
1314 | File::Find now has pre- and post-processing callbacks. It also | |
1315 | correctly changes directories when chasing symbolic links. Callbacks | |
1316 | (naughtily) exiting with "next;" instead of "return;" now work. | |
1317 | ||
1318 | =item * | |
1319 | ||
1320 | File::Find is now (again) reentrant. It also has been made | |
1321 | more portable. | |
1322 | ||
1323 | =item * | |
1324 | ||
1325 | The warnings issued by File::Find now belong to their own category. | |
1326 | You can enable/disable them with C<use/no warnings 'File::Find';>. | |
1327 | ||
1328 | =item * | |
1329 | ||
1330 | File::Glob::glob() has been renamed to File::Glob::bsd_glob() | |
1331 | because the name clashes with the builtin glob(). The older | |
1332 | name is still available for compatibility, but is deprecated. [561] | |
1333 | ||
1334 | =item * | |
1335 | ||
1336 | File::Glob now supports C<GLOB_LIMIT> constant to limit the size of | |
1337 | the returned list of filenames. | |
1338 | ||
1339 | =item * | |
1340 | ||
1341 | IPC::Open3 now allows the use of numeric file descriptors. | |
1342 | ||
1343 | =item * | |
1344 | ||
1345 | IO::Socket now has an atmark() method, which returns true if the socket | |
1346 | is positioned at the out-of-band mark. The method is also exportable | |
1347 | as a sockatmark() function. | |
1348 | ||
1349 | =item * | |
1350 | ||
1351 | IO::Socket::INET failed to open the specified port if the service name | |
1352 | was not known. It now correctly uses the supplied port number as is. [561] | |
1353 | ||
1354 | =item * | |
1355 | ||
1356 | IO::Socket::INET has support for the ReusePort option (if your | |
1357 | platform supports it). The Reuse option now has an alias, ReuseAddr. | |
1358 | For clarity, you may want to prefer ReuseAddr. | |
1359 | ||
1360 | =item * | |
1361 | ||
1362 | IO::Socket::INET now supports a value of zero for C<LocalPort> | |
1363 | (usually meaning that the operating system will make one up.) | |
1364 | ||
1365 | =item * | |
1366 | ||
1367 | 'use lib' now works identically to @INC. Removing directories | |
1368 | with 'no lib' now works. | |
1369 | ||
1370 | =item * | |
1371 | ||
1372 | Math::BigFloat and Math::BigInt have undergone a full rewrite by Tels. | |
1373 | They are now magnitudes faster, and they support various bignum | |
1374 | libraries such as GMP and PARI as their backends. | |
1375 | ||
1376 | =item * | |
1377 | ||
1378 | Math::Complex handles inf, NaN etc., better. | |
1379 | ||
1380 | =item * | |
1381 | ||
1382 | Net::Ping has been considerably enhanced by Rob Brown: multihoming is | |
1383 | now supported, Win32 functionality is better, there is now time | |
1384 | measuring functionality (optionally high-resolution using | |
1385 | Time::HiRes), and there is now "external" protocol which uses | |
1386 | Net::Ping::External module which runs your external ping utility and | |
1387 | parses the output. A version of Net::Ping::External is available in | |
1388 | CPAN. | |
1389 | ||
1390 | Note that some of the Net::Ping tests are disabled when running | |
1391 | under the Perl distribution since one cannot assume one or more | |
1392 | of the following: enabled echo port at localhost, full Internet | |
1393 | connectivity, or sympathetic firewalls. You can set the environment | |
1394 | variable PERL_TEST_Net_Ping to "1" (one) before running the Perl test | |
1395 | suite to enable all the Net::Ping tests. | |
1396 | ||
1397 | =item * | |
1398 | ||
1399 | POSIX::sigaction() is now much more flexible and robust. | |
1400 | You can now install coderef handlers, 'DEFAULT', and 'IGNORE' | |
1401 | handlers, installing new handlers was not atomic. | |
1402 | ||
1403 | =item * | |
1404 | ||
1405 | In Safe, C<%INC> is now localised in a Safe compartment so that | |
1406 | use/require work. | |
1407 | ||
1408 | =item * | |
1409 | ||
1410 | In SDBM_File on dosish platforms, some keys went missing because of | |
1411 | lack of support for files with "holes". A workaround for the problem | |
1412 | has been added. | |
1413 | ||
1414 | =item * | |
1415 | ||
1416 | In Search::Dict one can now have a pre-processing hook for the | |
1417 | lines being searched. | |
1418 | ||
1419 | =item * | |
1420 | ||
1421 | The Shell module now has an OO interface. | |
1422 | ||
1423 | =item * | |
1424 | ||
1425 | In Sys::Syslog there is now a failover mechanism that will go | |
1426 | through alternative connection mechanisms until the message | |
1427 | is successfully logged. | |
1428 | ||
1429 | =item * | |
1430 | ||
1431 | The Test module has been significantly enhanced. | |
1432 | ||
1433 | =item * | |
1434 | ||
1435 | Time::Local::timelocal() does not handle fractional seconds anymore. | |
1436 | The rationale is that neither does localtime(), and timelocal() and | |
1437 | localtime() are supposed to be inverses of each other. | |
1438 | ||
1439 | =item * | |
1440 | ||
1441 | The vars pragma now supports declaring fully qualified variables. | |
1442 | (Something that C<our()> does not and will not support.) | |
1443 | ||
1444 | =item * | |
1445 | ||
1446 | The C<utf8::> name space (as in the pragma) provides various | |
1447 | Perl-callable functions to provide low level access to Perl's | |
1448 | internal Unicode representation. At the moment only length() | |
1449 | has been implemented. | |
1450 | ||
1451 | =back | |
1452 | ||
1453 | =head1 Utility Changes | |
1454 | ||
1455 | =over 4 | |
1456 | ||
1457 | =item * | |
1458 | ||
1459 | Emacs perl mode (emacs/cperl-mode.el) has been updated to version | |
1460 | 4.31. | |
1461 | ||
1462 | =item * | |
1463 | ||
1464 | F<emacs/e2ctags.pl> is now much faster. | |
1465 | ||
1466 | =item * | |
1467 | ||
1468 | C<enc2xs> is a tool for people adding their own encodings to the | |
1469 | Encode module. | |
1470 | ||
1471 | =item * | |
1472 | ||
1473 | C<h2ph> now supports C trigraphs. | |
1474 | ||
1475 | =item * | |
1476 | ||
1477 | C<h2xs> now produces a template README. | |
1478 | ||
1479 | =item * | |
1480 | ||
1481 | C<h2xs> now uses C<Devel::PPPort> for better portability between | |
1482 | different versions of Perl. | |
1483 | ||
1484 | =item * | |
1485 | ||
1486 | C<h2xs> uses the new L<ExtUtils::Constant|ExtUtils::Constant> module | |
1487 | which will affect newly created extensions that define constants. | |
1488 | Since the new code is more correct (if you have two constants where the | |
1489 | first one is a prefix of the second one, the first constant B<never> | |
1490 | got defined), less lossy (it uses integers for integer constant, | |
1491 | as opposed to the old code that used floating point numbers even for | |
1492 | integer constants), and slightly faster, you might want to consider | |
1493 | regenerating your extension code (the new scheme makes regenerating | |
1494 | easy). L<h2xs> now also supports C trigraphs. | |
1495 | ||
1496 | =item * | |
1497 | ||
1498 | C<libnetcfg> has been added to configure libnet. | |
1499 | ||
1500 | =item * | |
1501 | ||
1502 | C<perlbug> is now much more robust. It also sends the bug report to | |
1503 | perl.org, not perl.com. | |
1504 | ||
1505 | =item * | |
1506 | ||
1507 | C<perlcc> has been rewritten and its user interface (that is, | |
1508 | command line) is much more like that of the UNIX C compiler, cc. | |
1509 | (The perlbc tools has been removed. Use C<perlcc -B> instead.) | |
1510 | B<Note that perlcc is still considered very experimental and | |
1511 | unsupported.> [561] | |
1512 | ||
1513 | =item * | |
1514 | ||
1515 | C<perlivp> is a new Installation Verification Procedure utility | |
1516 | for running any time after installing Perl. | |
1517 | ||
1518 | =item * | |
1519 | ||
1520 | C<piconv> is an implementation of the character conversion utility | |
1521 | C<iconv>, demonstrating the new Encode module. | |
1522 | ||
1523 | =item * | |
1524 | ||
1525 | C<pod2html> now allows specifying a cache directory. | |
1526 | ||
1527 | =item * | |
1528 | ||
1529 | C<pod2html> now produces XHTML 1.0. | |
1530 | ||
1531 | =item * | |
1532 | ||
1533 | C<pod2html> now understands POD written using different line endings | |
1534 | (PC-like CRLF versus UNIX-like LF versus MacClassic-like CR). | |
1535 | ||
1536 | =item * | |
1537 | ||
1538 | C<s2p> has been completely rewritten in Perl. (It is in fact a full | |
1539 | implementation of sed in Perl: you can use the sed functionality by | |
1540 | using the C<psed> utility.) | |
1541 | ||
1542 | =item * | |
1543 | ||
1544 | C<xsubpp> now understands POD documentation embedded in the *.xs | |
1545 | files. [561] | |
1546 | ||
1547 | =item * | |
1548 | ||
1549 | C<xsubpp> now supports the OUT keyword. | |
1550 | ||
1551 | =back | |
1552 | ||
1553 | =head1 New Documentation | |
1554 | ||
1555 | =over 4 | |
1556 | ||
1557 | =item * | |
1558 | ||
1559 | perl56delta details the changes between the 5.005 release and the | |
1560 | 5.6.0 release. | |
1561 | ||
1562 | =item * | |
1563 | ||
1564 | perlclib documents the internal replacements for standard C library | |
1565 | functions. (Interesting only for extension writers and Perl core | |
1566 | hackers.) [561+] | |
1567 | ||
1568 | =item * | |
1569 | ||
1570 | perldebtut is a Perl debugging tutorial. [561+] | |
1571 | ||
1572 | =item * | |
1573 | ||
1574 | perlebcdic contains considerations for running Perl on EBCDIC | |
1575 | platforms. [561+] | |
1576 | ||
1577 | =item * | |
1578 | ||
1579 | perlintro is a gentle introduction to Perl. | |
1580 | ||
1581 | =item * | |
1582 | ||
1583 | perliol documents the internals of PerlIO with layers. | |
1584 | ||
1585 | =item * | |
1586 | ||
1587 | perlmodstyle is a style guide for writing modules. | |
1588 | ||
1589 | =item * | |
1590 | ||
1591 | perlnewmod tells about writing and submitting a new module. [561+] | |
1592 | ||
1593 | =item * | |
1594 | ||
1595 | perlpacktut is a pack() tutorial. | |
1596 | ||
1597 | =item * | |
1598 | ||
1599 | perlpod has been rewritten to be clearer and to record the best | |
1600 | practices gathered over the years. | |
1601 | ||
1602 | =item * | |
1603 | ||
1604 | perlpodspec is a more formal specification of the pod format, | |
1605 | mainly of interest for writers of pod applications, not to | |
1606 | people writing in pod. | |
1607 | ||
1608 | =item * | |
1609 | ||
1610 | perlretut is a regular expression tutorial. [561+] | |
1611 | ||
1612 | =item * | |
1613 | ||
1614 | perlrequick is a regular expressions quick-start guide. | |
1615 | Yes, much quicker than perlretut. [561] | |
1616 | ||
1617 | =item * | |
1618 | ||
1619 | perltodo has been updated. | |
1620 | ||
1621 | =item * | |
1622 | ||
1623 | perltootc has been renamed as perltooc (to not to conflict | |
1624 | with perltoot in filesystems restricted to "8.3" names). | |
1625 | ||
1626 | =item * | |
1627 | ||
1628 | perluniintro is an introduction to using Unicode in Perl. | |
1629 | (perlunicode is more of a detailed reference and background | |
1630 | information) | |
1631 | ||
1632 | =item * | |
1633 | ||
1634 | perlutil explains the command line utilities packaged with the Perl | |
1635 | distribution. [561+] | |
1636 | ||
1637 | =back | |
1638 | ||
1639 | The following platform-specific documents are available before | |
1640 | the installation as README.I<platform>, and after the installation | |
1641 | as perlI<platform>: | |
1642 | ||
1643 | perlaix perlamiga perlapollo perlbeos perlbs2000 | |
1644 | perlce perlcygwin perldgux perldos perlepoc perlfreebsd perlhpux | |
1645 | perlhurd perlirix perlmachten perlmacos perlmint perlmpeix | |
1646 | perlnetware perlos2 perlos390 perlplan9 perlqnx perlsolaris | |
1647 | perltru64 perluts perlvmesa perlvms perlvos perlwin32 | |
1648 | ||
1649 | These documents usually detail one or more of the following subjects: | |
1650 | configuring, building, testing, installing, and sometimes also using | |
1651 | Perl on the said platform. | |
1652 | ||
1653 | Eastern Asian Perl users are now welcomed in their own languages: | |
1654 | README.jp (Japanese), README.ko (Korean), README.cn (simplified | |
1655 | Chinese) and README.tw (traditional Chinese), which are written in | |
1656 | normal pod but encoded in EUC-JP, EUC-KR, EUC-CN and Big5. These | |
1657 | will get installed as | |
1658 | ||
1659 | perljp perlko perlcn perltw | |
1660 | ||
1661 | =over 4 | |
1662 | ||
1663 | =item * | |
1664 | ||
1665 | The documentation for the POSIX-BC platform is called "BS2000", to avoid | |
1666 | confusion with the Perl POSIX module. | |
1667 | ||
1668 | =item * | |
1669 | ||
1670 | The documentation for the WinCE platform is called perlce (README.ce | |
1671 | in the source code kit), to avoid confusion with the perlwin32 | |
1672 | documentation on 8.3-restricted filesystems. | |
1673 | ||
1674 | =back | |
1675 | ||
1676 | =head1 Performance Enhancements | |
1677 | ||
1678 | =over 4 | |
1679 | ||
1680 | =item * | |
1681 | ||
1682 | map() could get pathologically slow when the result list it generates | |
1683 | is larger than the source list. The performance has been improved for | |
1684 | common scenarios. [561] | |
1685 | ||
1686 | =item * | |
1687 | ||
1688 | sort() is also fully reentrant, in the sense that the sort function | |
1689 | can itself call sort(). This did not work reliably in previous | |
1690 | releases. [561] | |
1691 | ||
1692 | =item * | |
1693 | ||
1694 | sort() has been changed to use primarily mergesort internally as | |
1695 | opposed to the earlier quicksort. For very small lists this may | |
1696 | result in slightly slower sorting times, but in general the speedup | |
1697 | should be at least 20%. Additional bonuses are that the worst case | |
1698 | behaviour of sort() is now better (in computer science terms it now | |
1699 | runs in time O(N log N), as opposed to quicksort's Theta(N**2) | |
1700 | worst-case run time behaviour), and that sort() is now stable | |
1701 | (meaning that elements with identical keys will stay ordered as they | |
1702 | were before the sort). See the C<sort> pragma for information. | |
1703 | ||
1704 | The story in more detail: suppose you want to serve yourself a little | |
1705 | slice of Pi. | |
1706 | ||
1707 | @digits = ( 3,1,4,1,5,9 ); | |
1708 | ||
1709 | A numerical sort of the digits will yield (1,1,3,4,5,9), as expected. | |
1710 | Which C<1> comes first is hard to know, since one C<1> looks pretty | |
1711 | much like any other. You can regard this as totally trivial, | |
1712 | or somewhat profound. However, if you just want to sort the even | |
1713 | digits ahead of the odd ones, then what will | |
1714 | ||
1715 | sort { ($a % 2) <=> ($b % 2) } @digits; | |
1716 | ||
1717 | yield? The only even digit, C<4>, will come first. But how about | |
1718 | the odd numbers, which all compare equal? With the quicksort algorithm | |
1719 | used to implement Perl 5.6 and earlier, the order of ties is left up | |
1720 | to the sort. So, as you add more and more digits of Pi, the order | |
1721 | in which the sorted even and odd digits appear will change. | |
1722 | and, for sufficiently large slices of Pi, the quicksort algorithm | |
1723 | in Perl 5.8 won't return the same results even if reinvoked with the | |
1724 | same input. The justification for this rests with quicksort's | |
1725 | worst case behavior. If you run | |
1726 | ||
1727 | sort { $a <=> $b } ( 1 .. $N , 1 .. $N ); | |
1728 | ||
1729 | (something you might approximate if you wanted to merge two sorted | |
1730 | arrays using sort), doubling $N doesn't just double the quicksort time, | |
1731 | it I<quadruples> it. Quicksort has a worst case run time that can | |
1732 | grow like N**2, so-called I<quadratic> behaviour, and it can happen | |
1733 | on patterns that may well arise in normal use. You won't notice this | |
1734 | for small arrays, but you I<will> notice it with larger arrays, | |
1735 | and you may not live long enough for the sort to complete on arrays | |
1736 | of a million elements. So the 5.8 quicksort scrambles large arrays | |
1737 | before sorting them, as a statistical defence against quadratic behaviour. | |
1738 | But that means if you sort the same large array twice, ties may be | |
1739 | broken in different ways. | |
1740 | ||
1741 | Because of the unpredictability of tie-breaking order, and the quadratic | |
1742 | worst-case behaviour, quicksort was I<almost> replaced completely with | |
1743 | a stable mergesort. I<Stable> means that ties are broken to preserve | |
1744 | the original order of appearance in the input array. So | |
1745 | ||
1746 | sort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9); | |
1747 | ||
1748 | will yield (4,3,1,1,5,9), guaranteed. The even and odd numbers | |
1749 | appear in the output in the same order they appeared in the input. | |
1750 | Mergesort has worst case O(N log N) behaviour, the best value | |
1751 | attainable. And, ironically, this mergesort does particularly | |
1752 | well where quicksort goes quadratic: mergesort sorts (1..$N, 1..$N) | |
1753 | in O(N) time. But quicksort was rescued at the last moment because | |
1754 | it is faster than mergesort on certain inputs and platforms. | |
1755 | For example, if you really I<don't> care about the order of even | |
1756 | and odd digits, quicksort will run in O(N) time; it's very good | |
1757 | at sorting many repetitions of a small number of distinct elements. | |
1758 | The quicksort divide and conquer strategy works well on platforms | |
1759 | with relatively small, very fast, caches. Eventually, the problem gets | |
1760 | whittled down to one that fits in the cache, from which point it | |
1761 | benefits from the increased memory speed. | |
1762 | ||
1763 | Quicksort was rescued by implementing a sort pragma to control aspects | |
1764 | of the sort. The B<stable> subpragma forces stable behaviour, | |
1765 | regardless of algorithm. The B<_quicksort> and B<_mergesort> | |
1766 | subpragmas are heavy-handed ways to select the underlying implementation. | |
1767 | The leading C<_> is a reminder that these subpragmas may not survive | |
1768 | beyond 5.8. More appropriate mechanisms for selecting the implementation | |
1769 | exist, but they wouldn't have arrived in time to save quicksort. | |
1770 | ||
1771 | =item * | |
1772 | ||
1773 | Hashes now use Bob Jenkins "One-at-a-Time" hashing key algorithm | |
1774 | ( http://burtleburtle.net/bob/hash/doobs.html ). This algorithm is | |
1775 | reasonably fast while producing a much better spread of values than | |
1776 | the old hashing algorithm (originally by Chris Torek, later tweaked by | |
1777 | Ilya Zakharevich). Hash values output from the algorithm on a hash of | |
1778 | all 3-char printable ASCII keys comes much closer to passing the | |
1779 | DIEHARD random number generation tests. According to perlbench, this | |
1780 | change has not affected the overall speed of Perl. | |
1781 | ||
1782 | =item * | |
1783 | ||
1784 | unshift() should now be noticeably faster. | |
1785 | ||
1786 | =back | |
1787 | ||
1788 | =head1 Installation and Configuration Improvements | |
1789 | ||
1790 | =head2 Generic Improvements | |
1791 | ||
1792 | =over 4 | |
1793 | ||
1794 | =item * | |
1795 | ||
1796 | INSTALL now explains how you can configure Perl to use 64-bit | |
1797 | integers even on non-64-bit platforms. | |
1798 | ||
1799 | =item * | |
1800 | ||
1801 | Policy.sh policy change: if you are reusing a Policy.sh file | |
1802 | (see INSTALL) and you use Configure -Dprefix=/foo/bar and in the old | |
1803 | Policy $prefix eq $siteprefix and $prefix eq $vendorprefix, all of | |
1804 | them will now be changed to the new prefix, /foo/bar. (Previously | |
1805 | only $prefix changed.) If you do not like this new behaviour, | |
1806 | specify prefix, siteprefix, and vendorprefix explicitly. | |
1807 | ||
1808 | =item * | |
1809 | ||
1810 | A new optional location for Perl libraries, otherlibdirs, is available. | |
1811 | It can be used for example for vendor add-ons without disturbing Perl's | |
1812 | own library directories. | |
1813 | ||
1814 | =item * | |
1815 | ||
1816 | In many platforms, the vendor-supplied 'cc' is too stripped-down to | |
1817 | build Perl (basically, 'cc' doesn't do ANSI C). If this seems | |
1818 | to be the case and 'cc' does not seem to be the GNU C compiler | |
1819 | 'gcc', an automatic attempt is made to find and use 'gcc' instead. | |
1820 | ||
1821 | =item * | |
1822 | ||
1823 | gcc needs to closely track the operating system release to avoid | |
1824 | build problems. If Configure finds that gcc was built for a different | |
1825 | operating system release than is running, it now gives a clearly visible | |
1826 | warning that there may be trouble ahead. | |
1827 | ||
1828 | =item * | |
1829 | ||
1830 | Since Perl 5.8 is not binary-compatible with previous releases | |
1831 | of Perl, Configure no longer suggests including the 5.005 | |
1832 | modules in @INC. | |
1833 | ||
1834 | =item * | |
1835 | ||
1836 | Configure C<-S> can now run non-interactively. [561] | |
1837 | ||
1838 | =item * | |
1839 | ||
1840 | Configure support for pdp11-style memory models has been removed due | |
1841 | to obsolescence. [561] | |
1842 | ||
1843 | =item * | |
1844 | ||
1845 | configure.gnu now works with options with whitespace in them. | |
1846 | ||
1847 | =item * | |
1848 | ||
1849 | installperl now outputs everything to STDERR. | |
1850 | ||
1851 | =item * | |
1852 | ||
1853 | Because PerlIO is now the default on most platforms, "-perlio" doesn't | |
1854 | get appended to the $Config{archname} (also known as $^O) anymore. | |
1855 | Instead, if you explicitly choose not to use perlio (Configure command | |
1856 | line option -Uuseperlio), you will get "-stdio" appended. | |
1857 | ||
1858 | =item * | |
1859 | ||
1860 | Another change related to the architecture name is that "-64all" | |
1861 | (-Duse64bitall, or "maximally 64-bit") is appended only if your | |
1862 | pointers are 64 bits wide. (To be exact, the use64bitall is ignored.) | |
1863 | ||
1864 | =item * | |
1865 | ||
1866 | In AFS installations, one can configure the root of the AFS to be | |
1867 | somewhere else than the default F</afs> by using the Configure | |
1868 | parameter C<-Dafsroot=/some/where/else>. | |
1869 | ||
1870 | =item * | |
1871 | ||
1872 | APPLLIB_EXP, a lesser-known configuration-time definition, has been | |
1873 | documented. It can be used to prepend site-specific directories | |
1874 | to Perl's default search path (@INC); see INSTALL for information. | |
1875 | ||
1876 | =item * | |
1877 | ||
1878 | The version of Berkeley DB used when the Perl (and, presumably, the | |
1879 | DB_File extension) was built is now available as | |
1880 | C<@Config{qw(db_version_major db_version_minor db_version_patch)}> | |
1881 | from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG | |
1882 | DB_VERSION_PATCH_CFG> from C. | |
1883 | ||
1884 | =item * | |
1885 | ||
1886 | Building Berkeley DB3 for compatibility modes for DB, NDBM, and ODBM | |
1887 | has been documented in INSTALL. | |
1888 | ||
1889 | =item * | |
1890 | ||
1891 | If you have CPAN access (either network or a local copy such as a | |
1892 | CD-ROM) you can during specify extra modules to Configure to build and | |
1893 | install with Perl using the -Dextras=... option. See INSTALL for | |
1894 | more details. | |
1895 | ||
1896 | =item * | |
1897 | ||
1898 | In addition to config.over, a new override file, config.arch, is | |
1899 | available. This file is supposed to be used by hints file writers | |
1900 | for architecture-wide changes (as opposed to config.over which is | |
1901 | for site-wide changes). | |
1902 | ||
1903 | =item * | |
1904 | ||
1905 | If your file system supports symbolic links, you can build Perl outside | |
1906 | of the source directory by | |
1907 | ||
1908 | mkdir /tmp/perl/build/directory | |
1909 | cd /tmp/perl/build/directory | |
1910 | sh /path/to/perl/source/Configure -Dmksymlinks ... | |
1911 | ||
1912 | This will create in /tmp/perl/build/directory a tree of symbolic links | |
1913 | pointing to files in /path/to/perl/source. The original files are left | |
1914 | unaffected. After Configure has finished, you can just say | |
1915 | ||
1916 | make all test | |
1917 | ||
1918 | and Perl will be built and tested, all in /tmp/perl/build/directory. | |
1919 | [561] | |
1920 | ||
1921 | =item * | |
1922 | ||
1923 | For Perl developers, several new make targets for profiling | |
1924 | and debugging have been added; see L<perlhack>. | |
1925 | ||
1926 | =over 8 | |
1927 | ||
1928 | =item * | |
1929 | ||
1930 | Use of the F<gprof> tool to profile Perl has been documented in | |
1931 | L<perlhack>. There is a make target called "perl.gprof" for | |
1932 | generating a gprofiled Perl executable. | |
1933 | ||
1934 | =item * | |
1935 | ||
1936 | If you have GCC 3, there is a make target called "perl.gcov" for | |
1937 | creating a gcoved Perl executable for coverage analysis. See | |
1938 | L<perlhack>. | |
1939 | ||
1940 | =item * | |
1941 | ||
1942 | If you are on IRIX or Tru64 platforms, new profiling/debugging options | |
1943 | have been added; see L<perlhack> for more information about pixie and | |
1944 | Third Degree. | |
1945 | ||
1946 | =back | |
1947 | ||
1948 | =item * | |
1949 | ||
1950 | Guidelines of how to construct minimal Perl installations have | |
1951 | been added to INSTALL. | |
1952 | ||
1953 | =item * | |
1954 | ||
1955 | The Thread extension is now not built at all under ithreads | |
1956 | (C<Configure -Duseithreads>) because it wouldn't work anyway (the | |
1957 | Thread extension requires being Configured with C<-Duse5005threads>). | |
1958 | ||
1959 | B<Note that the 5.005 threads are unsupported and deprecated: if you | |
1960 | have code written for the old threads you should migrate it to the | |
1961 | new ithreads model.> | |
1962 | ||
1963 | =item * | |
1964 | ||
1965 | The Gconvert macro ($Config{d_Gconvert}) used by perl for stringifying | |
1966 | floating-point numbers is now more picky about using sprintf %.*g | |
1967 | rules for the conversion. Some platforms that used to use gcvt may | |
1968 | now resort to the slower sprintf. | |
1969 | ||
1970 | =item * | |
1971 | ||
1972 | The obsolete method of making a special (e.g., debugging) flavor | |
1973 | of perl by saying | |
1974 | ||
1975 | make LIBPERL=libperld.a | |
1976 | ||
1977 | has been removed. Use -DDEBUGGING instead. | |
1978 | ||
1979 | =back | |
1980 | ||
1981 | =head2 New Or Improved Platforms | |
1982 | ||
1983 | For the list of platforms known to support Perl, | |
1984 | see L<perlport/"Supported Platforms">. | |
1985 | ||
1986 | =over 4 | |
1987 | ||
1988 | =item * | |
1989 | ||
1990 | AIX dynamic loading should be now better supported. | |
1991 | ||
1992 | =item * | |
1993 | ||
1994 | AIX should now work better with gcc, threads, and 64-bitness. Also the | |
1995 | long doubles support in AIX should be better now. See L<perlaix>. | |
1996 | ||
1997 | =item * | |
1998 | ||
1999 | AtheOS ( http://www.atheos.cx/ ) is a new platform. | |
2000 | ||
2001 | =item * | |
2002 | ||
2003 | BeOS has been reclaimed. | |
2004 | ||
2005 | =item * | |
2006 | ||
2007 | The DG/UX platform now supports 5.005-style threads. | |
2008 | See L<perldgux>. | |
2009 | ||
2010 | =item * | |
2011 | ||
2012 | The DYNIX/ptx platform (also known as dynixptx) is supported at or | |
2013 | near osvers 4.5.2. | |
2014 | ||
2015 | =item * | |
2016 | ||
2017 | EBCDIC platforms (z/OS (also known as OS/390), POSIX-BC, and VM/ESA) | |
2018 | have been regained. Many test suite tests still fail and the | |
2019 | co-existence of Unicode and EBCDIC isn't quite settled, but the | |
2020 | situation is much better than with Perl 5.6. See L<perlos390>, | |
2021 | L<perlbs2000> (for POSIX-BC), and L<perlvmesa> for more information. | |
2022 | ||
2023 | =item * | |
2024 | ||
2025 | Building perl with -Duseithreads or -Duse5005threads now works under | |
2026 | HP-UX 10.20 (previously it only worked under 10.30 or later). You will | |
2027 | need a thread library package installed. See README.hpux. [561] | |
2028 | ||
2029 | =item * | |
2030 | ||
2031 | Mac OS Classic is now supported in the mainstream source package | |
2032 | (MacPerl has of course been available since perl 5.004 but now the | |
2033 | source code bases of standard Perl and MacPerl have been synchronised) | |
2034 | [561] | |
2035 | ||
2036 | =item * | |
2037 | ||
2038 | Mac OS X (or Darwin) should now be able to build Perl even on HFS+ | |
2039 | filesystems. (The case-insensitivity used to confuse the Perl build | |
2040 | process.) | |
2041 | ||
2042 | =item * | |
2043 | ||
2044 | NCR MP-RAS is now supported. [561] | |
2045 | ||
2046 | =item * | |
2047 | ||
2048 | All the NetBSD specific patches (except for the installation | |
2049 | specific ones) have been merged back to the main distribution. | |
2050 | ||
2051 | =item * | |
2052 | ||
2053 | NetWare from Novell is now supported. See L<perlnetware>. | |
2054 | ||
2055 | =item * | |
2056 | ||
2057 | NonStop-UX is now supported. [561] | |
2058 | ||
2059 | =item * | |
2060 | ||
2061 | NEC SUPER-UX is now supported. | |
2062 | ||
2063 | =item * | |
2064 | ||
2065 | All the OpenBSD specific patches (except for the installation | |
2066 | specific ones) have been merged back to the main distribution. | |
2067 | ||
2068 | =item * | |
2069 | ||
2070 | Perl has been tested with the GNU pth userlevel thread package | |
2071 | ( http://www.gnu.org/software/pth/pth.html ). All thread tests | |
2072 | of Perl now work, but not without adding some yield()s to the tests, | |
2073 | so while pth (and other userlevel thread implementations) can be | |
2074 | considered to be "working" with Perl ithreads, keep in mind the | |
2075 | possible non-preemptability of the underlying thread implementation. | |
2076 | ||
2077 | =item * | |
2078 | ||
2079 | Stratus VOS is now supported using Perl's native build method | |
2080 | (Configure). This is the recommended method to build Perl on | |
2081 | VOS. The older methods, which build miniperl, are still | |
2082 | available. See L<perlvos>. [561+] | |
2083 | ||
2084 | =item * | |
2085 | ||
2086 | The Amdahl UTS UNIX mainframe platform is now supported. [561] | |
2087 | ||
2088 | =item * | |
2089 | ||
2090 | WinCE is now supported. See L<perlce>. | |
2091 | ||
2092 | =item * | |
2093 | ||
2094 | z/OS (formerly known as OS/390, formerly known as MVS OE) now has | |
2095 | support for dynamic loading. This is not selected by default, | |
2096 | however, you must specify -Dusedl in the arguments of Configure. [561] | |
2097 | ||
2098 | =back | |
2099 | ||
2100 | =head1 Selected Bug Fixes | |
2101 | ||
2102 | Numerous memory leaks and uninitialized memory accesses have been | |
2103 | hunted down. Most importantly, anonymous subs used to leak quite | |
2104 | a bit. [561] | |
2105 | ||
2106 | =over 4 | |
2107 | ||
2108 | =item * | |
2109 | ||
2110 | The autouse pragma didn't work for Multi::Part::Function::Names. | |
2111 | ||
2112 | =item * | |
2113 | ||
2114 | caller() could cause core dumps in certain situations. Carp was | |
2115 | sometimes affected by this problem. In particular, caller() now | |
2116 | returns a subroutine name of C<(unknown)> for subroutines that have | |
2117 | been removed from the symbol table. | |
2118 | ||
2119 | =item * | |
2120 | ||
2121 | chop(@list) in list context returned the characters chopped in | |
2122 | reverse order. This has been reversed to be in the right order. [561] | |
2123 | ||
2124 | =item * | |
2125 | ||
2126 | Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm) | |
2127 | when building the Perl binary. The only exception to this is SunOS 4.x, | |
2128 | which needs them. [561] | |
2129 | ||
2130 | =item * | |
2131 | ||
2132 | The behaviour of non-decimal but numeric string constants such as | |
2133 | "0x23" was platform-dependent: in some platforms that was seen as 35, | |
2134 | in some as 0, in some as a floating point number (don't ask). This | |
2135 | was caused by Perl's using the operating system libraries in a situation | |
2136 | where the result of the string to number conversion is undefined: now | |
2137 | Perl consistently handles such strings as zero in numeric contexts. | |
2138 | ||
2139 | =item * | |
2140 | ||
2141 | Several debugger fixes: exit code now reflects the script exit code, | |
2142 | condition C<"0"> now treated correctly, the C<d> command now checks | |
2143 | line number, C<$.> no longer gets corrupted, and all debugger output | |
2144 | now goes correctly to the socket if RemotePort is set. [561] | |
2145 | ||
2146 | =item * | |
2147 | ||
2148 | The debugger (perl5db.pl) has been modified to present a more | |
2149 | consistent commands interface, via (CommandSet=580). perl5db.t was | |
2150 | also added to test the changes, and as a placeholder for further tests. | |
2151 | ||
2152 | See L<perldebug>. | |
2153 | ||
2154 | =item * | |
2155 | ||
2156 | The debugger has a new C<dumpDepth> option to control the maximum | |
2157 | depth to which nested structures are dumped. The C<x> command has | |
2158 | been extended so that C<x N EXPR> dumps out the value of I<EXPR> to a | |
2159 | depth of at most I<N> levels. | |
2160 | ||
2161 | =item * | |
2162 | ||
2163 | The debugger can now show lexical variables if you have the CPAN | |
2164 | module PadWalker installed. | |
2165 | ||
2166 | =item * | |
2167 | ||
2168 | The order of DESTROYs has been made more predictable. | |
2169 | ||
2170 | =item * | |
2171 | ||
2172 | Perl 5.6.0 could emit spurious warnings about redefinition of | |
2173 | dl_error() when statically building extensions into perl. | |
2174 | This has been corrected. [561] | |
2175 | ||
2176 | =item * | |
2177 | ||
2178 | L<dprofpp> -R didn't work. | |
2179 | ||
2180 | =item * | |
2181 | ||
2182 | C<*foo{FORMAT}> now works. | |
2183 | ||
2184 | =item * | |
2185 | ||
2186 | Infinity is now recognized as a number. | |
2187 | ||
2188 | =item * | |
2189 | ||
2190 | UNIVERSAL::isa no longer caches methods incorrectly. (This broke | |
2191 | the Tk extension with 5.6.0.) [561] | |
2192 | ||
2193 | =item * | |
2194 | ||
2195 | Lexicals I: lexicals outside an eval "" weren't resolved | |
2196 | correctly inside a subroutine definition inside the eval "" if they | |
2197 | were not already referenced in the top level of the eval""ed code. | |
2198 | ||
2199 | =item * | |
2200 | ||
2201 | Lexicals II: lexicals leaked at file scope into subroutines that | |
2202 | were declared before the lexicals. | |
2203 | ||
2204 | =item * | |
2205 | ||
2206 | Lexical warnings now propagating correctly between scopes | |
2207 | and into C<eval "...">. | |
2208 | ||
2209 | =item * | |
2210 | ||
2211 | C<use warnings qw(FATAL all)> did not work as intended. This has been | |
2212 | corrected. [561] | |
2213 | ||
2214 | =item * | |
2215 | ||
2216 | warnings::enabled() now reports the state of $^W correctly if the caller | |
2217 | isn't using lexical warnings. [561] | |
2218 | ||
2219 | =item * | |
2220 | ||
2221 | Line renumbering with eval and C<#line> now works. [561] | |
2222 | ||
2223 | =item * | |
2224 | ||
2225 | Fixed numerous memory leaks, especially in eval "". | |
2226 | ||
2227 | =item * | |
2228 | ||
2229 | Localised tied variables no longer leak memory | |
2230 | ||
2231 | use Tie::Hash; | |
2232 | tie my %tied_hash => 'Tie::StdHash'; | |
2233 | ||
2234 | ... | |
2235 | ||
2236 | # Used to leak memory every time local() was called; | |
2237 | # in a loop, this added up. | |
2238 | local($tied_hash{Foo}) = 1; | |
2239 | ||
2240 | =item * | |
2241 | ||
2242 | Localised hash elements (and %ENV) are correctly unlocalised to not | |
2243 | exist, if they didn't before they were localised. | |
2244 | ||
2245 | ||
2246 | use Tie::Hash; | |
2247 | tie my %tied_hash => 'Tie::StdHash'; | |
2248 | ||
2249 | ... | |
2250 | ||
2251 | # Nothing has set the FOO element so far | |
2252 | ||
2253 | { local $tied_hash{FOO} = 'Bar' } | |
2254 | ||
2255 | # This used to print, but not now. | |
2256 | print "exists!\n" if exists $tied_hash{FOO}; | |
2257 | ||
2258 | As a side effect of this fix, tied hash interfaces B<must> define | |
2259 | the EXISTS and DELETE methods. | |
2260 | ||
2261 | =item * | |
2262 | ||
2263 | mkdir() now ignores trailing slashes in the directory name, | |
2264 | as mandated by POSIX. | |
2265 | ||
2266 | =item * | |
2267 | ||
2268 | Some versions of glibc have a broken modfl(). This affects builds | |
2269 | with C<-Duselongdouble>. This version of Perl detects this brokenness | |
2270 | and has a workaround for it. The glibc release 2.2.2 is known to have | |
2271 | fixed the modfl() bug. | |
2272 | ||
2273 | =item * | |
2274 | ||
2275 | Modulus of unsigned numbers now works (4063328477 % 65535 used to | |
2276 | return 27406, instead of 27047). [561] | |
2277 | ||
2278 | =item * | |
2279 | ||
2280 | Some "not a number" warnings introduced in 5.6.0 eliminated to be | |
2281 | more compatible with 5.005. Infinity is now recognised as a number. [561] | |
2282 | ||
2283 | =item * | |
2284 | ||
2285 | Numeric conversions did not recognize changes in the string value | |
2286 | properly in certain circumstances. [561] | |
2287 | ||
2288 | =item * | |
2289 | ||
2290 | Attributes (such as :shared) didn't work with our(). | |
2291 | ||
2292 | =item * | |
2293 | ||
2294 | our() variables will not cause bogus "Variable will not stay shared" | |
2295 | warnings. [561] | |
2296 | ||
2297 | =item * | |
2298 | ||
2299 | "our" variables of the same name declared in two sibling blocks | |
2300 | resulted in bogus warnings about "redeclaration" of the variables. | |
2301 | The problem has been corrected. [561] | |
2302 | ||
2303 | =item * | |
2304 | ||
2305 | pack "Z" now correctly terminates the string with "\0". | |
2306 | ||
2307 | =item * | |
2308 | ||
2309 | Fix password routines which in some shadow password platforms | |
2310 | (e.g. HP-UX) caused getpwent() to return every other entry. | |
2311 | ||
2312 | =item * | |
2313 | ||
2314 | The PERL5OPT environment variable (for passing command line arguments | |
2315 | to Perl) didn't work for more than a single group of options. [561] | |
2316 | ||
2317 | =item * | |
2318 | ||
2319 | PERL5OPT with embedded spaces didn't work. | |
2320 | ||
2321 | =item * | |
2322 | ||
2323 | printf() no longer resets the numeric locale to "C". | |
2324 | ||
2325 | =item * | |
2326 | ||
2327 | C<qw(a\\b)> now parses correctly as C<'a\\b'>: that is, as three | |
2328 | characters, not four. [561] | |
2329 | ||
2330 | =item * | |
2331 | ||
2332 | pos() did not return the correct value within s///ge in earlier | |
2333 | versions. This is now handled correctly. [561] | |
2334 | ||
2335 | =item * | |
2336 | ||
2337 | Printing quads (64-bit integers) with printf/sprintf now works | |
2338 | without the q L ll prefixes (assuming you are on a quad-capable platform). | |
2339 | ||
2340 | =item * | |
2341 | ||
2342 | Regular expressions on references and overloaded scalars now work. [561+] | |
2343 | ||
2344 | =item * | |
2345 | ||
2346 | Right-hand side magic (GMAGIC) could in many cases such as string | |
2347 | concatenation be invoked too many times. | |
2348 | ||
2349 | =item * | |
2350 | ||
2351 | scalar() now forces scalar context even when used in void context. | |
2352 | ||
2353 | =item * | |
2354 | ||
2355 | SOCKS support is now much more robust. | |
2356 | ||
2357 | =item * | |
2358 | ||
2359 | sort() arguments are now compiled in the right wantarray context | |
2360 | (they were accidentally using the context of the sort() itself). | |
2361 | The comparison block is now run in scalar context, and the arguments | |
2362 | to be sorted are always provided list context. [561] | |
2363 | ||
2364 | =item * | |
2365 | ||
2366 | Changed the POSIX character class C<[[:space:]]> to include the (very | |
2367 | rarely used) vertical tab character. Added a new POSIX-ish character | |
2368 | class C<[[:blank:]]> which stands for horizontal whitespace | |
2369 | (currently, the space and the tab). | |
2370 | ||
2371 | =item * | |
2372 | ||
2373 | The tainting behaviour of sprintf() has been rationalized. It does | |
2374 | not taint the result of floating point formats anymore, making the | |
2375 | behaviour consistent with that of string interpolation. [561] | |
2376 | ||
2377 | =item * | |
2378 | ||
2379 | Some cases of inconsistent taint propagation (such as within hash | |
2380 | values) have been fixed. | |
2381 | ||
2382 | =item * | |
2383 | ||
2384 | The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds | |
2385 | of simple pattern matches. These are now handled better. [561] | |
2386 | ||
2387 | =item * | |
2388 | ||
2389 | Regular expression debug output (whether through C<use re 'debug'> | |
2390 | or via C<-Dr>) now looks better. [561] | |
2391 | ||
2392 | =item * | |
2393 | ||
2394 | Multi-line matches like C<"a\nxb\n" =~ /(?!\A)x/m> were flawed. The | |
2395 | bug has been fixed. [561] | |
2396 | ||
2397 | =item * | |
2398 | ||
2399 | Use of $& could trigger a core dump under some situations. This | |
2400 | is now avoided. [561] | |
2401 | ||
2402 | =item * | |
2403 | ||
2404 | The regular expression captured submatches ($1, $2, ...) are now | |
2405 | more consistently unset if the match fails, instead of leaving false | |
2406 | data lying around in them. [561] | |
2407 | ||
2408 | =item * | |
2409 | ||
2410 | readline() on files opened in "slurp" mode could return an extra | |
2411 | "" (blank line) at the end in certain situations. This has been | |
2412 | corrected. [561] | |
2413 | ||
2414 | =item * | |
2415 | ||
2416 | Autovivification of symbolic references of special variables described | |
2417 | in L<perlvar> (as in C<${$num}>) was accidentally disabled. This works | |
2418 | again now. [561] | |
2419 | ||
2420 | =item * | |
2421 | ||
2422 | Sys::Syslog ignored the C<LOG_AUTH> constant. | |
2423 | ||
2424 | =item * | |
2425 | ||
2426 | $AUTOLOAD, sort(), lock(), and spawning subprocesses | |
2427 | in multiple threads simultaneously are now thread-safe. | |
2428 | ||
2429 | =item * | |
2430 | ||
2431 | Tie::Array's SPLICE method was broken. | |
2432 | ||
2433 | =item * | |
2434 | ||
2435 | Allow a read-only string on the left-hand side of a non-modifying tr///. | |
2436 | ||
2437 | =item * | |
2438 | ||
2439 | If C<STDERR> is tied, warnings caused by C<warn> and C<die> now | |
2440 | correctly pass to it. | |
2441 | ||
2442 | =item * | |
2443 | ||
2444 | Several Unicode fixes. | |
2445 | ||
2446 | =over 8 | |
2447 | ||
2448 | =item * | |
2449 | ||
2450 | BOMs (byte order marks) at the beginning of Perl files | |
2451 | (scripts, modules) should now be transparently skipped. | |
2452 | UTF-16 and UCS-2 encoded Perl files should now be read correctly. | |
2453 | ||
2454 | =item * | |
2455 | ||
2456 | The character tables have been updated to Unicode 3.2.0. | |
2457 | ||
2458 | =item * | |
2459 | ||
2460 | Comparing with utf8 data does not magically upgrade non-utf8 data | |
2461 | into utf8. (This was a problem for example if you were mixing data | |
2462 | from I/O and Unicode data: your output might have got magically encoded | |
2463 | as UTF-8.) | |
2464 | ||
2465 | =item * | |
2466 | ||
2467 | Generating illegal Unicode code points such as U+FFFE, or the UTF-16 | |
2468 | surrogates, now also generates an optional warning. | |
2469 | ||
2470 | =item * | |
2471 | ||
2472 | C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase. | |
2473 | ||
2474 | =item * | |
2475 | ||
2476 | Concatenation with the C<.> operator or via variable interpolation, | |
2477 | C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator, | |
2478 | substitution with C<s///>, single-quoted UTF8, should now work. | |
2479 | ||
2480 | =item * | |
2481 | ||
2482 | The C<tr///> operator now works. Note that the C<tr///CU> | |
2483 | functionality has been removed (but see pack('U0', ...)). | |
2484 | ||
2485 | =item * | |
2486 | ||
2487 | C<eval "v200"> now works. | |
2488 | ||
2489 | =item * | |
2490 | ||
2491 | Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious warnings. | |
2492 | This has been corrected. [561] | |
2493 | ||
2494 | =item * | |
2495 | ||
2496 | Zero entries were missing from the Unicode classes such as C<IsDigit>. | |
2497 | ||
2498 | =back | |
2499 | ||
2500 | =item * | |
2501 | ||
2502 | Large unsigned numbers (those above 2**31) could sometimes lose their | |
2503 | unsignedness, causing bogus results in arithmetic operations. [561] | |
2504 | ||
2505 | =item * | |
2506 | ||
2507 | The Perl parser has been stress tested using both random input and | |
2508 | Markov chain input and the few found crashes and lockups have been | |
2509 | fixed. | |
2510 | ||
2511 | =back | |
2512 | ||
2513 | =head2 Platform Specific Changes and Fixes | |
2514 | ||
2515 | =over 4 | |
2516 | ||
2517 | =item * | |
2518 | ||
2519 | BSDI 4.* | |
2520 | ||
2521 | Perl now works on post-4.0 BSD/OSes. | |
2522 | ||
2523 | =item * | |
2524 | ||
2525 | All BSDs | |
2526 | ||
2527 | Setting C<$0> now works (as much as possible; see L<perlvar> for details). | |
2528 | ||
2529 | =item * | |
2530 | ||
2531 | Cygwin | |
2532 | ||
2533 | Numerous updates; currently synchronised with Cygwin 1.3.10. | |
2534 | ||
2535 | =item * | |
2536 | ||
2537 | Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O. | |
2538 | ||
2539 | =item * | |
2540 | ||
2541 | EPOC | |
2542 | ||
2543 | EPOC now better supported. See README.epoc. [561] | |
2544 | ||
2545 | =item * | |
2546 | ||
2547 | FreeBSD 3.* | |
2548 | ||
2549 | Perl now works on post-3.0 FreeBSDs. | |
2550 | ||
2551 | =item * | |
2552 | ||
2553 | HP-UX | |
2554 | ||
2555 | README.hpux updated; C<Configure -Duse64bitall> now works; | |
2556 | now uses HP-UX malloc instead of Perl malloc. | |
2557 | ||
2558 | =item * | |
2559 | ||
2560 | IRIX | |
2561 | ||
2562 | Numerous compilation flag and hint enhancements; accidental mixing | |
2563 | of 32-bit and 64-bit libraries (a doomed attempt) made much harder. | |
2564 | ||
2565 | =item * | |
2566 | ||
2567 | Linux | |
2568 | ||
2569 | =over 8 | |
2570 | ||
2571 | =item * | |
2572 | ||
2573 | Long doubles should now work (see INSTALL). [561] | |
2574 | ||
2575 | =item * | |
2576 | ||
2577 | Linux previously had problems related to sockaddrlen when using | |
2578 | accept(), recvfrom() (in Perl: recv()), getpeername(), and | |
2579 | getsockname(). | |
2580 | ||
2581 | =back | |
2582 | ||
2583 | =item * | |
2584 | ||
2585 | Mac OS Classic | |
2586 | ||
2587 | Compilation of the standard Perl distribution in Mac OS Classic should | |
2588 | now work if you have the Metrowerks development environment and the | |
2589 | missing Mac-specific toolkit bits. Contact the macperl mailing list | |
2590 | for details. | |
2591 | ||
2592 | =item * | |
2593 | ||
2594 | MPE/iX | |
2595 | ||
2596 | MPE/iX update after Perl 5.6.0. See README.mpeix. [561] | |
2597 | ||
2598 | =item * | |
2599 | ||
2600 | NetBSD/threads: try installing the GNU pth (should be in the | |
2601 | packages collection, or http://www.gnu.org/software/pth/), | |
2602 | and Configure with -Duseithreads. | |
2603 | ||
2604 | =item * | |
2605 | ||
2606 | NetBSD/sparc | |
2607 | ||
2608 | Perl now works on NetBSD/sparc. | |
2609 | ||
2610 | =item * | |
2611 | ||
2612 | OS/2 | |
2613 | ||
2614 | Now works with usethreads (see INSTALL). [561] | |
2615 | ||
2616 | =item * | |
2617 | ||
2618 | Solaris | |
2619 | ||
2620 | 64-bitness using the Sun Workshop compiler now works. | |
2621 | ||
2622 | =item * | |
2623 | ||
2624 | Stratus VOS | |
2625 | ||
2626 | The native build method requires at least VOS Release 14.5.0 | |
2627 | and GNU C++/GNU Tools 2.0.1 or later. The Perl pack function | |
2628 | now maps overflowed values to +infinity and underflowed values | |
2629 | to -infinity. | |
2630 | ||
2631 | =item * | |
2632 | ||
2633 | Tru64 (aka Digital UNIX, aka DEC OSF/1) | |
2634 | ||
2635 | The operating system version letter now recorded in $Config{osvers}. | |
2636 | Allow compiling with gcc (previously explicitly forbidden). Compiling | |
2637 | with gcc still not recommended because buggy code results, even with | |
2638 | gcc 2.95.2. | |
2639 | ||
2640 | =item * | |
2641 | ||
2642 | Unicos | |
2643 | ||
2644 | Fixed various alignment problems that lead into core dumps either | |
2645 | during build or later; no longer dies on math errors at runtime; | |
2646 | now using full quad integers (64 bits), previously was using | |
2647 | only 46 bit integers for speed. | |
2648 | ||
2649 | =item * | |
2650 | ||
2651 | VMS | |
2652 | ||
2653 | See L</"Socket Extension Dynamic in VMS"> and L</"IEEE-format Floating Point | |
2654 | Default on OpenVMS Alpha"> for important changes not otherwise listed here. | |
2655 | ||
2656 | chdir() now works better despite a CRT bug; now works with MULTIPLICITY | |
2657 | (see INSTALL); now works with Perl's malloc. | |
2658 | ||
2659 | The tainting of C<%ENV> elements via C<keys> or C<values> was previously | |
2660 | unimplemented. It now works as documented. | |
2661 | ||
2662 | The C<waitpid> emulation has been improved. The worst bug (now fixed) | |
2663 | was that a pid of -1 would cause a wildcard search of all processes on | |
2664 | the system. | |
2665 | ||
2666 | POSIX-style signals are now emulated much better on VMS versions prior | |
2667 | to 7.0. | |
2668 | ||
2669 | The C<system> function and backticks operator have improved | |
2670 | functionality and better error handling. [561] | |
2671 | ||
2672 | File access tests now use current process privileges rather than the | |
2673 | user's default privileges, which could sometimes result in a mismatch | |
2674 | between reported access and actual access. This improvement is only | |
2675 | available on VMS v6.0 and later. | |
2676 | ||
2677 | There is a new C<kill> implementation based on C<sys$sigprc> that allows | |
2678 | older VMS systems (pre-7.0) to use C<kill> to send signals rather than | |
2679 | simply force exit. This implementation also allows later systems to | |
2680 | call C<kill> from within a signal handler. | |
2681 | ||
2682 | Iterative logical name translations are now limited to 10 iterations in | |
2683 | imitation of SHOW LOGICAL and other OpenVMS facilities. | |
2684 | ||
2685 | =item * | |
2686 | ||
2687 | Windows | |
2688 | ||
2689 | =over 8 | |
2690 | ||
2691 | =item * | |
2692 | ||
2693 | Signal handling now works better than it used to. It is now implemented | |
2694 | using a Windows message loop, and is therefore less prone to random | |
2695 | crashes. | |
2696 | ||
2697 | =item * | |
2698 | ||
2699 | fork() emulation is now more robust, but still continues to have a few | |
2700 | esoteric bugs and caveats. See L<perlfork> for details. [561+] | |
2701 | ||
2702 | =item * | |
2703 | ||
2704 | A failed (pseudo)fork now returns undef and sets errno to EAGAIN. [561] | |
2705 | ||
2706 | =item * | |
2707 | ||
2708 | The following modules now work on Windows: | |
2709 | ||
2710 | ExtUtils::Embed [561] | |
2711 | IO::Pipe | |
2712 | IO::Poll | |
2713 | Net::Ping | |
2714 | ||
2715 | =item * | |
2716 | ||
2717 | IO::File::new_tmpfile() is no longer limited to 32767 invocations | |
2718 | per-process. | |
2719 | ||
2720 | =item * | |
2721 | ||
2722 | Better chdir() return value for a non-existent directory. | |
2723 | ||
2724 | =item * | |
2725 | ||
2726 | Compiling perl using the 64-bit Platform SDK tools is now supported. | |
2727 | ||
2728 | =item * | |
2729 | ||
2730 | The Win32::SetChildShowWindow() builtin can be used to control the | |
2731 | visibility of windows created by child processes. See L<Win32> for | |
2732 | details. | |
2733 | ||
2734 | =item * | |
2735 | ||
2736 | Non-blocking waits for child processes (or pseudo-processes) are | |
2737 | supported via C<waitpid($pid, &POSIX::WNOHANG)>. | |
2738 | ||
2739 | =item * | |
2740 | ||
2741 | The behavior of system() with multiple arguments has been rationalized. | |
2742 | Each unquoted argument will be automatically quoted to protect whitespace, | |
2743 | and any existing whitespace in the arguments will be preserved. This | |
2744 | improves the portability of system(@args) by avoiding the need for | |
2745 | Windows C<cmd> shell specific quoting in perl programs. | |
2746 | ||
2747 | Note that this means that some scripts that may have relied on earlier | |
2748 | buggy behavior may no longer work correctly. For example, | |
2749 | C<system("nmake /nologo", @args)> will now attempt to run the file | |
2750 | C<nmake /nologo> and will fail when such a file isn't found. | |
2751 | On the other hand, perl will now execute code such as | |
2752 | C<system("c:/Program Files/MyApp/foo.exe", @args)> correctly. | |
2753 | ||
2754 | =item * | |
2755 | ||
2756 | The perl header files no longer suppress common warnings from the | |
2757 | Microsoft Visual C++ compiler. This means that additional warnings may | |
2758 | now show up when compiling XS code. | |
2759 | ||
2760 | =item * | |
2761 | ||
2762 | Borland C++ v5.5 is now a supported compiler that can build Perl. | |
2763 | However, the generated binaries continue to be incompatible with those | |
2764 | generated by the other supported compilers (GCC and Visual C++). [561] | |
2765 | ||
2766 | =item * | |
2767 | ||
2768 | Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x. | |
2769 | [561] | |
2770 | ||
2771 | =item * | |
2772 | ||
2773 | Current directory entries in %ENV are now correctly propagated to child | |
2774 | processes. [561] | |
2775 | ||
2776 | =item * | |
2777 | ||
2778 | New %ENV entries now propagate to subprocesses. [561] | |
2779 | ||
2780 | =item * | |
2781 | ||
2782 | Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root. | |
2783 | Other bugs in chdir() and Cwd::cwd() have also been fixed. [561] | |
2784 | ||
2785 | =item * | |
2786 | ||
2787 | The makefiles now default to the features enabled in ActiveState ActivePerl | |
2788 | (a popular Win32 binary distribution). [561] | |
2789 | ||
2790 | =item * | |
2791 | ||
2792 | HTML files will now be installed in c:\perl\html instead of | |
2793 | c:\perl\lib\pod\html | |
2794 | ||
2795 | =item * | |
2796 | ||
2797 | REG_EXPAND_SZ keys are now allowed in registry settings used by perl. [561] | |
2798 | ||
2799 | =item * | |
2800 | ||
2801 | Can now send() from all threads, not just the first one. [561] | |
2802 | ||
2803 | =item * | |
2804 | ||
2805 | ExtUtils::MakeMaker now uses $ENV{LIB} to search for libraries. [561] | |
2806 | ||
2807 | =item * | |
2808 | ||
2809 | Less stack reserved per thread so that more threads can run | |
2810 | concurrently. (Still 16M per thread.) [561] | |
2811 | ||
2812 | =item * | |
2813 | ||
2814 | C<< File::Spec->tmpdir() >> now prefers C:/temp over /tmp | |
2815 | (works better when perl is running as service). | |
2816 | ||
2817 | =item * | |
2818 | ||
2819 | Better UNC path handling under ithreads. [561] | |
2820 | ||
2821 | =item * | |
2822 | ||
2823 | wait(), waitpid(), and backticks now return the correct exit status | |
2824 | under Windows 9x. [561] | |
2825 | ||
2826 | =item * | |
2827 | ||
2828 | A socket handle leak in accept() has been fixed. [561] | |
2829 | ||
2830 | =back | |
2831 | ||
2832 | =back | |
2833 | ||
2834 | =head1 New or Changed Diagnostics | |
2835 | ||
2836 | Please see L<perldiag> for more details. | |
2837 | ||
2838 | =over 4 | |
2839 | ||
2840 | =item * | |
2841 | ||
2842 | Ambiguous range in the transliteration operator (like a-z-9) now | |
2843 | gives a warning. | |
2844 | ||
2845 | =item * | |
2846 | ||
2847 | chdir("") and chdir(undef) now give a deprecation warning because they | |
2848 | cause a possible unintentional chdir to the home directory. | |
2849 | Say chdir() if you really mean that. | |
2850 | ||
2851 | =item * | |
2852 | ||
2853 | Two new debugging options have been added: if you have compiled your | |
2854 | Perl with debugging, you can use the -DT [561] and -DR options to trace | |
2855 | tokenising and to add reference counts to displaying variables, | |
2856 | respectively. | |
2857 | ||
2858 | =item * | |
2859 | ||
2860 | The lexical warnings category "deprecated" is no longer a sub-category | |
2861 | of the "syntax" category. It is now a top-level category in its own | |
2862 | right. | |
2863 | ||
2864 | =item * | |
2865 | ||
2866 | Unadorned dump() will now give a warning suggesting to | |
2867 | use explicit CORE::dump() if that's what really is meant. | |
2868 | ||
2869 | =item * | |
2870 | ||
2871 | The "Unrecognized escape" warning has been extended to include C<\8>, | |
2872 | C<\9>, and C<\_>. There is no need to escape any of the C<\w> characters. | |
2873 | ||
2874 | =item * | |
2875 | ||
2876 | All regular expression compilation error messages are now hopefully | |
2877 | easier to understand both because the error message now comes before | |
2878 | the failed regex and because the point of failure is now clearly | |
2879 | marked by a C<E<lt>-- HERE> marker. | |
2880 | ||
2881 | =item * | |
2882 | ||
2883 | Various I/O (and socket) functions like binmode(), close(), and so | |
2884 | forth now more consistently warn if they are used illogically either | |
2885 | on a yet unopened or on an already closed filehandle (or socket). | |
2886 | ||
2887 | =item * | |
2888 | ||
2889 | Using lstat() on a filehandle now gives a warning. (It's a non-sensical | |
2890 | thing to do.) | |
2891 | ||
2892 | =item * | |
2893 | ||
2894 | The C<-M> and C<-m> options now warn if you didn't supply the module name. | |
2895 | ||
2896 | =item * | |
2897 | ||
2898 | If you in C<use> specify a required minimum version, modules matching | |
2899 | the name and but not defining a $VERSION will cause a fatal failure. | |
2900 | ||
2901 | =item * | |
2902 | ||
2903 | Using negative offset for vec() in lvalue context is now a warnable offense. | |
2904 | ||
2905 | =item * | |
2906 | ||
70a63dff | 2907 | Odd number of arguments to overload::constant now elicits a warning. |
55e8fca7 JH |
2908 | |
2909 | =item * | |
2910 | ||
70a63dff | 2911 | Odd number of elements in anonymous hash now elicits a warning. |
55e8fca7 JH |
2912 | |
2913 | =item * | |
2914 | ||
2915 | The various "opened only for", "on closed", "never opened" warnings | |
2916 | drop the C<main::> prefix for filehandles in the C<main> package, | |
2917 | for example C<STDIN> instead of C<main::STDIN>. | |
2918 | ||
2919 | =item * | |
2920 | ||
2921 | Subroutine prototypes are now checked more carefully, you may | |
2922 | get warnings for example if you have used non-prototype characters. | |
2923 | ||
2924 | =item * | |
2925 | ||
2926 | If an attempt to use a (non-blessed) reference as an array index | |
2927 | is made, a warning is given. | |
2928 | ||
2929 | =item * | |
2930 | ||
2931 | C<push @a;> and C<unshift @a;> (with no values to push or unshift) | |
2932 | now give a warning. This may be a problem for generated and evaled | |
2933 | code. | |
2934 | ||
2935 | =item * | |
2936 | ||
2937 | If you try to L<perlfunc/pack> a number less than 0 or larger than 255 | |
2938 | using the C<"C"> format you will get an optional warning. Similarly | |
2939 | for the C<"c"> format and a number less than -128 or more than 127. | |
2940 | ||
2941 | =item * | |
2942 | ||
2943 | pack C<P> format now demands an explicit size. | |
2944 | ||
2945 | =item * | |
2946 | ||
2947 | unpack C<w> now warns of unterminated compressed integers. | |
2948 | ||
2949 | =item * | |
2950 | ||
2951 | Warnings relating to the use of PerlIO have been added. | |
2952 | ||
2953 | =item * | |
2954 | ||
2955 | Certain regex modifiers such as C<(?o)> make sense only if applied to | |
2956 | the entire regex. You will get an optional warning if you try to do | |
2957 | otherwise. | |
2958 | ||
2959 | =item * | |
2960 | ||
2961 | Variable length lookbehind has not yet been implemented, trying to | |
2962 | use it will tell that. | |
2963 | ||
2964 | =item * | |
2965 | ||
2966 | Using arrays or hashes as references (e.g. C<< %foo->{bar} >> | |
2967 | has been deprecated for a while. Now you will get an optional warning. | |
2968 | ||
2969 | =item * | |
2970 | ||
2971 | Warnings relating to the use of the new restricted hashes feature | |
2972 | have been added. | |
2973 | ||
2974 | =item * | |
2975 | ||
2976 | Self-ties of arrays and hashes are not supported and fatal errors | |
2977 | will happen even at an attempt to do so. | |
2978 | ||
2979 | =item * | |
2980 | ||
2981 | Using C<sort> in scalar context now issues an optional warning. | |
2982 | This didn't do anything useful, as the sort was not performed. | |
2983 | ||
2984 | =item * | |
2985 | ||
2986 | Using the /g modifier in split() is meaningless and will cause a warning. | |
2987 | ||
2988 | =item * | |
2989 | ||
2990 | Using splice() past the end of an array now causes a warning. | |
2991 | ||
2992 | =item * | |
2993 | ||
2994 | Malformed Unicode encodings (UTF-8 and UTF-16) cause a lot of warnings, | |
2995 | ad doestrying to use UTF-16 surrogates (which are unimplemented). | |
2996 | ||
2997 | =item * | |
2998 | ||
2999 | Trying to use Unicode characters on an I/O stream without marking the | |
3000 | stream's encoding (using open() or binmode()) will cause "Wide character" | |
3001 | warnings. | |
3002 | ||
3003 | =item * | |
3004 | ||
3005 | Use of v-strings in use/require causes a (backward) portability warning. | |
3006 | ||
3007 | =item * | |
3008 | ||
3009 | Warnings relating to the use interpreter threads and their shared data | |
3010 | have been added. | |
3011 | ||
3012 | =back | |
3013 | ||
3014 | =head1 Changed Internals | |
3015 | ||
3016 | =over 4 | |
3017 | ||
3018 | =item * | |
3019 | ||
3020 | PerlIO is now the default. | |
3021 | ||
3022 | =item * | |
3023 | ||
3024 | perlapi.pod (a companion to perlguts) now attempts to document the | |
3025 | internal API. | |
3026 | ||
3027 | =item * | |
3028 | ||
3029 | You can now build a really minimal perl called microperl. | |
3030 | Building microperl does not require even running Configure; | |
3031 | C<make -f Makefile.micro> should be enough. Beware: microperl makes | |
3032 | many assumptions, some of which may be too bold; the resulting | |
3033 | executable may crash or otherwise misbehave in wondrous ways. | |
3034 | For careful hackers only. | |
3035 | ||
3036 | =item * | |
3037 | ||
3038 | Added rsignal(), whichsig(), do_join(), op_clear, op_null, | |
3039 | ptr_table_clear(), ptr_table_free(), sv_setref_uv(), and several UTF-8 | |
3040 | interfaces to the publicised API. For the full list of the available | |
3041 | APIs see L<perlapi>. | |
3042 | ||
3043 | =item * | |
3044 | ||
3045 | Made possible to propagate customised exceptions via croak()ing. | |
3046 | ||
3047 | =item * | |
3048 | ||
3049 | Now xsubs can have attributes just like subs. (Well, at least the | |
3050 | built-in attributes.) | |
3051 | ||
3052 | =item * | |
3053 | ||
3054 | dTHR and djSP have been obsoleted; the former removed (because it's | |
3055 | a no-op) and the latter replaced with dSP. | |
3056 | ||
3057 | =item * | |
3058 | ||
3059 | PERL_OBJECT has been completely removed. | |
3060 | ||
3061 | =item * | |
3062 | ||
3063 | The MAGIC constants (e.g. C<'P'>) have been macrofied | |
3064 | (e.g. C<PERL_MAGIC_TIED>) for better source code readability | |
3065 | and maintainability. | |
3066 | ||
3067 | =item * | |
3068 | ||
3069 | The regex compiler now maintains a structure that identifies nodes in | |
3070 | the compiled bytecode with the corresponding syntactic features of the | |
3071 | original regex expression. The information is attached to the new | |
3072 | C<offsets> member of the C<struct regexp>. See L<perldebguts> for more | |
3073 | complete information. | |
3074 | ||
3075 | =item * | |
3076 | ||
3077 | The C code has been made much more C<gcc -Wall> clean. Some warning | |
3078 | messages still remain in some platforms, so if you are compiling with | |
3079 | gcc you may see some warnings about dubious practices. The warnings | |
3080 | are being worked on. | |
3081 | ||
3082 | =item * | |
3083 | ||
3084 | F<perly.c>, F<sv.c>, and F<sv.h> have now been extensively commented. | |
3085 | ||
3086 | =item * | |
3087 | ||
3088 | Documentation on how to use the Perl source repository has been added | |
3089 | to F<Porting/repository.pod>. | |
3090 | ||
3091 | =item * | |
3092 | ||
3093 | There are now several profiling make targets. | |
3094 | ||
3095 | =back | |
3096 | ||
3097 | =head1 Security Vulnerability Closed [561] | |
3098 | ||
3099 | (This change was already made in 5.7.0 but bears repeating here.) | |
3100 | (5.7.0 came out before 5.6.1: the development branch 5.7 released | |
3101 | earlier than the maintenance branch 5.6) | |
3102 | ||
3103 | A potential security vulnerability in the optional suidperl component | |
3104 | of Perl was identified in August 2000. suidperl is neither built nor | |
3105 | installed by default. As of November 2001 the only known vulnerable | |
3106 | platform is Linux, most likely all Linux distributions. CERT and | |
3107 | various vendors and distributors have been alerted about the vulnerability. | |
3108 | See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt | |
3109 | for more information. | |
3110 | ||
3111 | The problem was caused by Perl trying to report a suspected security | |
3112 | exploit attempt using an external program, /bin/mail. On Linux | |
3113 | platforms the /bin/mail program had an undocumented feature which | |
3114 | when combined with suidperl gave access to a root shell, resulting in | |
3115 | a serious compromise instead of reporting the exploit attempt. If you | |
3116 | don't have /bin/mail, or if you have 'safe setuid scripts', or if | |
3117 | suidperl is not installed, you are safe. | |
3118 | ||
3119 | The exploit attempt reporting feature has been completely removed from | |
3120 | Perl 5.8.0 (and the maintenance release 5.6.1, and it was removed also | |
3121 | from all the Perl 5.7 releases), so that particular vulnerability | |
3122 | isn't there anymore. However, further security vulnerabilities are, | |
3123 | unfortunately, always possible. The suidperl functionality is most | |
3124 | probably going to be removed in Perl 5.10. In any case, suidperl | |
3125 | should only be used by security experts who know exactly what they are | |
3126 | doing and why they are using suidperl instead of some other solution | |
3127 | such as sudo ( see http://www.courtesan.com/sudo/ ). | |
3128 | ||
3129 | =head1 New Tests | |
3130 | ||
3131 | Several new tests have been added, especially for the F<lib> and | |
3132 | F<ext> subsections. There are now about 69 000 individual tests | |
3133 | (spread over about 700 test scripts), in the regression suite (5.6.1 | |
3134 | has about 11 700 tests, in 258 test scripts) The exact numbers depend | |
3135 | on the platform and Perl configuration used. Many of the new tests | |
3136 | are of course introduced by the new modules, but still in general Perl | |
3137 | is now more thoroughly tested. | |
3138 | ||
3139 | Because of the large number of tests, running the regression suite | |
3140 | will take considerably longer time than it used to: expect the suite | |
3141 | to take up to 4-5 times longer to run than in perl 5.6. On a really | |
3142 | fast machine you can hope to finish the suite in about 6-8 minutes | |
3143 | (wallclock time). | |
3144 | ||
3145 | The tests are now reported in a different order than in earlier Perls. | |
3146 | (This happens because the test scripts from under t/lib have been moved | |
3147 | to be closer to the library/extension they are testing.) | |
3148 | ||
3149 | =head1 Known Problems | |
3150 | ||
3151 | =head2 The Compiler Suite Is Still Very Experimental | |
3152 | ||
3153 | The compiler suite is slowly getting better but it continues to be | |
3154 | highly experimental. Use in production environments is discouraged. | |
3155 | ||
3156 | =head2 Localising Tied Arrays and Hashes Is Broken | |
3157 | ||
3158 | local %tied_array; | |
3159 | ||
3160 | doesn't work as one would expect: the old value is restored | |
3161 | incorrectly. This will be changed in a future release, but we don't | |
3162 | know yet what the new semantics will exactly be. In any case, the | |
3163 | change will break existing code that relies on the current | |
3164 | (ill-defined) semantics, so just avoid doing this in general. | |
3165 | ||
3166 | =head2 Building Extensions Can Fail Because Of Largefiles | |
3167 | ||
3168 | Some extensions like mod_perl are known to have issues with | |
3169 | `largefiles', a change brought by Perl 5.6.0 in which file offsets | |
3170 | default to 64 bits wide, where supported. Modules may fail to compile | |
3171 | at all, or they may compile and work incorrectly. Currently, there | |
3172 | is no good solution for the problem, but Configure now provides | |
3173 | appropriate non-largefile ccflags, ldflags, libswanted, and libs | |
3174 | in the %Config hash (e.g., $Config{ccflags_nolargefiles}) so the | |
3175 | extensions that are having problems can try configuring themselves | |
3176 | without the largefileness. This is admittedly not a clean solution, | |
3177 | and the solution may not even work at all. One potential failure is | |
3178 | whether one can (or, if one can, whether it's a good idea to) link | |
3179 | together at all binaries with different ideas about file offsets; | |
3180 | all this is platform-dependent. | |
3181 | ||
3182 | =head2 Modifying $_ Inside for(..) | |
3183 | ||
3184 | for (1..5) { $_++ } | |
3185 | ||
3186 | works without complaint. It shouldn't. (You should be able to | |
3187 | modify only lvalue elements inside the loops.) You can see the | |
3188 | correct behaviour by replacing the 1..5 with 1, 2, 3, 4, 5. | |
3189 | ||
3190 | =head2 mod_perl 1.26 Doesn't Build With Threaded Perl | |
3191 | ||
3192 | Use mod_perl 1.27 or higher. | |
3193 | ||
3194 | =head2 lib/ftmp-security tests warn 'system possibly insecure' | |
3195 | ||
3196 | Don't panic. Read the 'make test' section of INSTALL instead. | |
3197 | ||
3198 | =head2 libwww-perl (LWP) fails base/date #51 | |
3199 | ||
3200 | Use libwww-perl 5.65 or later. | |
3201 | ||
3202 | =head2 PDL failing some tests | |
3203 | ||
3204 | Use PDL 2.3.4 or later. | |
3205 | ||
3206 | =head2 Perl_get_sv | |
3207 | ||
3208 | You may get errors like 'Undefined symbol "Perl_get_sv"' or "can't | |
3209 | resolve symbol 'Perl_get_sv'", or the symbol may be "Perl_sv_2pv". | |
3210 | This probably means that you are trying to use an older shared Perl | |
3211 | library (or extensions linked with such) with Perl 5.8.0 executable. | |
3212 | Perl used to have such a subroutine, but that is no more the case. | |
3213 | Check your shared library path, and any shared Perl libraries in those | |
3214 | directories. | |
3215 | ||
3216 | Sometimes this problem may also indicate a partial Perl 5.8.0 | |
3217 | installation, see L</"Mac OS X dyld undefined symbols"> for an | |
3218 | example and how to deal with it. | |
3219 | ||
3220 | =head2 Self-tying Problems | |
3221 | ||
3222 | Self-tying of arrays and hashes is broken in rather deep and | |
3223 | hard-to-fix ways. As a stop-gap measure to avoid people from getting | |
3224 | frustrated at the mysterious results (core dumps, most often), it is | |
3225 | forbidden for now (you will get a fatal error even from an attempt). | |
3226 | ||
3227 | A change to self-tying of globs has caused them to be recursively | |
3228 | referenced (see: L<perlobj/"Two-Phased Garbage Collection">). You | |
3229 | will now need an explicit untie to destroy a self-tied glob. This | |
3230 | behaviour may be fixed at a later date. | |
3231 | ||
3232 | Self-tying of scalars and IO thingies works. | |
3233 | ||
3234 | =head2 ext/threads/t/libc | |
3235 | ||
3236 | If this test fails, it indicates that your libc (C library) is not | |
3237 | threadsafe. This particular test stress tests the localtime() call to | |
3238 | find out whether it is threadsafe. See L<perlthrtut> for more information. | |
3239 | ||
3240 | =head2 Failure of Thread (5.005-style) tests | |
3241 | ||
3242 | B<Note that support for 5.005-style threading is deprecated, | |
3243 | experimental and practically unsupported. In 5.10, it is expected | |
3244 | to be removed. You should migrate your code to ithreads.> | |
3245 | ||
3246 | The following tests are known to fail due to fundamental problems in | |
3247 | the 5.005 threading implementation. These are not new failures--Perl | |
3248 | 5.005_0x has the same bugs, but didn't have these tests. | |
3249 | ||
3250 | ../ext/B/t/xref.t 255 65280 14 12 85.71% 3-14 | |
3251 | ../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7 | |
3252 | ../lib/English.t 2 512 54 2 3.70% 2-3 | |
3253 | ../lib/FileCache.t 5 1 20.00% 5 | |
3254 | ../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3 | |
3255 | ../lib/Filter/Simple/t/filter_only. 9 3 33.33% 1-2 5 | |
3256 | ../lib/Math/BigInt/t/bare_mbf.t 1627 4 0.25% 8 11 1626-1627 | |
3257 | ../lib/Math/BigInt/t/bigfltpm.t 1629 4 0.25% 10 13 1628- | |
3258 | 1629 | |
3259 | ../lib/Math/BigInt/t/sub_mbf.t 1633 4 0.24% 8 11 1632-1633 | |
3260 | ../lib/Math/BigInt/t/with_sub.t 1628 4 0.25% 9 12 1627-1628 | |
3261 | ../lib/Tie/File/t/31_autodefer.t 255 65280 65 32 49.23% 34-65 | |
3262 | ../lib/autouse.t 10 1 10.00% 4 | |
3263 | op/flip.t 15 1 6.67% 15 | |
3264 | ||
3265 | These failures are unlikely to get fixed as 5.005-style threads | |
3266 | are considered fundamentally broken. (Basically what happens is that | |
3267 | competing threads can corrupt shared global state, one good example | |
3268 | being regular expression engine's state.) | |
3269 | ||
3270 | =head2 Timing problems | |
3271 | ||
3272 | The following tests may fail intermittently because of timing | |
3273 | problems, for example if the system is heavily loaded. | |
3274 | ||
3275 | t/op/alarm.t | |
3276 | ext/Time/HiRes/HiRes.t | |
3277 | lib/Benchmark.t | |
3278 | lib/Memoize/t/expmod_t.t | |
3279 | lib/Memoize/t/speed.t | |
3280 | ||
3281 | In case of failure please try running them manually, for example | |
3282 | ||
3283 | ./perl -Ilib ext/Time/HiRes/HiRes.t | |
3284 | ||
3285 | =head2 Tied/Magical Array/Hash Elements Do Not Autovivify | |
3286 | ||
3287 | For normal arrays C<$foo = \$bar[1]> will assign C<undef> to | |
3288 | C<$bar[1]> (assuming that it didn't exist before), but for | |
3289 | tied/magical arrays and hashes such autovivification does not happen | |
3290 | because there is currently no way to catch the reference creation. | |
3291 | The same problem affects slicing over non-existent indices/keys of | |
3292 | a tied/magical array/hash. | |
3293 | ||
3294 | =head2 Unicode in package/class and subroutine names does not work | |
3295 | ||
3296 | One can have Unicode in identifier names, but not in package/class or | |
3297 | subroutine names. While some limited functionality towards this does | |
3298 | exist as of Perl 5.8.0, that is more accidental than designed; use of | |
3299 | Unicode for the said purposes is unsupported. | |
3300 | ||
3301 | One reason of this unfinishedness is its (currently) inherent | |
3302 | unportability: since both package names and subroutine names may | |
3303 | need to be mapped to file and directory names, the Unicode capability | |
3304 | of the filesystem becomes important-- and there unfortunately aren't | |
3305 | portable answers. | |
3306 | ||
3307 | =head1 Platform Specific Problems | |
3308 | ||
3309 | =head2 AIX | |
3310 | ||
3311 | =over 4 | |
3312 | ||
3313 | =item * | |
3314 | ||
3315 | If using the AIX native make command, instead of just "make" issue | |
3316 | "make all". In some setups the former has been known to spuriously | |
3317 | also try to run "make install". Alternatively, you may want to use | |
3318 | GNU make. | |
3319 | ||
3320 | =item * | |
3321 | ||
3322 | In AIX 4.2, Perl extensions that use C++ functions that use statics | |
3323 | may have problems in that the statics are not getting initialized. | |
3324 | In newer AIX releases, this has been solved by linking Perl with | |
3325 | the libC_r library, but unfortunately in AIX 4.2 the said library | |
3326 | has an obscure bug where the various functions related to time | |
3327 | (such as time() and gettimeofday()) return broken values, and | |
3328 | therefore in AIX 4.2 Perl is not linked against libC_r. | |
3329 | ||
3330 | =item * | |
3331 | ||
3332 | vac 5.0.0.0 May Produce Buggy Code For Perl | |
3333 | ||
3334 | The AIX C compiler vac version 5.0.0.0 may produce buggy code, | |
3335 | resulting in a few random tests failing when run as part of "make | |
3336 | test", but when the failing tests are run by hand, they succeed. | |
3337 | We suggest upgrading to at least vac version 5.0.1.0, that has been | |
3338 | known to compile Perl correctly. "lslpp -L|grep vac.C" will tell | |
3339 | you the vac version. See README.aix. | |
3340 | ||
3341 | =item * | |
3342 | ||
3343 | If building threaded Perl, you may get compilation warning from pp_sys.c: | |
3344 | ||
3345 | "pp_sys.c", line 4651.39: 1506-280 (W) Function argument assignment between types "unsigned char*" and "const void*" is not allowed. | |
3346 | ||
3347 | This is harmless; it is caused by the getnetbyaddr() and getnetbyaddr_r() | |
3348 | having slightly different types for their first argument. | |
3349 | ||
3350 | =back | |
3351 | ||
3352 | =head2 Alpha systems with old gccs fail several tests | |
3353 | ||
3354 | If you see op/pack, op/pat, op/regexp, or ext/Storable tests failing | |
3355 | in a Linux/alpha or *BSD/Alpha, it's probably time to upgrade your gcc. | |
3356 | gccs prior to 2.95.3 are definitely not good enough, and gcc 3.1 may | |
3357 | be even better. (RedHat Linux/alpha with gcc 3.1 reported no problems, | |
3358 | as did Linux 2.4.18 with gcc 2.95.4.) (In Tru64, it is preferable to | |
3359 | use the bundled C compiler.) | |
3360 | ||
3361 | =head2 AmigaOS | |
3362 | ||
3363 | Perl 5.8.0 doesn't build in AmigaOS. It broke at some point during | |
3364 | the ithreads work and we could not find Amiga experts to unbreak the | |
3365 | problems. Perl 5.6.1 still works for AmigaOS (as does the the 5.7.2 | |
3366 | development release). | |
3367 | ||
3368 | =head2 BeOS | |
3369 | ||
3370 | The following tests fail on 5.8.0 Perl in BeOS Personal 5.03: | |
3371 | ||
3372 | t/op/lfs............................FAILED at test 17 | |
3373 | t/op/magic..........................FAILED at test 24 | |
3374 | ext/Fcntl/t/syslfs..................FAILED at test 17 | |
3375 | ext/File/Glob/t/basic...............FAILED at test 3 | |
3376 | ext/POSIX/t/sigaction...............FAILED at test 13 | |
3377 | ext/POSIX/t/waitpid.................FAILED at test 1 | |
3378 | ||
3379 | See L<perlbeos> (README.beos) for more details. | |
3380 | ||
3381 | =head2 Cygwin "unable to remap" | |
3382 | ||
3383 | For example when building the Tk extension for Cygwin, | |
3384 | you may get an error message saying "unable to remap". | |
3385 | This is known problem with Cygwin, and a workaround is | |
3386 | detailed in here: http://sources.redhat.com/ml/cygwin/2001-12/msg00894.html | |
3387 | ||
3388 | =head2 Cygwin ndbm tests fail on FAT | |
3389 | ||
3390 | One can build but not install (or test the build of) the NDBM_File | |
3391 | on FAT filesystems. Installation (or build) on NTFS works fine. | |
3392 | If one attempts the test on a FAT install (or build) the following | |
3393 | failures are expected: | |
3394 | ||
3395 | ../ext/NDBM_File/ndbm.t 13 3328 71 59 83.10% 1-2 4 16-71 | |
3396 | ../ext/ODBM_File/odbm.t 255 65280 ?? ?? % ?? | |
3397 | ../lib/AnyDBM_File.t 2 512 12 2 16.67% 1 4 | |
3398 | ../lib/Memoize/t/errors.t 0 139 11 5 45.45% 7-11 | |
3399 | ../lib/Memoize/t/tie_ndbm.t 13 3328 4 4 100.00% 1-4 | |
3400 | run/fresh_perl.t 97 1 1.03% 91 | |
3401 | ||
3402 | NDBM_File fails and ODBM_File just coredumps. | |
3403 | ||
3404 | =head2 DJGPP Failures | |
3405 | ||
3406 | t/op/stat............................FAILED at test 29 | |
3407 | lib/File/Find/t/find.................FAILED at test 1 | |
3408 | lib/File/Find/t/taint................FAILED at test 1 | |
3409 | lib/h2xs.............................FAILED at test 15 | |
3410 | lib/Pod/t/eol........................FAILED at test 1 | |
3411 | lib/Test/Harness/t/strap-analyze.....FAILED at test 8 | |
3412 | lib/Test/Harness/t/test-harness......FAILED at test 23 | |
3413 | lib/Test/Simple/t/exit...............FAILED at test 1 | |
3414 | ||
3415 | The above failures are known as of 5.8.0 with native builds with long | |
3416 | filenames, but there are a few more if running under dosemu because of | |
3417 | limitations (and maybe bugs) of dosemu: | |
3418 | ||
3419 | t/comp/cpp...........................FAILED at test 3 | |
3420 | t/op/inccode.........................(crash) | |
3421 | ||
3422 | and a few lib/ExtUtils tests, and several hundred Encode/t/Aliases.t | |
3423 | failures that work fine with long filenames. So you really might | |
3424 | prefer native builds and long filenames. | |
3425 | ||
3426 | =head2 FreeBSD built with ithreads coredumps reading large directories | |
3427 | ||
3428 | This is a known bug in FreeBSD 4.5's readdir_r(), it has been fixed in | |
3429 | FreeBSD 4.6 (see L<perlfreebsd> (README.freebsd)). | |
3430 | ||
3431 | =head2 FreeBSD Failing locale Test 117 For ISO 8859-15 Locales | |
3432 | ||
3433 | The ISO 8859-15 locales may fail the locale test 117 in FreeBSD. | |
3434 | This is caused by the characters \xFF (y with diaeresis) and \xBE | |
3435 | (Y with diaeresis) not behaving correctly when being matched | |
3436 | case-insensitively. Apparently this problem has been fixed in | |
3437 | the latest FreeBSD releases. | |
3438 | ( http://www.freebsd.org/cgi/query-pr.cgi?pr=34308 ) | |
3439 | ||
3440 | =head2 IRIX fails ext/List/Util/t/shuffle.t or Digest::MD5 | |
3441 | ||
3442 | IRIX with MIPSpro 7.3.1.2m or 7.3.1.3m compiler may fail the List::Util | |
3443 | test ext/List/Util/t/shuffle.t by dumping core. This seems to be | |
3444 | a compiler error since if compiled with gcc no core dump ensues, and | |
3445 | no failures have been seen on the said test on any other platform. | |
3446 | ||
3447 | Similarly, building the Digest::MD5 extension has been | |
3448 | known to fail with "*** Termination code 139 (bu21)". | |
3449 | ||
3450 | The cure is to drop optimization level (Configure -Doptimize=-O2). | |
3451 | ||
3452 | =head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured | |
3453 | ||
3454 | If perl is configured with -Duse64bitall, the successful result of the | |
3455 | subtest 10 of lib/posix may arrive before the successful result of the | |
3456 | subtest 9, which confuses the test harness so much that it thinks the | |
3457 | subtest 9 failed. | |
3458 | ||
3459 | =head2 Linux with glibc 2.2.5 fails t/op/int subtest #6 with -Duse64bitint | |
3460 | ||
3461 | This is a known bug in the glibc 2.2.5 with long long integers. | |
3462 | ( http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=65612 ) | |
3463 | ||
3464 | =head2 Linux With Sfio Fails op/misc Test 48 | |
3465 | ||
3466 | No known fix. | |
3467 | ||
3468 | =head2 Mac OS X | |
3469 | ||
3470 | Please remember to set your environment variable LC_ALL to "C" | |
3471 | (setenv LC_ALL C) before running "make test" to avoid a lot of | |
3472 | warnings about the broken locales of Mac OS X. | |
3473 | ||
3474 | The following tests are known to fail in Mac OS X 10.1.5 because of | |
3475 | buggy (old) implementations of Berkeley DB included in Mac OS X: | |
3476 | ||
3477 | Failed Test Stat Wstat Total Fail Failed List of Failed | |
3478 | ------------------------------------------------------------------------- | |
3479 | ../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ?? | |
3480 | ../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65 | |
3481 | ||
3482 | If you are building on a UFS partition, you will also probably see | |
3483 | t/op/stat.t subtest #9 fail. This is caused by Darwin's UFS not | |
3484 | supporting inode change time. | |
3485 | ||
3486 | Also the ext/POSIX/t/posix.t subtest #10 fails but it is skipped for | |
3487 | now because the failure is Apple's fault, not Perl's (blocked signals | |
3488 | are lost). | |
3489 | ||
3490 | If you Configure with ithreads, ext/threads/t/libc.t will fail. Again, | |
3491 | this is not Perl's fault-- the libc of Mac OS X is not threadsafe | |
3492 | (in this particular test, the localtime() call is found to be | |
3493 | threadunsafe.) | |
3494 | ||
3495 | =head2 Mac OS X dyld undefined symbols | |
3496 | ||
3497 | If after installing Perl 5.8.0 you are getting warnings about missing | |
3498 | symbols, for example | |
3499 | ||
3500 | dyld: perl Undefined symbols | |
3501 | _perl_sv_2pv | |
3502 | _perl_get_sv | |
3503 | ||
3504 | you probably have an old pre-Perl-5.8.0 installation (or parts of one) | |
3505 | in /Library/Perl (the undefined symbols used to exist in pre-5.8.0 Perls). | |
3506 | It seems that for some reason "make install" doesn't always completely | |
3507 | overwrite the files in /Library/Perl. You can move the old Perl | |
3508 | shared library out of the way like this: | |
3509 | ||
3510 | cd /Library/Perl/darwin/CORE | |
3511 | mv libperl.dylib libperlold.dylib | |
3512 | ||
3513 | and then reissue "make install". Note that the above of course is | |
3514 | extremely disruptive for anything using the /usr/local/bin/perl. | |
3515 | If that doesn't help, you may have to try removing all the .bundle | |
3516 | files from beneath /Library/Perl, and again "make install"-ing. | |
3517 | ||
3518 | =head2 OS/2 Test Failures | |
3519 | ||
3520 | The following tests are known to fail on OS/2 (for clarity | |
3521 | only the failures are shown, not the full error messages): | |
3522 | ||
3523 | ../lib/ExtUtils/t/Mkbootstrap.t 1 256 18 1 5.56% 8 | |
3524 | ../lib/ExtUtils/t/Packlist.t 1 256 34 1 2.94% 17 | |
3525 | ../lib/ExtUtils/t/basic.t 1 256 17 1 5.88% 14 | |
3526 | lib/os2_process.t 2 512 227 2 0.88% 174 209 | |
3527 | lib/os2_process_kid.t 227 2 0.88% 174 209 | |
3528 | lib/rx_cmprt.t 255 65280 18 3 16.67% 16-18 | |
3529 | ||
3530 | =head2 op/sprintf tests 91, 129, and 130 | |
3531 | ||
3532 | The op/sprintf tests 91, 129, and 130 are known to fail on some platforms. | |
3533 | Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX. | |
3534 | ||
3535 | Test 91 is known to fail on QNX6 (nto), because C<sprintf '%e',0> | |
3536 | incorrectly produces C<0.000000e+0> instead of C<0.000000e+00>. | |
3537 | ||
3538 | For tests 129 and 130, the failing platforms do not comply with | |
3539 | the ANSI C Standard: lines 19ff on page 134 of ANSI X3.159 1989, to | |
3540 | be exact. (They produce something other than "1" and "-1" when | |
3541 | formatting 0.6 and -0.6 using the printf format "%.0f"; most often, | |
3542 | they produce "0" and "-0".) | |
3543 | ||
3544 | =head2 Solaris 2.5 | |
3545 | ||
3546 | In case you are still using Solaris 2.5 (aka SunOS 5.5), you may | |
3547 | experience failures (the test core dumping) in lib/locale.t. | |
3548 | The suggested cure is to upgrade your Solaris. | |
3549 | ||
3550 | =head2 Solaris x86 Fails Tests With -Duse64bitint | |
3551 | ||
3552 | The following tests are known to fail in Solaris x86 with Perl | |
3553 | configured to use 64 bit integers: | |
3554 | ||
3555 | ext/Data/Dumper/t/dumper.............FAILED at test 268 | |
3556 | ext/Devel/Peek/Peek..................FAILED at test 7 | |
3557 | ||
3558 | =head2 SUPER-UX (NEC SX) | |
3559 | ||
3560 | The following tests are known to fail on SUPER-UX: | |
3561 | ||
3562 | op/64bitint...........................FAILED tests 29-30, 32-33, 35-36 | |
3563 | op/arith..............................FAILED tests 128-130 | |
3564 | op/pack...............................FAILED tests 25-5625 | |
3565 | op/pow................................ | |
3566 | op/taint..............................# msgsnd failed | |
3567 | ../ext/IO/lib/IO/t/io_poll............FAILED tests 3-4 | |
3568 | ../ext/IPC/SysV/ipcsysv...............FAILED tests 2, 5-6 | |
3569 | ../ext/IPC/SysV/t/msg.................FAILED tests 2, 4-6 | |
3570 | ../ext/Socket/socketpair..............FAILED tests 12 | |
3571 | ../lib/IPC/SysV.......................FAILED tests 2, 5-6 | |
3572 | ../lib/warnings.......................FAILED tests 115-116, 118-119 | |
3573 | ||
3574 | The op/pack failure ("Cannot compress negative numbers at op/pack.t line 126") | |
3575 | is serious but as of yet unsolved. It points at some problems with the | |
3576 | signedness handling of the C compiler, as do the 64bitint, arith, and pow | |
3577 | failures. Most of the rest point at problems with SysV IPC. | |
3578 | ||
3579 | =head2 Term::ReadKey not working on Win32 | |
3580 | ||
3581 | Use Term::ReadKey 2.20 or later. | |
3582 | ||
3583 | =head2 UNICOS/mk | |
3584 | ||
3585 | =over 4 | |
3586 | ||
3587 | =item * | |
3588 | ||
3589 | During Configure, the test | |
3590 | ||
3591 | Guessing which symbols your C compiler and preprocessor define... | |
3592 | ||
3593 | will probably fail with error messages like | |
3594 | ||
3595 | CC-20 cc: ERROR File = try.c, Line = 3 | |
3596 | The identifier "bad" is undefined. | |
3597 | ||
3598 | bad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K | |
3599 | ^ | |
3600 | ||
3601 | CC-65 cc: ERROR File = try.c, Line = 3 | |
3602 | A semicolon is expected at this point. | |
3603 | ||
3604 | This is caused by a bug in the awk utility of UNICOS/mk. You can ignore | |
3605 | the error, but it does cause a slight problem: you cannot fully | |
3606 | benefit from the h2ph utility (see L<h2ph>) that can be used to | |
3607 | convert C headers to Perl libraries, mainly used to be able to access | |
3608 | from Perl the constants defined using C preprocessor, cpp. Because of | |
3609 | the above error, parts of the converted headers will be invisible. | |
3610 | Luckily, these days the need for h2ph is rare. | |
3611 | ||
3612 | =item * | |
3613 | ||
3614 | If building Perl with interpreter threads (ithreads), the | |
3615 | getgrent(), getgrnam(), and getgrgid() functions cannot return the | |
3616 | list of the group members due to a bug in the multithreaded support of | |
3617 | UNICOS/mk. What this means is that in list context the functions will | |
3618 | return only three values, not four. | |
3619 | ||
3620 | =back | |
3621 | ||
3622 | =head2 UTS | |
3623 | ||
3624 | There are a few known test failures, see L<perluts> (README.uts). | |
3625 | ||
3626 | =head2 VOS (Stratus) | |
3627 | ||
3628 | When Perl is built using the native build process on VOS Release | |
3629 | 14.5.0 and GNU C++/GNU Tools 2.0.1, all attempted tests either | |
3630 | pass or result in TODO (ignored) failures. | |
3631 | ||
3632 | =head2 VMS | |
3633 | ||
3634 | There should be no reported test failures with a default configuration, | |
3635 | though there are a number of tests marked TODO that point to areas | |
3636 | needing further debugging and/or porting work. | |
3637 | ||
3638 | =head2 Win32 | |
3639 | ||
3640 | In multi-CPU boxes, there are some problems with the I/O buffering: | |
3641 | some output may appear twice. | |
3642 | ||
3643 | =head2 XML::Parser not working | |
3644 | ||
3645 | Use XML::Parser 2.31 or later. | |
3646 | ||
3647 | =head2 z/OS (OS/390) | |
3648 | ||
3649 | z/OS has rather many test failures but the situation is actually much | |
3650 | better than it was in 5.6.0; it's just that so many new modules and | |
3651 | tests have been added. | |
3652 | ||
3653 | Failed Test Stat Wstat Total Fail Failed List of Failed | |
3654 | --------------------------------------------------------------------------- | |
3655 | ../ext/Data/Dumper/t/dumper.t 357 8 2.24% 311 314 325 327 | |
3656 | 331 333 337 339 | |
3657 | ../ext/IO/lib/IO/t/io_unix.t 5 4 80.00% 2-5 | |
3658 | ../ext/Storable/t/downgrade.t 12 3072 169 12 7.10% 14-15 46-47 78-79 | |
3659 | 110-111 150 161 | |
3660 | ../lib/ExtUtils/t/Constant.t 121 30976 48 48 100.00% 1-48 | |
3661 | ../lib/ExtUtils/t/Embed.t 9 9 100.00% 1-9 | |
3662 | op/pat.t 922 7 0.76% 665 776 785 832- | |
3663 | 834 845 | |
3664 | op/sprintf.t 224 3 1.34% 98 100 136 | |
3665 | op/tr.t 97 5 5.15% 63 71-74 | |
3666 | uni/fold.t 780 6 0.77% 61 169 196 661 | |
3667 | 710-711 | |
3668 | ||
3669 | The failures in dumper.t and downgrade.t are problems in the tests, | |
3670 | those in io_unix and sprintf are problems in the USS (UDP sockets and | |
3671 | printf formats). The pat, tr, and fold failures are genuine Perl | |
3672 | problems caused by EBCDIC (and in the pat and fold cases, combining | |
3673 | that with Unicode). The Constant and Embed are probably problems in | |
3674 | the tests (since they test Perl's ability to build extensions, and | |
3675 | that seems to be working reasonably well.) | |
3676 | ||
3677 | =head2 Unicode Support on EBCDIC Still Spotty | |
3678 | ||
3679 | Though mostly working, Unicode support still has problem spots on | |
3680 | EBCDIC platforms. One such known spot are the C<\p{}> and C<\P{}> | |
3681 | regular expression constructs for code points less than 256: the | |
3682 | C<pP> are testing for Unicode code points, not knowing about EBCDIC. | |
3683 | ||
3684 | =head2 Seen In Perl 5.7 But Gone Now | |
3685 | ||
3686 | C<Time::Piece> (previously known as C<Time::Object>) was removed | |
3687 | because it was felt that it didn't have enough value in it to be a | |
3688 | core module. It is still a useful module, though, and is available | |
3689 | from the CPAN. | |
3690 | ||
3691 | Perl 5.8 unfortunately does not build anymore on AmigaOS; this broke | |
3692 | accidentally at some point. Since there are not that many Amiga | |
3693 | developers available, we could not get this fixed and tested in time | |
3694 | for 5.8.0. Perl 5.6.1 still works for AmigaOS (as does the the 5.7.2 | |
3695 | development release). | |
3696 | ||
3697 | The C<PerlIO::Scalar> and C<PerlIO::Via> (capitalised) were renamed as | |
3698 | C<PerlIO::scalar> and C<PerlIO::via> (all lowercase) just before 5.8.0. | |
3699 | The main rationale was to have all core PerlIO layers to have all | |
3700 | lowercase names. The "plugins" are named as usual, for example | |
3701 | C<PerlIO::via::QuotedPrint>. | |
3702 | ||
3703 | The C<threads::shared::queue> and C<threads::shared::semaphore> were | |
3704 | renamed as C<Thread::Queue> and C<Thread::Semaphore> just before 5.8.0. | |
3705 | The main rationale was to have thread modules to obey normal naming, | |
3706 | C<Thread::> (the C<threads> and C<threads::shared> themselves are | |
3707 | more pragma-like, they affect compile-time, so they stay lowercase). | |
3708 | ||
3709 | =head1 Reporting Bugs | |
3710 | ||
3711 | If you find what you think is a bug, you might check the articles | |
3712 | recently posted to the comp.lang.perl.misc newsgroup and the perl | |
3713 | bug database at http://bugs.perl.org/ . There may also be | |
3714 | information at http://www.perl.com/ , the Perl Home Page. | |
3715 | ||
3716 | If you believe you have an unreported bug, please run the B<perlbug> | |
3717 | program included with your release. Be sure to trim your bug down | |
3718 | to a tiny but sufficient test case. Your bug report, along with the | |
3719 | output of C<perl -V>, will be sent off to perlbug@perl.org to be | |
3720 | analysed by the Perl porting team. | |
3721 | ||
3722 | =head1 SEE ALSO | |
3723 | ||
3724 | The F<Changes> file for exhaustive details on what changed. | |
3725 | ||
3726 | The F<INSTALL> file for how to build Perl. | |
3727 | ||
3728 | The F<README> file for general stuff. | |
3729 | ||
3730 | The F<Artistic> and F<Copying> files for copyright information. | |
3731 | ||
3732 | =head1 HISTORY | |
3733 | ||
3734 | Written by Jarkko Hietaniemi <F<jhi@iki.fi>>. | |
3735 | ||
3736 | =cut |