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Revision 1404 - (show annotations)
Tue Nov 19 15:36:57 2013 UTC (7 years, 2 months ago) by ph10
File size: 27250 byte(s)
Source tidies for 8.34-RC1.
1 News about PCRE releases
2 ------------------------
4 Release 8.34 19-November-2013
5 -----------------------------
7 As well as fixing the inevitable bugs, performance has been improved by
8 refactoring and extending the amount of "auto-possessification" that PCRE does.
9 Other notable changes:
11 . Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
12 an empty string. If it can, pcretest shows this in its information output.
14 . A back reference to a named subpattern when there is more than one of the
15 same name now checks them in the order in which they appear in the pattern.
16 The first one that is set is used for the reference. Previously only the
17 first one was inspected. This change makes PCRE more compatible with Perl.
19 . Unicode character properties were updated from Unicode 6.3.0.
21 . The character VT has been added to the set of characters that match \s and
22 are generally treated as white space, following this same change in Perl
23 5.18. There is now no difference between "Perl space" and "POSIX space".
25 . Perl has changed its handling of \8 and \9. If there is no previously
26 encountered capturing group of those numbers, they are treated as the
27 literal characters 8 and 9 instead of a binary zero followed by the
28 literals. PCRE now does the same.
30 . Following Perl, added \o{} to specify codepoints in octal, making it
31 possible to specify values greater than 0777 and also making them
32 unambiguous.
34 . In UCP mode, \s was not matching two of the characters that Perl matches,
35 namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
36 were matched by \h.
38 . Add JIT support for the 64 bit TileGX architecture.
40 . Upgraded the handling of the POSIX classes [:graph:], [:print:], and
41 [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
42 does in Unicode mode.
44 . Perl no longer allows group names to start with digits, so I have made this
45 change also in PCRE.
48 Release 8.33 28-May-2013
49 --------------------------
51 A number of bugs are fixed, and some performance improvements have been made.
52 There are also some new features, of which these are the most important:
54 . The behaviour of the backtracking verbs has been rationalized and
55 documented in more detail.
57 . JIT now supports callouts and all of the backtracking verbs.
59 . Unicode validation has been updated in the light of Unicode Corrigendum #9,
60 which points out that "non characters" are not "characters that may not
61 appear in Unicode strings" but rather "characters that are reserved for
62 internal use and have only local meaning".
64 . (*LIMIT_MATCH=d) and (*LIMIT_RECURSION=d) have been added so that the
65 creator of a pattern can specify lower (but not higher) limits for the
66 matching process.
68 . The PCRE_NEVER_UTF option is available to prevent pattern-writers from using
69 the (*UTF) feature, as this could be a security issue.
72 Release 8.32 30-November-2012
73 -----------------------------
75 This release fixes a number of bugs, but also has some new features. These are
76 the highlights:
78 . There is now support for 32-bit character strings and UTF-32. Like the
79 16-bit support, this is done by compiling a separate 32-bit library.
81 . \X now matches a Unicode extended grapheme cluster.
83 . Case-independent matching of Unicode characters that have more than one
84 "other case" now makes all three (or more) characters equivalent. This
85 applies, for example, to Greek Sigma, which has two lowercase versions.
87 . Unicode character properties are updated to Unicode 6.2.0.
89 . The EBCDIC support, which had decayed, has had a spring clean.
91 . A number of JIT optimizations have been added, which give faster JIT
92 execution speed. In addition, a new direct interface to JIT execution is
93 available. This bypasses some of the sanity checks of pcre_exec() to give a
94 noticeable speed-up.
96 . A number of issues in pcregrep have been fixed, making it more compatible
97 with GNU grep. In particular, --exclude and --include (and variants) apply
98 to all files now, not just those obtained from scanning a directory
99 recursively. In Windows environments, the default action for directories is
100 now "skip" instead of "read" (which provokes an error).
102 . If the --only-matching (-o) option in pcregrep is specified multiple
103 times, each one causes appropriate output. For example, -o1 -o2 outputs the
104 substrings matched by the 1st and 2nd capturing parentheses. A separating
105 string can be specified by --om-separator (default empty).
107 . When PCRE is built via Autotools using a version of gcc that has the
108 "visibility" feature, it is used to hide internal library functions that are
109 not part of the public API.
112 Release 8.31 06-July-2012
113 -------------------------
115 This is mainly a bug-fixing release, with a small number of developments:
117 . The JIT compiler now supports partial matching and the (*MARK) and
118 (*COMMIT) verbs.
120 . PCRE_INFO_MAXLOOKBEHIND can be used to find the longest lookbehind in a
121 pattern.
123 . There should be a performance improvement when using the heap instead of the
124 stack for recursion.
126 . pcregrep can now be linked with libedit as an alternative to libreadline.
128 . pcregrep now has a --file-list option where the list of files to scan is
129 given as a file.
131 . pcregrep now recognizes binary files and there are related options.
133 . The Unicode tables have been updated to 6.1.0.
135 As always, the full list of changes is in the ChangeLog file.
138 Release 8.30 04-February-2012
139 -----------------------------
141 Release 8.30 introduces a major new feature: support for 16-bit character
142 strings, compiled as a separate library. There are a few changes to the
143 8-bit library, in addition to some bug fixes.
145 . The pcre_info() function, which has been obsolete for over 10 years, has
146 been removed.
148 . When a compiled pattern was saved to a file and later reloaded on a host
149 with different endianness, PCRE used automatically to swap the bytes in some
150 of the data fields. With the advent of the 16-bit library, where more of this
151 swapping is needed, it is no longer done automatically. Instead, the bad
152 endianness is detected and a specific error is given. The user can then call
153 a new function called pcre_pattern_to_host_byte_order() (or an equivalent
154 16-bit function) to do the swap.
156 . In UTF-8 mode, the values 0xd800 to 0xdfff are not legal Unicode
157 code points and are now faulted. (They are the so-called "surrogates"
158 that are reserved for coding high values in UTF-16.)
161 Release 8.21 12-Dec-2011
162 ------------------------
164 This is almost entirely a bug-fix release. The only new feature is the ability
165 to obtain the size of the memory used by the JIT compiler.
168 Release 8.20 21-Oct-2011
169 ------------------------
171 The main change in this release is the inclusion of Zoltan Herczeg's
172 just-in-time compiler support, which can be accessed by building PCRE with
173 --enable-jit. Large performance benefits can be had in many situations. 8.20
174 also fixes an unfortunate bug that was introduced in 8.13 as well as tidying up
175 a number of infelicities and differences from Perl.
178 Release 8.13 16-Aug-2011
179 ------------------------
181 This is mainly a bug-fix release. There has been a lot of internal refactoring.
182 The Unicode tables have been updated. The only new feature in the library is
183 the passing of *MARK information to callouts. Some additions have been made to
184 pcretest to make testing easier and more comprehensive. There is a new option
185 for pcregrep to adjust its internal buffer size.
188 Release 8.12 15-Jan-2011
189 ------------------------
191 This release fixes some bugs in pcregrep, one of which caused the tests to fail
192 on 64-bit big-endian systems. There are no changes to the code of the library.
195 Release 8.11 10-Dec-2010
196 ------------------------
198 A number of bugs in the library and in pcregrep have been fixed. As always, see
199 ChangeLog for details. The following are the non-bug-fix changes:
201 . Added --match-limit and --recursion-limit to pcregrep.
203 . Added an optional parentheses number to the -o and --only-matching options
204 of pcregrep.
206 . Changed the way PCRE_PARTIAL_HARD affects the matching of $, \z, \Z, \b, and
207 \B.
209 . Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
210 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
212 . Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
213 START_OPTIMIZE option, which is now allowed at compile time
216 Release 8.10 25-Jun-2010
217 ------------------------
219 There are two major additions: support for (*MARK) and friends, and the option
220 PCRE_UCP, which changes the behaviour of \b, \d, \s, and \w (and their
221 opposites) so that they make use of Unicode properties. There are also a number
222 of lesser new features, and several bugs have been fixed. A new option,
223 --line-buffered, has been added to pcregrep, for use when it is connected to
224 pipes.
227 Release 8.02 19-Mar-2010
228 ------------------------
230 Another bug-fix release.
233 Release 8.01 19-Jan-2010
234 ------------------------
236 This is a bug-fix release. Several bugs in the code itself and some bugs and
237 infelicities in the build system have been fixed.
240 Release 8.00 19-Oct-09
241 ----------------------
243 Bugs have been fixed in the library and in pcregrep. There are also some
244 enhancements. Restrictions on patterns used for partial matching have been
245 removed, extra information is given for partial matches, the partial matching
246 process has been improved, and an option to make a partial match override a
247 full match is available. The "study" process has been enhanced by finding a
248 lower bound matching length. Groups with duplicate numbers may now have
249 duplicated names without the use of PCRE_DUPNAMES. However, they may not have
250 different names. The documentation has been revised to reflect these changes.
251 The version number has been expanded to 3 digits as it is clear that the rate
252 of change is not slowing down.
255 Release 7.9 11-Apr-09
256 ---------------------
258 Mostly bugfixes and tidies with just a couple of minor functional additions.
261 Release 7.8 05-Sep-08
262 ---------------------
264 More bug fixes, plus a performance improvement in Unicode character property
265 lookup.
268 Release 7.7 07-May-08
269 ---------------------
271 This is once again mainly a bug-fix release, but there are a couple of new
272 features.
275 Release 7.6 28-Jan-08
276 ---------------------
278 The main reason for having this release so soon after 7.5 is because it fixes a
279 potential buffer overflow problem in pcre_compile() when run in UTF-8 mode. In
280 addition, the CMake configuration files have been brought up to date.
283 Release 7.5 10-Jan-08
284 ---------------------
286 This is mainly a bug-fix release. However the ability to link pcregrep with
287 libz or libbz2 and the ability to link pcretest with libreadline have been
288 added. Also the --line-offsets and --file-offsets options were added to
289 pcregrep.
292 Release 7.4 21-Sep-07
293 ---------------------
295 The only change of specification is the addition of options to control whether
296 \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
297 Otherwise, the changes are bug fixes and a refactoring to reduce the number of
298 relocations needed in a shared library. There have also been some documentation
299 updates, in particular, some more information about using CMake to build PCRE
300 has been added to the NON-UNIX-USE file.
303 Release 7.3 28-Aug-07
304 ---------------------
306 Most changes are bug fixes. Some that are not:
308 1. There is some support for Perl 5.10's experimental "backtracking control
309 verbs" such as (*PRUNE).
311 2. UTF-8 checking is now as per RFC 3629 instead of RFC 2279; this is more
312 restrictive in the strings it accepts.
314 3. Checking for potential integer overflow has been made more dynamic, and as a
315 consequence there is no longer a hard limit on the size of a subpattern that
316 has a limited repeat count.
318 4. When CRLF is a valid line-ending sequence, pcre_exec() and pcre_dfa_exec()
319 no longer advance by two characters instead of one when an unanchored match
320 fails at CRLF if there are explicit CR or LF matches within the pattern.
321 This gets rid of some anomalous effects that previously occurred.
323 5. Some PCRE-specific settings for varying the newline options at the start of
324 a pattern have been added.
327 Release 7.2 19-Jun-07
328 ---------------------
330 WARNING: saved patterns that were compiled by earlier versions of PCRE must be
331 recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
332 and \V).
334 Correction to the notes for 7.1: the note about shared libraries for Windows is
335 wrong. Previously, three libraries were built, but each could function
336 independently. For example, the pcreposix library also included all the
337 functions from the basic pcre library. The change is that the three libraries
338 are no longer independent. They are like the Unix libraries. To use the
339 pcreposix functions, for example, you need to link with both the pcreposix and
340 the basic pcre library.
342 Some more features from Perl 5.10 have been added:
344 (?-n) and (?+n) relative references for recursion and subroutines.
346 (?(-n) and (?(+n) relative references as conditions.
348 \k{name} and \g{name} are synonyms for \k<name>.
350 \K to reset the start of the matched string; for example, (foo)\Kbar
351 matches bar preceded by foo, but only sets bar as the matched string.
353 (?| introduces a group where the capturing parentheses in each alternative
354 start from the same number; for example, (?|(abc)|(xyz)) sets capturing
355 parentheses number 1 in both cases.
357 \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
360 Release 7.1 24-Apr-07
361 ---------------------
363 There is only one new feature in this release: a linebreak setting of
364 PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
365 recognizes only CRLF, CR, and LF as linebreaks.
367 A few bugs are fixed (see ChangeLog for details), but the major change is a
368 complete re-implementation of the build system. This now has full Autotools
369 support and so is now "standard" in some sense. It should help with compiling
370 PCRE in a wide variety of environments.
372 NOTE: when building shared libraries for Windows, three dlls are now built,
373 called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
374 included in a single dll.
376 Another important change is that the dftables auxiliary program is no longer
377 compiled and run at "make" time by default. Instead, a default set of character
378 tables (assuming ASCII coding) is used. If you want to use dftables to generate
379 the character tables as previously, add --enable-rebuild-chartables to the
380 "configure" command. You must do this if you are compiling PCRE to run on a
381 system that uses EBCDIC code.
383 There is a discussion about character tables in the README file. The default is
384 not to use dftables so that that there is no problem when cross-compiling.
387 Release 7.0 19-Dec-06
388 ---------------------
390 This release has a new major number because there have been some internal
391 upheavals to facilitate the addition of new optimizations and other facilities,
392 and to make subsequent maintenance and extension easier. Compilation is likely
393 to be a bit slower, but there should be no major effect on runtime performance.
394 Previously compiled patterns are NOT upwards compatible with this release. If
395 you have saved compiled patterns from a previous release, you will have to
396 re-compile them. Important changes that are visible to users are:
398 1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
399 some more scripts.
401 2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
402 sequence as a newline.
404 3. The \R escape matches a single Unicode newline sequence as a single unit.
406 4. New features that will appear in Perl 5.10 are now in PCRE. These include
407 alternative Perl syntax for named parentheses, and Perl syntax for
408 recursion.
410 5. The C++ wrapper interface has been extended by the addition of a
411 QuoteMeta function and the ability to allow copy construction and
412 assignment.
414 For a complete list of changes, see the ChangeLog file.
417 Release 6.7 04-Jul-06
418 ---------------------
420 The main additions to this release are the ability to use the same name for
421 multiple sets of parentheses, and support for CRLF line endings in both the
422 library and pcregrep (and in pcretest for testing).
424 Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
425 significantly reduced for certain subject strings.
428 Release 6.5 01-Feb-06
429 ---------------------
431 Important changes in this release:
433 1. A number of new features have been added to pcregrep.
435 2. The Unicode property tables have been updated to Unicode 4.1.0, and the
436 supported properties have been extended with script names such as "Arabic",
437 and the derived properties "Any" and "L&". This has necessitated a change to
438 the interal format of compiled patterns. Any saved compiled patterns that
439 use \p or \P must be recompiled.
441 3. The specification of recursion in patterns has been changed so that all
442 recursive subpatterns are automatically treated as atomic groups. Thus, for
443 example, (?R) is treated as if it were (?>(?R)). This is necessary because
444 otherwise there are situations where recursion does not work.
446 See the ChangeLog for a complete list of changes, which include a number of bug
447 fixes and tidies.
450 Release 6.0 07-Jun-05
451 ---------------------
453 The release number has been increased to 6.0 because of the addition of several
454 major new pieces of functionality.
456 A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
457 algorithm, has been added. This has a number of advantages for certain cases,
458 though it does run more slowly, and lacks the ability to capture substrings. On
459 the other hand, it does find all matches, not just the first, and it works
460 better for partial matching. The pcrematching man page discusses the
461 differences.
463 The pcretest program has been enhanced so that it can make use of the new
464 pcre_dfa_exec() matching function and the extra features it provides.
466 The distribution now includes a C++ wrapper library. This is built
467 automatically if a C++ compiler is found. The pcrecpp man page discusses this
468 interface.
470 The code itself has been re-organized into many more files, one for each
471 function, so it no longer requires everything to be linked in when static
472 linkage is used. As a consequence, some internal functions have had to have
473 their names exposed. These functions all have names starting with _pcre_. They
474 are undocumented, and are not intended for use by outside callers.
476 The pcregrep program has been enhanced with new functionality such as
477 multiline-matching and options for output more matching context. See the
478 ChangeLog for a complete list of changes to the library and the utility
479 programs.
482 Release 5.0 13-Sep-04
483 ---------------------
485 The licence under which PCRE is released has been changed to the more
486 conventional "BSD" licence.
488 In the code, some bugs have been fixed, and there are also some major changes
489 in this release (which is why I've increased the number to 5.0). Some changes
490 are internal rearrangements, and some provide a number of new facilities. The
491 new features are:
493 1. There's an "automatic callout" feature that inserts callouts before every
494 item in the regex, and there's a new callout field that gives the position
495 in the pattern - useful for debugging and tracing.
497 2. The extra_data structure can now be used to pass in a set of character
498 tables at exec time. This is useful if compiled regex are saved and re-used
499 at a later time when the tables may not be at the same address. If the
500 default internal tables are used, the pointer saved with the compiled
501 pattern is now set to NULL, which means that you don't need to do anything
502 special unless you are using custom tables.
504 3. It is possible, with some restrictions on the content of the regex, to
505 request "partial" matching. A special return code is given if all of the
506 subject string matched part of the regex. This could be useful for testing
507 an input field as it is being typed.
509 4. There is now some optional support for Unicode character properties, which
510 means that the patterns items such as \p{Lu} and \X can now be used. Only
511 the general category properties are supported. If PCRE is compiled with this
512 support, an additional 90K data structure is include, which increases the
513 size of the library dramatically.
515 5. There is support for saving compiled patterns and re-using them later.
517 6. There is support for running regular expressions that were compiled on a
518 different host with the opposite endianness.
520 7. The pcretest program has been extended to accommodate the new features.
522 The main internal rearrangement is that sequences of literal characters are no
523 longer handled as strings. Instead, each character is handled on its own. This
524 makes some UTF-8 handling easier, and makes the support of partial matching
525 possible. Compiled patterns containing long literal strings will be larger as a
526 result of this change; I hope that performance will not be much affected.
529 Release 4.5 01-Dec-03
530 ---------------------
532 Again mainly a bug-fix and tidying release, with only a couple of new features:
534 1. It's possible now to compile PCRE so that it does not use recursive
535 function calls when matching. Instead it gets memory from the heap. This slows
536 things down, but may be necessary on systems with limited stacks.
538 2. UTF-8 string checking has been tightened to reject overlong sequences and to
539 check that a starting offset points to the start of a character. Failure of the
540 latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
542 3. PCRE can now be compiled for systems that use EBCDIC code.
545 Release 4.4 21-Aug-03
546 ---------------------
548 This is mainly a bug-fix and tidying release. The only new feature is that PCRE
549 checks UTF-8 strings for validity by default. There is an option to suppress
550 this, just in case anybody wants that teeny extra bit of performance.
553 Releases 4.1 - 4.3
554 ------------------
556 Sorry, I forgot about updating the NEWS file for these releases. Please take a
557 look at ChangeLog.
560 Release 4.0 17-Feb-03
561 ---------------------
563 There have been a lot of changes for the 4.0 release, adding additional
564 functionality and mending bugs. Below is a list of the highlights of the new
565 functionality. For full details of these features, please consult the
566 documentation. For a complete list of changes, see the ChangeLog file.
568 1. Support for Perl's \Q...\E escapes.
570 2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
571 package. They provide some syntactic sugar for simple cases of "atomic
572 grouping".
574 3. Support for the \G assertion. It is true when the current matching position
575 is at the start point of the match.
577 4. A new feature that provides some of the functionality that Perl provides
578 with (?{...}). The facility is termed a "callout". The way it is done in PCRE
579 is for the caller to provide an optional function, by setting pcre_callout to
580 its entry point. To get the function called, the regex must include (?C) at
581 appropriate points.
583 5. Support for recursive calls to individual subpatterns. This makes it really
584 easy to get totally confused.
586 6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
587 name a group.
589 7. Several extensions to UTF-8 support; it is now fairly complete. There is an
590 option for pcregrep to make it operate in UTF-8 mode.
592 8. The single man page has been split into a number of separate man pages.
593 These also give rise to individual HTML pages which are put in a separate
594 directory. There is an index.html page that lists them all. Some hyperlinking
595 between the pages has been installed.
598 Release 3.5 15-Aug-01
599 ---------------------
601 1. The configuring system has been upgraded to use later versions of autoconf
602 and libtool. By default it builds both a shared and a static library if the OS
603 supports it. You can use --disable-shared or --disable-static on the configure
604 command if you want only one of them.
606 2. The pcretest utility is now installed along with pcregrep because it is
607 useful for users (to test regexs) and by doing this, it automatically gets
608 relinked by libtool. The documentation has been turned into a man page, so
609 there are now .1, .txt, and .html versions in /doc.
611 3. Upgrades to pcregrep:
612 (i) Added long-form option names like gnu grep.
613 (ii) Added --help to list all options with an explanatory phrase.
614 (iii) Added -r, --recursive to recurse into sub-directories.
615 (iv) Added -f, --file to read patterns from a file.
617 4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
618 script, to force use of CR or LF instead of \n in the source. On non-Unix
619 systems, the value can be set in config.h.
621 5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
622 absolute limit. Changed the text of the error message to make this clear, and
623 likewise updated the man page.
625 6. The limit of 99 on the number of capturing subpatterns has been removed.
626 The new limit is 65535, which I hope will not be a "real" limit.
629 Release 3.3 01-Aug-00
630 ---------------------
632 There is some support for UTF-8 character strings. This is incomplete and
633 experimental. The documentation describes what is and what is not implemented.
634 Otherwise, this is just a bug-fixing release.
637 Release 3.0 01-Feb-00
638 ---------------------
640 1. A "configure" script is now used to configure PCRE for Unix systems. It
641 builds a Makefile, a config.h file, and the pcre-config script.
643 2. PCRE is built as a shared library by default.
645 3. There is support for POSIX classes such as [:alpha:].
647 5. There is an experimental recursion feature.
649 ----------------------------------------------------------------------------
652 Please note that there has been a change in the API such that a larger
653 ovector is required at matching time, to provide some additional workspace.
654 The new man page has details. This change was necessary in order to support
655 some of the new functionality in Perl 5.005.
659 Another (I hope this is the last!) change has been made to the API for the
660 pcre_compile() function. An additional argument has been added to make it
661 possible to pass over a pointer to character tables built in the current
662 locale by pcre_maketables(). To use the default tables, this new argument
663 should be passed as NULL.
667 Yet another (and again I hope this really is the last) change has been made
668 to the API for the pcre_exec() function. An additional argument has been
669 added to make it possible to start the match other than at the start of the
670 subject string. This is important if there are lookbehinds. The new man
671 page has the details, but you just want to convert existing programs, all
672 you need to do is to stick in a new fifth argument to pcre_exec(), with a
673 value of zero. For example, change
675 pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
676 to
677 pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
679 ****


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