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Revision 489 - (show annotations)
Tue Jan 19 16:42:21 2010 UTC (11 years, 1 month ago) by ph10
File size: 18286 byte(s)
File tidies and documentation update for 8.01.
1 News about PCRE releases
2 ------------------------
4 Release 8.01 19-Jan-2010
5 ------------------------
7 This is a bug-fix release. Several bugs in the code itself and some bugs and
8 infelicities in the build system have been fixed.
11 Release 8.00 19-Oct-09
12 ----------------------
14 Bugs have been fixed in the library and in pcregrep. There are also some
15 enhancements. Restrictions on patterns used for partial matching have been
16 removed, extra information is given for partial matches, the partial matching
17 process has been improved, and an option to make a partial match override a
18 full match is available. The "study" process has been enhanced by finding a
19 lower bound matching length. Groups with duplicate numbers may now have
20 duplicated names without the use of PCRE_DUPNAMES. However, they may not have
21 different names. The documentation has been revised to reflect these changes.
22 The version number has been expanded to 3 digits as it is clear that the rate
23 of change is not slowing down.
26 Release 7.9 11-Apr-09
27 ---------------------
29 Mostly bugfixes and tidies with just a couple of minor functional additions.
32 Release 7.8 05-Sep-08
33 ---------------------
35 More bug fixes, plus a performance improvement in Unicode character property
36 lookup.
39 Release 7.7 07-May-08
40 ---------------------
42 This is once again mainly a bug-fix release, but there are a couple of new
43 features.
46 Release 7.6 28-Jan-08
47 ---------------------
49 The main reason for having this release so soon after 7.5 is because it fixes a
50 potential buffer overflow problem in pcre_compile() when run in UTF-8 mode. In
51 addition, the CMake configuration files have been brought up to date.
54 Release 7.5 10-Jan-08
55 ---------------------
57 This is mainly a bug-fix release. However the ability to link pcregrep with
58 libz or libbz2 and the ability to link pcretest with libreadline have been
59 added. Also the --line-offsets and --file-offsets options were added to
60 pcregrep.
63 Release 7.4 21-Sep-07
64 ---------------------
66 The only change of specification is the addition of options to control whether
67 \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
68 Otherwise, the changes are bug fixes and a refactoring to reduce the number of
69 relocations needed in a shared library. There have also been some documentation
70 updates, in particular, some more information about using CMake to build PCRE
71 has been added to the NON-UNIX-USE file.
74 Release 7.3 28-Aug-07
75 ---------------------
77 Most changes are bug fixes. Some that are not:
79 1. There is some support for Perl 5.10's experimental "backtracking control
80 verbs" such as (*PRUNE).
82 2. UTF-8 checking is now as per RFC 3629 instead of RFC 2279; this is more
83 restrictive in the strings it accepts.
85 3. Checking for potential integer overflow has been made more dynamic, and as a
86 consequence there is no longer a hard limit on the size of a subpattern that
87 has a limited repeat count.
89 4. When CRLF is a valid line-ending sequence, pcre_exec() and pcre_dfa_exec()
90 no longer advance by two characters instead of one when an unanchored match
91 fails at CRLF if there are explicit CR or LF matches within the pattern.
92 This gets rid of some anomalous effects that previously occurred.
94 5. Some PCRE-specific settings for varying the newline options at the start of
95 a pattern have been added.
98 Release 7.2 19-Jun-07
99 ---------------------
101 WARNING: saved patterns that were compiled by earlier versions of PCRE must be
102 recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
103 and \V).
105 Correction to the notes for 7.1: the note about shared libraries for Windows is
106 wrong. Previously, three libraries were built, but each could function
107 independently. For example, the pcreposix library also included all the
108 functions from the basic pcre library. The change is that the three libraries
109 are no longer independent. They are like the Unix libraries. To use the
110 pcreposix functions, for example, you need to link with both the pcreposix and
111 the basic pcre library.
113 Some more features from Perl 5.10 have been added:
115 (?-n) and (?+n) relative references for recursion and subroutines.
117 (?(-n) and (?(+n) relative references as conditions.
119 \k{name} and \g{name} are synonyms for \k<name>.
121 \K to reset the start of the matched string; for example, (foo)\Kbar
122 matches bar preceded by foo, but only sets bar as the matched string.
124 (?| introduces a group where the capturing parentheses in each alternative
125 start from the same number; for example, (?|(abc)|(xyz)) sets capturing
126 parentheses number 1 in both cases.
128 \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
131 Release 7.1 24-Apr-07
132 ---------------------
134 There is only one new feature in this release: a linebreak setting of
135 PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
136 recognizes only CRLF, CR, and LF as linebreaks.
138 A few bugs are fixed (see ChangeLog for details), but the major change is a
139 complete re-implementation of the build system. This now has full Autotools
140 support and so is now "standard" in some sense. It should help with compiling
141 PCRE in a wide variety of environments.
143 NOTE: when building shared libraries for Windows, three dlls are now built,
144 called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
145 included in a single dll.
147 Another important change is that the dftables auxiliary program is no longer
148 compiled and run at "make" time by default. Instead, a default set of character
149 tables (assuming ASCII coding) is used. If you want to use dftables to generate
150 the character tables as previously, add --enable-rebuild-chartables to the
151 "configure" command. You must do this if you are compiling PCRE to run on a
152 system that uses EBCDIC code.
154 There is a discussion about character tables in the README file. The default is
155 not to use dftables so that that there is no problem when cross-compiling.
158 Release 7.0 19-Dec-06
159 ---------------------
161 This release has a new major number because there have been some internal
162 upheavals to facilitate the addition of new optimizations and other facilities,
163 and to make subsequent maintenance and extension easier. Compilation is likely
164 to be a bit slower, but there should be no major effect on runtime performance.
165 Previously compiled patterns are NOT upwards compatible with this release. If
166 you have saved compiled patterns from a previous release, you will have to
167 re-compile them. Important changes that are visible to users are:
169 1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
170 some more scripts.
172 2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
173 sequence as a newline.
175 3. The \R escape matches a single Unicode newline sequence as a single unit.
177 4. New features that will appear in Perl 5.10 are now in PCRE. These include
178 alternative Perl syntax for named parentheses, and Perl syntax for
179 recursion.
181 5. The C++ wrapper interface has been extended by the addition of a
182 QuoteMeta function and the ability to allow copy construction and
183 assignment.
185 For a complete list of changes, see the ChangeLog file.
188 Release 6.7 04-Jul-06
189 ---------------------
191 The main additions to this release are the ability to use the same name for
192 multiple sets of parentheses, and support for CRLF line endings in both the
193 library and pcregrep (and in pcretest for testing).
195 Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
196 significantly reduced for certain subject strings.
199 Release 6.5 01-Feb-06
200 ---------------------
202 Important changes in this release:
204 1. A number of new features have been added to pcregrep.
206 2. The Unicode property tables have been updated to Unicode 4.1.0, and the
207 supported properties have been extended with script names such as "Arabic",
208 and the derived properties "Any" and "L&". This has necessitated a change to
209 the interal format of compiled patterns. Any saved compiled patterns that
210 use \p or \P must be recompiled.
212 3. The specification of recursion in patterns has been changed so that all
213 recursive subpatterns are automatically treated as atomic groups. Thus, for
214 example, (?R) is treated as if it were (?>(?R)). This is necessary because
215 otherwise there are situations where recursion does not work.
217 See the ChangeLog for a complete list of changes, which include a number of bug
218 fixes and tidies.
221 Release 6.0 07-Jun-05
222 ---------------------
224 The release number has been increased to 6.0 because of the addition of several
225 major new pieces of functionality.
227 A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
228 algorithm, has been added. This has a number of advantages for certain cases,
229 though it does run more slowly, and lacks the ability to capture substrings. On
230 the other hand, it does find all matches, not just the first, and it works
231 better for partial matching. The pcrematching man page discusses the
232 differences.
234 The pcretest program has been enhanced so that it can make use of the new
235 pcre_dfa_exec() matching function and the extra features it provides.
237 The distribution now includes a C++ wrapper library. This is built
238 automatically if a C++ compiler is found. The pcrecpp man page discusses this
239 interface.
241 The code itself has been re-organized into many more files, one for each
242 function, so it no longer requires everything to be linked in when static
243 linkage is used. As a consequence, some internal functions have had to have
244 their names exposed. These functions all have names starting with _pcre_. They
245 are undocumented, and are not intended for use by outside callers.
247 The pcregrep program has been enhanced with new functionality such as
248 multiline-matching and options for output more matching context. See the
249 ChangeLog for a complete list of changes to the library and the utility
250 programs.
253 Release 5.0 13-Sep-04
254 ---------------------
256 The licence under which PCRE is released has been changed to the more
257 conventional "BSD" licence.
259 In the code, some bugs have been fixed, and there are also some major changes
260 in this release (which is why I've increased the number to 5.0). Some changes
261 are internal rearrangements, and some provide a number of new facilities. The
262 new features are:
264 1. There's an "automatic callout" feature that inserts callouts before every
265 item in the regex, and there's a new callout field that gives the position
266 in the pattern - useful for debugging and tracing.
268 2. The extra_data structure can now be used to pass in a set of character
269 tables at exec time. This is useful if compiled regex are saved and re-used
270 at a later time when the tables may not be at the same address. If the
271 default internal tables are used, the pointer saved with the compiled
272 pattern is now set to NULL, which means that you don't need to do anything
273 special unless you are using custom tables.
275 3. It is possible, with some restrictions on the content of the regex, to
276 request "partial" matching. A special return code is given if all of the
277 subject string matched part of the regex. This could be useful for testing
278 an input field as it is being typed.
280 4. There is now some optional support for Unicode character properties, which
281 means that the patterns items such as \p{Lu} and \X can now be used. Only
282 the general category properties are supported. If PCRE is compiled with this
283 support, an additional 90K data structure is include, which increases the
284 size of the library dramatically.
286 5. There is support for saving compiled patterns and re-using them later.
288 6. There is support for running regular expressions that were compiled on a
289 different host with the opposite endianness.
291 7. The pcretest program has been extended to accommodate the new features.
293 The main internal rearrangement is that sequences of literal characters are no
294 longer handled as strings. Instead, each character is handled on its own. This
295 makes some UTF-8 handling easier, and makes the support of partial matching
296 possible. Compiled patterns containing long literal strings will be larger as a
297 result of this change; I hope that performance will not be much affected.
300 Release 4.5 01-Dec-03
301 ---------------------
303 Again mainly a bug-fix and tidying release, with only a couple of new features:
305 1. It's possible now to compile PCRE so that it does not use recursive
306 function calls when matching. Instead it gets memory from the heap. This slows
307 things down, but may be necessary on systems with limited stacks.
309 2. UTF-8 string checking has been tightened to reject overlong sequences and to
310 check that a starting offset points to the start of a character. Failure of the
311 latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
313 3. PCRE can now be compiled for systems that use EBCDIC code.
316 Release 4.4 21-Aug-03
317 ---------------------
319 This is mainly a bug-fix and tidying release. The only new feature is that PCRE
320 checks UTF-8 strings for validity by default. There is an option to suppress
321 this, just in case anybody wants that teeny extra bit of performance.
324 Releases 4.1 - 4.3
325 ------------------
327 Sorry, I forgot about updating the NEWS file for these releases. Please take a
328 look at ChangeLog.
331 Release 4.0 17-Feb-03
332 ---------------------
334 There have been a lot of changes for the 4.0 release, adding additional
335 functionality and mending bugs. Below is a list of the highlights of the new
336 functionality. For full details of these features, please consult the
337 documentation. For a complete list of changes, see the ChangeLog file.
339 1. Support for Perl's \Q...\E escapes.
341 2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
342 package. They provide some syntactic sugar for simple cases of "atomic
343 grouping".
345 3. Support for the \G assertion. It is true when the current matching position
346 is at the start point of the match.
348 4. A new feature that provides some of the functionality that Perl provides
349 with (?{...}). The facility is termed a "callout". The way it is done in PCRE
350 is for the caller to provide an optional function, by setting pcre_callout to
351 its entry point. To get the function called, the regex must include (?C) at
352 appropriate points.
354 5. Support for recursive calls to individual subpatterns. This makes it really
355 easy to get totally confused.
357 6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
358 name a group.
360 7. Several extensions to UTF-8 support; it is now fairly complete. There is an
361 option for pcregrep to make it operate in UTF-8 mode.
363 8. The single man page has been split into a number of separate man pages.
364 These also give rise to individual HTML pages which are put in a separate
365 directory. There is an index.html page that lists them all. Some hyperlinking
366 between the pages has been installed.
369 Release 3.5 15-Aug-01
370 ---------------------
372 1. The configuring system has been upgraded to use later versions of autoconf
373 and libtool. By default it builds both a shared and a static library if the OS
374 supports it. You can use --disable-shared or --disable-static on the configure
375 command if you want only one of them.
377 2. The pcretest utility is now installed along with pcregrep because it is
378 useful for users (to test regexs) and by doing this, it automatically gets
379 relinked by libtool. The documentation has been turned into a man page, so
380 there are now .1, .txt, and .html versions in /doc.
382 3. Upgrades to pcregrep:
383 (i) Added long-form option names like gnu grep.
384 (ii) Added --help to list all options with an explanatory phrase.
385 (iii) Added -r, --recursive to recurse into sub-directories.
386 (iv) Added -f, --file to read patterns from a file.
388 4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
389 script, to force use of CR or LF instead of \n in the source. On non-Unix
390 systems, the value can be set in config.h.
392 5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
393 absolute limit. Changed the text of the error message to make this clear, and
394 likewise updated the man page.
396 6. The limit of 99 on the number of capturing subpatterns has been removed.
397 The new limit is 65535, which I hope will not be a "real" limit.
400 Release 3.3 01-Aug-00
401 ---------------------
403 There is some support for UTF-8 character strings. This is incomplete and
404 experimental. The documentation describes what is and what is not implemented.
405 Otherwise, this is just a bug-fixing release.
408 Release 3.0 01-Feb-00
409 ---------------------
411 1. A "configure" script is now used to configure PCRE for Unix systems. It
412 builds a Makefile, a config.h file, and the pcre-config script.
414 2. PCRE is built as a shared library by default.
416 3. There is support for POSIX classes such as [:alpha:].
418 5. There is an experimental recursion feature.
420 ----------------------------------------------------------------------------
423 Please note that there has been a change in the API such that a larger
424 ovector is required at matching time, to provide some additional workspace.
425 The new man page has details. This change was necessary in order to support
426 some of the new functionality in Perl 5.005.
430 Another (I hope this is the last!) change has been made to the API for the
431 pcre_compile() function. An additional argument has been added to make it
432 possible to pass over a pointer to character tables built in the current
433 locale by pcre_maketables(). To use the default tables, this new arguement
434 should be passed as NULL.
438 Yet another (and again I hope this really is the last) change has been made
439 to the API for the pcre_exec() function. An additional argument has been
440 added to make it possible to start the match other than at the start of the
441 subject string. This is important if there are lookbehinds. The new man
442 page has the details, but you just want to convert existing programs, all
443 you need to do is to stick in a new fifth argument to pcre_exec(), with a
444 value of zero. For example, change
446 pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
447 to
448 pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
450 ****


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