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Revision 347 - (show annotations) (download)
Wed May 7 16:38:04 2008 UTC (6 years, 6 months ago) by ph10
File size: 17087 byte(s)
Final updates for 7.7 release.

1 News about PCRE releases
2 ------------------------
3
4
5 Release 7.7 07-May-08
6 ---------------------
7
8 This is once again mainly a bug-fix release, but there are a couple of new
9 features.
10
11
12 Release 7.6 28-Jan-08
13 ---------------------
14
15 The main reason for having this release so soon after 7.5 is because it fixes a
16 potential buffer overflow problem in pcre_compile() when run in UTF-8 mode. In
17 addition, the CMake configuration files have been brought up to date.
18
19
20 Release 7.5 10-Jan-08
21 ---------------------
22
23 This is mainly a bug-fix release. However the ability to link pcregrep with
24 libz or libbz2 and the ability to link pcretest with libreadline have been
25 added. Also the --line-offsets and --file-offsets options were added to
26 pcregrep.
27
28
29 Release 7.4 21-Sep-07
30 ---------------------
31
32 The only change of specification is the addition of options to control whether
33 \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
34 Otherwise, the changes are bug fixes and a refactoring to reduce the number of
35 relocations needed in a shared library. There have also been some documentation
36 updates, in particular, some more information about using CMake to build PCRE
37 has been added to the NON-UNIX-USE file.
38
39
40 Release 7.3 28-Aug-07
41 ---------------------
42
43 Most changes are bug fixes. Some that are not:
44
45 1. There is some support for Perl 5.10's experimental "backtracking control
46 verbs" such as (*PRUNE).
47
48 2. UTF-8 checking is now as per RFC 3629 instead of RFC 2279; this is more
49 restrictive in the strings it accepts.
50
51 3. Checking for potential integer overflow has been made more dynamic, and as a
52 consequence there is no longer a hard limit on the size of a subpattern that
53 has a limited repeat count.
54
55 4. When CRLF is a valid line-ending sequence, pcre_exec() and pcre_dfa_exec()
56 no longer advance by two characters instead of one when an unanchored match
57 fails at CRLF if there are explicit CR or LF matches within the pattern.
58 This gets rid of some anomalous effects that previously occurred.
59
60 5. Some PCRE-specific settings for varying the newline options at the start of
61 a pattern have been added.
62
63
64 Release 7.2 19-Jun-07
65 ---------------------
66
67 WARNING: saved patterns that were compiled by earlier versions of PCRE must be
68 recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
69 and \V).
70
71 Correction to the notes for 7.1: the note about shared libraries for Windows is
72 wrong. Previously, three libraries were built, but each could function
73 independently. For example, the pcreposix library also included all the
74 functions from the basic pcre library. The change is that the three libraries
75 are no longer independent. They are like the Unix libraries. To use the
76 pcreposix functions, for example, you need to link with both the pcreposix and
77 the basic pcre library.
78
79 Some more features from Perl 5.10 have been added:
80
81 (?-n) and (?+n) relative references for recursion and subroutines.
82
83 (?(-n) and (?(+n) relative references as conditions.
84
85 \k{name} and \g{name} are synonyms for \k<name>.
86
87 \K to reset the start of the matched string; for example, (foo)\Kbar
88 matches bar preceded by foo, but only sets bar as the matched string.
89
90 (?| introduces a group where the capturing parentheses in each alternative
91 start from the same number; for example, (?|(abc)|(xyz)) sets capturing
92 parentheses number 1 in both cases.
93
94 \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
95
96
97 Release 7.1 24-Apr-07
98 ---------------------
99
100 There is only one new feature in this release: a linebreak setting of
101 PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
102 recognizes only CRLF, CR, and LF as linebreaks.
103
104 A few bugs are fixed (see ChangeLog for details), but the major change is a
105 complete re-implementation of the build system. This now has full Autotools
106 support and so is now "standard" in some sense. It should help with compiling
107 PCRE in a wide variety of environments.
108
109 NOTE: when building shared libraries for Windows, three dlls are now built,
110 called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
111 included in a single dll.
112
113 Another important change is that the dftables auxiliary program is no longer
114 compiled and run at "make" time by default. Instead, a default set of character
115 tables (assuming ASCII coding) is used. If you want to use dftables to generate
116 the character tables as previously, add --enable-rebuild-chartables to the
117 "configure" command. You must do this if you are compiling PCRE to run on a
118 system that uses EBCDIC code.
119
120 There is a discussion about character tables in the README file. The default is
121 not to use dftables so that that there is no problem when cross-compiling.
122
123
124 Release 7.0 19-Dec-06
125 ---------------------
126
127 This release has a new major number because there have been some internal
128 upheavals to facilitate the addition of new optimizations and other facilities,
129 and to make subsequent maintenance and extension easier. Compilation is likely
130 to be a bit slower, but there should be no major effect on runtime performance.
131 Previously compiled patterns are NOT upwards compatible with this release. If
132 you have saved compiled patterns from a previous release, you will have to
133 re-compile them. Important changes that are visible to users are:
134
135 1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
136 some more scripts.
137
138 2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
139 sequence as a newline.
140
141 3. The \R escape matches a single Unicode newline sequence as a single unit.
142
143 4. New features that will appear in Perl 5.10 are now in PCRE. These include
144 alternative Perl syntax for named parentheses, and Perl syntax for
145 recursion.
146
147 5. The C++ wrapper interface has been extended by the addition of a
148 QuoteMeta function and the ability to allow copy construction and
149 assignment.
150
151 For a complete list of changes, see the ChangeLog file.
152
153
154 Release 6.7 04-Jul-06
155 ---------------------
156
157 The main additions to this release are the ability to use the same name for
158 multiple sets of parentheses, and support for CRLF line endings in both the
159 library and pcregrep (and in pcretest for testing).
160
161 Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
162 significantly reduced for certain subject strings.
163
164
165 Release 6.5 01-Feb-06
166 ---------------------
167
168 Important changes in this release:
169
170 1. A number of new features have been added to pcregrep.
171
172 2. The Unicode property tables have been updated to Unicode 4.1.0, and the
173 supported properties have been extended with script names such as "Arabic",
174 and the derived properties "Any" and "L&". This has necessitated a change to
175 the interal format of compiled patterns. Any saved compiled patterns that
176 use \p or \P must be recompiled.
177
178 3. The specification of recursion in patterns has been changed so that all
179 recursive subpatterns are automatically treated as atomic groups. Thus, for
180 example, (?R) is treated as if it were (?>(?R)). This is necessary because
181 otherwise there are situations where recursion does not work.
182
183 See the ChangeLog for a complete list of changes, which include a number of bug
184 fixes and tidies.
185
186
187 Release 6.0 07-Jun-05
188 ---------------------
189
190 The release number has been increased to 6.0 because of the addition of several
191 major new pieces of functionality.
192
193 A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
194 algorithm, has been added. This has a number of advantages for certain cases,
195 though it does run more slowly, and lacks the ability to capture substrings. On
196 the other hand, it does find all matches, not just the first, and it works
197 better for partial matching. The pcrematching man page discusses the
198 differences.
199
200 The pcretest program has been enhanced so that it can make use of the new
201 pcre_dfa_exec() matching function and the extra features it provides.
202
203 The distribution now includes a C++ wrapper library. This is built
204 automatically if a C++ compiler is found. The pcrecpp man page discusses this
205 interface.
206
207 The code itself has been re-organized into many more files, one for each
208 function, so it no longer requires everything to be linked in when static
209 linkage is used. As a consequence, some internal functions have had to have
210 their names exposed. These functions all have names starting with _pcre_. They
211 are undocumented, and are not intended for use by outside callers.
212
213 The pcregrep program has been enhanced with new functionality such as
214 multiline-matching and options for output more matching context. See the
215 ChangeLog for a complete list of changes to the library and the utility
216 programs.
217
218
219 Release 5.0 13-Sep-04
220 ---------------------
221
222 The licence under which PCRE is released has been changed to the more
223 conventional "BSD" licence.
224
225 In the code, some bugs have been fixed, and there are also some major changes
226 in this release (which is why I've increased the number to 5.0). Some changes
227 are internal rearrangements, and some provide a number of new facilities. The
228 new features are:
229
230 1. There's an "automatic callout" feature that inserts callouts before every
231 item in the regex, and there's a new callout field that gives the position
232 in the pattern - useful for debugging and tracing.
233
234 2. The extra_data structure can now be used to pass in a set of character
235 tables at exec time. This is useful if compiled regex are saved and re-used
236 at a later time when the tables may not be at the same address. If the
237 default internal tables are used, the pointer saved with the compiled
238 pattern is now set to NULL, which means that you don't need to do anything
239 special unless you are using custom tables.
240
241 3. It is possible, with some restrictions on the content of the regex, to
242 request "partial" matching. A special return code is given if all of the
243 subject string matched part of the regex. This could be useful for testing
244 an input field as it is being typed.
245
246 4. There is now some optional support for Unicode character properties, which
247 means that the patterns items such as \p{Lu} and \X can now be used. Only
248 the general category properties are supported. If PCRE is compiled with this
249 support, an additional 90K data structure is include, which increases the
250 size of the library dramatically.
251
252 5. There is support for saving compiled patterns and re-using them later.
253
254 6. There is support for running regular expressions that were compiled on a
255 different host with the opposite endianness.
256
257 7. The pcretest program has been extended to accommodate the new features.
258
259 The main internal rearrangement is that sequences of literal characters are no
260 longer handled as strings. Instead, each character is handled on its own. This
261 makes some UTF-8 handling easier, and makes the support of partial matching
262 possible. Compiled patterns containing long literal strings will be larger as a
263 result of this change; I hope that performance will not be much affected.
264
265
266 Release 4.5 01-Dec-03
267 ---------------------
268
269 Again mainly a bug-fix and tidying release, with only a couple of new features:
270
271 1. It's possible now to compile PCRE so that it does not use recursive
272 function calls when matching. Instead it gets memory from the heap. This slows
273 things down, but may be necessary on systems with limited stacks.
274
275 2. UTF-8 string checking has been tightened to reject overlong sequences and to
276 check that a starting offset points to the start of a character. Failure of the
277 latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
278
279 3. PCRE can now be compiled for systems that use EBCDIC code.
280
281
282 Release 4.4 21-Aug-03
283 ---------------------
284
285 This is mainly a bug-fix and tidying release. The only new feature is that PCRE
286 checks UTF-8 strings for validity by default. There is an option to suppress
287 this, just in case anybody wants that teeny extra bit of performance.
288
289
290 Releases 4.1 - 4.3
291 ------------------
292
293 Sorry, I forgot about updating the NEWS file for these releases. Please take a
294 look at ChangeLog.
295
296
297 Release 4.0 17-Feb-03
298 ---------------------
299
300 There have been a lot of changes for the 4.0 release, adding additional
301 functionality and mending bugs. Below is a list of the highlights of the new
302 functionality. For full details of these features, please consult the
303 documentation. For a complete list of changes, see the ChangeLog file.
304
305 1. Support for Perl's \Q...\E escapes.
306
307 2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
308 package. They provide some syntactic sugar for simple cases of "atomic
309 grouping".
310
311 3. Support for the \G assertion. It is true when the current matching position
312 is at the start point of the match.
313
314 4. A new feature that provides some of the functionality that Perl provides
315 with (?{...}). The facility is termed a "callout". The way it is done in PCRE
316 is for the caller to provide an optional function, by setting pcre_callout to
317 its entry point. To get the function called, the regex must include (?C) at
318 appropriate points.
319
320 5. Support for recursive calls to individual subpatterns. This makes it really
321 easy to get totally confused.
322
323 6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
324 name a group.
325
326 7. Several extensions to UTF-8 support; it is now fairly complete. There is an
327 option for pcregrep to make it operate in UTF-8 mode.
328
329 8. The single man page has been split into a number of separate man pages.
330 These also give rise to individual HTML pages which are put in a separate
331 directory. There is an index.html page that lists them all. Some hyperlinking
332 between the pages has been installed.
333
334
335 Release 3.5 15-Aug-01
336 ---------------------
337
338 1. The configuring system has been upgraded to use later versions of autoconf
339 and libtool. By default it builds both a shared and a static library if the OS
340 supports it. You can use --disable-shared or --disable-static on the configure
341 command if you want only one of them.
342
343 2. The pcretest utility is now installed along with pcregrep because it is
344 useful for users (to test regexs) and by doing this, it automatically gets
345 relinked by libtool. The documentation has been turned into a man page, so
346 there are now .1, .txt, and .html versions in /doc.
347
348 3. Upgrades to pcregrep:
349 (i) Added long-form option names like gnu grep.
350 (ii) Added --help to list all options with an explanatory phrase.
351 (iii) Added -r, --recursive to recurse into sub-directories.
352 (iv) Added -f, --file to read patterns from a file.
353
354 4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
355 script, to force use of CR or LF instead of \n in the source. On non-Unix
356 systems, the value can be set in config.h.
357
358 5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
359 absolute limit. Changed the text of the error message to make this clear, and
360 likewise updated the man page.
361
362 6. The limit of 99 on the number of capturing subpatterns has been removed.
363 The new limit is 65535, which I hope will not be a "real" limit.
364
365
366 Release 3.3 01-Aug-00
367 ---------------------
368
369 There is some support for UTF-8 character strings. This is incomplete and
370 experimental. The documentation describes what is and what is not implemented.
371 Otherwise, this is just a bug-fixing release.
372
373
374 Release 3.0 01-Feb-00
375 ---------------------
376
377 1. A "configure" script is now used to configure PCRE for Unix systems. It
378 builds a Makefile, a config.h file, and the pcre-config script.
379
380 2. PCRE is built as a shared library by default.
381
382 3. There is support for POSIX classes such as [:alpha:].
383
384 5. There is an experimental recursion feature.
385
386 ----------------------------------------------------------------------------
387 IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00
388
389 Please note that there has been a change in the API such that a larger
390 ovector is required at matching time, to provide some additional workspace.
391 The new man page has details. This change was necessary in order to support
392 some of the new functionality in Perl 5.005.
393
394 IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.00
395
396 Another (I hope this is the last!) change has been made to the API for the
397 pcre_compile() function. An additional argument has been added to make it
398 possible to pass over a pointer to character tables built in the current
399 locale by pcre_maketables(). To use the default tables, this new arguement
400 should be passed as NULL.
401
402 IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.05
403
404 Yet another (and again I hope this really is the last) change has been made
405 to the API for the pcre_exec() function. An additional argument has been
406 added to make it possible to start the match other than at the start of the
407 subject string. This is important if there are lookbehinds. The new man
408 page has the details, but you just want to convert existing programs, all
409 you need to do is to stick in a new fifth argument to pcre_exec(), with a
410 value of zero. For example, change
411
412 pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
413 to
414 pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
415
416 ****

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