/[pcre]/code/tags/pcre-7.6/NEWS
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Contents of /code/tags/pcre-7.6/NEWS

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Revision 320 - (show annotations) (download)
Tue Feb 12 08:48:01 2008 UTC (6 years, 5 months ago) by ph10
File size: 16954 byte(s)
Create a tagged copy of 7.6.

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

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