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Revision 371 - (show annotations)
Mon Aug 25 18:28:05 2008 UTC (12 years, 6 months ago) by ph10
File size: 17219 byte(s)
Source tidies for 7.8-RC1 
1 News about PCRE releases
2 ------------------------
5 Release 7.8 25-Aug-08
6 ---------------------
8 More bug fixes, plus a performance improvement in Unicode character property
9 lookup.
12 Release 7.7 07-May-08
13 ---------------------
15 This is once again mainly a bug-fix release, but there are a couple of new
16 features.
19 Release 7.6 28-Jan-08
20 ---------------------
22 The main reason for having this release so soon after 7.5 is because it fixes a
23 potential buffer overflow problem in pcre_compile() when run in UTF-8 mode. In
24 addition, the CMake configuration files have been brought up to date.
27 Release 7.5 10-Jan-08
28 ---------------------
30 This is mainly a bug-fix release. However the ability to link pcregrep with
31 libz or libbz2 and the ability to link pcretest with libreadline have been
32 added. Also the --line-offsets and --file-offsets options were added to
33 pcregrep.
36 Release 7.4 21-Sep-07
37 ---------------------
39 The only change of specification is the addition of options to control whether
40 \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
41 Otherwise, the changes are bug fixes and a refactoring to reduce the number of
42 relocations needed in a shared library. There have also been some documentation
43 updates, in particular, some more information about using CMake to build PCRE
44 has been added to the NON-UNIX-USE file.
47 Release 7.3 28-Aug-07
48 ---------------------
50 Most changes are bug fixes. Some that are not:
52 1. There is some support for Perl 5.10's experimental "backtracking control
53 verbs" such as (*PRUNE).
55 2. UTF-8 checking is now as per RFC 3629 instead of RFC 2279; this is more
56 restrictive in the strings it accepts.
58 3. Checking for potential integer overflow has been made more dynamic, and as a
59 consequence there is no longer a hard limit on the size of a subpattern that
60 has a limited repeat count.
62 4. When CRLF is a valid line-ending sequence, pcre_exec() and pcre_dfa_exec()
63 no longer advance by two characters instead of one when an unanchored match
64 fails at CRLF if there are explicit CR or LF matches within the pattern.
65 This gets rid of some anomalous effects that previously occurred.
67 5. Some PCRE-specific settings for varying the newline options at the start of
68 a pattern have been added.
71 Release 7.2 19-Jun-07
72 ---------------------
74 WARNING: saved patterns that were compiled by earlier versions of PCRE must be
75 recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
76 and \V).
78 Correction to the notes for 7.1: the note about shared libraries for Windows is
79 wrong. Previously, three libraries were built, but each could function
80 independently. For example, the pcreposix library also included all the
81 functions from the basic pcre library. The change is that the three libraries
82 are no longer independent. They are like the Unix libraries. To use the
83 pcreposix functions, for example, you need to link with both the pcreposix and
84 the basic pcre library.
86 Some more features from Perl 5.10 have been added:
88 (?-n) and (?+n) relative references for recursion and subroutines.
90 (?(-n) and (?(+n) relative references as conditions.
92 \k{name} and \g{name} are synonyms for \k<name>.
94 \K to reset the start of the matched string; for example, (foo)\Kbar
95 matches bar preceded by foo, but only sets bar as the matched string.
97 (?| introduces a group where the capturing parentheses in each alternative
98 start from the same number; for example, (?|(abc)|(xyz)) sets capturing
99 parentheses number 1 in both cases.
101 \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
104 Release 7.1 24-Apr-07
105 ---------------------
107 There is only one new feature in this release: a linebreak setting of
108 PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
109 recognizes only CRLF, CR, and LF as linebreaks.
111 A few bugs are fixed (see ChangeLog for details), but the major change is a
112 complete re-implementation of the build system. This now has full Autotools
113 support and so is now "standard" in some sense. It should help with compiling
114 PCRE in a wide variety of environments.
116 NOTE: when building shared libraries for Windows, three dlls are now built,
117 called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
118 included in a single dll.
120 Another important change is that the dftables auxiliary program is no longer
121 compiled and run at "make" time by default. Instead, a default set of character
122 tables (assuming ASCII coding) is used. If you want to use dftables to generate
123 the character tables as previously, add --enable-rebuild-chartables to the
124 "configure" command. You must do this if you are compiling PCRE to run on a
125 system that uses EBCDIC code.
127 There is a discussion about character tables in the README file. The default is
128 not to use dftables so that that there is no problem when cross-compiling.
131 Release 7.0 19-Dec-06
132 ---------------------
134 This release has a new major number because there have been some internal
135 upheavals to facilitate the addition of new optimizations and other facilities,
136 and to make subsequent maintenance and extension easier. Compilation is likely
137 to be a bit slower, but there should be no major effect on runtime performance.
138 Previously compiled patterns are NOT upwards compatible with this release. If
139 you have saved compiled patterns from a previous release, you will have to
140 re-compile them. Important changes that are visible to users are:
142 1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
143 some more scripts.
145 2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
146 sequence as a newline.
148 3. The \R escape matches a single Unicode newline sequence as a single unit.
150 4. New features that will appear in Perl 5.10 are now in PCRE. These include
151 alternative Perl syntax for named parentheses, and Perl syntax for
152 recursion.
154 5. The C++ wrapper interface has been extended by the addition of a
155 QuoteMeta function and the ability to allow copy construction and
156 assignment.
158 For a complete list of changes, see the ChangeLog file.
161 Release 6.7 04-Jul-06
162 ---------------------
164 The main additions to this release are the ability to use the same name for
165 multiple sets of parentheses, and support for CRLF line endings in both the
166 library and pcregrep (and in pcretest for testing).
168 Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
169 significantly reduced for certain subject strings.
172 Release 6.5 01-Feb-06
173 ---------------------
175 Important changes in this release:
177 1. A number of new features have been added to pcregrep.
179 2. The Unicode property tables have been updated to Unicode 4.1.0, and the
180 supported properties have been extended with script names such as "Arabic",
181 and the derived properties "Any" and "L&". This has necessitated a change to
182 the interal format of compiled patterns. Any saved compiled patterns that
183 use \p or \P must be recompiled.
185 3. The specification of recursion in patterns has been changed so that all
186 recursive subpatterns are automatically treated as atomic groups. Thus, for
187 example, (?R) is treated as if it were (?>(?R)). This is necessary because
188 otherwise there are situations where recursion does not work.
190 See the ChangeLog for a complete list of changes, which include a number of bug
191 fixes and tidies.
194 Release 6.0 07-Jun-05
195 ---------------------
197 The release number has been increased to 6.0 because of the addition of several
198 major new pieces of functionality.
200 A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
201 algorithm, has been added. This has a number of advantages for certain cases,
202 though it does run more slowly, and lacks the ability to capture substrings. On
203 the other hand, it does find all matches, not just the first, and it works
204 better for partial matching. The pcrematching man page discusses the
205 differences.
207 The pcretest program has been enhanced so that it can make use of the new
208 pcre_dfa_exec() matching function and the extra features it provides.
210 The distribution now includes a C++ wrapper library. This is built
211 automatically if a C++ compiler is found. The pcrecpp man page discusses this
212 interface.
214 The code itself has been re-organized into many more files, one for each
215 function, so it no longer requires everything to be linked in when static
216 linkage is used. As a consequence, some internal functions have had to have
217 their names exposed. These functions all have names starting with _pcre_. They
218 are undocumented, and are not intended for use by outside callers.
220 The pcregrep program has been enhanced with new functionality such as
221 multiline-matching and options for output more matching context. See the
222 ChangeLog for a complete list of changes to the library and the utility
223 programs.
226 Release 5.0 13-Sep-04
227 ---------------------
229 The licence under which PCRE is released has been changed to the more
230 conventional "BSD" licence.
232 In the code, some bugs have been fixed, and there are also some major changes
233 in this release (which is why I've increased the number to 5.0). Some changes
234 are internal rearrangements, and some provide a number of new facilities. The
235 new features are:
237 1. There's an "automatic callout" feature that inserts callouts before every
238 item in the regex, and there's a new callout field that gives the position
239 in the pattern - useful for debugging and tracing.
241 2. The extra_data structure can now be used to pass in a set of character
242 tables at exec time. This is useful if compiled regex are saved and re-used
243 at a later time when the tables may not be at the same address. If the
244 default internal tables are used, the pointer saved with the compiled
245 pattern is now set to NULL, which means that you don't need to do anything
246 special unless you are using custom tables.
248 3. It is possible, with some restrictions on the content of the regex, to
249 request "partial" matching. A special return code is given if all of the
250 subject string matched part of the regex. This could be useful for testing
251 an input field as it is being typed.
253 4. There is now some optional support for Unicode character properties, which
254 means that the patterns items such as \p{Lu} and \X can now be used. Only
255 the general category properties are supported. If PCRE is compiled with this
256 support, an additional 90K data structure is include, which increases the
257 size of the library dramatically.
259 5. There is support for saving compiled patterns and re-using them later.
261 6. There is support for running regular expressions that were compiled on a
262 different host with the opposite endianness.
264 7. The pcretest program has been extended to accommodate the new features.
266 The main internal rearrangement is that sequences of literal characters are no
267 longer handled as strings. Instead, each character is handled on its own. This
268 makes some UTF-8 handling easier, and makes the support of partial matching
269 possible. Compiled patterns containing long literal strings will be larger as a
270 result of this change; I hope that performance will not be much affected.
273 Release 4.5 01-Dec-03
274 ---------------------
276 Again mainly a bug-fix and tidying release, with only a couple of new features:
278 1. It's possible now to compile PCRE so that it does not use recursive
279 function calls when matching. Instead it gets memory from the heap. This slows
280 things down, but may be necessary on systems with limited stacks.
282 2. UTF-8 string checking has been tightened to reject overlong sequences and to
283 check that a starting offset points to the start of a character. Failure of the
284 latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
286 3. PCRE can now be compiled for systems that use EBCDIC code.
289 Release 4.4 21-Aug-03
290 ---------------------
292 This is mainly a bug-fix and tidying release. The only new feature is that PCRE
293 checks UTF-8 strings for validity by default. There is an option to suppress
294 this, just in case anybody wants that teeny extra bit of performance.
297 Releases 4.1 - 4.3
298 ------------------
300 Sorry, I forgot about updating the NEWS file for these releases. Please take a
301 look at ChangeLog.
304 Release 4.0 17-Feb-03
305 ---------------------
307 There have been a lot of changes for the 4.0 release, adding additional
308 functionality and mending bugs. Below is a list of the highlights of the new
309 functionality. For full details of these features, please consult the
310 documentation. For a complete list of changes, see the ChangeLog file.
312 1. Support for Perl's \Q...\E escapes.
314 2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
315 package. They provide some syntactic sugar for simple cases of "atomic
316 grouping".
318 3. Support for the \G assertion. It is true when the current matching position
319 is at the start point of the match.
321 4. A new feature that provides some of the functionality that Perl provides
322 with (?{...}). The facility is termed a "callout". The way it is done in PCRE
323 is for the caller to provide an optional function, by setting pcre_callout to
324 its entry point. To get the function called, the regex must include (?C) at
325 appropriate points.
327 5. Support for recursive calls to individual subpatterns. This makes it really
328 easy to get totally confused.
330 6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
331 name a group.
333 7. Several extensions to UTF-8 support; it is now fairly complete. There is an
334 option for pcregrep to make it operate in UTF-8 mode.
336 8. The single man page has been split into a number of separate man pages.
337 These also give rise to individual HTML pages which are put in a separate
338 directory. There is an index.html page that lists them all. Some hyperlinking
339 between the pages has been installed.
342 Release 3.5 15-Aug-01
343 ---------------------
345 1. The configuring system has been upgraded to use later versions of autoconf
346 and libtool. By default it builds both a shared and a static library if the OS
347 supports it. You can use --disable-shared or --disable-static on the configure
348 command if you want only one of them.
350 2. The pcretest utility is now installed along with pcregrep because it is
351 useful for users (to test regexs) and by doing this, it automatically gets
352 relinked by libtool. The documentation has been turned into a man page, so
353 there are now .1, .txt, and .html versions in /doc.
355 3. Upgrades to pcregrep:
356 (i) Added long-form option names like gnu grep.
357 (ii) Added --help to list all options with an explanatory phrase.
358 (iii) Added -r, --recursive to recurse into sub-directories.
359 (iv) Added -f, --file to read patterns from a file.
361 4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
362 script, to force use of CR or LF instead of \n in the source. On non-Unix
363 systems, the value can be set in config.h.
365 5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
366 absolute limit. Changed the text of the error message to make this clear, and
367 likewise updated the man page.
369 6. The limit of 99 on the number of capturing subpatterns has been removed.
370 The new limit is 65535, which I hope will not be a "real" limit.
373 Release 3.3 01-Aug-00
374 ---------------------
376 There is some support for UTF-8 character strings. This is incomplete and
377 experimental. The documentation describes what is and what is not implemented.
378 Otherwise, this is just a bug-fixing release.
381 Release 3.0 01-Feb-00
382 ---------------------
384 1. A "configure" script is now used to configure PCRE for Unix systems. It
385 builds a Makefile, a config.h file, and the pcre-config script.
387 2. PCRE is built as a shared library by default.
389 3. There is support for POSIX classes such as [:alpha:].
391 5. There is an experimental recursion feature.
393 ----------------------------------------------------------------------------
396 Please note that there has been a change in the API such that a larger
397 ovector is required at matching time, to provide some additional workspace.
398 The new man page has details. This change was necessary in order to support
399 some of the new functionality in Perl 5.005.
403 Another (I hope this is the last!) change has been made to the API for the
404 pcre_compile() function. An additional argument has been added to make it
405 possible to pass over a pointer to character tables built in the current
406 locale by pcre_maketables(). To use the default tables, this new arguement
407 should be passed as NULL.
411 Yet another (and again I hope this really is the last) change has been made
412 to the API for the pcre_exec() function. An additional argument has been
413 added to make it possible to start the match other than at the start of the
414 subject string. This is important if there are lookbehinds. The new man
415 page has the details, but you just want to convert existing programs, all
416 you need to do is to stick in a new fifth argument to pcre_exec(), with a
417 value of zero. For example, change
419 pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
420 to
421 pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
423 ****


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