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Thu Jan 10 17:09:12 2008 UTC (13 years, 9 months ago) by ph10
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Tidies for the 7.5 release.
1 News about PCRE releases
2 ------------------------
4 Release 7.5 10-Jan-08
5 ---------------------
7 This is mainly a bug-fix release. However the ability to link pcregrep with
8 libz or libbz2 and the ability to link pcretest with libreadline have been
9 added. Also the --line-offsets and --file-offsets options were added to
10 pcregrep.
13 Release 7.4 21-Sep-07
14 ---------------------
16 The only change of specification is the addition of options to control whether
17 \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
18 Otherwise, the changes are bug fixes and a refactoring to reduce the number of
19 relocations needed in a shared library. There have also been some documentation
20 updates, in particular, some more information about using CMake to build PCRE
21 has been added to the NON-UNIX-USE file.
24 Release 7.3 28-Aug-07
25 ---------------------
27 Most changes are bug fixes. Some that are not:
29 1. There is some support for Perl 5.10's experimental "backtracking control
30 verbs" such as (*PRUNE).
32 2. UTF-8 checking is now as per RFC 3629 instead of RFC 2279; this is more
33 restrictive in the strings it accepts.
35 3. Checking for potential integer overflow has been made more dynamic, and as a
36 consequence there is no longer a hard limit on the size of a subpattern that
37 has a limited repeat count.
39 4. When CRLF is a valid line-ending sequence, pcre_exec() and pcre_dfa_exec()
40 no longer advance by two characters instead of one when an unanchored match
41 fails at CRLF if there are explicit CR or LF matches within the pattern.
42 This gets rid of some anomalous effects that previously occurred.
44 5. Some PCRE-specific settings for varying the newline options at the start of
45 a pattern have been added.
48 Release 7.2 19-Jun-07
49 ---------------------
51 WARNING: saved patterns that were compiled by earlier versions of PCRE must be
52 recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
53 and \V).
55 Correction to the notes for 7.1: the note about shared libraries for Windows is
56 wrong. Previously, three libraries were built, but each could function
57 independently. For example, the pcreposix library also included all the
58 functions from the basic pcre library. The change is that the three libraries
59 are no longer independent. They are like the Unix libraries. To use the
60 pcreposix functions, for example, you need to link with both the pcreposix and
61 the basic pcre library.
63 Some more features from Perl 5.10 have been added:
65 (?-n) and (?+n) relative references for recursion and subroutines.
67 (?(-n) and (?(+n) relative references as conditions.
69 \k{name} and \g{name} are synonyms for \k<name>.
71 \K to reset the start of the matched string; for example, (foo)\Kbar
72 matches bar preceded by foo, but only sets bar as the matched string.
74 (?| introduces a group where the capturing parentheses in each alternative
75 start from the same number; for example, (?|(abc)|(xyz)) sets capturing
76 parentheses number 1 in both cases.
78 \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
81 Release 7.1 24-Apr-07
82 ---------------------
84 There is only one new feature in this release: a linebreak setting of
85 PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
86 recognizes only CRLF, CR, and LF as linebreaks.
88 A few bugs are fixed (see ChangeLog for details), but the major change is a
89 complete re-implementation of the build system. This now has full Autotools
90 support and so is now "standard" in some sense. It should help with compiling
91 PCRE in a wide variety of environments.
93 NOTE: when building shared libraries for Windows, three dlls are now built,
94 called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
95 included in a single dll.
97 Another important change is that the dftables auxiliary program is no longer
98 compiled and run at "make" time by default. Instead, a default set of character
99 tables (assuming ASCII coding) is used. If you want to use dftables to generate
100 the character tables as previously, add --enable-rebuild-chartables to the
101 "configure" command. You must do this if you are compiling PCRE to run on a
102 system that uses EBCDIC code.
104 There is a discussion about character tables in the README file. The default is
105 not to use dftables so that that there is no problem when cross-compiling.
108 Release 7.0 19-Dec-06
109 ---------------------
111 This release has a new major number because there have been some internal
112 upheavals to facilitate the addition of new optimizations and other facilities,
113 and to make subsequent maintenance and extension easier. Compilation is likely
114 to be a bit slower, but there should be no major effect on runtime performance.
115 Previously compiled patterns are NOT upwards compatible with this release. If
116 you have saved compiled patterns from a previous release, you will have to
117 re-compile them. Important changes that are visible to users are:
119 1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
120 some more scripts.
122 2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
123 sequence as a newline.
125 3. The \R escape matches a single Unicode newline sequence as a single unit.
127 4. New features that will appear in Perl 5.10 are now in PCRE. These include
128 alternative Perl syntax for named parentheses, and Perl syntax for
129 recursion.
131 5. The C++ wrapper interface has been extended by the addition of a
132 QuoteMeta function and the ability to allow copy construction and
133 assignment.
135 For a complete list of changes, see the ChangeLog file.
138 Release 6.7 04-Jul-06
139 ---------------------
141 The main additions to this release are the ability to use the same name for
142 multiple sets of parentheses, and support for CRLF line endings in both the
143 library and pcregrep (and in pcretest for testing).
145 Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
146 significantly reduced for certain subject strings.
149 Release 6.5 01-Feb-06
150 ---------------------
152 Important changes in this release:
154 1. A number of new features have been added to pcregrep.
156 2. The Unicode property tables have been updated to Unicode 4.1.0, and the
157 supported properties have been extended with script names such as "Arabic",
158 and the derived properties "Any" and "L&". This has necessitated a change to
159 the interal format of compiled patterns. Any saved compiled patterns that
160 use \p or \P must be recompiled.
162 3. The specification of recursion in patterns has been changed so that all
163 recursive subpatterns are automatically treated as atomic groups. Thus, for
164 example, (?R) is treated as if it were (?>(?R)). This is necessary because
165 otherwise there are situations where recursion does not work.
167 See the ChangeLog for a complete list of changes, which include a number of bug
168 fixes and tidies.
171 Release 6.0 07-Jun-05
172 ---------------------
174 The release number has been increased to 6.0 because of the addition of several
175 major new pieces of functionality.
177 A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
178 algorithm, has been added. This has a number of advantages for certain cases,
179 though it does run more slowly, and lacks the ability to capture substrings. On
180 the other hand, it does find all matches, not just the first, and it works
181 better for partial matching. The pcrematching man page discusses the
182 differences.
184 The pcretest program has been enhanced so that it can make use of the new
185 pcre_dfa_exec() matching function and the extra features it provides.
187 The distribution now includes a C++ wrapper library. This is built
188 automatically if a C++ compiler is found. The pcrecpp man page discusses this
189 interface.
191 The code itself has been re-organized into many more files, one for each
192 function, so it no longer requires everything to be linked in when static
193 linkage is used. As a consequence, some internal functions have had to have
194 their names exposed. These functions all have names starting with _pcre_. They
195 are undocumented, and are not intended for use by outside callers.
197 The pcregrep program has been enhanced with new functionality such as
198 multiline-matching and options for output more matching context. See the
199 ChangeLog for a complete list of changes to the library and the utility
200 programs.
203 Release 5.0 13-Sep-04
204 ---------------------
206 The licence under which PCRE is released has been changed to the more
207 conventional "BSD" licence.
209 In the code, some bugs have been fixed, and there are also some major changes
210 in this release (which is why I've increased the number to 5.0). Some changes
211 are internal rearrangements, and some provide a number of new facilities. The
212 new features are:
214 1. There's an "automatic callout" feature that inserts callouts before every
215 item in the regex, and there's a new callout field that gives the position
216 in the pattern - useful for debugging and tracing.
218 2. The extra_data structure can now be used to pass in a set of character
219 tables at exec time. This is useful if compiled regex are saved and re-used
220 at a later time when the tables may not be at the same address. If the
221 default internal tables are used, the pointer saved with the compiled
222 pattern is now set to NULL, which means that you don't need to do anything
223 special unless you are using custom tables.
225 3. It is possible, with some restrictions on the content of the regex, to
226 request "partial" matching. A special return code is given if all of the
227 subject string matched part of the regex. This could be useful for testing
228 an input field as it is being typed.
230 4. There is now some optional support for Unicode character properties, which
231 means that the patterns items such as \p{Lu} and \X can now be used. Only
232 the general category properties are supported. If PCRE is compiled with this
233 support, an additional 90K data structure is include, which increases the
234 size of the library dramatically.
236 5. There is support for saving compiled patterns and re-using them later.
238 6. There is support for running regular expressions that were compiled on a
239 different host with the opposite endianness.
241 7. The pcretest program has been extended to accommodate the new features.
243 The main internal rearrangement is that sequences of literal characters are no
244 longer handled as strings. Instead, each character is handled on its own. This
245 makes some UTF-8 handling easier, and makes the support of partial matching
246 possible. Compiled patterns containing long literal strings will be larger as a
247 result of this change; I hope that performance will not be much affected.
250 Release 4.5 01-Dec-03
251 ---------------------
253 Again mainly a bug-fix and tidying release, with only a couple of new features:
255 1. It's possible now to compile PCRE so that it does not use recursive
256 function calls when matching. Instead it gets memory from the heap. This slows
257 things down, but may be necessary on systems with limited stacks.
259 2. UTF-8 string checking has been tightened to reject overlong sequences and to
260 check that a starting offset points to the start of a character. Failure of the
261 latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
263 3. PCRE can now be compiled for systems that use EBCDIC code.
266 Release 4.4 21-Aug-03
267 ---------------------
269 This is mainly a bug-fix and tidying release. The only new feature is that PCRE
270 checks UTF-8 strings for validity by default. There is an option to suppress
271 this, just in case anybody wants that teeny extra bit of performance.
274 Releases 4.1 - 4.3
275 ------------------
277 Sorry, I forgot about updating the NEWS file for these releases. Please take a
278 look at ChangeLog.
281 Release 4.0 17-Feb-03
282 ---------------------
284 There have been a lot of changes for the 4.0 release, adding additional
285 functionality and mending bugs. Below is a list of the highlights of the new
286 functionality. For full details of these features, please consult the
287 documentation. For a complete list of changes, see the ChangeLog file.
289 1. Support for Perl's \Q...\E escapes.
291 2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
292 package. They provide some syntactic sugar for simple cases of "atomic
293 grouping".
295 3. Support for the \G assertion. It is true when the current matching position
296 is at the start point of the match.
298 4. A new feature that provides some of the functionality that Perl provides
299 with (?{...}). The facility is termed a "callout". The way it is done in PCRE
300 is for the caller to provide an optional function, by setting pcre_callout to
301 its entry point. To get the function called, the regex must include (?C) at
302 appropriate points.
304 5. Support for recursive calls to individual subpatterns. This makes it really
305 easy to get totally confused.
307 6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
308 name a group.
310 7. Several extensions to UTF-8 support; it is now fairly complete. There is an
311 option for pcregrep to make it operate in UTF-8 mode.
313 8. The single man page has been split into a number of separate man pages.
314 These also give rise to individual HTML pages which are put in a separate
315 directory. There is an index.html page that lists them all. Some hyperlinking
316 between the pages has been installed.
319 Release 3.5 15-Aug-01
320 ---------------------
322 1. The configuring system has been upgraded to use later versions of autoconf
323 and libtool. By default it builds both a shared and a static library if the OS
324 supports it. You can use --disable-shared or --disable-static on the configure
325 command if you want only one of them.
327 2. The pcretest utility is now installed along with pcregrep because it is
328 useful for users (to test regexs) and by doing this, it automatically gets
329 relinked by libtool. The documentation has been turned into a man page, so
330 there are now .1, .txt, and .html versions in /doc.
332 3. Upgrades to pcregrep:
333 (i) Added long-form option names like gnu grep.
334 (ii) Added --help to list all options with an explanatory phrase.
335 (iii) Added -r, --recursive to recurse into sub-directories.
336 (iv) Added -f, --file to read patterns from a file.
338 4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
339 script, to force use of CR or LF instead of \n in the source. On non-Unix
340 systems, the value can be set in config.h.
342 5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
343 absolute limit. Changed the text of the error message to make this clear, and
344 likewise updated the man page.
346 6. The limit of 99 on the number of capturing subpatterns has been removed.
347 The new limit is 65535, which I hope will not be a "real" limit.
350 Release 3.3 01-Aug-00
351 ---------------------
353 There is some support for UTF-8 character strings. This is incomplete and
354 experimental. The documentation describes what is and what is not implemented.
355 Otherwise, this is just a bug-fixing release.
358 Release 3.0 01-Feb-00
359 ---------------------
361 1. A "configure" script is now used to configure PCRE for Unix systems. It
362 builds a Makefile, a config.h file, and the pcre-config script.
364 2. PCRE is built as a shared library by default.
366 3. There is support for POSIX classes such as [:alpha:].
368 5. There is an experimental recursion feature.
370 ----------------------------------------------------------------------------
373 Please note that there has been a change in the API such that a larger
374 ovector is required at matching time, to provide some additional workspace.
375 The new man page has details. This change was necessary in order to support
376 some of the new functionality in Perl 5.005.
380 Another (I hope this is the last!) change has been made to the API for the
381 pcre_compile() function. An additional argument has been added to make it
382 possible to pass over a pointer to character tables built in the current
383 locale by pcre_maketables(). To use the default tables, this new arguement
384 should be passed as NULL.
388 Yet another (and again I hope this really is the last) change has been made
389 to the API for the pcre_exec() function. An additional argument has been
390 added to make it possible to start the match other than at the start of the
391 subject string. This is important if there are lookbehinds. The new man
392 page has the details, but you just want to convert existing programs, all
393 you need to do is to stick in a new fifth argument to pcre_exec(), with a
394 value of zero. For example, change
396 pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
397 to
398 pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
400 ****


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