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1 nigel 41 News about PCRE releases
2     ------------------------
4 ph10 411 Release 7.9 01-Apr-09
5     ---------------------
6 ph10 345
7 ph10 411 Mostly bugfixes and tidies with just a couple of minor functional additions.
10 ph10 374 Release 7.8 05-Sep-08
11 ph10 371 ---------------------
13     More bug fixes, plus a performance improvement in Unicode character property
14     lookup.
17 ph10 347 Release 7.7 07-May-08
18 ph10 345 ---------------------
20     This is once again mainly a bug-fix release, but there are a couple of new
21     features.
24 ph10 319 Release 7.6 28-Jan-08
25 ph10 309 ---------------------
27     The main reason for having this release so soon after 7.5 is because it fixes a
28     potential buffer overflow problem in pcre_compile() when run in UTF-8 mode. In
29     addition, the CMake configuration files have been brought up to date.
32 ph10 298 Release 7.5 10-Jan-08
33 ph10 289 ---------------------
34 ph10 122
35 ph10 289 This is mainly a bug-fix release. However the ability to link pcregrep with
36     libz or libbz2 and the ability to link pcretest with libreadline have been
37     added. Also the --line-offsets and --file-offsets options were added to
38     pcregrep.
41 ph10 260 Release 7.4 21-Sep-07
42 ph10 242 ---------------------
44 ph10 243 The only change of specification is the addition of options to control whether
45 ph10 242 \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
46 ph10 243 Otherwise, the changes are bug fixes and a refactoring to reduce the number of
47 ph10 261 relocations needed in a shared library. There have also been some documentation
48     updates, in particular, some more information about using CMake to build PCRE
49     has been added to the NON-UNIX-USE file.
50 ph10 242
52 ph10 228 Release 7.3 28-Aug-07
53 ph10 212 ---------------------
55     Most changes are bug fixes. Some that are not:
57     1. There is some support for Perl 5.10's experimental "backtracking control
58     verbs" such as (*PRUNE).
60     2. UTF-8 checking is now as per RFC 3629 instead of RFC 2279; this is more
61     restrictive in the strings it accepts.
63     3. Checking for potential integer overflow has been made more dynamic, and as a
64     consequence there is no longer a hard limit on the size of a subpattern that
65     has a limited repeat count.
66 ph10 227
67     4. When CRLF is a valid line-ending sequence, pcre_exec() and pcre_dfa_exec()
68     no longer advance by two characters instead of one when an unanchored match
69     fails at CRLF if there are explicit CR or LF matches within the pattern.
70 ph10 226 This gets rid of some anomalous effects that previously occurred.
71 ph10 212
72 ph10 227 5. Some PCRE-specific settings for varying the newline options at the start of
73     a pattern have been added.
74 ph10 212
75 ph10 227
76 ph10 184 Release 7.2 19-Jun-07
77 ph10 157 ---------------------
79 ph10 172 WARNING: saved patterns that were compiled by earlier versions of PCRE must be
80 ph10 181 recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
81     and \V).
82 ph10 168
83 ph10 159 Correction to the notes for 7.1: the note about shared libraries for Windows is
84     wrong. Previously, three libraries were built, but each could function
85     independently. For example, the pcreposix library also included all the
86     functions from the basic pcre library. The change is that the three libraries
87     are no longer independent. They are like the Unix libraries. To use the
88     pcreposix functions, for example, you need to link with both the pcreposix and
89 ph10 157 the basic pcre library.
91 ph10 166 Some more features from Perl 5.10 have been added:
92 ph10 157
93 ph10 166 (?-n) and (?+n) relative references for recursion and subroutines.
94 ph10 172
95     (?(-n) and (?(+n) relative references as conditions.
96 ph10 182
97 ph10 181 \k{name} and \g{name} are synonyms for \k<name>.
98 ph10 172
99 ph10 168 \K to reset the start of the matched string; for example, (foo)\Kbar
100 ph10 175 matches bar preceded by foo, but only sets bar as the matched string.
101 ph10 182
102     (?| introduces a group where the capturing parentheses in each alternative
103     start from the same number; for example, (?|(abc)|(xyz)) sets capturing
104 ph10 175 parentheses number 1 in both cases.
105 ph10 166
106 ph10 182 \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
107 ph10 166
108 ph10 182
109 ph10 155 Release 7.1 24-Apr-07
110 nigel 93 ---------------------
112 ph10 155 There is only one new feature in this release: a linebreak setting of
113     PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
114     recognizes only CRLF, CR, and LF as linebreaks.
115 ph10 122
116 ph10 155 A few bugs are fixed (see ChangeLog for details), but the major change is a
117     complete re-implementation of the build system. This now has full Autotools
118     support and so is now "standard" in some sense. It should help with compiling
119     PCRE in a wide variety of environments.
121 ph10 146 NOTE: when building shared libraries for Windows, three dlls are now built,
122     called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
123     included in a single dll.
125     Another important change is that the dftables auxiliary program is no longer
126 ph10 128 compiled and run at "make" time by default. Instead, a default set of character
127     tables (assuming ASCII coding) is used. If you want to use dftables to generate
128     the character tables as previously, add --enable-rebuild-chartables to the
129     "configure" command. You must do this if you are compiling PCRE to run on a
130     system that uses EBCDIC code.
131 ph10 122
132 ph10 128 There is a discussion about character tables in the README file. The default is
133     not to use dftables so that that there is no problem when cross-compiling.
136 ph10 122 Release 7.0 19-Dec-06
137     ---------------------
139 nigel 93 This release has a new major number because there have been some internal
140     upheavals to facilitate the addition of new optimizations and other facilities,
141     and to make subsequent maintenance and extension easier. Compilation is likely
142     to be a bit slower, but there should be no major effect on runtime performance.
143     Previously compiled patterns are NOT upwards compatible with this release. If
144     you have saved compiled patterns from a previous release, you will have to
145     re-compile them. Important changes that are visible to users are:
147     1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
148     some more scripts.
150     2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
151     sequence as a newline.
153     3. The \R escape matches a single Unicode newline sequence as a single unit.
155     4. New features that will appear in Perl 5.10 are now in PCRE. These include
156     alternative Perl syntax for named parentheses, and Perl syntax for
157     recursion.
159     5. The C++ wrapper interface has been extended by the addition of a
160     QuoteMeta function and the ability to allow copy construction and
161     assignment.
163     For a complete list of changes, see the ChangeLog file.
166 nigel 91 Release 6.7 04-Jul-06
167     ---------------------
169     The main additions to this release are the ability to use the same name for
170     multiple sets of parentheses, and support for CRLF line endings in both the
171     library and pcregrep (and in pcretest for testing).
173     Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
174     significantly reduced for certain subject strings.
177 nigel 87 Release 6.5 01-Feb-06
178     ---------------------
180     Important changes in this release:
182     1. A number of new features have been added to pcregrep.
184     2. The Unicode property tables have been updated to Unicode 4.1.0, and the
185     supported properties have been extended with script names such as "Arabic",
186     and the derived properties "Any" and "L&". This has necessitated a change to
187     the interal format of compiled patterns. Any saved compiled patterns that
188     use \p or \P must be recompiled.
190     3. The specification of recursion in patterns has been changed so that all
191     recursive subpatterns are automatically treated as atomic groups. Thus, for
192     example, (?R) is treated as if it were (?>(?R)). This is necessary because
193     otherwise there are situations where recursion does not work.
195     See the ChangeLog for a complete list of changes, which include a number of bug
196     fixes and tidies.
199 nigel 77 Release 6.0 07-Jun-05
200     ---------------------
202     The release number has been increased to 6.0 because of the addition of several
203     major new pieces of functionality.
205     A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
206     algorithm, has been added. This has a number of advantages for certain cases,
207     though it does run more slowly, and lacks the ability to capture substrings. On
208     the other hand, it does find all matches, not just the first, and it works
209     better for partial matching. The pcrematching man page discusses the
210     differences.
212     The pcretest program has been enhanced so that it can make use of the new
213     pcre_dfa_exec() matching function and the extra features it provides.
215     The distribution now includes a C++ wrapper library. This is built
216     automatically if a C++ compiler is found. The pcrecpp man page discusses this
217     interface.
219     The code itself has been re-organized into many more files, one for each
220     function, so it no longer requires everything to be linked in when static
221     linkage is used. As a consequence, some internal functions have had to have
222     their names exposed. These functions all have names starting with _pcre_. They
223     are undocumented, and are not intended for use by outside callers.
225     The pcregrep program has been enhanced with new functionality such as
226     multiline-matching and options for output more matching context. See the
227     ChangeLog for a complete list of changes to the library and the utility
228     programs.
231 nigel 75 Release 5.0 13-Sep-04
232     ---------------------
234     The licence under which PCRE is released has been changed to the more
235     conventional "BSD" licence.
237     In the code, some bugs have been fixed, and there are also some major changes
238     in this release (which is why I've increased the number to 5.0). Some changes
239     are internal rearrangements, and some provide a number of new facilities. The
240     new features are:
242     1. There's an "automatic callout" feature that inserts callouts before every
243     item in the regex, and there's a new callout field that gives the position
244     in the pattern - useful for debugging and tracing.
246     2. The extra_data structure can now be used to pass in a set of character
247     tables at exec time. This is useful if compiled regex are saved and re-used
248     at a later time when the tables may not be at the same address. If the
249     default internal tables are used, the pointer saved with the compiled
250     pattern is now set to NULL, which means that you don't need to do anything
251     special unless you are using custom tables.
253     3. It is possible, with some restrictions on the content of the regex, to
254     request "partial" matching. A special return code is given if all of the
255     subject string matched part of the regex. This could be useful for testing
256     an input field as it is being typed.
258     4. There is now some optional support for Unicode character properties, which
259     means that the patterns items such as \p{Lu} and \X can now be used. Only
260     the general category properties are supported. If PCRE is compiled with this
261     support, an additional 90K data structure is include, which increases the
262     size of the library dramatically.
264     5. There is support for saving compiled patterns and re-using them later.
266     6. There is support for running regular expressions that were compiled on a
267     different host with the opposite endianness.
269     7. The pcretest program has been extended to accommodate the new features.
271     The main internal rearrangement is that sequences of literal characters are no
272     longer handled as strings. Instead, each character is handled on its own. This
273     makes some UTF-8 handling easier, and makes the support of partial matching
274     possible. Compiled patterns containing long literal strings will be larger as a
275     result of this change; I hope that performance will not be much affected.
278 nigel 73 Release 4.5 01-Dec-03
279     ---------------------
281     Again mainly a bug-fix and tidying release, with only a couple of new features:
283     1. It's possible now to compile PCRE so that it does not use recursive
284     function calls when matching. Instead it gets memory from the heap. This slows
285     things down, but may be necessary on systems with limited stacks.
287     2. UTF-8 string checking has been tightened to reject overlong sequences and to
288     check that a starting offset points to the start of a character. Failure of the
289     latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
291     3. PCRE can now be compiled for systems that use EBCDIC code.
294 nigel 71 Release 4.4 21-Aug-03
295     ---------------------
297     This is mainly a bug-fix and tidying release. The only new feature is that PCRE
298     checks UTF-8 strings for validity by default. There is an option to suppress
299     this, just in case anybody wants that teeny extra bit of performance.
302     Releases 4.1 - 4.3
303     ------------------
305     Sorry, I forgot about updating the NEWS file for these releases. Please take a
306     look at ChangeLog.
309 nigel 63 Release 4.0 17-Feb-03
310     ---------------------
312     There have been a lot of changes for the 4.0 release, adding additional
313     functionality and mending bugs. Below is a list of the highlights of the new
314     functionality. For full details of these features, please consult the
315     documentation. For a complete list of changes, see the ChangeLog file.
317     1. Support for Perl's \Q...\E escapes.
319     2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
320     package. They provide some syntactic sugar for simple cases of "atomic
321     grouping".
323     3. Support for the \G assertion. It is true when the current matching position
324     is at the start point of the match.
326     4. A new feature that provides some of the functionality that Perl provides
327     with (?{...}). The facility is termed a "callout". The way it is done in PCRE
328     is for the caller to provide an optional function, by setting pcre_callout to
329     its entry point. To get the function called, the regex must include (?C) at
330     appropriate points.
332     5. Support for recursive calls to individual subpatterns. This makes it really
333     easy to get totally confused.
335     6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
336     name a group.
338     7. Several extensions to UTF-8 support; it is now fairly complete. There is an
339     option for pcregrep to make it operate in UTF-8 mode.
341     8. The single man page has been split into a number of separate man pages.
342     These also give rise to individual HTML pages which are put in a separate
343     directory. There is an index.html page that lists them all. Some hyperlinking
344     between the pages has been installed.
347 nigel 53 Release 3.5 15-Aug-01
348     ---------------------
350     1. The configuring system has been upgraded to use later versions of autoconf
351     and libtool. By default it builds both a shared and a static library if the OS
352     supports it. You can use --disable-shared or --disable-static on the configure
353     command if you want only one of them.
355     2. The pcretest utility is now installed along with pcregrep because it is
356     useful for users (to test regexs) and by doing this, it automatically gets
357     relinked by libtool. The documentation has been turned into a man page, so
358     there are now .1, .txt, and .html versions in /doc.
360     3. Upgrades to pcregrep:
361     (i) Added long-form option names like gnu grep.
362     (ii) Added --help to list all options with an explanatory phrase.
363     (iii) Added -r, --recursive to recurse into sub-directories.
364     (iv) Added -f, --file to read patterns from a file.
366     4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
367     script, to force use of CR or LF instead of \n in the source. On non-Unix
368     systems, the value can be set in config.h.
370     5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
371     absolute limit. Changed the text of the error message to make this clear, and
372     likewise updated the man page.
374     6. The limit of 99 on the number of capturing subpatterns has been removed.
375     The new limit is 65535, which I hope will not be a "real" limit.
378 nigel 49 Release 3.3 01-Aug-00
379     ---------------------
381     There is some support for UTF-8 character strings. This is incomplete and
382     experimental. The documentation describes what is and what is not implemented.
383     Otherwise, this is just a bug-fixing release.
386 nigel 43 Release 3.0 01-Feb-00
387     ---------------------
388 nigel 41
389 nigel 43 1. A "configure" script is now used to configure PCRE for Unix systems. It
390     builds a Makefile, a config.h file, and the pcre-config script.
392     2. PCRE is built as a shared library by default.
394     3. There is support for POSIX classes such as [:alpha:].
396     5. There is an experimental recursion feature.
398 nigel 41 ----------------------------------------------------------------------------
401     Please note that there has been a change in the API such that a larger
402     ovector is required at matching time, to provide some additional workspace.
403     The new man page has details. This change was necessary in order to support
404     some of the new functionality in Perl 5.005.
408     Another (I hope this is the last!) change has been made to the API for the
409     pcre_compile() function. An additional argument has been added to make it
410     possible to pass over a pointer to character tables built in the current
411     locale by pcre_maketables(). To use the default tables, this new arguement
412     should be passed as NULL.
416     Yet another (and again I hope this really is the last) change has been made
417     to the API for the pcre_exec() function. An additional argument has been
418     added to make it possible to start the match other than at the start of the
419     subject string. This is important if there are lookbehinds. The new man
420     page has the details, but you just want to convert existing programs, all
421     you need to do is to stick in a new fifth argument to pcre_exec(), with a
422     value of zero. For example, change
424     pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
425     to
426     pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
428     ****


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