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1  News about PCRE releases  News about PCRE releases
2  ------------------------  ------------------------
3    
4  A "configure" script is now used to configure PCRE for Unix systems. It builds  Release 8.10 03-Jun-2010
5  a Makefile and a config.h file.  ------------------------
6    
7    There are two major additions: support for (*MAKR) and friends, and the option
8    PCRE_UCP, which changes the behaviour of \b, \d, \s, and \w (and their
9    opposites) so that they make use of Unicode properties. There are also a number
10    of lesser new features, and several bugs have been fixed. A new option,
11    --line-buffered, has been added to pcregrep, for use when it is connected to
12    pipes.
13    
14    
15    Release 8.02 19-Mar-2010
16    ------------------------
17    
18    Another bug-fix release.
19    
20    
21    Release 8.01 19-Jan-2010
22    ------------------------
23    
24    This is a bug-fix release. Several bugs in the code itself and some bugs and
25    infelicities in the build system have been fixed.
26    
27    
28    Release 8.00 19-Oct-09
29    ----------------------
30    
31    Bugs have been fixed in the library and in pcregrep. There are also some
32    enhancements. Restrictions on patterns used for partial matching have been
33    removed, extra information is given for partial matches, the partial matching
34    process has been improved, and an option to make a partial match override a
35    full match is available. The "study" process has been enhanced by finding a
36    lower bound matching length. Groups with duplicate numbers may now have
37    duplicated names without the use of PCRE_DUPNAMES. However, they may not have
38    different names. The documentation has been revised to reflect these changes.
39    The version number has been expanded to 3 digits as it is clear that the rate
40    of change is not slowing down.
41    
42    
43    Release 7.9 11-Apr-09
44    ---------------------
45    
46    Mostly bugfixes and tidies with just a couple of minor functional additions.
47    
48    
49    Release 7.8 05-Sep-08
50    ---------------------
51    
52    More bug fixes, plus a performance improvement in Unicode character property
53    lookup.
54    
55    
56    Release 7.7 07-May-08
57    ---------------------
58    
59    This is once again mainly a bug-fix release, but there are a couple of new
60    features.
61    
62    
63    Release 7.6 28-Jan-08
64    ---------------------
65    
66    The main reason for having this release so soon after 7.5 is because it fixes a
67    potential buffer overflow problem in pcre_compile() when run in UTF-8 mode. In
68    addition, the CMake configuration files have been brought up to date.
69    
70    
71    Release 7.5 10-Jan-08
72    ---------------------
73    
74    This is mainly a bug-fix release. However the ability to link pcregrep with
75    libz or libbz2 and the ability to link pcretest with libreadline have been
76    added. Also the --line-offsets and --file-offsets options were added to
77    pcregrep.
78    
79    
80    Release 7.4 21-Sep-07
81    ---------------------
82    
83    The only change of specification is the addition of options to control whether
84    \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
85    Otherwise, the changes are bug fixes and a refactoring to reduce the number of
86    relocations needed in a shared library. There have also been some documentation
87    updates, in particular, some more information about using CMake to build PCRE
88    has been added to the NON-UNIX-USE file.
89    
90    
91    Release 7.3 28-Aug-07
92    ---------------------
93    
94    Most changes are bug fixes. Some that are not:
95    
96    1. There is some support for Perl 5.10's experimental "backtracking control
97       verbs" such as (*PRUNE).
98    
99    2. UTF-8 checking is now as per RFC 3629 instead of RFC 2279; this is more
100       restrictive in the strings it accepts.
101    
102    3. Checking for potential integer overflow has been made more dynamic, and as a
103       consequence there is no longer a hard limit on the size of a subpattern that
104       has a limited repeat count.
105    
106    4. When CRLF is a valid line-ending sequence, pcre_exec() and pcre_dfa_exec()
107       no longer advance by two characters instead of one when an unanchored match
108       fails at CRLF if there are explicit CR or LF matches within the pattern.
109       This gets rid of some anomalous effects that previously occurred.
110    
111    5. Some PCRE-specific settings for varying the newline options at the start of
112       a pattern have been added.
113    
114    
115    Release 7.2 19-Jun-07
116    ---------------------
117    
118    WARNING: saved patterns that were compiled by earlier versions of PCRE must be
119    recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
120    and \V).
121    
122    Correction to the notes for 7.1: the note about shared libraries for Windows is
123    wrong. Previously, three libraries were built, but each could function
124    independently. For example, the pcreposix library also included all the
125    functions from the basic pcre library. The change is that the three libraries
126    are no longer independent. They are like the Unix libraries. To use the
127    pcreposix functions, for example, you need to link with both the pcreposix and
128    the basic pcre library.
129    
130    Some more features from Perl 5.10 have been added:
131    
132      (?-n) and (?+n) relative references for recursion and subroutines.
133    
134      (?(-n) and (?(+n) relative references as conditions.
135    
136      \k{name} and \g{name} are synonyms for \k<name>.
137    
138      \K to reset the start of the matched string; for example, (foo)\Kbar
139      matches bar preceded by foo, but only sets bar as the matched string.
140    
141      (?| introduces a group where the capturing parentheses in each alternative
142      start from the same number; for example, (?|(abc)|(xyz)) sets capturing
143      parentheses number 1 in both cases.
144    
145      \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
146    
147    
148    Release 7.1 24-Apr-07
149    ---------------------
150    
151    There is only one new feature in this release: a linebreak setting of
152    PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
153    recognizes only CRLF, CR, and LF as linebreaks.
154    
155    A few bugs are fixed (see ChangeLog for details), but the major change is a
156    complete re-implementation of the build system. This now has full Autotools
157    support and so is now "standard" in some sense. It should help with compiling
158    PCRE in a wide variety of environments.
159    
160    NOTE: when building shared libraries for Windows, three dlls are now built,
161    called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
162    included in a single dll.
163    
164    Another important change is that the dftables auxiliary program is no longer
165    compiled and run at "make" time by default. Instead, a default set of character
166    tables (assuming ASCII coding) is used. If you want to use dftables to generate
167    the character tables as previously, add --enable-rebuild-chartables to the
168    "configure" command. You must do this if you are compiling PCRE to run on a
169    system that uses EBCDIC code.
170    
171    There is a discussion about character tables in the README file. The default is
172    not to use dftables so that that there is no problem when cross-compiling.
173    
174    
175    Release 7.0 19-Dec-06
176    ---------------------
177    
178    This release has a new major number because there have been some internal
179    upheavals to facilitate the addition of new optimizations and other facilities,
180    and to make subsequent maintenance and extension easier. Compilation is likely
181    to be a bit slower, but there should be no major effect on runtime performance.
182    Previously compiled patterns are NOT upwards compatible with this release. If
183    you have saved compiled patterns from a previous release, you will have to
184    re-compile them. Important changes that are visible to users are:
185    
186    1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
187       some more scripts.
188    
189    2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
190       sequence as a newline.
191    
192    3. The \R escape matches a single Unicode newline sequence as a single unit.
193    
194    4. New features that will appear in Perl 5.10 are now in PCRE. These include
195       alternative Perl syntax for named parentheses, and Perl syntax for
196       recursion.
197    
198    5. The C++ wrapper interface has been extended by the addition of a
199       QuoteMeta function and the ability to allow copy construction and
200       assignment.
201    
202    For a complete list of changes, see the ChangeLog file.
203    
204    
205    Release 6.7 04-Jul-06
206    ---------------------
207    
208    The main additions to this release are the ability to use the same name for
209    multiple sets of parentheses, and support for CRLF line endings in both the
210    library and pcregrep (and in pcretest for testing).
211    
212    Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
213    significantly reduced for certain subject strings.
214    
215    
216    Release 6.5 01-Feb-06
217    ---------------------
218    
219    Important changes in this release:
220    
221    1. A number of new features have been added to pcregrep.
222    
223    2. The Unicode property tables have been updated to Unicode 4.1.0, and the
224       supported properties have been extended with script names such as "Arabic",
225       and the derived properties "Any" and "L&". This has necessitated a change to
226       the interal format of compiled patterns. Any saved compiled patterns that
227       use \p or \P must be recompiled.
228    
229    3. The specification of recursion in patterns has been changed so that all
230       recursive subpatterns are automatically treated as atomic groups. Thus, for
231       example, (?R) is treated as if it were (?>(?R)). This is necessary because
232       otherwise there are situations where recursion does not work.
233    
234    See the ChangeLog for a complete list of changes, which include a number of bug
235    fixes and tidies.
236    
237    
238    Release 6.0 07-Jun-05
239    ---------------------
240    
241    The release number has been increased to 6.0 because of the addition of several
242    major new pieces of functionality.
243    
244    A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
245    algorithm, has been added. This has a number of advantages for certain cases,
246    though it does run more slowly, and lacks the ability to capture substrings. On
247    the other hand, it does find all matches, not just the first, and it works
248    better for partial matching. The pcrematching man page discusses the
249    differences.
250    
251    The pcretest program has been enhanced so that it can make use of the new
252    pcre_dfa_exec() matching function and the extra features it provides.
253    
254    The distribution now includes a C++ wrapper library. This is built
255    automatically if a C++ compiler is found. The pcrecpp man page discusses this
256    interface.
257    
258    The code itself has been re-organized into many more files, one for each
259    function, so it no longer requires everything to be linked in when static
260    linkage is used. As a consequence, some internal functions have had to have
261    their names exposed. These functions all have names starting with _pcre_. They
262    are undocumented, and are not intended for use by outside callers.
263    
264    The pcregrep program has been enhanced with new functionality such as
265    multiline-matching and options for output more matching context. See the
266    ChangeLog for a complete list of changes to the library and the utility
267    programs.
268    
269    
270    Release 5.0 13-Sep-04
271    ---------------------
272    
273    The licence under which PCRE is released has been changed to the more
274    conventional "BSD" licence.
275    
276    In the code, some bugs have been fixed, and there are also some major changes
277    in this release (which is why I've increased the number to 5.0). Some changes
278    are internal rearrangements, and some provide a number of new facilities. The
279    new features are:
280    
281    1. There's an "automatic callout" feature that inserts callouts before every
282       item in the regex, and there's a new callout field that gives the position
283       in the pattern - useful for debugging and tracing.
284    
285    2. The extra_data structure can now be used to pass in a set of character
286       tables at exec time. This is useful if compiled regex are saved and re-used
287       at a later time when the tables may not be at the same address. If the
288       default internal tables are used, the pointer saved with the compiled
289       pattern is now set to NULL, which means that you don't need to do anything
290       special unless you are using custom tables.
291    
292    3. It is possible, with some restrictions on the content of the regex, to
293       request "partial" matching. A special return code is given if all of the
294       subject string matched part of the regex. This could be useful for testing
295       an input field as it is being typed.
296    
297    4. There is now some optional support for Unicode character properties, which
298       means that the patterns items such as \p{Lu} and \X can now be used. Only
299       the general category properties are supported. If PCRE is compiled with this
300       support, an additional 90K data structure is include, which increases the
301       size of the library dramatically.
302    
303    5. There is support for saving compiled patterns and re-using them later.
304    
305    6. There is support for running regular expressions that were compiled on a
306       different host with the opposite endianness.
307    
308    7. The pcretest program has been extended to accommodate the new features.
309    
310    The main internal rearrangement is that sequences of literal characters are no
311    longer handled as strings. Instead, each character is handled on its own. This
312    makes some UTF-8 handling easier, and makes the support of partial matching
313    possible. Compiled patterns containing long literal strings will be larger as a
314    result of this change; I hope that performance will not be much affected.
315    
316    
317    Release 4.5 01-Dec-03
318    ---------------------
319    
320    Again mainly a bug-fix and tidying release, with only a couple of new features:
321    
322    1. It's possible now to compile PCRE so that it does not use recursive
323    function calls when matching. Instead it gets memory from the heap. This slows
324    things down, but may be necessary on systems with limited stacks.
325    
326    2. UTF-8 string checking has been tightened to reject overlong sequences and to
327    check that a starting offset points to the start of a character. Failure of the
328    latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
329    
330    3. PCRE can now be compiled for systems that use EBCDIC code.
331    
332    
333    Release 4.4 21-Aug-03
334    ---------------------
335    
336    This is mainly a bug-fix and tidying release. The only new feature is that PCRE
337    checks UTF-8 strings for validity by default. There is an option to suppress
338    this, just in case anybody wants that teeny extra bit of performance.
339    
340    
341    Releases 4.1 - 4.3
342    ------------------
343    
344    Sorry, I forgot about updating the NEWS file for these releases. Please take a
345    look at ChangeLog.
346    
347    
348    Release 4.0 17-Feb-03
349    ---------------------
350    
351    There have been a lot of changes for the 4.0 release, adding additional
352    functionality and mending bugs. Below is a list of the highlights of the new
353    functionality. For full details of these features, please consult the
354    documentation. For a complete list of changes, see the ChangeLog file.
355    
356    1. Support for Perl's \Q...\E escapes.
357    
358    2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
359    package. They provide some syntactic sugar for simple cases of "atomic
360    grouping".
361    
362    3. Support for the \G assertion. It is true when the current matching position
363    is at the start point of the match.
364    
365    4. A new feature that provides some of the functionality that Perl provides
366    with (?{...}). The facility is termed a "callout". The way it is done in PCRE
367    is for the caller to provide an optional function, by setting pcre_callout to
368    its entry point. To get the function called, the regex must include (?C) at
369    appropriate points.
370    
371    5. Support for recursive calls to individual subpatterns. This makes it really
372    easy to get totally confused.
373    
374    6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
375    name a group.
376    
377    7. Several extensions to UTF-8 support; it is now fairly complete. There is an
378    option for pcregrep to make it operate in UTF-8 mode.
379    
380    8. The single man page has been split into a number of separate man pages.
381    These also give rise to individual HTML pages which are put in a separate
382    directory. There is an index.html page that lists them all. Some hyperlinking
383    between the pages has been installed.
384    
385    
386    Release 3.5 15-Aug-01
387    ---------------------
388    
389    1. The configuring system has been upgraded to use later versions of autoconf
390    and libtool. By default it builds both a shared and a static library if the OS
391    supports it. You can use --disable-shared or --disable-static on the configure
392    command if you want only one of them.
393    
394    2. The pcretest utility is now installed along with pcregrep because it is
395    useful for users (to test regexs) and by doing this, it automatically gets
396    relinked by libtool. The documentation has been turned into a man page, so
397    there are now .1, .txt, and .html versions in /doc.
398    
399    3. Upgrades to pcregrep:
400       (i)   Added long-form option names like gnu grep.
401       (ii)  Added --help to list all options with an explanatory phrase.
402       (iii) Added -r, --recursive to recurse into sub-directories.
403       (iv)  Added -f, --file to read patterns from a file.
404    
405    4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
406    script, to force use of CR or LF instead of \n in the source. On non-Unix
407    systems, the value can be set in config.h.
408    
409    5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
410    absolute limit. Changed the text of the error message to make this clear, and
411    likewise updated the man page.
412    
413    6. The limit of 99 on the number of capturing subpatterns has been removed.
414    The new limit is 65535, which I hope will not be a "real" limit.
415    
416    
417    Release 3.3 01-Aug-00
418    ---------------------
419    
420    There is some support for UTF-8 character strings. This is incomplete and
421    experimental. The documentation describes what is and what is not implemented.
422    Otherwise, this is just a bug-fixing release.
423    
424    
425    Release 3.0 01-Feb-00
426    ---------------------
427    
428    1. A "configure" script is now used to configure PCRE for Unix systems. It
429    builds a Makefile, a config.h file, and the pcre-config script.
430    
431    2. PCRE is built as a shared library by default.
432    
433    3. There is support for POSIX classes such as [:alpha:].
434    
435    5. There is an experimental recursion feature.
436    
437  ----------------------------------------------------------------------------  ----------------------------------------------------------------------------
438            IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00            IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00

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