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

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