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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 7.9 11-Apr-09
5  a Makefile and a config.h file.  ---------------------
6    
7    Mostly bugfixes and tidies with just a couple of minor functional additions.
8    
9    
10    Release 7.8 05-Sep-08
11    ---------------------
12    
13    More bug fixes, plus a performance improvement in Unicode character property
14    lookup.
15    
16    
17    Release 7.7 07-May-08
18    ---------------------
19    
20    This is once again mainly a bug-fix release, but there are a couple of new
21    features.
22    
23    
24    Release 7.6 28-Jan-08
25    ---------------------
26    
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.
30    
31    
32    Release 7.5 10-Jan-08
33    ---------------------
34    
35    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.
39    
40    
41    Release 7.4 21-Sep-07
42    ---------------------
43    
44    The only change of specification is the addition of options to control whether
45    \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
46    Otherwise, the changes are bug fixes and a refactoring to reduce the number of
47    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    
51    
52    Release 7.3 28-Aug-07
53    ---------------------
54    
55    Most changes are bug fixes. Some that are not:
56    
57    1. There is some support for Perl 5.10's experimental "backtracking control
58       verbs" such as (*PRUNE).
59    
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.
62    
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    
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       This gets rid of some anomalous effects that previously occurred.
71    
72    5. Some PCRE-specific settings for varying the newline options at the start of
73       a pattern have been added.
74    
75    
76    Release 7.2 19-Jun-07
77    ---------------------
78    
79    WARNING: saved patterns that were compiled by earlier versions of PCRE must be
80    recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
81    and \V).
82    
83    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    the basic pcre library.
90    
91    Some more features from Perl 5.10 have been added:
92    
93      (?-n) and (?+n) relative references for recursion and subroutines.
94    
95      (?(-n) and (?(+n) relative references as conditions.
96    
97      \k{name} and \g{name} are synonyms for \k<name>.
98    
99      \K to reset the start of the matched string; for example, (foo)\Kbar
100      matches bar preceded by foo, but only sets bar as the matched string.
101    
102      (?| introduces a group where the capturing parentheses in each alternative
103      start from the same number; for example, (?|(abc)|(xyz)) sets capturing
104      parentheses number 1 in both cases.
105    
106      \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
107    
108    
109    Release 7.1 24-Apr-07
110    ---------------------
111    
112    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    
116    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.
120    
121    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.
124    
125    Another important change is that the dftables auxiliary program is no longer
126    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    
132    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.
134    
135    
136    Release 7.0 19-Dec-06
137    ---------------------
138    
139    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:
146    
147    1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
148       some more scripts.
149    
150    2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
151       sequence as a newline.
152    
153    3. The \R escape matches a single Unicode newline sequence as a single unit.
154    
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.
158    
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.
162    
163    For a complete list of changes, see the ChangeLog file.
164    
165    
166    Release 6.7 04-Jul-06
167    ---------------------
168    
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).
172    
173    Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
174    significantly reduced for certain subject strings.
175    
176    
177    Release 6.5 01-Feb-06
178    ---------------------
179    
180    Important changes in this release:
181    
182    1. A number of new features have been added to pcregrep.
183    
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.
189    
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.
194    
195    See the ChangeLog for a complete list of changes, which include a number of bug
196    fixes and tidies.
197    
198    
199    Release 6.0 07-Jun-05
200    ---------------------
201    
202    The release number has been increased to 6.0 because of the addition of several
203    major new pieces of functionality.
204    
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.
211    
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.
214    
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.
218    
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.
224    
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.
229    
230    
231    Release 5.0 13-Sep-04
232    ---------------------
233    
234    The licence under which PCRE is released has been changed to the more
235    conventional "BSD" licence.
236    
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:
241    
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.
245    
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.
252    
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.
257    
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.
263    
264    5. There is support for saving compiled patterns and re-using them later.
265    
266    6. There is support for running regular expressions that were compiled on a
267       different host with the opposite endianness.
268    
269    7. The pcretest program has been extended to accommodate the new features.
270    
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.
276    
277    
278    Release 4.5 01-Dec-03
279    ---------------------
280    
281    Again mainly a bug-fix and tidying release, with only a couple of new features:
282    
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.
286    
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.
290    
291    3. PCRE can now be compiled for systems that use EBCDIC code.
292    
293    
294    Release 4.4 21-Aug-03
295    ---------------------
296    
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.
300    
301    
302    Releases 4.1 - 4.3
303    ------------------
304    
305    Sorry, I forgot about updating the NEWS file for these releases. Please take a
306    look at ChangeLog.
307    
308    
309    Release 4.0 17-Feb-03
310    ---------------------
311    
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.
316    
317    1. Support for Perl's \Q...\E escapes.
318    
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".
322    
323    3. Support for the \G assertion. It is true when the current matching position
324    is at the start point of the match.
325    
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.
331    
332    5. Support for recursive calls to individual subpatterns. This makes it really
333    easy to get totally confused.
334    
335    6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
336    name a group.
337    
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.
340    
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.
345    
346    
347    Release 3.5 15-Aug-01
348    ---------------------
349    
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.
354    
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.
359    
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.
365    
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.
369    
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.
373    
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.
376    
377    
378    Release 3.3 01-Aug-00
379    ---------------------
380    
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.
384    
385    
386    Release 3.0 01-Feb-00
387    ---------------------
388    
389    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.
391    
392    2. PCRE is built as a shared library by default.
393    
394    3. There is support for POSIX classes such as [:alpha:].
395    
396    5. There is an experimental recursion feature.
397    
398  ----------------------------------------------------------------------------  ----------------------------------------------------------------------------
399            IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00            IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00

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