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revision 73 by nigel, Sat Feb 24 21:40:30 2007 UTC revision 489 by ph10, Tue Jan 19 16:42:21 2010 UTC
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1  News about PCRE releases  News about PCRE releases
2  ------------------------  ------------------------
3    
4    Release 8.01 19-Jan-2010
5    ------------------------
6    
7    This is a bug-fix release. Several bugs in the code itself and some bugs and
8    infelicities in the build system have been fixed.
9    
10    
11    Release 8.00 19-Oct-09
12    ----------------------
13    
14    Bugs have been fixed in the library and in pcregrep. There are also some
15    enhancements. Restrictions on patterns used for partial matching have been
16    removed, extra information is given for partial matches, the partial matching
17    process has been improved, and an option to make a partial match override a
18    full match is available. The "study" process has been enhanced by finding a
19    lower bound matching length. Groups with duplicate numbers may now have
20    duplicated names without the use of PCRE_DUPNAMES. However, they may not have
21    different names. The documentation has been revised to reflect these changes.
22    The version number has been expanded to 3 digits as it is clear that the rate
23    of change is not slowing down.
24    
25    
26    Release 7.9 11-Apr-09
27    ---------------------
28    
29    Mostly bugfixes and tidies with just a couple of minor functional additions.
30    
31    
32    Release 7.8 05-Sep-08
33    ---------------------
34    
35    More bug fixes, plus a performance improvement in Unicode character property
36    lookup.
37    
38    
39    Release 7.7 07-May-08
40    ---------------------
41    
42    This is once again mainly a bug-fix release, but there are a couple of new
43    features.
44    
45    
46    Release 7.6 28-Jan-08
47    ---------------------
48    
49    The main reason for having this release so soon after 7.5 is because it fixes a
50    potential buffer overflow problem in pcre_compile() when run in UTF-8 mode. In
51    addition, the CMake configuration files have been brought up to date.
52    
53    
54    Release 7.5 10-Jan-08
55    ---------------------
56    
57    This is mainly a bug-fix release. However the ability to link pcregrep with
58    libz or libbz2 and the ability to link pcretest with libreadline have been
59    added. Also the --line-offsets and --file-offsets options were added to
60    pcregrep.
61    
62    
63    Release 7.4 21-Sep-07
64    ---------------------
65    
66    The only change of specification is the addition of options to control whether
67    \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
68    Otherwise, the changes are bug fixes and a refactoring to reduce the number of
69    relocations needed in a shared library. There have also been some documentation
70    updates, in particular, some more information about using CMake to build PCRE
71    has been added to the NON-UNIX-USE file.
72    
73    
74    Release 7.3 28-Aug-07
75    ---------------------
76    
77    Most changes are bug fixes. Some that are not:
78    
79    1. There is some support for Perl 5.10's experimental "backtracking control
80       verbs" such as (*PRUNE).
81    
82    2. UTF-8 checking is now as per RFC 3629 instead of RFC 2279; this is more
83       restrictive in the strings it accepts.
84    
85    3. Checking for potential integer overflow has been made more dynamic, and as a
86       consequence there is no longer a hard limit on the size of a subpattern that
87       has a limited repeat count.
88    
89    4. When CRLF is a valid line-ending sequence, pcre_exec() and pcre_dfa_exec()
90       no longer advance by two characters instead of one when an unanchored match
91       fails at CRLF if there are explicit CR or LF matches within the pattern.
92       This gets rid of some anomalous effects that previously occurred.
93    
94    5. Some PCRE-specific settings for varying the newline options at the start of
95       a pattern have been added.
96    
97    
98    Release 7.2 19-Jun-07
99    ---------------------
100    
101    WARNING: saved patterns that were compiled by earlier versions of PCRE must be
102    recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
103    and \V).
104    
105    Correction to the notes for 7.1: the note about shared libraries for Windows is
106    wrong. Previously, three libraries were built, but each could function
107    independently. For example, the pcreposix library also included all the
108    functions from the basic pcre library. The change is that the three libraries
109    are no longer independent. They are like the Unix libraries. To use the
110    pcreposix functions, for example, you need to link with both the pcreposix and
111    the basic pcre library.
112    
113    Some more features from Perl 5.10 have been added:
114    
115      (?-n) and (?+n) relative references for recursion and subroutines.
116    
117      (?(-n) and (?(+n) relative references as conditions.
118    
119      \k{name} and \g{name} are synonyms for \k<name>.
120    
121      \K to reset the start of the matched string; for example, (foo)\Kbar
122      matches bar preceded by foo, but only sets bar as the matched string.
123    
124      (?| introduces a group where the capturing parentheses in each alternative
125      start from the same number; for example, (?|(abc)|(xyz)) sets capturing
126      parentheses number 1 in both cases.
127    
128      \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
129    
130    
131    Release 7.1 24-Apr-07
132    ---------------------
133    
134    There is only one new feature in this release: a linebreak setting of
135    PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
136    recognizes only CRLF, CR, and LF as linebreaks.
137    
138    A few bugs are fixed (see ChangeLog for details), but the major change is a
139    complete re-implementation of the build system. This now has full Autotools
140    support and so is now "standard" in some sense. It should help with compiling
141    PCRE in a wide variety of environments.
142    
143    NOTE: when building shared libraries for Windows, three dlls are now built,
144    called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
145    included in a single dll.
146    
147    Another important change is that the dftables auxiliary program is no longer
148    compiled and run at "make" time by default. Instead, a default set of character
149    tables (assuming ASCII coding) is used. If you want to use dftables to generate
150    the character tables as previously, add --enable-rebuild-chartables to the
151    "configure" command. You must do this if you are compiling PCRE to run on a
152    system that uses EBCDIC code.
153    
154    There is a discussion about character tables in the README file. The default is
155    not to use dftables so that that there is no problem when cross-compiling.
156    
157    
158    Release 7.0 19-Dec-06
159    ---------------------
160    
161    This release has a new major number because there have been some internal
162    upheavals to facilitate the addition of new optimizations and other facilities,
163    and to make subsequent maintenance and extension easier. Compilation is likely
164    to be a bit slower, but there should be no major effect on runtime performance.
165    Previously compiled patterns are NOT upwards compatible with this release. If
166    you have saved compiled patterns from a previous release, you will have to
167    re-compile them. Important changes that are visible to users are:
168    
169    1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
170       some more scripts.
171    
172    2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
173       sequence as a newline.
174    
175    3. The \R escape matches a single Unicode newline sequence as a single unit.
176    
177    4. New features that will appear in Perl 5.10 are now in PCRE. These include
178       alternative Perl syntax for named parentheses, and Perl syntax for
179       recursion.
180    
181    5. The C++ wrapper interface has been extended by the addition of a
182       QuoteMeta function and the ability to allow copy construction and
183       assignment.
184    
185    For a complete list of changes, see the ChangeLog file.
186    
187    
188    Release 6.7 04-Jul-06
189    ---------------------
190    
191    The main additions to this release are the ability to use the same name for
192    multiple sets of parentheses, and support for CRLF line endings in both the
193    library and pcregrep (and in pcretest for testing).
194    
195    Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
196    significantly reduced for certain subject strings.
197    
198    
199    Release 6.5 01-Feb-06
200    ---------------------
201    
202    Important changes in this release:
203    
204    1. A number of new features have been added to pcregrep.
205    
206    2. The Unicode property tables have been updated to Unicode 4.1.0, and the
207       supported properties have been extended with script names such as "Arabic",
208       and the derived properties "Any" and "L&". This has necessitated a change to
209       the interal format of compiled patterns. Any saved compiled patterns that
210       use \p or \P must be recompiled.
211    
212    3. The specification of recursion in patterns has been changed so that all
213       recursive subpatterns are automatically treated as atomic groups. Thus, for
214       example, (?R) is treated as if it were (?>(?R)). This is necessary because
215       otherwise there are situations where recursion does not work.
216    
217    See the ChangeLog for a complete list of changes, which include a number of bug
218    fixes and tidies.
219    
220    
221    Release 6.0 07-Jun-05
222    ---------------------
223    
224    The release number has been increased to 6.0 because of the addition of several
225    major new pieces of functionality.
226    
227    A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
228    algorithm, has been added. This has a number of advantages for certain cases,
229    though it does run more slowly, and lacks the ability to capture substrings. On
230    the other hand, it does find all matches, not just the first, and it works
231    better for partial matching. The pcrematching man page discusses the
232    differences.
233    
234    The pcretest program has been enhanced so that it can make use of the new
235    pcre_dfa_exec() matching function and the extra features it provides.
236    
237    The distribution now includes a C++ wrapper library. This is built
238    automatically if a C++ compiler is found. The pcrecpp man page discusses this
239    interface.
240    
241    The code itself has been re-organized into many more files, one for each
242    function, so it no longer requires everything to be linked in when static
243    linkage is used. As a consequence, some internal functions have had to have
244    their names exposed. These functions all have names starting with _pcre_. They
245    are undocumented, and are not intended for use by outside callers.
246    
247    The pcregrep program has been enhanced with new functionality such as
248    multiline-matching and options for output more matching context. See the
249    ChangeLog for a complete list of changes to the library and the utility
250    programs.
251    
252    
253    Release 5.0 13-Sep-04
254    ---------------------
255    
256    The licence under which PCRE is released has been changed to the more
257    conventional "BSD" licence.
258    
259    In the code, some bugs have been fixed, and there are also some major changes
260    in this release (which is why I've increased the number to 5.0). Some changes
261    are internal rearrangements, and some provide a number of new facilities. The
262    new features are:
263    
264    1. There's an "automatic callout" feature that inserts callouts before every
265       item in the regex, and there's a new callout field that gives the position
266       in the pattern - useful for debugging and tracing.
267    
268    2. The extra_data structure can now be used to pass in a set of character
269       tables at exec time. This is useful if compiled regex are saved and re-used
270       at a later time when the tables may not be at the same address. If the
271       default internal tables are used, the pointer saved with the compiled
272       pattern is now set to NULL, which means that you don't need to do anything
273       special unless you are using custom tables.
274    
275    3. It is possible, with some restrictions on the content of the regex, to
276       request "partial" matching. A special return code is given if all of the
277       subject string matched part of the regex. This could be useful for testing
278       an input field as it is being typed.
279    
280    4. There is now some optional support for Unicode character properties, which
281       means that the patterns items such as \p{Lu} and \X can now be used. Only
282       the general category properties are supported. If PCRE is compiled with this
283       support, an additional 90K data structure is include, which increases the
284       size of the library dramatically.
285    
286    5. There is support for saving compiled patterns and re-using them later.
287    
288    6. There is support for running regular expressions that were compiled on a
289       different host with the opposite endianness.
290    
291    7. The pcretest program has been extended to accommodate the new features.
292    
293    The main internal rearrangement is that sequences of literal characters are no
294    longer handled as strings. Instead, each character is handled on its own. This
295    makes some UTF-8 handling easier, and makes the support of partial matching
296    possible. Compiled patterns containing long literal strings will be larger as a
297    result of this change; I hope that performance will not be much affected.
298    
299    
300  Release 4.5 01-Dec-03  Release 4.5 01-Dec-03
301  ---------------------  ---------------------
302    

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