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revision 41 by nigel, Sat Feb 24 21:39:17 2007 UTC revision 123 by ph10, Mon Mar 12 15:19:06 2007 UTC
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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  
5  a Makefile and a config.h file.  Release 7.1 12-Mar-07
6    ---------------------
7    
8    There are no new features in this release. A few bugs are fixed (see ChangeLog
9    for details), but the major change is a complete re-implementation of the build
10    system. This now has full Autotools support and so is now "standard" in some
11    sense. It should help with compiling PCRE in a wide variety of environments.
12    
13    
14    Release 7.0 19-Dec-06
15    ---------------------
16    
17    This release has a new major number because there have been some internal
18    upheavals to facilitate the addition of new optimizations and other facilities,
19    and to make subsequent maintenance and extension easier. Compilation is likely
20    to be a bit slower, but there should be no major effect on runtime performance.
21    Previously compiled patterns are NOT upwards compatible with this release. If
22    you have saved compiled patterns from a previous release, you will have to
23    re-compile them. Important changes that are visible to users are:
24    
25    1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
26       some more scripts.
27    
28    2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
29       sequence as a newline.
30    
31    3. The \R escape matches a single Unicode newline sequence as a single unit.
32    
33    4. New features that will appear in Perl 5.10 are now in PCRE. These include
34       alternative Perl syntax for named parentheses, and Perl syntax for
35       recursion.
36    
37    5. The C++ wrapper interface has been extended by the addition of a
38       QuoteMeta function and the ability to allow copy construction and
39       assignment.
40    
41    For a complete list of changes, see the ChangeLog file.
42    
43    
44    Release 6.7 04-Jul-06
45    ---------------------
46    
47    The main additions to this release are the ability to use the same name for
48    multiple sets of parentheses, and support for CRLF line endings in both the
49    library and pcregrep (and in pcretest for testing).
50    
51    Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
52    significantly reduced for certain subject strings.
53    
54    
55    Release 6.5 01-Feb-06
56    ---------------------
57    
58    Important changes in this release:
59    
60    1. A number of new features have been added to pcregrep.
61    
62    2. The Unicode property tables have been updated to Unicode 4.1.0, and the
63       supported properties have been extended with script names such as "Arabic",
64       and the derived properties "Any" and "L&". This has necessitated a change to
65       the interal format of compiled patterns. Any saved compiled patterns that
66       use \p or \P must be recompiled.
67    
68    3. The specification of recursion in patterns has been changed so that all
69       recursive subpatterns are automatically treated as atomic groups. Thus, for
70       example, (?R) is treated as if it were (?>(?R)). This is necessary because
71       otherwise there are situations where recursion does not work.
72    
73    See the ChangeLog for a complete list of changes, which include a number of bug
74    fixes and tidies.
75    
76    
77    Release 6.0 07-Jun-05
78    ---------------------
79    
80    The release number has been increased to 6.0 because of the addition of several
81    major new pieces of functionality.
82    
83    A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
84    algorithm, has been added. This has a number of advantages for certain cases,
85    though it does run more slowly, and lacks the ability to capture substrings. On
86    the other hand, it does find all matches, not just the first, and it works
87    better for partial matching. The pcrematching man page discusses the
88    differences.
89    
90    The pcretest program has been enhanced so that it can make use of the new
91    pcre_dfa_exec() matching function and the extra features it provides.
92    
93    The distribution now includes a C++ wrapper library. This is built
94    automatically if a C++ compiler is found. The pcrecpp man page discusses this
95    interface.
96    
97    The code itself has been re-organized into many more files, one for each
98    function, so it no longer requires everything to be linked in when static
99    linkage is used. As a consequence, some internal functions have had to have
100    their names exposed. These functions all have names starting with _pcre_. They
101    are undocumented, and are not intended for use by outside callers.
102    
103    The pcregrep program has been enhanced with new functionality such as
104    multiline-matching and options for output more matching context. See the
105    ChangeLog for a complete list of changes to the library and the utility
106    programs.
107    
108    
109    Release 5.0 13-Sep-04
110    ---------------------
111    
112    The licence under which PCRE is released has been changed to the more
113    conventional "BSD" licence.
114    
115    In the code, some bugs have been fixed, and there are also some major changes
116    in this release (which is why I've increased the number to 5.0). Some changes
117    are internal rearrangements, and some provide a number of new facilities. The
118    new features are:
119    
120    1. There's an "automatic callout" feature that inserts callouts before every
121       item in the regex, and there's a new callout field that gives the position
122       in the pattern - useful for debugging and tracing.
123    
124    2. The extra_data structure can now be used to pass in a set of character
125       tables at exec time. This is useful if compiled regex are saved and re-used
126       at a later time when the tables may not be at the same address. If the
127       default internal tables are used, the pointer saved with the compiled
128       pattern is now set to NULL, which means that you don't need to do anything
129       special unless you are using custom tables.
130    
131    3. It is possible, with some restrictions on the content of the regex, to
132       request "partial" matching. A special return code is given if all of the
133       subject string matched part of the regex. This could be useful for testing
134       an input field as it is being typed.
135    
136    4. There is now some optional support for Unicode character properties, which
137       means that the patterns items such as \p{Lu} and \X can now be used. Only
138       the general category properties are supported. If PCRE is compiled with this
139       support, an additional 90K data structure is include, which increases the
140       size of the library dramatically.
141    
142    5. There is support for saving compiled patterns and re-using them later.
143    
144    6. There is support for running regular expressions that were compiled on a
145       different host with the opposite endianness.
146    
147    7. The pcretest program has been extended to accommodate the new features.
148    
149    The main internal rearrangement is that sequences of literal characters are no
150    longer handled as strings. Instead, each character is handled on its own. This
151    makes some UTF-8 handling easier, and makes the support of partial matching
152    possible. Compiled patterns containing long literal strings will be larger as a
153    result of this change; I hope that performance will not be much affected.
154    
155    
156    Release 4.5 01-Dec-03
157    ---------------------
158    
159    Again mainly a bug-fix and tidying release, with only a couple of new features:
160    
161    1. It's possible now to compile PCRE so that it does not use recursive
162    function calls when matching. Instead it gets memory from the heap. This slows
163    things down, but may be necessary on systems with limited stacks.
164    
165    2. UTF-8 string checking has been tightened to reject overlong sequences and to
166    check that a starting offset points to the start of a character. Failure of the
167    latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
168    
169    3. PCRE can now be compiled for systems that use EBCDIC code.
170    
171    
172    Release 4.4 21-Aug-03
173    ---------------------
174    
175    This is mainly a bug-fix and tidying release. The only new feature is that PCRE
176    checks UTF-8 strings for validity by default. There is an option to suppress
177    this, just in case anybody wants that teeny extra bit of performance.
178    
179    
180    Releases 4.1 - 4.3
181    ------------------
182    
183    Sorry, I forgot about updating the NEWS file for these releases. Please take a
184    look at ChangeLog.
185    
186    
187    Release 4.0 17-Feb-03
188    ---------------------
189    
190    There have been a lot of changes for the 4.0 release, adding additional
191    functionality and mending bugs. Below is a list of the highlights of the new
192    functionality. For full details of these features, please consult the
193    documentation. For a complete list of changes, see the ChangeLog file.
194    
195    1. Support for Perl's \Q...\E escapes.
196    
197    2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
198    package. They provide some syntactic sugar for simple cases of "atomic
199    grouping".
200    
201    3. Support for the \G assertion. It is true when the current matching position
202    is at the start point of the match.
203    
204    4. A new feature that provides some of the functionality that Perl provides
205    with (?{...}). The facility is termed a "callout". The way it is done in PCRE
206    is for the caller to provide an optional function, by setting pcre_callout to
207    its entry point. To get the function called, the regex must include (?C) at
208    appropriate points.
209    
210    5. Support for recursive calls to individual subpatterns. This makes it really
211    easy to get totally confused.
212    
213    6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
214    name a group.
215    
216    7. Several extensions to UTF-8 support; it is now fairly complete. There is an
217    option for pcregrep to make it operate in UTF-8 mode.
218    
219    8. The single man page has been split into a number of separate man pages.
220    These also give rise to individual HTML pages which are put in a separate
221    directory. There is an index.html page that lists them all. Some hyperlinking
222    between the pages has been installed.
223    
224    
225    Release 3.5 15-Aug-01
226    ---------------------
227    
228    1. The configuring system has been upgraded to use later versions of autoconf
229    and libtool. By default it builds both a shared and a static library if the OS
230    supports it. You can use --disable-shared or --disable-static on the configure
231    command if you want only one of them.
232    
233    2. The pcretest utility is now installed along with pcregrep because it is
234    useful for users (to test regexs) and by doing this, it automatically gets
235    relinked by libtool. The documentation has been turned into a man page, so
236    there are now .1, .txt, and .html versions in /doc.
237    
238    3. Upgrades to pcregrep:
239       (i)   Added long-form option names like gnu grep.
240       (ii)  Added --help to list all options with an explanatory phrase.
241       (iii) Added -r, --recursive to recurse into sub-directories.
242       (iv)  Added -f, --file to read patterns from a file.
243    
244    4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
245    script, to force use of CR or LF instead of \n in the source. On non-Unix
246    systems, the value can be set in config.h.
247    
248    5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
249    absolute limit. Changed the text of the error message to make this clear, and
250    likewise updated the man page.
251    
252    6. The limit of 99 on the number of capturing subpatterns has been removed.
253    The new limit is 65535, which I hope will not be a "real" limit.
254    
255    
256    Release 3.3 01-Aug-00
257    ---------------------
258    
259    There is some support for UTF-8 character strings. This is incomplete and
260    experimental. The documentation describes what is and what is not implemented.
261    Otherwise, this is just a bug-fixing release.
262    
263    
264    Release 3.0 01-Feb-00
265    ---------------------
266    
267    1. A "configure" script is now used to configure PCRE for Unix systems. It
268    builds a Makefile, a config.h file, and the pcre-config script.
269    
270    2. PCRE is built as a shared library by default.
271    
272    3. There is support for POSIX classes such as [:alpha:].
273    
274    5. There is an experimental recursion feature.
275    
276  ----------------------------------------------------------------------------  ----------------------------------------------------------------------------
277            IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00            IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00

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