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Revision 123 - (show annotations) (download)
Mon Mar 12 15:19:06 2007 UTC (7 years, 8 months ago) by ph10
File size: 12770 byte(s)
Removal of trailing spaces.

1 News about PCRE releases
2 ------------------------
3
4
5 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
278
279 Please note that there has been a change in the API such that a larger
280 ovector is required at matching time, to provide some additional workspace.
281 The new man page has details. This change was necessary in order to support
282 some of the new functionality in Perl 5.005.
283
284 IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.00
285
286 Another (I hope this is the last!) change has been made to the API for the
287 pcre_compile() function. An additional argument has been added to make it
288 possible to pass over a pointer to character tables built in the current
289 locale by pcre_maketables(). To use the default tables, this new arguement
290 should be passed as NULL.
291
292 IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.05
293
294 Yet another (and again I hope this really is the last) change has been made
295 to the API for the pcre_exec() function. An additional argument has been
296 added to make it possible to start the match other than at the start of the
297 subject string. This is important if there are lookbehinds. The new man
298 page has the details, but you just want to convert existing programs, all
299 you need to do is to stick in a new fifth argument to pcre_exec(), with a
300 value of zero. For example, change
301
302 pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
303 to
304 pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
305
306 ****

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