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Revision 371 - (hide annotations) (download)
Mon Aug 25 18:28:05 2008 UTC (6 years, 3 months ago) by ph10
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Source tidies for 7.8-RC1 

1 nigel 41 News about PCRE releases
2     ------------------------
3    
4 ph10 345
5 ph10 371 Release 7.8 25-Aug-08
6     ---------------------
7    
8     More bug fixes, plus a performance improvement in Unicode character property
9     lookup.
10    
11    
12 ph10 347 Release 7.7 07-May-08
13 ph10 345 ---------------------
14    
15     This is once again mainly a bug-fix release, but there are a couple of new
16     features.
17    
18    
19 ph10 319 Release 7.6 28-Jan-08
20 ph10 309 ---------------------
21    
22     The main reason for having this release so soon after 7.5 is because it fixes a
23     potential buffer overflow problem in pcre_compile() when run in UTF-8 mode. In
24     addition, the CMake configuration files have been brought up to date.
25    
26    
27 ph10 298 Release 7.5 10-Jan-08
28 ph10 289 ---------------------
29 ph10 122
30 ph10 289 This is mainly a bug-fix release. However the ability to link pcregrep with
31     libz or libbz2 and the ability to link pcretest with libreadline have been
32     added. Also the --line-offsets and --file-offsets options were added to
33     pcregrep.
34    
35    
36 ph10 260 Release 7.4 21-Sep-07
37 ph10 242 ---------------------
38    
39 ph10 243 The only change of specification is the addition of options to control whether
40 ph10 242 \R matches any Unicode line ending (the default) or just CR, LF, and CRLF.
41 ph10 243 Otherwise, the changes are bug fixes and a refactoring to reduce the number of
42 ph10 261 relocations needed in a shared library. There have also been some documentation
43     updates, in particular, some more information about using CMake to build PCRE
44     has been added to the NON-UNIX-USE file.
45 ph10 242
46    
47 ph10 228 Release 7.3 28-Aug-07
48 ph10 212 ---------------------
49    
50     Most changes are bug fixes. Some that are not:
51    
52     1. There is some support for Perl 5.10's experimental "backtracking control
53     verbs" such as (*PRUNE).
54    
55     2. UTF-8 checking is now as per RFC 3629 instead of RFC 2279; this is more
56     restrictive in the strings it accepts.
57    
58     3. Checking for potential integer overflow has been made more dynamic, and as a
59     consequence there is no longer a hard limit on the size of a subpattern that
60     has a limited repeat count.
61 ph10 227
62     4. When CRLF is a valid line-ending sequence, pcre_exec() and pcre_dfa_exec()
63     no longer advance by two characters instead of one when an unanchored match
64     fails at CRLF if there are explicit CR or LF matches within the pattern.
65 ph10 226 This gets rid of some anomalous effects that previously occurred.
66 ph10 212
67 ph10 227 5. Some PCRE-specific settings for varying the newline options at the start of
68     a pattern have been added.
69 ph10 212
70 ph10 227
71 ph10 184 Release 7.2 19-Jun-07
72 ph10 157 ---------------------
73    
74 ph10 172 WARNING: saved patterns that were compiled by earlier versions of PCRE must be
75 ph10 181 recompiled for use with 7.2 (necessitated by the addition of \K, \h, \H, \v,
76     and \V).
77 ph10 168
78 ph10 159 Correction to the notes for 7.1: the note about shared libraries for Windows is
79     wrong. Previously, three libraries were built, but each could function
80     independently. For example, the pcreposix library also included all the
81     functions from the basic pcre library. The change is that the three libraries
82     are no longer independent. They are like the Unix libraries. To use the
83     pcreposix functions, for example, you need to link with both the pcreposix and
84 ph10 157 the basic pcre library.
85    
86 ph10 166 Some more features from Perl 5.10 have been added:
87 ph10 157
88 ph10 166 (?-n) and (?+n) relative references for recursion and subroutines.
89 ph10 172
90     (?(-n) and (?(+n) relative references as conditions.
91 ph10 182
92 ph10 181 \k{name} and \g{name} are synonyms for \k<name>.
93 ph10 172
94 ph10 168 \K to reset the start of the matched string; for example, (foo)\Kbar
95 ph10 175 matches bar preceded by foo, but only sets bar as the matched string.
96 ph10 182
97     (?| introduces a group where the capturing parentheses in each alternative
98     start from the same number; for example, (?|(abc)|(xyz)) sets capturing
99 ph10 175 parentheses number 1 in both cases.
100 ph10 166
101 ph10 182 \h, \H, \v, \V match horizontal and vertical whitespace, respectively.
102 ph10 166
103 ph10 182
104 ph10 155 Release 7.1 24-Apr-07
105 nigel 93 ---------------------
106    
107 ph10 155 There is only one new feature in this release: a linebreak setting of
108     PCRE_NEWLINE_ANYCRLF. It is a cut-down version of PCRE_NEWLINE_ANY, which
109     recognizes only CRLF, CR, and LF as linebreaks.
110 ph10 122
111 ph10 155 A few bugs are fixed (see ChangeLog for details), but the major change is a
112     complete re-implementation of the build system. This now has full Autotools
113     support and so is now "standard" in some sense. It should help with compiling
114     PCRE in a wide variety of environments.
115    
116 ph10 146 NOTE: when building shared libraries for Windows, three dlls are now built,
117     called libpcre, libpcreposix, and libpcrecpp. Previously, everything was
118     included in a single dll.
119    
120     Another important change is that the dftables auxiliary program is no longer
121 ph10 128 compiled and run at "make" time by default. Instead, a default set of character
122     tables (assuming ASCII coding) is used. If you want to use dftables to generate
123     the character tables as previously, add --enable-rebuild-chartables to the
124     "configure" command. You must do this if you are compiling PCRE to run on a
125     system that uses EBCDIC code.
126 ph10 122
127 ph10 128 There is a discussion about character tables in the README file. The default is
128     not to use dftables so that that there is no problem when cross-compiling.
129    
130    
131 ph10 122 Release 7.0 19-Dec-06
132     ---------------------
133    
134 nigel 93 This release has a new major number because there have been some internal
135     upheavals to facilitate the addition of new optimizations and other facilities,
136     and to make subsequent maintenance and extension easier. Compilation is likely
137     to be a bit slower, but there should be no major effect on runtime performance.
138     Previously compiled patterns are NOT upwards compatible with this release. If
139     you have saved compiled patterns from a previous release, you will have to
140     re-compile them. Important changes that are visible to users are:
141    
142     1. The Unicode property tables have been updated to Unicode 5.0.0, which adds
143     some more scripts.
144    
145     2. The option PCRE_NEWLINE_ANY causes PCRE to recognize any Unicode newline
146     sequence as a newline.
147    
148     3. The \R escape matches a single Unicode newline sequence as a single unit.
149    
150     4. New features that will appear in Perl 5.10 are now in PCRE. These include
151     alternative Perl syntax for named parentheses, and Perl syntax for
152     recursion.
153    
154     5. The C++ wrapper interface has been extended by the addition of a
155     QuoteMeta function and the ability to allow copy construction and
156     assignment.
157    
158     For a complete list of changes, see the ChangeLog file.
159    
160    
161 nigel 91 Release 6.7 04-Jul-06
162     ---------------------
163    
164     The main additions to this release are the ability to use the same name for
165     multiple sets of parentheses, and support for CRLF line endings in both the
166     library and pcregrep (and in pcretest for testing).
167    
168     Thanks to Ian Taylor, the stack usage for many kinds of pattern has been
169     significantly reduced for certain subject strings.
170    
171    
172 nigel 87 Release 6.5 01-Feb-06
173     ---------------------
174    
175     Important changes in this release:
176    
177     1. A number of new features have been added to pcregrep.
178    
179     2. The Unicode property tables have been updated to Unicode 4.1.0, and the
180     supported properties have been extended with script names such as "Arabic",
181     and the derived properties "Any" and "L&". This has necessitated a change to
182     the interal format of compiled patterns. Any saved compiled patterns that
183     use \p or \P must be recompiled.
184    
185     3. The specification of recursion in patterns has been changed so that all
186     recursive subpatterns are automatically treated as atomic groups. Thus, for
187     example, (?R) is treated as if it were (?>(?R)). This is necessary because
188     otherwise there are situations where recursion does not work.
189    
190     See the ChangeLog for a complete list of changes, which include a number of bug
191     fixes and tidies.
192    
193    
194 nigel 77 Release 6.0 07-Jun-05
195     ---------------------
196    
197     The release number has been increased to 6.0 because of the addition of several
198     major new pieces of functionality.
199    
200     A new function, pcre_dfa_exec(), which implements pattern matching using a DFA
201     algorithm, has been added. This has a number of advantages for certain cases,
202     though it does run more slowly, and lacks the ability to capture substrings. On
203     the other hand, it does find all matches, not just the first, and it works
204     better for partial matching. The pcrematching man page discusses the
205     differences.
206    
207     The pcretest program has been enhanced so that it can make use of the new
208     pcre_dfa_exec() matching function and the extra features it provides.
209    
210     The distribution now includes a C++ wrapper library. This is built
211     automatically if a C++ compiler is found. The pcrecpp man page discusses this
212     interface.
213    
214     The code itself has been re-organized into many more files, one for each
215     function, so it no longer requires everything to be linked in when static
216     linkage is used. As a consequence, some internal functions have had to have
217     their names exposed. These functions all have names starting with _pcre_. They
218     are undocumented, and are not intended for use by outside callers.
219    
220     The pcregrep program has been enhanced with new functionality such as
221     multiline-matching and options for output more matching context. See the
222     ChangeLog for a complete list of changes to the library and the utility
223     programs.
224    
225    
226 nigel 75 Release 5.0 13-Sep-04
227     ---------------------
228    
229     The licence under which PCRE is released has been changed to the more
230     conventional "BSD" licence.
231    
232     In the code, some bugs have been fixed, and there are also some major changes
233     in this release (which is why I've increased the number to 5.0). Some changes
234     are internal rearrangements, and some provide a number of new facilities. The
235     new features are:
236    
237     1. There's an "automatic callout" feature that inserts callouts before every
238     item in the regex, and there's a new callout field that gives the position
239     in the pattern - useful for debugging and tracing.
240    
241     2. The extra_data structure can now be used to pass in a set of character
242     tables at exec time. This is useful if compiled regex are saved and re-used
243     at a later time when the tables may not be at the same address. If the
244     default internal tables are used, the pointer saved with the compiled
245     pattern is now set to NULL, which means that you don't need to do anything
246     special unless you are using custom tables.
247    
248     3. It is possible, with some restrictions on the content of the regex, to
249     request "partial" matching. A special return code is given if all of the
250     subject string matched part of the regex. This could be useful for testing
251     an input field as it is being typed.
252    
253     4. There is now some optional support for Unicode character properties, which
254     means that the patterns items such as \p{Lu} and \X can now be used. Only
255     the general category properties are supported. If PCRE is compiled with this
256     support, an additional 90K data structure is include, which increases the
257     size of the library dramatically.
258    
259     5. There is support for saving compiled patterns and re-using them later.
260    
261     6. There is support for running regular expressions that were compiled on a
262     different host with the opposite endianness.
263    
264     7. The pcretest program has been extended to accommodate the new features.
265    
266     The main internal rearrangement is that sequences of literal characters are no
267     longer handled as strings. Instead, each character is handled on its own. This
268     makes some UTF-8 handling easier, and makes the support of partial matching
269     possible. Compiled patterns containing long literal strings will be larger as a
270     result of this change; I hope that performance will not be much affected.
271    
272    
273 nigel 73 Release 4.5 01-Dec-03
274     ---------------------
275    
276     Again mainly a bug-fix and tidying release, with only a couple of new features:
277    
278     1. It's possible now to compile PCRE so that it does not use recursive
279     function calls when matching. Instead it gets memory from the heap. This slows
280     things down, but may be necessary on systems with limited stacks.
281    
282     2. UTF-8 string checking has been tightened to reject overlong sequences and to
283     check that a starting offset points to the start of a character. Failure of the
284     latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.
285    
286     3. PCRE can now be compiled for systems that use EBCDIC code.
287    
288    
289 nigel 71 Release 4.4 21-Aug-03
290     ---------------------
291    
292     This is mainly a bug-fix and tidying release. The only new feature is that PCRE
293     checks UTF-8 strings for validity by default. There is an option to suppress
294     this, just in case anybody wants that teeny extra bit of performance.
295    
296    
297     Releases 4.1 - 4.3
298     ------------------
299    
300     Sorry, I forgot about updating the NEWS file for these releases. Please take a
301     look at ChangeLog.
302    
303    
304 nigel 63 Release 4.0 17-Feb-03
305     ---------------------
306    
307     There have been a lot of changes for the 4.0 release, adding additional
308     functionality and mending bugs. Below is a list of the highlights of the new
309     functionality. For full details of these features, please consult the
310     documentation. For a complete list of changes, see the ChangeLog file.
311    
312     1. Support for Perl's \Q...\E escapes.
313    
314     2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
315     package. They provide some syntactic sugar for simple cases of "atomic
316     grouping".
317    
318     3. Support for the \G assertion. It is true when the current matching position
319     is at the start point of the match.
320    
321     4. A new feature that provides some of the functionality that Perl provides
322     with (?{...}). The facility is termed a "callout". The way it is done in PCRE
323     is for the caller to provide an optional function, by setting pcre_callout to
324     its entry point. To get the function called, the regex must include (?C) at
325     appropriate points.
326    
327     5. Support for recursive calls to individual subpatterns. This makes it really
328     easy to get totally confused.
329    
330     6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
331     name a group.
332    
333     7. Several extensions to UTF-8 support; it is now fairly complete. There is an
334     option for pcregrep to make it operate in UTF-8 mode.
335    
336     8. The single man page has been split into a number of separate man pages.
337     These also give rise to individual HTML pages which are put in a separate
338     directory. There is an index.html page that lists them all. Some hyperlinking
339     between the pages has been installed.
340    
341    
342 nigel 53 Release 3.5 15-Aug-01
343     ---------------------
344    
345     1. The configuring system has been upgraded to use later versions of autoconf
346     and libtool. By default it builds both a shared and a static library if the OS
347     supports it. You can use --disable-shared or --disable-static on the configure
348     command if you want only one of them.
349    
350     2. The pcretest utility is now installed along with pcregrep because it is
351     useful for users (to test regexs) and by doing this, it automatically gets
352     relinked by libtool. The documentation has been turned into a man page, so
353     there are now .1, .txt, and .html versions in /doc.
354    
355     3. Upgrades to pcregrep:
356     (i) Added long-form option names like gnu grep.
357     (ii) Added --help to list all options with an explanatory phrase.
358     (iii) Added -r, --recursive to recurse into sub-directories.
359     (iv) Added -f, --file to read patterns from a file.
360    
361     4. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
362     script, to force use of CR or LF instead of \n in the source. On non-Unix
363     systems, the value can be set in config.h.
364    
365     5. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
366     absolute limit. Changed the text of the error message to make this clear, and
367     likewise updated the man page.
368    
369     6. The limit of 99 on the number of capturing subpatterns has been removed.
370     The new limit is 65535, which I hope will not be a "real" limit.
371    
372    
373 nigel 49 Release 3.3 01-Aug-00
374     ---------------------
375    
376     There is some support for UTF-8 character strings. This is incomplete and
377     experimental. The documentation describes what is and what is not implemented.
378     Otherwise, this is just a bug-fixing release.
379    
380    
381 nigel 43 Release 3.0 01-Feb-00
382     ---------------------
383 nigel 41
384 nigel 43 1. A "configure" script is now used to configure PCRE for Unix systems. It
385     builds a Makefile, a config.h file, and the pcre-config script.
386    
387     2. PCRE is built as a shared library by default.
388    
389     3. There is support for POSIX classes such as [:alpha:].
390    
391     5. There is an experimental recursion feature.
392    
393 nigel 41 ----------------------------------------------------------------------------
394     IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00
395    
396     Please note that there has been a change in the API such that a larger
397     ovector is required at matching time, to provide some additional workspace.
398     The new man page has details. This change was necessary in order to support
399     some of the new functionality in Perl 5.005.
400    
401     IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.00
402    
403     Another (I hope this is the last!) change has been made to the API for the
404     pcre_compile() function. An additional argument has been added to make it
405     possible to pass over a pointer to character tables built in the current
406     locale by pcre_maketables(). To use the default tables, this new arguement
407     should be passed as NULL.
408    
409     IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.05
410    
411     Yet another (and again I hope this really is the last) change has been made
412     to the API for the pcre_exec() function. An additional argument has been
413     added to make it possible to start the match other than at the start of the
414     subject string. This is important if there are lookbehinds. The new man
415     page has the details, but you just want to convert existing programs, all
416     you need to do is to stick in a new fifth argument to pcre_exec(), with a
417     value of zero. For example, change
418    
419     pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
420     to
421     pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)
422    
423     ****

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