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Revision 226 - (hide annotations) (download)
Tue Aug 21 11:46:08 2007 UTC (7 years, 7 months ago) by ph10
File size: 15816 byte(s)
Don't advance by 2 if explicit \r or \n in the pattern. Add 

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


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