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Revision 178 - (show annotations) (download)
Wed Jun 13 08:44:34 2007 UTC (6 years, 10 months ago) by ph10
File size: 129536 byte(s)
Add support for \h, \H, \v, \V.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 7.2 05-June-07
5 ---------------------
6
7 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
8 which is apparently normally available under Windows.
9
10 2. Re-jig the pcregrep tests with different newline settings in an attempt
11 to make them independent of the local environment's newline setting.
12
13 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
14
15 4. Some of the "internals" tests were previously cut out when the link size
16 was not 2, because the output contained actual offsets. The recent new
17 "Z" feature of pcretest means that these can be cut out, making the tests
18 usable with all link sizes.
19
20 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
21 stack recursion. This gives a massive performance boost under BSD, but just
22 a small improvement under Linux. However, it saves one field in the frame
23 in all cases.
24
25 6. Added more features from the forthcoming Perl 5.10:
26
27 (a) (?-n) (where n is a string of digits) is a relative subroutine or
28 recursion call. It refers to the nth most recently opened parentheses.
29
30 (b) (?+n) is also a relative subroutine call; it refers to the nth next
31 to be opened parentheses.
32
33 (c) Conditions that refer to capturing parentheses can be specified
34 relatively, for example, (?(-2)... or (?(+3)...
35
36 (d) \K resets the start of the current match so that everything before
37 is not part of it.
38
39 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
40
41 (f) \g{name} is another synonym - part of Perl 5.10's unification of
42 reference syntax.
43
44 (g) (?| introduces a group in which the numbering of parentheses in each
45 alternative starts with the same number.
46
47 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
48
49 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
50 PCRE_INFO_JCHANGED.
51
52 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
53 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
54 for detecting groups that can match an empty string.
55
56 9. A pattern with a very large number of alternatives (more than several
57 hundred) was running out of internal workspace during the pre-compile
58 phase, where pcre_compile() figures out how much memory will be needed. A
59 bit of new cunning has reduced the workspace needed for groups with
60 alternatives. The 1000-alternative test pattern now uses 12 bytes of
61 workspace instead of running out of the 4096 that are available.
62
63 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
64
65
66 Version 7.1 24-Apr-07
67 ---------------------
68
69 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
70 that is more "standard", making use of automake and other Autotools. There
71 is some re-arrangement of the files and adjustment of comments consequent
72 on this.
73
74 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
75 for recursive directory scanning broke on some systems because the files
76 are not scanned in any specific order and on different systems the order
77 was different. A call to "sort" has been inserted into RunGrepTest for the
78 approprate test as a short-term fix. In the longer term there may be an
79 alternative.
80
81 3. I had an email from Eric Raymond about problems translating some of PCRE's
82 man pages to HTML (despite the fact that I distribute HTML pages, some
83 people do their own conversions for various reasons). The problems
84 concerned the use of low-level troff macros .br and .in. I have therefore
85 removed all such uses from the man pages (some were redundant, some could
86 be replaced by .nf/.fi pairs). The 132html script that I use to generate
87 HTML has been updated to handle .nf/.fi and to complain if it encounters
88 .br or .in.
89
90 4. Updated comments in configure.ac that get placed in config.h.in and also
91 arranged for config.h to be included in the distribution, with the name
92 config.h.generic, for the benefit of those who have to compile without
93 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
94
95 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
96 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
97 makevp.bat for the current PCRE, using the additional files
98 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
99
100 6. A Windows user reported a minor discrepancy with test 2, which turned out
101 to be caused by a trailing space on an input line that had got lost in his
102 copy. The trailing space was an accident, so I've just removed it.
103
104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
105 that is needed.
106
107 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
108 as "const" (a) because they are and (b) because it helps the PHP
109 maintainers who have recently made a script to detect big data structures
110 in the php code that should be moved to the .rodata section. I remembered
111 to update Builducptable as well, so it won't revert if ucptable.h is ever
112 re-created.
113
114 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
115 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
116 order to be able to cut out the UTF-8 tables in the latter when UTF-8
117 support is not required. This saves 1.5-2K of code, which is important in
118 some applications.
119
120 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
121 so as not to refer to the tables, even though these functions will never be
122 called when UTF-8 support is disabled. Otherwise there are problems with a
123 shared library.
124
125 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
126
127 (a) It was defining its arguments as char * instead of void *.
128
129 (b) It was assuming that all moves were upwards in memory; this was true
130 a long time ago when I wrote it, but is no longer the case.
131
132 The emulated memove() is provided for those environments that have neither
133 memmove() nor bcopy(). I didn't think anyone used it these days, but that
134 is clearly not the case, as these two bugs were recently reported.
135
136 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
137 and Detrail to create the HTML documentation, the .txt form of the man
138 pages, and it removes trailing spaces from listed files. It also creates
139 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
140 case, it wraps all the #defines with #ifndefs. This script should be run
141 before "make dist".
142
143 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
144 with Unicode property support.
145
146 (a) For a maximizing quantifier, if the two different cases of the
147 character were of different lengths in their UTF-8 codings (there are
148 some cases like this - I found 11), and the matching function had to
149 back up over a mixture of the two cases, it incorrectly assumed they
150 were both the same length.
151
152 (b) When PCRE was configured to use the heap rather than the stack for
153 recursion during matching, it was not correctly preserving the data for
154 the other case of a UTF-8 character when checking ahead for a match
155 while processing a minimizing repeat. If the check also involved
156 matching a wide character, but failed, corruption could cause an
157 erroneous result when trying to check for a repeat of the original
158 character.
159
160 13. Some tidying changes to the testing mechanism:
161
162 (a) The RunTest script now detects the internal link size and whether there
163 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
164 values substituted by "configure". (The RunGrepTest script already did
165 this for UTF-8.) The configure.ac script no longer substitutes the
166 relevant variables.
167
168 (b) The debugging options /B and /D in pcretest show the compiled bytecode
169 with length and offset values. This means that the output is different
170 for different internal link sizes. Test 2 is skipped for link sizes
171 other than 2 because of this, bypassing the problem. Unfortunately,
172 there was also a test in test 3 (the locale tests) that used /B and
173 failed for link sizes other than 2. Rather than cut the whole test out,
174 I have added a new /Z option to pcretest that replaces the length and
175 offset values with spaces. This is now used to make test 3 independent
176 of link size. (Test 2 will be tidied up later.)
177
178 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
179 segmentation fault instead of returning the appropriate error message.
180
181 15. In multiline mode when the newline sequence was set to "any", the pattern
182 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
183 This doesn't seem right; it now treats the CRLF combination as the line
184 ending, and so does not match in that case. It's only a pattern such as ^$
185 that would hit this one: something like ^ABC$ would have failed after \r
186 and then tried again after \r\n.
187
188 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
189 in an attempt to make files that differ only in their line terminators
190 compare equal. This works on Linux.
191
192 17. Under certain error circumstances pcregrep might try to free random memory
193 as it exited. This is now fixed, thanks to valgrind.
194
195 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
196 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
197 was because its rules for how to advance for /g after matching an empty
198 string at the end of a line did not allow for this case. They now check for
199 it specially.
200
201 20. pcretest is supposed to handle patterns and data of any length, by
202 extending its buffers when necessary. It was getting this wrong when the
203 buffer for a data line had to be extended.
204
205 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
206 CRLF as a newline sequence.
207
208 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
209 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
210 I have nevertheless tidied it up.
211
212 23. Added some casts to kill warnings from HP-UX ia64 compiler.
213
214 24. Added a man page for pcre-config.
215
216
217 Version 7.0 19-Dec-06
218 ---------------------
219
220 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
221 moving to gcc 4.1.1.
222
223 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
224 sys/time.h, which is documented as needed for this function. It doesn't
225 seem to matter on Linux, but it showed up on some releases of OS X.
226
227 3. It seems that there are systems where bytes whose values are greater than
228 127 match isprint() in the "C" locale. The "C" locale should be the
229 default when a C program starts up. In most systems, only ASCII printing
230 characters match isprint(). This difference caused the output from pcretest
231 to vary, making some of the tests fail. I have changed pcretest so that:
232
233 (a) When it is outputting text in the compiled version of a pattern, bytes
234 other than 32-126 are always shown as hex escapes.
235
236 (b) When it is outputting text that is a matched part of a subject string,
237 it does the same, unless a different locale has been set for the match
238 (using the /L modifier). In this case, it uses isprint() to decide.
239
240 4. Fixed a major bug that caused incorrect computation of the amount of memory
241 required for a compiled pattern when options that changed within the
242 pattern affected the logic of the preliminary scan that determines the
243 length. The relevant options are -x, and -i in UTF-8 mode. The result was
244 that the computed length was too small. The symptoms of this bug were
245 either the PCRE error "internal error: code overflow" from pcre_compile(),
246 or a glibc crash with a message such as "pcretest: free(): invalid next
247 size (fast)". Examples of patterns that provoked this bug (shown in
248 pcretest format) are:
249
250 /(?-x: )/x
251 /(?x)(?-x: \s*#\s*)/
252 /((?i)[\x{c0}])/8
253 /(?i:[\x{c0}])/8
254
255 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
256 is now done differently.
257
258 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
259 wrapper classes; (b) implement a new function in the C++ scanner that is
260 more efficient than the old way of doing things because it avoids levels of
261 recursion in the regex matching; (c) add a paragraph to the documentation
262 for the FullMatch() function.
263
264 6. The escape sequence \n was being treated as whatever was defined as
265 "newline". Not only was this contrary to the documentation, which states
266 that \n is character 10 (hex 0A), but it also went horribly wrong when
267 "newline" was defined as CRLF. This has been fixed.
268
269 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
270 was being set to -1 for the "end of line" case (supposedly a value that no
271 character can have). Though this value is never used (the check for end of
272 line is "zero bytes in current character"), it caused compiler complaints.
273 I've changed it to 0xffffffff.
274
275 8. In pcre_version.c, the version string was being built by a sequence of
276 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
277 string (as it is for production releases) called a macro with an empty
278 argument. The C standard says the result of this is undefined. The gcc
279 compiler treats it as an empty string (which was what was wanted) but it is
280 reported that Visual C gives an error. The source has been hacked around to
281 avoid this problem.
282
283 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
284 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
285 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
286 of them did).
287
288 10. Originally, pcretest opened its input and output without "b"; then I was
289 told that "b" was needed in some environments, so it was added for release
290 5.0 to both the input and output. (It makes no difference on Unix-like
291 systems.) Later I was told that it is wrong for the input on Windows. I've
292 now abstracted the modes into two macros, to make it easier to fiddle with
293 them, and removed "b" from the input mode under Windows.
294
295 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
296
297 12. Added -help and --help to pcretest as an official way of being reminded
298 of the options.
299
300 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
301 and pcrecpp.cc because they annoy compilers at high warning levels.
302
303 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
304
305 15. Fixed an occurrence of == in configure.ac that should have been = (shell
306 scripts are not C programs :-) and which was not noticed because it works
307 on Linux.
308
309 16. pcretest is supposed to handle any length of pattern and data line (as one
310 line or as a continued sequence of lines) by extending its input buffer if
311 necessary. This feature was broken for very long pattern lines, leading to
312 a string of junk being passed to pcre_compile() if the pattern was longer
313 than about 50K.
314
315 17. I have done a major re-factoring of the way pcre_compile() computes the
316 amount of memory needed for a compiled pattern. Previously, there was code
317 that made a preliminary scan of the pattern in order to do this. That was
318 OK when PCRE was new, but as the facilities have expanded, it has become
319 harder and harder to keep it in step with the real compile phase, and there
320 have been a number of bugs (see for example, 4 above). I have now found a
321 cunning way of running the real compile function in a "fake" mode that
322 enables it to compute how much memory it would need, while actually only
323 ever using a few hundred bytes of working memory and without too many
324 tests of the mode. This should make future maintenance and development
325 easier. A side effect of this work is that the limit of 200 on the nesting
326 depth of parentheses has been removed (though this was never a serious
327 limitation, I suspect). However, there is a downside: pcre_compile() now
328 runs more slowly than before (30% or more, depending on the pattern). I
329 hope this isn't a big issue. There is no effect on runtime performance.
330
331 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
332 newline (only possible for the last line of a file) and it was a
333 pattern that set a locale (followed by /Lsomething), pcretest crashed.
334
335 19. Added additional timing features to pcretest. (1) The -tm option now times
336 matching only, not compiling. (2) Both -t and -tm can be followed, as a
337 separate command line item, by a number that specifies the number of
338 repeats to use when timing. The default is 50000; this gives better
339 precision, but takes uncomfortably long for very large patterns.
340
341 20. Extended pcre_study() to be more clever in cases where a branch of a
342 subpattern has no definite first character. For example, (a*|b*)[cd] would
343 previously give no result from pcre_study(). Now it recognizes that the
344 first character must be a, b, c, or d.
345
346 21. There was an incorrect error "recursive call could loop indefinitely" if
347 a subpattern (or the entire pattern) that was being tested for matching an
348 empty string contained only one non-empty item after a nested subpattern.
349 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
350 incorrectly, because the \d was being skipped in the check.
351
352 22. The pcretest program now has a new pattern option /B and a command line
353 option -b, which is equivalent to adding /B to every pattern. This causes
354 it to show the compiled bytecode, without the additional information that
355 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
356 is the same as /B/I).
357
358 23. A new optimization is now able automatically to treat some sequences such
359 as a*b as a*+b. More specifically, if something simple (such as a character
360 or a simple class like \d) has an unlimited quantifier, and is followed by
361 something that cannot possibly match the quantified thing, the quantifier
362 is automatically "possessified".
363
364 24. A recursive reference to a subpattern whose number was greater than 39
365 went wrong under certain circumstances in UTF-8 mode. This bug could also
366 have affected the operation of pcre_study().
367
368 25. Realized that a little bit of performance could be had by replacing
369 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
370
371 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
372
373 27. Possessive quantifiers such as a++ were previously implemented by turning
374 them into atomic groups such as ($>a+). Now they have their own opcodes,
375 which improves performance. This includes the automatically created ones
376 from 23 above.
377
378 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
379 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
380 the first matched character to be a colon. This applied both to named and
381 numbered groups.
382
383 29. The ucpinternal.h header file was missing its idempotency #ifdef.
384
385 30. I was sent a "project" file called libpcre.a.dev which I understand makes
386 building PCRE on Windows easier, so I have included it in the distribution.
387
388 31. There is now a check in pcretest against a ridiculously large number being
389 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
390 loop, the loop is abandoned.
391
392 32. Forward references to subpatterns in conditions such as (?(2)...) where
393 subpattern 2 is defined later cause pcre_compile() to search forwards in
394 the pattern for the relevant set of parentheses. This search went wrong
395 when there were unescaped parentheses in a character class, parentheses
396 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
397
398 33. "Subroutine" calls and backreferences were previously restricted to
399 referencing subpatterns earlier in the regex. This restriction has now
400 been removed.
401
402 34. Added a number of extra features that are going to be in Perl 5.10. On the
403 whole, these are just syntactic alternatives for features that PCRE had
404 previously implemented using the Python syntax or my own invention. The
405 other formats are all retained for compatibility.
406
407 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
408 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
409 also .NET compatible.
410
411 (b) A recursion or subroutine call to a named group can now be defined as
412 (?&name) as well as (?P>name).
413
414 (c) A backreference to a named group can now be defined as \k<name> or
415 \k'name' as well as (?P=name). The new forms, as well as being in Perl
416 5.10, are also .NET compatible.
417
418 (d) A conditional reference to a named group can now use the syntax
419 (?(<name>) or (?('name') as well as (?(name).
420
421 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
422 groups (named and numbered) that are never evaluated inline, but can be
423 called as "subroutines" from elsewhere. In effect, the DEFINE condition
424 is always false. There may be only one alternative in such a group.
425
426 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
427 as the simple (?(R). The condition is true only if the most recent
428 recursion is that of the given number or name. It does not search out
429 through the entire recursion stack.
430
431 (g) The escape \gN or \g{N} has been added, where N is a positive or
432 negative number, specifying an absolute or relative reference.
433
434 35. Tidied to get rid of some further signed/unsigned compiler warnings and
435 some "unreachable code" warnings.
436
437 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
438 things, this adds five new scripts.
439
440 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
441 There were also incompatibilities regarding the handling of \Q..\E inside
442 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
443 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
444
445 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
446 matches an empty string, and forcibly breaks the loop. There were bugs in
447 this code in non-simple cases. For a pattern such as ^(a()*)* matched
448 against aaaa the result was just "a" rather than "aaaa", for example. Two
449 separate and independent bugs (that affected different cases) have been
450 fixed.
451
452 39. Refactored the code to abolish the use of different opcodes for small
453 capturing bracket numbers. This is a tidy that I avoided doing when I
454 removed the limit on the number of capturing brackets for 3.5 back in 2001.
455 The new approach is not only tidier, it makes it possible to reduce the
456 memory needed to fix the previous bug (38).
457
458 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
459 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
460 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
461 mode.
462
463 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
464 report.
465
466 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
467 copy construction and assignment in the C++ wrapper.
468
469 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
470 couple of bugs that could have given wrong results in the "--newline=crlf"
471 case.
472
473 44. Added a number of casts and did some reorganization of signed/unsigned int
474 variables following suggestions from Dair Grant. Also renamed the variable
475 "this" as "item" because it is a C++ keyword.
476
477 45. Arranged for dftables to add
478
479 #include "pcre_internal.h"
480
481 to pcre_chartables.c because without it, gcc 4.x may remove the array
482 definition from the final binary if PCRE is built into a static library and
483 dead code stripping is activated.
484
485 46. For an unanchored pattern, if a match attempt fails at the start of a
486 newline sequence, and the newline setting is CRLF or ANY, and the next two
487 characters are CRLF, advance by two characters instead of one.
488
489
490 Version 6.7 04-Jul-06
491 ---------------------
492
493 1. In order to handle tests when input lines are enormously long, pcretest has
494 been re-factored so that it automatically extends its buffers when
495 necessary. The code is crude, but this _is_ just a test program. The
496 default size has been increased from 32K to 50K.
497
498 2. The code in pcre_study() was using the value of the re argument before
499 testing it for NULL. (Of course, in any sensible call of the function, it
500 won't be NULL.)
501
502 3. The memmove() emulation function in pcre_internal.h, which is used on
503 systems that lack both memmove() and bcopy() - that is, hardly ever -
504 was missing a "static" storage class specifier.
505
506 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
507 containing an extended class (one that cannot be represented by a bitmap
508 because it contains high-valued characters or Unicode property items, e.g.
509 [\pZ]). Almost always one would set UTF-8 mode when processing such a
510 pattern, but PCRE should not loop if you do not (it no longer does).
511 [Detail: two cases were found: (a) a repeated subpattern containing an
512 extended class; (b) a recursive reference to a subpattern that followed a
513 previous extended class. It wasn't skipping over the extended class
514 correctly when UTF-8 mode was not set.]
515
516 5. A negated single-character class was not being recognized as fixed-length
517 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
518 compile error "lookbehind assertion is not fixed length".
519
520 6. The RunPerlTest auxiliary script was showing an unexpected difference
521 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
522 write a Perl script that can interpret lines of an input file either as
523 byte characters or as UTF-8, which is what "perltest" was being required to
524 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
525 can't do is switch easily at run time between having the "use utf8;" pragma
526 or not. In the end, I fudged it by using the RunPerlTest script to insert
527 "use utf8;" explicitly for the UTF-8 tests.
528
529 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
530 the end of the subject string, contrary to the documentation and to what
531 Perl does. This was true of both matching functions. Now it matches only at
532 the start of the subject and immediately after *internal* newlines.
533
534 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
535 a pointer to an int instead of a pointer to an unsigned long int. This
536 caused problems on 64-bit systems.
537
538 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
539 instance of the 'standard' template library not being so standard".
540
541 10. There was no check on the number of named subpatterns nor the maximum
542 length of a subpattern name. The product of these values is used to compute
543 the size of the memory block for a compiled pattern. By supplying a very
544 long subpattern name and a large number of named subpatterns, the size
545 computation could be caused to overflow. This is now prevented by limiting
546 the length of names to 32 characters, and the number of named subpatterns
547 to 10,000.
548
549 11. Subpatterns that are repeated with specific counts have to be replicated in
550 the compiled pattern. The size of memory for this was computed from the
551 length of the subpattern and the repeat count. The latter is limited to
552 65535, but there was no limit on the former, meaning that integer overflow
553 could in principle occur. The compiled length of a repeated subpattern is
554 now limited to 30,000 bytes in order to prevent this.
555
556 12. Added the optional facility to have named substrings with the same name.
557
558 13. Added the ability to use a named substring as a condition, using the
559 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
560 are numbers (not recommended). Forward references are permitted.
561
562 14. Added forward references in named backreferences (if you see what I mean).
563
564 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
565 pattern could run off the end of the subject. For example, the pattern
566 "(?s)(.{1,5})"8 did this with the subject "ab".
567
568 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
569 PCRE_CASELESS was set when matching characters that were quantified with ?
570 or *.
571
572 17. A character class other than a single negated character that had a minimum
573 but no maximum quantifier - for example [ab]{6,} - was not handled
574 correctly by pce_dfa_exec(). It would match only one character.
575
576 18. A valid (though odd) pattern that looked like a POSIX character
577 class but used an invalid character after [ (for example [[,abc,]]) caused
578 pcre_compile() to give the error "Failed: internal error: code overflow" or
579 in some cases to crash with a glibc free() error. This could even happen if
580 the pattern terminated after [[ but there just happened to be a sequence of
581 letters, a binary zero, and a closing ] in the memory that followed.
582
583 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
584 over the years. Originally (before any Unicode support), just the bottom 8
585 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
586 output from "man perlunicode" includes this:
587
588 The regular expression compiler produces polymorphic opcodes. That
589 is, the pattern adapts to the data and automatically switches to
590 the Unicode character scheme when presented with Unicode data--or
591 instead uses a traditional byte scheme when presented with byte
592 data.
593
594 Sadly, a wide octal escape does not cause a switch, and in a string with
595 no other multibyte characters, these octal escapes are treated as before.
596 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
597 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
598 Unicode string.
599
600 I have not perpetrated such confusion in PCRE. Up till now, it took just
601 the bottom 8 bits, as in old Perl. I have now made octal escapes with
602 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
603 translate to the appropriate multibyte character.
604
605 29. Applied some refactoring to reduce the number of warnings from Microsoft
606 and Borland compilers. This has included removing the fudge introduced
607 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
608 a warning about an unused variable.
609
610 21. PCRE has not included VT (character 0x0b) in the set of whitespace
611 characters since release 4.0, because Perl (from release 5.004) does not.
612 [Or at least, is documented not to: some releases seem to be in conflict
613 with the documentation.] However, when a pattern was studied with
614 pcre_study() and all its branches started with \s, PCRE still included VT
615 as a possible starting character. Of course, this did no harm; it just
616 caused an unnecessary match attempt.
617
618 22. Removed a now-redundant internal flag bit that recorded the fact that case
619 dependency changed within the pattern. This was once needed for "required
620 byte" processing, but is no longer used. This recovers a now-scarce options
621 bit. Also moved the least significant internal flag bit to the most-
622 significant bit of the word, which was not previously used (hangover from
623 the days when it was an int rather than a uint) to free up another bit for
624 the future.
625
626 23. Added support for CRLF line endings as well as CR and LF. As well as the
627 default being selectable at build time, it can now be changed at runtime
628 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
629 specify that it is scanning data with non-default line endings.
630
631 24. Changed the definition of CXXLINK to make it agree with the definition of
632 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
633
634 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
635 recursions. This makes a big different to stack usage for some patterns.
636
637 26. If a subpattern containing a named recursion or subroutine reference such
638 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
639 the space required for the compiled pattern went wrong and gave too small a
640 value. Depending on the environment, this could lead to "Failed: internal
641 error: code overflow at offset 49" or "glibc detected double free or
642 corruption" errors.
643
644 27. Applied patches from Google (a) to support the new newline modes and (b) to
645 advance over multibyte UTF-8 characters in GlobalReplace.
646
647 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
648 difference for some implementation of PCRE in some Windows version.
649
650 29. Added some extra testing facilities to pcretest:
651
652 \q<number> in a data line sets the "match limit" value
653 \Q<number> in a data line sets the "match recursion limt" value
654 -S <number> sets the stack size, where <number> is in megabytes
655
656 The -S option isn't available for Windows.
657
658
659 Version 6.6 06-Feb-06
660 ---------------------
661
662 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
663 in pcreposix.h. I have copied the definition from pcre.h.
664
665 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
666 because pcre.h is no longer a built file.
667
668 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
669 not normally included in the compiled code.
670
671
672 Version 6.5 01-Feb-06
673 ---------------------
674
675 1. When using the partial match feature with pcre_dfa_exec(), it was not
676 anchoring the second and subsequent partial matches at the new starting
677 point. This could lead to incorrect results. For example, with the pattern
678 /1234/, partially matching against "123" and then "a4" gave a match.
679
680 2. Changes to pcregrep:
681
682 (a) All non-match returns from pcre_exec() were being treated as failures
683 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
684 error message is output. Some extra information is given for the
685 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
686 probably the only errors that are likely to be caused by users (by
687 specifying a regex that has nested indefinite repeats, for instance).
688 If there are more than 20 of these errors, pcregrep is abandoned.
689
690 (b) A binary zero was treated as data while matching, but terminated the
691 output line if it was written out. This has been fixed: binary zeroes
692 are now no different to any other data bytes.
693
694 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
695 used to set a locale for matching. The --locale=xxxx long option has
696 been added (no short equivalent) to specify a locale explicitly on the
697 pcregrep command, overriding the environment variables.
698
699 (d) When -B was used with -n, some line numbers in the output were one less
700 than they should have been.
701
702 (e) Added the -o (--only-matching) option.
703
704 (f) If -A or -C was used with -c (count only), some lines of context were
705 accidentally printed for the final match.
706
707 (g) Added the -H (--with-filename) option.
708
709 (h) The combination of options -rh failed to suppress file names for files
710 that were found from directory arguments.
711
712 (i) Added the -D (--devices) and -d (--directories) options.
713
714 (j) Added the -F (--fixed-strings) option.
715
716 (k) Allow "-" to be used as a file name for -f as well as for a data file.
717
718 (l) Added the --colo(u)r option.
719
720 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
721 is not present by default.
722
723 3. A nasty bug was discovered in the handling of recursive patterns, that is,
724 items such as (?R) or (?1), when the recursion could match a number of
725 alternatives. If it matched one of the alternatives, but subsequently,
726 outside the recursion, there was a failure, the code tried to back up into
727 the recursion. However, because of the way PCRE is implemented, this is not
728 possible, and the result was an incorrect result from the match.
729
730 In order to prevent this happening, the specification of recursion has
731 been changed so that all such subpatterns are automatically treated as
732 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
733
734 4. I had overlooked the fact that, in some locales, there are characters for
735 which isalpha() is true but neither isupper() nor islower() are true. In
736 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
737 and ordfeminine) are like this. This affected the treatment of \w and \W
738 when they appeared in character classes, but not when they appeared outside
739 a character class. The bit map for "word" characters is now created
740 separately from the results of isalnum() instead of just taking it from the
741 upper, lower, and digit maps. (Plus the underscore character, of course.)
742
743 5. The above bug also affected the handling of POSIX character classes such as
744 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
745 permanent tables. Instead, the bit maps for such a class were previously
746 created as the appropriate unions of the upper, lower, and digit bitmaps.
747 Now they are created by subtraction from the [[:word:]] class, which has
748 its own bitmap.
749
750 6. The [[:blank:]] character class matches horizontal, but not vertical space.
751 It is created by subtracting the vertical space characters (\x09, \x0a,
752 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
753 subtraction was done in the overall bitmap for a character class, meaning
754 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
755 be recognized. This bug has been fixed.
756
757 7. Patches from the folks at Google:
758
759 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
760 real life, but is still worth protecting against".
761
762 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
763 regular expressions".
764
765 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
766 have it.
767
768 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
769 "configure" and the latter not, in order to fix a problem somebody had
770 with compiling the Arg class on HP-UX.
771
772 (e) Improve the error-handling of the C++ wrapper a little bit.
773
774 (f) New tests for checking recursion limiting.
775
776 8. The pcre_memmove() function, which is used only if the environment does not
777 have a standard memmove() function (and is therefore rarely compiled),
778 contained two bugs: (a) use of int instead of size_t, and (b) it was not
779 returning a result (though PCRE never actually uses the result).
780
781 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
782 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
783 returned instead of calling malloc() with an overflowing number that would
784 most likely cause subsequent chaos.
785
786 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
787
788 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
789 with this option is matched, the nmatch and pmatch options of regexec() are
790 ignored.
791
792 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
793 provided in case anyone wants to the the POSIX interface with UTF-8
794 strings.
795
796 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
797 C++ linking (needed for some HP-UX environments).
798
799 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
800 (unused parameter) and in the pcre_printint() function (omitted "default"
801 switch label when the default is to do nothing).
802
803 15. Added some code to make it possible, when PCRE is compiled as a C++
804 library, to replace subject pointers for pcre_exec() with a smart pointer
805 class, thus making it possible to process discontinuous strings.
806
807 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
808 much the same function. They were added by different people who were trying
809 to make PCRE easy to compile on non-Unix systems. It has been suggested
810 that PCRE_EXPORT be abolished now that there is more automatic apparatus
811 for compiling on Windows systems. I have therefore replaced it with
812 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
813 defaults to "extern" for C or "extern C" for C++, which works fine on
814 Unix-like systems. It is now possible to override the value of PCRE_DATA_
815 SCOPE with something explicit in config.h. In addition:
816
817 (a) pcreposix.h still had just "extern" instead of either of these macros;
818 I have replaced it with PCRE_DATA_SCOPE.
819
820 (b) Functions such as _pcre_xclass(), which are internal to the library,
821 but external in the C sense, all had PCRE_EXPORT in their definitions.
822 This is apparently wrong for the Windows case, so I have removed it.
823 (It makes no difference on Unix-like systems.)
824
825 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
826 of recursive calls to match(). This is different to MATCH_LIMIT because
827 that limits the total number of calls to match(), not all of which increase
828 the depth of recursion. Limiting the recursion depth limits the amount of
829 stack (or heap if NO_RECURSE is set) that is used. The default can be set
830 when PCRE is compiled, and changed at run time. A patch from Google adds
831 this functionality to the C++ interface.
832
833 18. Changes to the handling of Unicode character properties:
834
835 (a) Updated the table to Unicode 4.1.0.
836
837 (b) Recognize characters that are not in the table as "Cn" (undefined).
838
839 (c) I revised the way the table is implemented to a much improved format
840 which includes recognition of ranges. It now supports the ranges that
841 are defined in UnicodeData.txt, and it also amalgamates other
842 characters into ranges. This has reduced the number of entries in the
843 table from around 16,000 to around 3,000, thus reducing its size
844 considerably. I realized I did not need to use a tree structure after
845 all - a binary chop search is just as efficient. Having reduced the
846 number of entries, I extended their size from 6 bytes to 8 bytes to
847 allow for more data.
848
849 (d) Added support for Unicode script names via properties such as \p{Han}.
850
851 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
852 matching that character.
853
854 20. When matching a repeated Unicode property with a minimum greater than zero,
855 (for example \pL{2,}), PCRE could look past the end of the subject if it
856 reached it while seeking the minimum number of characters. This could
857 happen only if some of the characters were more than one byte long, because
858 there is a check for at least the minimum number of bytes.
859
860 21. Refactored the implementation of \p and \P so as to be more general, to
861 allow for more different types of property in future. This has changed the
862 compiled form incompatibly. Anybody with saved compiled patterns that use
863 \p or \P will have to recompile them.
864
865 22. Added "Any" and "L&" to the supported property types.
866
867 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
868 but give a compile time error if the value is greater than 0xff.
869
870 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
871 accidentally not being installed or uninstalled.
872
873 25. The pcre.h file was built from pcre.h.in, but the only changes that were
874 made were to insert the current release number. This seemed silly, because
875 it made things harder for people building PCRE on systems that don't run
876 "configure". I have turned pcre.h into a distributed file, no longer built
877 by "configure", with the version identification directly included. There is
878 no longer a pcre.h.in file.
879
880 However, this change necessitated a change to the pcre-config script as
881 well. It is built from pcre-config.in, and one of the substitutions was the
882 release number. I have updated configure.ac so that ./configure now finds
883 the release number by grepping pcre.h.
884
885 26. Added the ability to run the tests under valgrind.
886
887
888 Version 6.4 05-Sep-05
889 ---------------------
890
891 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
892 "--" to be printed when multiple files were scanned, even when none of the
893 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
894 consider it to be a bug, and have restored the previous behaviour.
895
896 2. A couple of code tidies to get rid of compiler warnings.
897
898 3. The pcretest program used to cheat by referring to symbols in the library
899 whose names begin with _pcre_. These are internal symbols that are not
900 really supposed to be visible externally, and in some environments it is
901 possible to suppress them. The cheating is now confined to including
902 certain files from the library's source, which is a bit cleaner.
903
904 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
905 file's purpose clearer.
906
907 5. Reorganized pcre_ucp_findchar().
908
909
910 Version 6.3 15-Aug-05
911 ---------------------
912
913 1. The file libpcre.pc.in did not have general read permission in the tarball.
914
915 2. There were some problems when building without C++ support:
916
917 (a) If C++ support was not built, "make install" and "make test" still
918 tried to test it.
919
920 (b) There were problems when the value of CXX was explicitly set. Some
921 changes have been made to try to fix these, and ...
922
923 (c) --disable-cpp can now be used to explicitly disable C++ support.
924
925 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
926 backslash in a target when C++ was disabled. This confuses some
927 versions of "make", apparently. Using an intermediate variable solves
928 this. (Same for CPP_LOBJ.)
929
930 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
931 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
932 necessary on certain architectures.
933
934 4. Added a setting of -export-symbols-regex to the link command to remove
935 those symbols that are exported in the C sense, but actually are local
936 within the library, and not documented. Their names all begin with
937 "_pcre_". This is not a perfect job, because (a) we have to except some
938 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
939 available (and never for static libraries). I have made a note to try to
940 find a way round (a) in the future.
941
942
943 Version 6.2 01-Aug-05
944 ---------------------
945
946 1. There was no test for integer overflow of quantifier values. A construction
947 such as {1111111111111111} would give undefined results. What is worse, if
948 a minimum quantifier for a parenthesized subpattern overflowed and became
949 negative, the calculation of the memory size went wrong. This could have
950 led to memory overwriting.
951
952 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
953
954 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
955 operating environments where this matters.
956
957 4. Applied Giuseppe Maxia's patch to add additional features for controlling
958 PCRE options from within the C++ wrapper.
959
960 5. Named capturing subpatterns were not being correctly counted when a pattern
961 was compiled. This caused two problems: (a) If there were more than 100
962 such subpatterns, the calculation of the memory needed for the whole
963 compiled pattern went wrong, leading to an overflow error. (b) Numerical
964 back references of the form \12, where the number was greater than 9, were
965 not recognized as back references, even though there were sufficient
966 previous subpatterns.
967
968 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
969 versions of gcc, e.g. 2.95.4.
970
971
972 Version 6.1 21-Jun-05
973 ---------------------
974
975 1. There was one reference to the variable "posix" in pcretest.c that was not
976 surrounded by "#if !defined NOPOSIX".
977
978 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
979 the cross-check on the old pcre_info() function, for the benefit of the
980 cut-down version of PCRE that is currently imported into Exim.
981
982 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
983 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
984 patterns that start (?i) but I don't think that matters. The use of (?i) is
985 just an example; this all applies to the other options as well.
986
987 4. Since libtool seems to echo the compile commands it is issuing, the output
988 from "make" can be reduced a bit by putting "@" in front of each libtool
989 compile command.
990
991 5. Patch from the folks at Google for configure.in to be a bit more thorough
992 in checking for a suitable C++ installation before trying to compile the
993 C++ stuff. This should fix a reported problem when a compiler was present,
994 but no suitable headers.
995
996 6. The man pages all had just "PCRE" as their title. I have changed them to
997 be the relevant file name. I have also arranged that these names are
998 retained in the file doc/pcre.txt, which is a concatenation in text format
999 of all the man pages except the little individual ones for each function.
1000
1001 7. The NON-UNIX-USE file had not been updated for the different set of source
1002 files that come with release 6. I also added a few comments about the C++
1003 wrapper.
1004
1005
1006 Version 6.0 07-Jun-05
1007 ---------------------
1008
1009 1. Some minor internal re-organization to help with my DFA experiments.
1010
1011 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1012 didn't matter for the library itself when fully configured, but did matter
1013 when compiling without UCP support, or within Exim, where the ucp files are
1014 not imported.
1015
1016 3. Refactoring of the library code to split up the various functions into
1017 different source modules. The addition of the new DFA matching code (see
1018 below) to a single monolithic source would have made it really too
1019 unwieldy, quite apart from causing all the code to be include in a
1020 statically linked application, when only some functions are used. This is
1021 relevant even without the DFA addition now that patterns can be compiled in
1022 one application and matched in another.
1023
1024 The downside of splitting up is that there have to be some external
1025 functions and data tables that are used internally in different modules of
1026 the library but which are not part of the API. These have all had their
1027 names changed to start with "_pcre_" so that they are unlikely to clash
1028 with other external names.
1029
1030 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1031 a different (DFA) algorithm. Although it is slower than the original
1032 function, it does have some advantages for certain types of matching
1033 problem.
1034
1035 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1036 including restarting after a partial match.
1037
1038 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1039 defined when compiling for Windows was sent to me. I have put it into the
1040 code, though I have no means of testing or verifying it.
1041
1042 7. Added the pcre_refcount() auxiliary function.
1043
1044 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1045 match before or at the first newline in the subject string. In pcretest,
1046 the /f option on a pattern can be used to set this.
1047
1048 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1049 would behave wrongly. This has been present in PCRE since release 4.0.
1050
1051 10. A number of changes to the pcregrep command:
1052
1053 (a) Refactored how -x works; insert ^(...)$ instead of setting
1054 PCRE_ANCHORED and checking the length, in preparation for adding
1055 something similar for -w.
1056
1057 (b) Added the -w (match as a word) option.
1058
1059 (c) Refactored the way lines are read and buffered so as to have more
1060 than one at a time available.
1061
1062 (d) Implemented a pcregrep test script.
1063
1064 (e) Added the -M (multiline match) option. This allows patterns to match
1065 over several lines of the subject. The buffering ensures that at least
1066 8K, or the rest of the document (whichever is the shorter) is available
1067 for matching (and similarly the previous 8K for lookbehind assertions).
1068
1069 (f) Changed the --help output so that it now says
1070
1071 -w, --word-regex(p)
1072
1073 instead of two lines, one with "regex" and the other with "regexp"
1074 because that confused at least one person since the short forms are the
1075 same. (This required a bit of code, as the output is generated
1076 automatically from a table. It wasn't just a text change.)
1077
1078 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1079 option but starts with a hyphen. Could be a pattern or a path name
1080 starting with a hyphen, for instance.
1081
1082 (h) "-" can be given as a file name to represent stdin.
1083
1084 (i) When file names are being printed, "(standard input)" is used for
1085 the standard input, for compatibility with GNU grep. Previously
1086 "<stdin>" was used.
1087
1088 (j) The option --label=xxx can be used to supply a name to be used for
1089 stdin when file names are being printed. There is no short form.
1090
1091 (k) Re-factored the options decoding logic because we are going to add
1092 two more options that take data. Such options can now be given in four
1093 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1094
1095 (l) Added the -A, -B, and -C options for requesting that lines of context
1096 around matches be printed.
1097
1098 (m) Added the -L option to print the names of files that do not contain
1099 any matching lines, that is, the complement of -l.
1100
1101 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1102 continue to scan other files.
1103
1104 (o) The -s option was incorrectly implemented. For compatibility with other
1105 greps, it now suppresses the error message for a non-existent or non-
1106 accessible file (but not the return code). There is a new option called
1107 -q that suppresses the output of matching lines, which was what -s was
1108 previously doing.
1109
1110 (p) Added --include and --exclude options to specify files for inclusion
1111 and exclusion when recursing.
1112
1113 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1114 Hopefully, it now does.
1115
1116 12. Missing cast in pcre_study().
1117
1118 13. Added an "uninstall" target to the makefile.
1119
1120 14. Replaced "extern" in the function prototypes in Makefile.in with
1121 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1122 world, but is set differently for Windows.
1123
1124 15. Added a second compiling function called pcre_compile2(). The only
1125 difference is that it has an extra argument, which is a pointer to an
1126 integer error code. When there is a compile-time failure, this is set
1127 non-zero, in addition to the error test pointer being set to point to an
1128 error message. The new argument may be NULL if no error number is required
1129 (but then you may as well call pcre_compile(), which is now just a
1130 wrapper). This facility is provided because some applications need a
1131 numeric error indication, but it has also enabled me to tidy up the way
1132 compile-time errors are handled in the POSIX wrapper.
1133
1134 16. Added VPATH=.libs to the makefile; this should help when building with one
1135 prefix path and installing with another. (Or so I'm told by someone who
1136 knows more about this stuff than I do.)
1137
1138 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1139 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1140 match everything, including newlines. This is not POSIX-compatible, but
1141 somebody wanted the feature. From pcretest it can be activated by using
1142 both the P and the s flags.
1143
1144 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1145
1146 19. libpcre.pc was being incorrectly installed as executable.
1147
1148 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1149 it now also looks for '\r' so that it will work unmodified on Windows.
1150
1151 21. Added Google's contributed C++ wrapper to the distribution.
1152
1153 22. Added some untidy missing memory free() calls in pcretest, to keep
1154 Electric Fence happy when testing.
1155
1156
1157
1158 Version 5.0 13-Sep-04
1159 ---------------------
1160
1161 1. Internal change: literal characters are no longer packed up into items
1162 containing multiple characters in a single byte-string. Each character
1163 is now matched using a separate opcode. However, there may be more than one
1164 byte in the character in UTF-8 mode.
1165
1166 2. The pcre_callout_block structure has two new fields: pattern_position and
1167 next_item_length. These contain the offset in the pattern to the next match
1168 item, and its length, respectively.
1169
1170 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1171 insertion of callouts before each pattern item. Added the /C option to
1172 pcretest to make use of this.
1173
1174 4. On the advice of a Windows user, the lines
1175
1176 #if defined(_WIN32) || defined(WIN32)
1177 _setmode( _fileno( stdout ), 0x8000 );
1178 #endif /* defined(_WIN32) || defined(WIN32) */
1179
1180 have been added to the source of pcretest. This apparently does useful
1181 magic in relation to line terminators.
1182
1183 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1184 for the benefit of those environments where the "b" makes a difference.
1185
1186 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1187 to know about it. I have put a hack into configure.in that adds in code
1188 to set GCC=yes if CC=icc. This seems to end up at a point in the
1189 generated configure script that is early enough to affect the setting of
1190 compiler options, which is what is needed, but I have no means of testing
1191 whether it really works. (The user who reported this had patched the
1192 generated configure script, which of course I cannot do.)
1193
1194 LATER: After change 22 below (new libtool files), the configure script
1195 seems to know about icc (and also ecc). Therefore, I have commented out
1196 this hack in configure.in.
1197
1198 7. Added support for pkg-config (2 patches were sent in).
1199
1200 8. Negated POSIX character classes that used a combination of internal tables
1201 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1202 [[:^ascii]]. Typically, they would match almost any characters. The other
1203 POSIX classes were not broken in this way.
1204
1205 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1206 to find the match, as PCRE was deluded into thinking that the match had to
1207 start at the start point or following a newline. The same bug applied to
1208 patterns with negative forward assertions or any backward assertions
1209 preceding ".*" at the start, unless the pattern required a fixed first
1210 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1211
1212 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1213 starting at the last subject character, bytes beyond the end of the subject
1214 string were read.
1215
1216 11. Renamed the variable "class" as "classbits" to make life easier for C++
1217 users. (Previously there was a macro definition, but it apparently wasn't
1218 enough.)
1219
1220 12. Added the new field "tables" to the extra data so that tables can be passed
1221 in at exec time, or the internal tables can be re-selected. This allows
1222 a compiled regex to be saved and re-used at a later time by a different
1223 program that might have everything at different addresses.
1224
1225 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1226 -R library as well as a -L library.
1227
1228 14. The debugging options of pcretest (-d on the command line or D on a
1229 pattern) showed incorrect output for anything following an extended class
1230 that contained multibyte characters and which was followed by a quantifier.
1231
1232 15. Added optional support for general category Unicode character properties
1233 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1234 support. It adds about 90K to the size of the library. The meanings of the
1235 inbuilt class escapes such as \d and \s have NOT been changed.
1236
1237 16. Updated pcredemo.c to include calls to free() to release the memory for the
1238 compiled pattern.
1239
1240 17. The generated file chartables.c was being created in the source directory
1241 instead of in the building directory. This caused the build to fail if the
1242 source directory was different from the building directory, and was
1243 read-only.
1244
1245 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1246 file. No doubt somebody will tell me if they don't make sense... Also added
1247 Dan Mooney's comments about building on OpenVMS.
1248
1249 19. Added support for partial matching via the PCRE_PARTIAL option for
1250 pcre_exec() and the \P data escape in pcretest.
1251
1252 20. Extended pcretest with 3 new pattern features:
1253
1254 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1255 write the compiled pattern to the file whose name is "rest-of-line".
1256 This is a straight binary dump of the data, with the saved pointer to
1257 the character tables forced to be NULL. The study data, if any, is
1258 written too. After writing, pcretest reads a new pattern.
1259
1260 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1261 compiled pattern from the given file. There must not be any
1262 occurrences of "<" in the file name (pretty unlikely); if there are,
1263 pcretest will instead treat the initial "<" as a pattern delimiter.
1264 After reading in the pattern, pcretest goes on to read data lines as
1265 usual.
1266
1267 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1268 and 16-bit fields in a compiled pattern, to simulate a pattern that
1269 was compiled on a host of opposite endianness.
1270
1271 21. The pcre-exec() function can now cope with patterns that were compiled on
1272 hosts of opposite endianness, with this restriction:
1273
1274 As for any compiled expression that is saved and used later, the tables
1275 pointer field cannot be preserved; the extra_data field in the arguments
1276 to pcre_exec() should be used to pass in a tables address if a value
1277 other than the default internal tables were used at compile time.
1278
1279 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1280 now diagnosed as an error. Previously, most of the time, a negative number
1281 would have been treated as zero, but if in addition "ovector" was passed as
1282 NULL, a crash could occur.
1283
1284 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1285 new versions from the libtool 1.5 distribution (the last one is a copy of
1286 a file called libtool.m4). This seems to have fixed the need to patch
1287 "configure" to support Darwin 1.3 (which I used to do). However, I still
1288 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1289 workstation).
1290
1291 24. Changed the PCRE licence to be the more standard "BSD" licence.
1292
1293
1294 Version 4.5 01-Dec-03
1295 ---------------------
1296
1297 1. There has been some re-arrangement of the code for the match() function so
1298 that it can be compiled in a version that does not call itself recursively.
1299 Instead, it keeps those local variables that need separate instances for
1300 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1301 needs to "recurse". Keeping track of where control must go is done by means
1302 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1303 hide most of the details from the main code, and operates only if
1304 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1305 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1306 operating.
1307
1308 To make it easier for callers to provide specially tailored get/free
1309 functions for this usage, two new functions, pcre_stack_malloc, and
1310 pcre_stack_free, are used. They are always called in strict stacking order,
1311 and the size of block requested is always the same.
1312
1313 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1314 PCRE has been compiled to use the stack or the heap for recursion. The
1315 -C option of pcretest uses this to show which version is compiled.
1316
1317 A new data escape \S, is added to pcretest; it causes the amounts of store
1318 obtained and freed by both kinds of malloc/free at match time to be added
1319 to the output.
1320
1321 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1322 what's available on my current Linux desktop machine.
1323
1324 3. When matching a UTF-8 string, the test for a valid string at the start has
1325 been extended. If start_offset is not zero, PCRE now checks that it points
1326 to a byte that is the start of a UTF-8 character. If not, it returns
1327 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1328 this is necessary because there may be backward assertions in the pattern.
1329 When matching the same subject several times, it may save resources to use
1330 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1331
1332 4. The code for checking the validity of UTF-8 strings has been tightened so
1333 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1334 containing "overlong sequences".
1335
1336 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1337 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1338 should have been "&", but it just so happened that all the cases this let
1339 through by mistake were picked up later in the function.
1340
1341 6. I had used a variable called "isblank" - this is a C99 function, causing
1342 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1343
1344 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1345 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1346 so the version is shown; (c) stop "make test" echoing "./RunTest".
1347
1348 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1349
1350 9. The prototype for memmove() for systems that don't have it was using
1351 size_t, but the inclusion of the header that defines size_t was later. I've
1352 moved the #includes for the C headers earlier to avoid this.
1353
1354 10. Added some adjustments to the code to make it easier to compiler on certain
1355 special systems:
1356
1357 (a) Some "const" qualifiers were missing.
1358 (b) Added the macro EXPORT before all exported functions; by default this
1359 is defined to be empty.
1360 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1361 that it reads its output file name as an argument instead of writing
1362 to the standard output and assuming this can be redirected.
1363
1364 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1365 class containing characters with values greater than 255, PCRE compilation
1366 went into a loop.
1367
1368 12. A recursive reference to a subpattern that was within another subpattern
1369 that had a minimum quantifier of zero caused PCRE to crash. For example,
1370 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1371 recursion. If the recursively-called subpattern itself had a zero repeat,
1372 that was OK.
1373
1374 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1375 buffer into which it was copied (for escape processing) was still set at
1376 1024, so long lines caused crashes.
1377
1378 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1379 "internal error: code overflow...". This applied to any character class
1380 that was followed by a possessive quantifier.
1381
1382 15. Modified the Makefile to add libpcre.la as a prerequisite for
1383 libpcreposix.la because I was told this is needed for a parallel build to
1384 work.
1385
1386 16. If a pattern that contained .* following optional items at the start was
1387 studied, the wrong optimizing data was generated, leading to matching
1388 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1389 matching string must start with a or b or c. The correct conclusion for
1390 this pattern is that a match can start with any character.
1391
1392
1393 Version 4.4 13-Aug-03
1394 ---------------------
1395
1396 1. In UTF-8 mode, a character class containing characters with values between
1397 127 and 255 was not handled correctly if the compiled pattern was studied.
1398 In fixing this, I have also improved the studying algorithm for such
1399 classes (slightly).
1400
1401 2. Three internal functions had redundant arguments passed to them. Removal
1402 might give a very teeny performance improvement.
1403
1404 3. Documentation bug: the value of the capture_top field in a callout is *one
1405 more than* the number of the hightest numbered captured substring.
1406
1407 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1408 in incorrectly linking with a previously installed version. They now link
1409 explicitly with libpcre.la.
1410
1411 5. configure.in no longer needs to recognize Cygwin specially.
1412
1413 6. A problem in pcre.in for Windows platforms is fixed.
1414
1415 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1416 pcretest, it used to include the size of the study block as part of its
1417 output. Unfortunately, the structure contains a field that has a different
1418 size on different hardware architectures. This meant that the tests that
1419 showed this size failed. As the block is currently always of a fixed size,
1420 this information isn't actually particularly useful in pcretest output, so
1421 I have just removed it.
1422
1423 8. Three pre-processor statements accidentally did not start in column 1.
1424 Sadly, there are *still* compilers around that complain, even though
1425 standard C has not required this for well over a decade. Sigh.
1426
1427 9. In pcretest, the code for checking callouts passed small integers in the
1428 callout_data field, which is a void * field. However, some picky compilers
1429 complained about the casts involved for this on 64-bit systems. Now
1430 pcretest passes the address of the small integer instead, which should get
1431 rid of the warnings.
1432
1433 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1434 both compile and run time, and gives an error if an invalid UTF-8 sequence
1435 is found. There is a option for disabling this check in cases where the
1436 string is known to be correct and/or the maximum performance is wanted.
1437
1438 11. In response to a bug report, I changed one line in Makefile.in from
1439
1440 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1441 to
1442 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1443
1444 to look similar to other lines, but I have no way of telling whether this
1445 is the right thing to do, as I do not use Windows. No doubt I'll get told
1446 if it's wrong...
1447
1448
1449 Version 4.3 21-May-03
1450 ---------------------
1451
1452 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1453 Makefile.
1454
1455 2. Some refactoring to improve the quality of the code:
1456
1457 (i) The utf8_table... variables are now declared "const".
1458
1459 (ii) The code for \cx, which used the "case flipping" table to upper case
1460 lower case letters, now just substracts 32. This is ASCII-specific,
1461 but the whole concept of \cx is ASCII-specific, so it seems
1462 reasonable.
1463
1464 (iii) PCRE was using its character types table to recognize decimal and
1465 hexadecimal digits in the pattern. This is silly, because it handles
1466 only 0-9, a-f, and A-F, but the character types table is locale-
1467 specific, which means strange things might happen. A private
1468 table is now used for this - though it costs 256 bytes, a table is
1469 much faster than multiple explicit tests. Of course, the standard
1470 character types table is still used for matching digits in subject
1471 strings against \d.
1472
1473 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1474 ending in _t are). So I've renamed it as ESC_tee.
1475
1476 3. The first argument for regexec() in the POSIX wrapper should have been
1477 defined as "const".
1478
1479 4. Changed pcretest to use malloc() for its buffers so that they can be
1480 Electric Fenced for debugging.
1481
1482 5. There were several places in the code where, in UTF-8 mode, PCRE would try
1483 to read one or more bytes before the start of the subject string. Often this
1484 had no effect on PCRE's behaviour, but in some circumstances it could
1485 provoke a segmentation fault.
1486
1487 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1488 to try to read one or more bytes before the start of the subject string.
1489
1490 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1491 UTF-8 support could misbehave in various ways if the subject string
1492 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1493 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1494 back over UTF-8 characters.)
1495
1496
1497 Version 4.2 14-Apr-03
1498 ---------------------
1499
1500 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1501
1502 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1503 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1504 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1505 [WIN_PREFIX]: new variable, "cyg" for Cygwin
1506 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1507 and BUILD_EXEEXT
1508 Note: automatic setting of the BUILD variables is not yet working
1509 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1510 compile-time but not at link-time
1511 [LINK]: use for linking executables only
1512 make different versions for Windows and non-Windows
1513 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1514 libraries
1515 [LINK_FOR_BUILD]: new variable
1516 [OBJEXT]: use throughout
1517 [EXEEXT]: use throughout
1518 <winshared>: new target
1519 <wininstall>: new target
1520 <dftables.o>: use native compiler
1521 <dftables>: use native linker
1522 <install>: handle Windows platform correctly
1523 <clean>: ditto
1524 <check>: ditto
1525 copy DLL to top builddir before testing
1526
1527 As part of these changes, -no-undefined was removed again. This was reported
1528 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1529 in any case.
1530
1531 3. Some tidies to get rid of compiler warnings:
1532
1533 . In the match_data structure, match_limit was an unsigned long int, whereas
1534 match_call_count was an int. I've made them both unsigned long ints.
1535
1536 . In pcretest the fact that a const uschar * doesn't automatically cast to
1537 a void * provoked a warning.
1538
1539 . Turning on some more compiler warnings threw up some "shadow" variables
1540 and a few more missing casts.
1541
1542 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1543 option, a class that contained a single character with a value between 128
1544 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1545
1546 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1547 option, a class that contained several characters, but with at least one
1548 whose value was between 128 and 255 caused PCRE to crash.
1549
1550
1551 Version 4.1 12-Mar-03
1552 ---------------------
1553
1554 1. Compiling with gcc -pedantic found a couple of places where casts were
1555 needed, and a string in dftables.c that was longer than standard compilers are
1556 required to support.
1557
1558 2. Compiling with Sun's compiler found a few more places where the code could
1559 be tidied up in order to avoid warnings.
1560
1561 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1562 first of these names is deprecated in the latest Autoconf in favour of the name
1563 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1564 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1565 analogy I have changed it to CFLAGS_FOR_BUILD.
1566
1567 4. Added -no-undefined to the linking command in the Makefile, because this is
1568 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1569 linking step for the pcreposix library.
1570
1571 5. PCRE was failing to diagnose the case of two named groups with the same
1572 name.
1573
1574 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1575 literal character that is needed in the subject for a match, and scans along to
1576 ensure that it is present before embarking on the full matching process. This
1577 saves time in cases of nested unlimited repeats that are never going to match.
1578 Problem: the scan can take a lot of time if the subject is very long (e.g.
1579 megabytes), thus penalizing straightforward matches. It is now done only if the
1580 amount of subject to be scanned is less than 1000 bytes.
1581
1582 7. A lesser problem with the same optimization is that it was recording the
1583 first character of an anchored pattern as "needed", thus provoking a search
1584 right along the subject, even when the first match of the pattern was going to
1585 fail. The "needed" character is now not set for anchored patterns, unless it
1586 follows something in the pattern that is of non-fixed length. Thus, it still
1587 fulfils its original purpose of finding quick non-matches in cases of nested
1588 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1589
1590
1591 Version 4.0 17-Feb-03
1592 ---------------------
1593
1594 1. If a comment in an extended regex that started immediately after a meta-item
1595 extended to the end of string, PCRE compiled incorrect data. This could lead to
1596 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1597
1598 2. Moved to autoconf 2.53 and libtool 1.4.2.
1599
1600 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1601 the special perltest8 script is no longer needed - all the tests can be run
1602 from a single perltest script.
1603
1604 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1605 by \s. It has now been removed in PCRE. This means it isn't recognized as
1606 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1607 class [:space:] *does* include VT, thereby creating a mess.
1608
1609 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1610 space and tab.
1611
1612 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1613 its new features into the main test script, reducing the number of scripts.
1614
1615 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1616 were backward compatible, and made the (?i) apply to the whole pattern, as if
1617 /i were given. Now it behaves more logically, and applies the option setting
1618 only to what follows. PCRE has been changed to follow suit. However, if it
1619 finds options settings right at the start of the pattern, it extracts them into
1620 the global options, as before. Thus, they show up in the info data.
1621
1622 8. Added support for the \Q...\E escape sequence. Characters in between are
1623 treated as literals. This is slightly different from Perl in that $ and @ are
1624 also handled as literals inside the quotes. In Perl, they will cause variable
1625 interpolation. Note the following examples:
1626
1627 Pattern PCRE matches Perl matches
1628
1629 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
1630 \Qabc\$xyz\E abc\$xyz abc\$xyz
1631 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
1632
1633 For compatibility with Perl, \Q...\E sequences are recognized inside character
1634 classes as well as outside them.
1635
1636 9. Re-organized 3 code statements in pcretest to avoid "overflow in
1637 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1638 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1639 signed/unsigned warnings.
1640
1641 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1642 option for pcretest, so I've replaced it by a simple function that does just
1643 that job.
1644
1645 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1646 "pcregrep -".
1647
1648 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1649 Java package. This provides some syntactic sugar for simple cases of what my
1650 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1651 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1652 item, you can use this simplified notation. Note that only makes sense with
1653 greedy quantifiers. Consequently, the use of the possessive quantifier forces
1654 greediness, whatever the setting of the PCRE_UNGREEDY option.
1655
1656 13. A change of greediness default within a pattern was not taking effect at
1657 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1658 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
1659 was abstracted outside.
1660
1661 14. PCRE now supports the \G assertion. It is true when the current matching
1662 position is at the start point of the match. This differs from \A when the
1663 starting offset is non-zero. Used with the /g option of pcretest (or similar
1664 code), it works in the same way as it does for Perl's /g option. If all
1665 alternatives of a regex begin with \G, the expression is anchored to the start
1666 match position, and the "anchored" flag is set in the compiled expression.
1667
1668 15. Some bugs concerning the handling of certain option changes within patterns
1669 have been fixed. These applied to options other than (?ims). For example,
1670 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
1671 been the other way round. Some of this was related to change 7 above.
1672
1673 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
1674 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
1675 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
1676 POSIX classes only within a class (e.g. /[[:alpha:]]/).
1677
1678 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
1679 mode. Unlike ".", it always matches newline, whatever the setting of
1680 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
1681 assertions. Perl allows it, but it doesn't (in general) work because it can't
1682 calculate the length of the lookbehind. At least, that's the case for Perl
1683 5.8.0 - I've been told they are going to document that it doesn't work in
1684 future.
1685
1686 18. Added an error diagnosis for escapes that PCRE does not support: these are
1687 \L, \l, \N, \P, \p, \U, \u, and \X.
1688
1689 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
1690 reading past the end of the pattern in cases such as /[abcd/.
1691
1692 20. PCRE was getting more memory than necessary for patterns with classes that
1693 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
1694
1695 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
1696 compiling PCRE for use with Virtual Pascal.
1697
1698 22. Small fix to the Makefile to make it work properly if the build is done
1699 outside the source tree.
1700
1701 23. Added a new extension: a condition to go with recursion. If a conditional
1702 subpattern starts with (?(R) the "true" branch is used if recursion has
1703 happened, whereas the "false" branch is used only at the top level.
1704
1705 24. When there was a very long string of literal characters (over 255 bytes
1706 without UTF support, over 250 bytes with UTF support), the computation of how
1707 much memory was required could be incorrect, leading to segfaults or other
1708 strange effects.
1709
1710 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
1711 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
1712 there was a subsequent back reference to those brackets. This meant that, for
1713 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
1714 possible to check for precisely this case. All we can do is abandon the
1715 optimization if .* occurs inside capturing brackets when there are any back
1716 references whatsoever. (See below for a better fix that came later.)
1717
1718 26. The handling of the optimization for finding the first character of a
1719 non-anchored pattern, and for finding a character that is required later in the
1720 match were failing in some cases. This didn't break the matching; it just
1721 failed to optimize when it could. The way this is done has been re-implemented.
1722
1723 27. Fixed typo in error message for invalid (?R item (it said "(?p").
1724
1725 28. Added a new feature that provides some of the functionality that Perl
1726 provides with (?{...}). The facility is termed a "callout". The way it is done
1727 in PCRE is for the caller to provide an optional function, by setting
1728 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
1729 global variable. By default it is unset, which disables all calling out. To get
1730 the function called, the regex must include (?C) at appropriate points. This
1731 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
1732 This provides a means of identifying different callout points. When PCRE
1733 reaches such a point in the regex, if pcre_callout has been set, the external
1734 function is called. It is provided with data in a structure called
1735 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
1736 matching continues; if it returns a non-zero value, the match at the current
1737 point fails. However, backtracking will occur if possible. [This was changed
1738 later and other features added - see item 49 below.]
1739
1740 29. pcretest is upgraded to test the callout functionality. It provides a
1741 callout function that displays information. By default, it shows the start of
1742 the match and the current position in the text. There are some new data escapes
1743 to vary what happens:
1744
1745 \C+ in addition, show current contents of captured substrings
1746 \C- do not supply a callout function
1747 \C!n return 1 when callout number n is reached
1748 \C!n!m return 1 when callout number n is reached for the mth time
1749
1750 30. If pcregrep was called with the -l option and just a single file name, it
1751 output "<stdin>" if a match was found, instead of the file name.
1752
1753 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
1754 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
1755 pcre_exec(). This saves a malloc/free per call. The default value of
1756 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
1757 when configuring.
1758
1759 32. The default maximum size of a compiled pattern is 64K. There have been a
1760 few cases of people hitting this limit. The code now uses macros to handle the
1761 storing of links as offsets within the compiled pattern. It defaults to 2-byte
1762 links, but this can be changed to 3 or 4 bytes by --with-link-size when
1763 configuring. Tests 2 and 5 work only with 2-byte links because they output
1764 debugging information about compiled patterns.
1765
1766 33. Internal code re-arrangements:
1767
1768 (a) Moved the debugging function for printing out a compiled regex into
1769 its own source file (printint.c) and used #include to pull it into
1770 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
1771 separate copies.
1772
1773 (b) Defined the list of op-code names for debugging as a macro in
1774 internal.h so that it is next to the definition of the opcodes.
1775
1776 (c) Defined a table of op-code lengths for simpler skipping along compiled
1777 code. This is again a macro in internal.h so that it is next to the
1778 definition of the opcodes.
1779
1780 34. Added support for recursive calls to individual subpatterns, along the
1781 lines of Robin Houston's patch (but implemented somewhat differently).
1782
1783 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
1784 allow it to read and process whole directories in Win32. This code was
1785 contributed by Lionel Fourquaux; it has not been tested by me.
1786
1787 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
1788 used to name a group. Names consist of alphanumerics and underscores, and must
1789 be unique. Back references use the syntax (?P=name) and recursive calls use
1790 (?P>name) which is a PCRE extension to the Python extension. Groups still have
1791 numbers. The function pcre_fullinfo() can be used after compilation to extract
1792 a name/number map. There are three relevant calls:
1793
1794 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
1795 PCRE_INFO_NAMECOUNT yields the number of entries
1796 PCRE_INFO_NAMETABLE yields a pointer to the map.
1797
1798 The map is a vector of fixed-size entries. The size of each entry depends on
1799 the length of the longest name used. The first two bytes of each entry are the
1800 group number, most significant byte first. There follows the corresponding
1801 name, zero terminated. The names are in alphabetical order.
1802
1803 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
1804 case instead of 255. Making it the same both with and without UTF-8 support
1805 means that the same test output works with both.
1806
1807 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
1808 calling malloc() with a zero argument.
1809
1810 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
1811 optimization. I've improved things by keeping a bitmap of backreferences with
1812 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
1813 fact referenced, the optimization can be applied. It is unlikely that a
1814 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
1815 the match to follow \n) will appear inside brackets with a number greater than
1816 31, but if it does, any back reference > 31 suppresses the optimization.
1817
1818 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
1819 of disabling numbered capturing parentheses. Any opening parenthesis that is
1820 not followed by ? behaves as if it were followed by ?: but named parentheses
1821 can still be used for capturing (and they will acquire numbers in the usual
1822 way).
1823
1824 41. Redesigned the return codes from the match() function into yes/no/error so
1825 that errors can be passed back from deep inside the nested calls. A malloc
1826 failure while inside a recursive subpattern call now causes the
1827 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
1828
1829 42. It is now possible to set a limit on the number of times the match()
1830 function is called in a call to pcre_exec(). This facility makes it possible to
1831 limit the amount of recursion and backtracking, though not in a directly
1832 obvious way, because the match() function is used in a number of different
1833 circumstances. The count starts from zero for each position in the subject
1834 string (for non-anchored patterns). The default limit is, for compatibility, a
1835 large number, namely 10 000 000. You can change this in two ways:
1836
1837 (a) When configuring PCRE before making, you can use --with-match-limit=n
1838 to set a default value for the compiled library.
1839
1840 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
1841 a different value is set. See 45 below.
1842
1843 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
1844
1845 43. Added a new function pcre_config(int, void *) to enable run-time extraction
1846 of things that can be changed at compile time. The first argument specifies
1847 what is wanted and the second points to where the information is to be placed.
1848 The current list of available information is:
1849
1850 PCRE_CONFIG_UTF8
1851
1852 The output is an integer that is set to one if UTF-8 support is available;
1853 otherwise it is set to zero.
1854
1855 PCRE_CONFIG_NEWLINE
1856
1857 The output is an integer that it set to the value of the code that is used for
1858 newline. It is either LF (10) or CR (13).
1859
1860 PCRE_CONFIG_LINK_SIZE
1861
1862 The output is an integer that contains the number of bytes used for internal
1863 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
1864
1865 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
1866
1867 The output is an integer that contains the threshold above which the POSIX
1868 interface uses malloc() for output vectors. See item 31 above.
1869
1870 PCRE_CONFIG_MATCH_LIMIT
1871
1872 The output is an unsigned integer that contains the default limit of the number
1873 of match() calls in a pcre_exec() execution. See 42 above.
1874
1875 44. pcretest has been upgraded by the addition of the -C option. This causes it
1876 to extract all the available output from the new pcre_config() function, and to
1877 output it. The program then exits immediately.
1878
1879 45. A need has arisen to pass over additional data with calls to pcre_exec() in
1880 order to support additional features. One way would have been to define
1881 pcre_exec2() (for example) with extra arguments, but this would not have been
1882 extensible, and would also have required all calls to the original function to
1883 be mapped to the new one. Instead, I have chosen to extend the mechanism that
1884 is used for passing in "extra" data from pcre_study().
1885
1886 The pcre_extra structure is now exposed and defined in pcre.h. It currently
1887 contains the following fields:
1888
1889 flags a bitmap indicating which of the following fields are set
1890 study_data opaque data from pcre_study()
1891 match_limit a way of specifying a limit on match() calls for a specific
1892 call to pcre_exec()
1893 callout_data data for callouts (see 49 below)
1894
1895 The flag bits are also defined in pcre.h, and are
1896
1897 PCRE_EXTRA_STUDY_DATA
1898 PCRE_EXTRA_MATCH_LIMIT
1899 PCRE_EXTRA_CALLOUT_DATA
1900
1901 The pcre_study() function now returns one of these new pcre_extra blocks, with
1902 the actual study data pointed to by the study_data field, and the
1903 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
1904 before. That is, this change is entirely upwards-compatible and requires no
1905 change to existing code.
1906
1907 If you want to pass in additional data to pcre_exec(), you can either place it
1908 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
1909 block.
1910
1911 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
1912 data string contains the escape sequence \M, pcretest calls pcre_exec() several
1913 times with different match limits, until it finds the minimum value needed for
1914 pcre_exec() to complete. The value is then output. This can be instructive; for
1915 most simple matches the number is quite small, but for pathological cases it
1916 gets very large very quickly.
1917
1918 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
1919 returns the size of the data block pointed to by the study_data field in a
1920 pcre_extra block, that is, the value that was passed as the argument to
1921 pcre_malloc() when PCRE was getting memory in which to place the information
1922 created by pcre_study(). The fourth argument should point to a size_t variable.
1923 pcretest has been extended so that this information is shown after a successful
1924 pcre_study() call when information about the compiled regex is being displayed.
1925
1926 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
1927 because what follows is always an absolute path. (Later: it turns out that this
1928 is more than cosmetic for MinGW, because it doesn't like empty path
1929 components.)
1930
1931 49. Some changes have been made to the callout feature (see 28 above):
1932
1933 (i) A callout function now has three choices for what it returns:
1934
1935 0 => success, carry on matching
1936 > 0 => failure at this point, but backtrack if possible
1937 < 0 => serious error, return this value from pcre_exec()
1938
1939 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
1940 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
1941 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
1942 use by callout functions. It will never be used by PCRE itself.
1943
1944 (ii) The pcre_extra structure (see 45 above) has a void * field called
1945 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
1946 pcre_callout_block structure has a field of the same name. The contents of
1947 the field passed in the pcre_extra structure are passed to the callout
1948 function in the corresponding field in the callout block. This makes it
1949 easier to use the same callout-containing regex from multiple threads. For
1950 testing, the pcretest program has a new data escape
1951
1952 \C*n pass the number n (may be negative) as callout_data
1953
1954 If the callout function in pcretest receives a non-zero value as
1955 callout_data, it returns that value.
1956
1957 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
1958 there were some redundant $(CFLAGS) in commands that are now specified as
1959 $(LINK), which already includes $(CFLAGS).
1960
1961 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
1962 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
1963 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
1964 one-byte characters throughout. Note that case-insensitive matching applies
1965 only to characters whose values are less than 256. PCRE doesn't support the
1966 notion of cases for higher-valued characters.
1967
1968 (i) A character class whose characters are all within 0-255 is handled as
1969 a bit map, and the map is inverted for negative classes. Previously, a
1970 character > 255 always failed to match such a class; however it should
1971 match if the class was a negative one (e.g. [^ab]). This has been fixed.
1972
1973 (ii) A negated character class with a single character < 255 is coded as
1974 "not this character" (OP_NOT). This wasn't working properly when the test
1975 character was multibyte, either singly or repeated.
1976
1977 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
1978 mode, for example: \x{100}{2,3}.
1979
1980 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
1981 singly or repeated) now correctly test multibyte characters. However,
1982 PCRE doesn't recognize any characters with values greater than 255 as
1983 digits, spaces, or word characters. Such characters always match \D, \S,
1984 and \W, and never match \d, \s, or \w.
1985
1986 (v) Classes may now contain characters and character ranges with values
1987 greater than 255. For example: [ab\x{100}-\x{400}].
1988
1989 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
1990 PCRE in UTF-8 mode.
1991
1992 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
1993 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
1994 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
1995 value.)
1996
1997 53. The single man page has become too large. I have therefore split it up into
1998 a number of separate man pages. These also give rise to individual HTML pages;
1999 these are now put in a separate directory, and there is an index.html page that
2000 lists them all. Some hyperlinking between the pages has been installed.
2001
2002 54. Added convenience functions for handling named capturing parentheses.
2003
2004 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2005 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2006 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2007 are faulted.
2008
2009 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2010 calling configure. These values are used when compiling the dftables.c program
2011 which is run to generate the source of the default character tables. They
2012 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2013 you will need to set these values.
2014
2015 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2016
2017
2018 Version 3.9 02-Jan-02
2019 ---------------------
2020
2021 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2022
2023 2. If --disable-static was given, the building process failed when trying to
2024 build pcretest and pcregrep. (For some reason it was using libtool to compile
2025 them, which is not right, as they aren't part of the library.)
2026
2027
2028 Version 3.8 18-Dec-01
2029 ---------------------
2030
2031 1. The experimental UTF-8 code was completely screwed up. It was packing the
2032 bytes in the wrong order. How dumb can you get?
2033
2034
2035 Version 3.7 29-Oct-01
2036 ---------------------
2037
2038 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2039 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2040 this didn't happen under Solaris 8, where I normally test things.
2041
2042 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2043 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2044 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2045 this fix an hour or so after the initial 3.7 release.)
2046
2047
2048 Version 3.6 23-Oct-01
2049 ---------------------
2050
2051 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2052 offsets passed as NULL with zero offset count.
2053
2054 2. The config.guess and config.sub files had not been updated when I moved to
2055 the latest autoconf.
2056
2057
2058 Version 3.5 15-Aug-01
2059 ---------------------
2060
2061 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2062 had been forgotten.
2063
2064 2. By using declared but undefined structures, we can avoid using "void"
2065 definitions in pcre.h while keeping the internal definitions of the structures
2066 private.
2067
2068 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2069 user point of view, this means that both static and shared libraries are built
2070 by default, but this can be individually controlled. More of the work of
2071 handling this static/shared cases is now inside libtool instead of PCRE's make
2072 file.
2073
2074 4. The pcretest utility is now installed along with pcregrep because it is
2075 useful for users (to test regexs) and by doing this, it automatically gets
2076 relinked by libtool. The documentation has been turned into a man page, so
2077 there are now .1, .txt, and .html versions in /doc.
2078
2079 5. Upgrades to pcregrep:
2080 (i) Added long-form option names like gnu grep.
2081 (ii) Added --help to list all options with an explanatory phrase.
2082 (iii) Added -r, --recursive to recurse into sub-directories.
2083 (iv) Added -f, --file to read patterns from a file.
2084
2085 6. pcre_exec() was referring to its "code" argument before testing that
2086 argument for NULL (and giving an error if it was NULL).
2087
2088 7. Upgraded Makefile.in to allow for compiling in a different directory from
2089 the source directory.
2090
2091 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2092 options bits, the pointer it was passed was to an int instead of to an unsigned
2093 long int. This mattered only on 64-bit systems.
2094
2095 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2096 generated) instead of pcre.in, which it its source. Also made the same change
2097 in several of the .c files.
2098
2099 10. A new release of gcc defines printf() as a macro, which broke pcretest
2100 because it had an ifdef in the middle of a string argument for printf(). Fixed
2101 by using separate calls to printf().
2102
2103 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2104 script, to force use of CR or LF instead of \n in the source. On non-Unix
2105 systems, the value can be set in config.h.
2106
2107 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2108 absolute limit. Changed the text of the error message to make this clear, and
2109 likewise updated the man page.
2110
2111 13. The limit of 99 on the number of capturing subpatterns has been removed.
2112 The new limit is 65535, which I hope will not be a "real" limit.
2113
2114
2115 Version 3.4 22-Aug-00
2116 ---------------------
2117
2118 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2119
2120 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2121
2122
2123 Version 3.3 01-Aug-00
2124 ---------------------
2125
2126 1. If an octal character was given, but the value was greater than \377, it
2127 was not getting masked to the least significant bits, as documented. This could
2128 lead to crashes in some systems.
2129
2130 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2131 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2132
2133 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2134 These just pass their arguments on to (pcre_free)(), but they are provided
2135 because some uses of PCRE bind it to non-C systems that can call its functions,
2136 but cannot call free() or pcre_free() directly.
2137
2138 4. Add "make test" as a synonym for "make check". Corrected some comments in
2139 the Makefile.
2140
2141 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2142 Makefile.
2143
2144 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2145 command called pgrep for grepping around the active processes.
2146
2147 7. Added the beginnings of support for UTF-8 character strings.
2148
2149 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2150 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2151 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2152 out for the ar command.)
2153
2154
2155 Version 3.2 12-May-00
2156 ---------------------
2157
2158 This is purely a bug fixing release.
2159
2160 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2161 of ZA. This was just one example of several cases that could provoke this bug,
2162 which was introduced by change 9 of version 2.00. The code for breaking
2163 infinite loops after an iteration that matches an empty string was't working
2164 correctly.
2165
2166 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2167 when matched against abbab (for example). After matching an empty string, it
2168 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2169 caused it to match further down the string than it should.
2170
2171 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2172 was there because it doesn't seem to be needed, and it causes trouble on some
2173 systems, as it is not a Standard C header. It has been removed.
2174
2175 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2176 were reported on the Macintosh. The changes were from
2177
2178 while ((c = *(++ptr)) != 0 && c != '\n');
2179 to
2180 while ((c = *(++ptr)) != 0 && c != '\n') ;
2181
2182 Totally extraordinary, but if that's what it takes...
2183
2184 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2185 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2186 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2187 assumes the way PCRE uses memmove() (always moving upwards).
2188
2189 6. PCRE is being used in one environment where strchr() is not available. There
2190 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2191 faster code anyway.
2192
2193
2194 Version 3.1 09-Feb-00
2195 ---------------------
2196
2197 The only change in this release is the fixing of some bugs in Makefile.in for
2198 the "install" target:
2199
2200 (1) It was failing to install pcreposix.h.
2201
2202 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2203
2204
2205 Version 3.0 01-Feb-00
2206 ---------------------
2207
2208 1. Add support for the /+ modifier to perltest (to output $` like it does in
2209 pcretest).
2210
2211 2. Add support for the /g modifier to perltest.
2212
2213 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2214 matches null strings.
2215
2216 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2217 pattern. Perl treats empty patterns specially - it reuses the most recent
2218 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2219 effect.
2220
2221 5. The POSIX interface was broken in that it was just handing over the POSIX
2222 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2223 required a bigger vector, with some working space on the end. This means that
2224 the POSIX wrapper now has to get and free some memory, and copy the results.
2225
2226 6. Added some simple autoconf support, placing the test data and the
2227 documentation in separate directories, re-organizing some of the
2228 information files, and making it build pcre-config (a GNU standard). Also added
2229 libtool support for building PCRE as a shared library, which is now the
2230 default.
2231
2232 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2233 09 are not valid octal constants. Single digits will be used for minor values
2234 less than 10.
2235
2236 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2237 existing programs that set these in the POSIX interface can use PCRE without
2238 modification.
2239
2240 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2241 return all that pcre_info() returns, plus additional data. The pcre_info()
2242 function is retained for compatibility, but is considered to be obsolete.
2243
2244 10. Added experimental recursion feature (?R) to handle one common case that
2245 Perl 5.6 will be able to do with (?p{...}).
2246
2247 11. Added support for POSIX character classes like [:alpha:], which Perl is
2248 adopting.
2249
2250
2251 Version 2.08 31-Aug-99
2252 ----------------------
2253
2254 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2255 trying to match at the startoffset position, but instead was moving forward to
2256 the next newline as if a previous match had failed.
2257
2258 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2259 and could get into a loop if a null string was matched other than at the start
2260 of the subject.
2261
2262 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2263 be distinguished at compile time, and for completeness also added PCRE_DATE.
2264
2265 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2266 in GnuWin32 environments.
2267
2268
2269 Version 2.07 29-Jul-99
2270 ----------------------
2271
2272 1. The documentation is now supplied in plain text form and HTML as well as in
2273 the form of man page sources.
2274
2275 2. C++ compilers don't like assigning (void *) values to other pointer types.
2276 In particular this affects malloc(). Although there is no problem in Standard
2277 C, I've put in casts to keep C++ compilers happy.
2278
2279 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2280 should be (const char *).
2281
2282 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2283 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2284 However, I haven't made this a standard facility. The documentation doesn't
2285 mention it, and the Makefile doesn't support it.
2286
2287 5. The Makefile now contains an "install" target, with editable destinations at
2288 the top of the file. The pcretest program is not installed.
2289
2290 6. pgrep -V now gives the PCRE version number and date.
2291
2292 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2293 causing the entire string to be ignored, instead of just the last character.
2294
2295 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2296 non-matching string, it can take a very, very long time, even for strings of
2297 quite modest length, because of the nested recursion. PCRE now does better in
2298 some of these cases. It does this by remembering the last required literal
2299 character in the pattern, and pre-searching the subject to ensure it is present
2300 before running the real match. In other words, it applies a heuristic to detect
2301 some types of certain failure quickly, and in the above example, if presented
2302 with a string that has no trailing " it gives "no match" very quickly.
2303
2304 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2305 other alternatives are tried instead.
2306
2307
2308 Version 2.06 09-Jun-99
2309 ----------------------
2310
2311 1. Change pcretest's output for amount of store used to show just the code
2312 space, because the remainder (the data block) varies in size between 32-bit and
2313 64-bit systems.
2314
2315 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2316 start matching at. This allows lookbehinds to work when searching for multiple
2317 occurrences in a string.
2318
2319 3. Added additional options to pcretest for testing multiple occurrences:
2320
2321 /+ outputs the rest of the string that follows a match
2322 /g loops for multiple occurrences, using the new startoffset argument
2323 /G loops for multiple occurrences by passing an incremented pointer
2324
2325 4. PCRE wasn't doing the "first character" optimization for patterns starting
2326 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2327 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2328 the letter 'x'. On long subject strings, this gives a significant speed-up.
2329
2330
2331 Version 2.05 21-Apr-99
2332 ----------------------
2333
2334 1. Changed the type of magic_number from int to long int so that it works
2335 properly on 16-bit systems.
2336
2337 2. Fixed a bug which caused patterns starting with .* not to work correctly
2338 when the subject string contained newline characters. PCRE was assuming
2339 anchoring for such patterns in all cases, which is not correct because .* will
2340 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2341 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2342 must be retried after every newline in the subject.
2343
2344
2345 Version 2.04 18-Feb-99
2346 ----------------------
2347
2348 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2349 computation of the store needed to hold the pattern was incorrect (too large).
2350 If such patterns were nested a few deep, this could multiply and become a real
2351 problem.
2352
2353 2. Added /M option to pcretest to show the memory requirement of a specific
2354 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2355
2356 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2357 compiled in such a way that the backtracking after subsequent failure was
2358 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2359 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2360
2361
2362 Version 2.03 02-Feb-99
2363 ----------------------
2364
2365 1. Fixed typo and small mistake in man page.
2366
2367 2. Added 4th condition (GPL supersedes if conflict) and created separate
2368 LICENCE file containing the conditions.
2369
2370 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2371 Perl, that is the internal \ allows the delimiter to be included in the
2372 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2373 the final delimiter, add \ to the end of the pattern (to test the error).
2374
2375 4. Added the convenience functions for extracting substrings after a successful
2376 match. Updated pcretest to make it able to test these functions.
2377
2378
2379 Version 2.02 14-Jan-99
2380 ----------------------
2381
2382 1. Initialized the working variables associated with each extraction so that
2383 their saving and restoring doesn't refer to uninitialized store.
2384
2385 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2386 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2387 fix the problem.
2388
2389 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2390 calls, and wasn't printing the correct value for compiling calls. Increased the
2391 default value of LOOPREPEAT, and the number of significant figures in the
2392 times.
2393
2394 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2395
2396 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2397 a building problem on Windows NT with a FAT file system.
2398
2399
2400 Version 2.01 21-Oct-98
2401 ----------------------
2402
2403 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2404 to character tables built by pcre_maketables() in the current locale. If NULL
2405 is passed, the default tables are used.
2406
2407
2408 Version 2.00 24-Sep-98
2409 ----------------------
2410
2411 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2412 it any more.
2413
2414 2. Allow quantification of (?>) groups, and make it work correctly.
2415
2416 3. The first character computation wasn't working for (?>) groups.
2417
2418 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2419 end of the subject) and add 5.005's \z, which really does match only at the
2420 very end of the subject.
2421
2422 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2423
2424 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2425 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2426 localized options. All options to pcre_study() were also removed.
2427
2428 7. Add other new features from 5.005:
2429
2430 $(?<= positive lookbehind
2431 $(?<! negative lookbehind
2432 (?imsx-imsx) added the unsetting capability
2433 such a setting is global if at outer level; local otherwise
2434 (?imsx-imsx:) non-capturing groups with option setting
2435 (?(cond)re|re) conditional pattern matching
2436
2437 A backreference to itself in a repeated group matches the previous
2438 captured string.
2439
2440 8. General tidying up of studying (both automatic and via "study")
2441 consequential on the addition of new assertions.
2442
2443 9. As in 5.005, unlimited repeated groups that could match an empty substring
2444 are no longer faulted at compile time. Instead, the loop is forcibly broken at
2445 runtime if any iteration does actually match an empty substring.
2446
2447 10. Include the RunTest script in the distribution.
2448
2449 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2450 discrepancies, some of which were old and were also with respect to 5.004. They
2451 have now been fixed.
2452
2453
2454 Version 1.09 28-Apr-98
2455 ----------------------
2456
2457 1. A negated single character class followed by a quantifier with a minimum
2458 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2459 program crashes, or just wrong answers. This did not apply to negated classes
2460 containing more than one character, or to minima other than one.
2461
2462
2463 Version 1.08 27-Mar-98
2464 ----------------------
2465
2466 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2467
2468 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2469 latter must appear before anything that relies on it in the pattern.
2470
2471
2472 Version 1.07 16-Feb-98
2473 ----------------------
2474
2475 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2476 repeat of a potentially empty string).
2477
2478
2479 Version 1.06 23-Jan-98
2480 ----------------------
2481
2482 1. Added Markus Oberhumer's little patches for C++.
2483
2484 2. Literal strings longer than 255 characters were broken.
2485
2486
2487 Version 1.05 23-Dec-97
2488 ----------------------
2489
2490 1. Negated character classes containing more than one character were failing if
2491 PCRE_CASELESS was set at run time.
2492
2493
2494 Version 1.04 19-Dec-97
2495 ----------------------
2496
2497 1. Corrected the man page, where some "const" qualifiers had been omitted.
2498
2499 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2500 input syntax.
2501
2502 3. Fixed memory leak which occurred when a regex with back references was
2503 matched with an offsets vector that wasn't big enough. The temporary memory
2504 that is used in this case wasn't being freed if the match failed.
2505
2506 4. Tidied pcretest to ensure it frees memory that it gets.
2507
2508 5. Temporary memory was being obtained in the case where the passed offsets
2509 vector was exactly big enough.
2510
2511 6. Corrected definition of offsetof() from change 5 below.
2512
2513 7. I had screwed up change 6 below and broken the rules for the use of
2514 setjmp(). Now fixed.
2515
2516
2517 Version 1.03 18-Dec-97
2518 ----------------------
2519
2520 1. A erroneous regex with a missing opening parenthesis was correctly
2521 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2522 on some systems.
2523
2524 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2525 it was reported that one broken compiler failed on the former because "code" is
2526 also an independent variable.
2527
2528 3. The erroneous regex a[]b caused an array overrun reference.
2529
2530 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2531 fail on data ending with that character. (It was going on too far, and checking
2532 the next character, typically a binary zero.) This was specific to the
2533 optimized code for single-character negative classes.
2534
2535 5. Added a contributed patch from the TIN world which does the following:
2536
2537 + Add an undef for memmove, in case the the system defines a macro for it.
2538
2539 + Add a definition of offsetof(), in case there isn't one. (I don't know
2540 the reason behind this - offsetof() is part of the ANSI standard - but
2541 it does no harm).
2542
2543 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2544 most of the places where whitespace preceded '#'. I have given up and
2545 allowed the remaining 2 cases to be at the margin.
2546
2547 + Rename some variables in pcre to eliminate shadowing. This seems very
2548 pedantic, but does no harm, of course.
2549
2550 6. Moved the call to setjmp() into its own function, to get rid of warnings
2551 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2552
2553 7. Constructs such as \d{8,} were compiling into the equivalent of
2554 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2555 outcome, but in this particular case used more store than had been allocated,
2556 which caused the bug to be discovered because it threw up an internal error.
2557
2558 8. The debugging code in both pcre and pcretest for outputting the compiled
2559 form of a regex was going wrong in the case of back references followed by
2560 curly-bracketed repeats.
2561
2562
2563 Version 1.02 12-Dec-97
2564 ----------------------
2565
2566 1. Typos in pcre.3 and comments in the source fixed.
2567
2568 2. Applied a contributed patch to get rid of places where it used to remove
2569 'const' from variables, and fixed some signed/unsigned and uninitialized
2570 variable warnings.
2571
2572 3. Added the "runtest" target to Makefile.
2573
2574 4. Set default compiler flag to -O2 rather than just -O.
2575
2576
2577 Version 1.01 19-Nov-97
2578 ----------------------
2579
2580 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2581 like /([ab]*)*/, that is, for classes with more than one character in them.
2582
2583 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2584 as /((?>a*))*/ (a PCRE_EXTRA facility).
2585
2586
2587 Version 1.00 18-Nov-97
2588 ----------------------
2589
2590 1. Added compile-time macros to support systems such as SunOS4 which don't have
2591 memmove() or strerror() but have other things that can be used instead.
2592
2593 2. Arranged that "make clean" removes the executables.
2594
2595
2596 Version 0.99 27-Oct-97
2597 ----------------------
2598
2599 1. Fixed bug in code for optimizing classes with only one character. It was
2600 initializing a 32-byte map regardless, which could cause it to run off the end
2601 of the memory it had got.
2602
2603 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
2604
2605
2606 Version 0.98 22-Oct-97
2607 ----------------------
2608
2609 1. Fixed bug in code for handling temporary memory usage when there are more
2610 back references than supplied space in the ovector. This could cause segfaults.
2611
2612
2613 Version 0.97 21-Oct-97
2614 ----------------------
2615
2616 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
2617
2618 2. Optimized negated single characters not to use a bit map.
2619
2620 3. Brought error texts together as macro definitions; clarified some of them;
2621 fixed one that was wrong - it said "range out of order" when it meant "invalid
2622 escape sequence".
2623
2624 4. Changed some char * arguments to const char *.
2625
2626 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
2627
2628 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
2629 pcretest.
2630
2631
2632 Version 0.96 16-Oct-97
2633 ----------------------
2634
2635 1. Added a simple "pgrep" utility to the distribution.
2636
2637 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
2638 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
2639 where "ddd" means "one or more decimal digits".
2640
2641 3. Fixed serious bug. If a pattern had a back reference, but the call to
2642 pcre_exec() didn't supply a large enough ovector to record the related
2643 identifying subpattern, the match always failed. PCRE now remembers the number
2644 of the largest back reference, and gets some temporary memory in which to save
2645 the offsets during matching if necessary, in order to ensure that
2646 backreferences always work.
2647
2648 4. Increased the compatibility with Perl in a number of ways:
2649
2650 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
2651 to request this handling. The option can be set at compile or exec time.
2652
2653 (b) $ matches before a terminating newline by default; an option
2654 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
2655 mode). The option can be set at compile or exec time.
2656
2657 (c) The handling of \ followed by a digit other than 0 is now supposed to be
2658 the same as Perl's. If the decimal number it represents is less than 10
2659 or there aren't that many previous left capturing parentheses, an octal
2660 escape is read. Inside a character class, it's always an octal escape,
2661 even if it is a single digit.
2662
2663 (d) An escaped but undefined alphabetic character is taken as a literal,
2664 unless PCRE_EXTRA is set. Currently this just reserves the remaining
2665 escapes.
2666
2667 (e) {0} is now permitted. (The previous item is removed from the compiled
2668 pattern).
2669
2670 5. Changed all the names of code files so that the basic parts are no longer
2671 than 10 characters, and abolished the teeny "globals.c" file.
2672
2673 6. Changed the handling of character classes; they are now done with a 32-byte
2674 bit map always.
2675
2676 7. Added the -d and /D options to pcretest to make it possible to look at the
2677 internals of compilation without having to recompile pcre.
2678
2679
2680 Version 0.95 23-Sep-97
2681 ----------------------
2682
2683 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
2684 \x20 at the start of a run of normal characters. These were being treated as
2685 real characters, instead of the source characters being re-checked.
2686
2687
2688 Version 0.94 18-Sep-97
2689 ----------------------
2690
2691 1. The functions are now thread-safe, with the caveat that the global variables
2692 containing pointers to malloc() and free() or alternative functions are the
2693 same for all threads.
2694
2695 2. Get pcre_study() to generate a bitmap of initial characters for non-
2696 anchored patterns when this is possible, and use it if passed to pcre_exec().
2697
2698
2699 Version 0.93 15-Sep-97
2700 ----------------------
2701
2702 1. /(b)|(:+)/ was computing an incorrect first character.
2703
2704 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
2705 but not actually doing anything yet.
2706
2707 3. Treat "-" characters in classes that cannot be part of ranges as literals,
2708 as Perl does (e.g. [-az] or [az-]).
2709
2710 4. Set the anchored flag if a branch starts with .* or .*? because that tests
2711 all possible positions.
2712
2713 5. Split up into different modules to avoid including unneeded functions in a
2714 compiled binary. However, compile and exec are still in one module. The "study"
2715 function is split off.
2716
2717 6. The character tables are now in a separate module whose source is generated
2718 by an auxiliary program - but can then be edited by hand if required. There are
2719 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
2720 toupper() in the code.
2721
2722 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
2723 make them global. Abolish the function for setting them, as the caller can now
2724 set them directly.
2725
2726
2727 Version 0.92 11-Sep-97
2728 ----------------------
2729
2730 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
2731 (e.g. /a{1,3}/) was broken (I mis-optimized it).
2732
2733 2. Caseless matching was not working in character classes if the characters in
2734 the pattern were in upper case.
2735
2736 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
2737
2738 4. Make PCRE_ANCHORED public and accept as a compile option.
2739
2740 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
2741 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
2742 pass them.
2743
2744 6. Give an error if bad option bits passed at compile or run time.
2745
2746 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
2747 pcretest to cause it to pass that flag.
2748
2749 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
2750 options, and the first character, if set.
2751
2752 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
2753
2754
2755 Version 0.91 10-Sep-97
2756 ----------------------
2757
2758 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
2759 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
2760
2761 2. PCRE was looping on encountering an indefinitely repeated back reference to
2762 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
2763 Perl does - treats the match as successful.
2764
2765 ****

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