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Revision 190 - (show annotations) (download)
Thu Jul 19 10:38:20 2007 UTC (7 years, 4 months ago) by ph10
File size: 131154 byte(s)
Fix bug with .*$ when run in not-DOTALL UTF-8 mode; small performance 
improvement for .* in DOTALL UTF-8 mode.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 7.3 05-Jul-07
5 ---------------------
6
7 1. In the rejigging of the build system that eventually resulted in 7.1, the
8 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
9 brackets there is not right, since it causes compilers to look for an
10 installed pcre.h, not the version that is in the source that is being
11 compiled (which of course may be different). I have changed it back to:
12
13 #include "pcre.h"
14
15 I have a vague recollection that the change was concerned with compiling in
16 different directories, but in the new build system, that is taken care of
17 by the VPATH setting the Makefile.
18
19 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
20 when the subject happened to end in the byte 0x85 (e.g. if the last
21 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
22 characters but of course it shouldn't be taken as a newline when it is part
23 of another character. The bug was that, for an unlimited repeat of . in
24 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
25 characters when looking for a newline.
26
27 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
28
29
30
31 Version 7.2 19-Jun-07
32 ---------------------
33
34 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
35 which is apparently normally available under Windows.
36
37 2. Re-jig the pcregrep tests with different newline settings in an attempt
38 to make them independent of the local environment's newline setting.
39
40 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
41
42 4. Some of the "internals" tests were previously cut out when the link size
43 was not 2, because the output contained actual offsets. The recent new
44 "Z" feature of pcretest means that these can be cut out, making the tests
45 usable with all link sizes.
46
47 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
48 stack recursion. This gives a massive performance boost under BSD, but just
49 a small improvement under Linux. However, it saves one field in the frame
50 in all cases.
51
52 6. Added more features from the forthcoming Perl 5.10:
53
54 (a) (?-n) (where n is a string of digits) is a relative subroutine or
55 recursion call. It refers to the nth most recently opened parentheses.
56
57 (b) (?+n) is also a relative subroutine call; it refers to the nth next
58 to be opened parentheses.
59
60 (c) Conditions that refer to capturing parentheses can be specified
61 relatively, for example, (?(-2)... or (?(+3)...
62
63 (d) \K resets the start of the current match so that everything before
64 is not part of it.
65
66 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
67
68 (f) \g{name} is another synonym - part of Perl 5.10's unification of
69 reference syntax.
70
71 (g) (?| introduces a group in which the numbering of parentheses in each
72 alternative starts with the same number.
73
74 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
75
76 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
77 PCRE_INFO_JCHANGED.
78
79 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
80 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
81 for detecting groups that can match an empty string.
82
83 9. A pattern with a very large number of alternatives (more than several
84 hundred) was running out of internal workspace during the pre-compile
85 phase, where pcre_compile() figures out how much memory will be needed. A
86 bit of new cunning has reduced the workspace needed for groups with
87 alternatives. The 1000-alternative test pattern now uses 12 bytes of
88 workspace instead of running out of the 4096 that are available.
89
90 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
91
92 11. Applied patch from Google to remove an optimization that didn't quite work.
93 The report of the bug said:
94
95 pcrecpp::RE("a*").FullMatch("aaa") matches, while
96 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
97 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
98
99 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
100 it matched the wrong number of bytes.
101
102
103 Version 7.1 24-Apr-07
104 ---------------------
105
106 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
107 that is more "standard", making use of automake and other Autotools. There
108 is some re-arrangement of the files and adjustment of comments consequent
109 on this.
110
111 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
112 for recursive directory scanning broke on some systems because the files
113 are not scanned in any specific order and on different systems the order
114 was different. A call to "sort" has been inserted into RunGrepTest for the
115 approprate test as a short-term fix. In the longer term there may be an
116 alternative.
117
118 3. I had an email from Eric Raymond about problems translating some of PCRE's
119 man pages to HTML (despite the fact that I distribute HTML pages, some
120 people do their own conversions for various reasons). The problems
121 concerned the use of low-level troff macros .br and .in. I have therefore
122 removed all such uses from the man pages (some were redundant, some could
123 be replaced by .nf/.fi pairs). The 132html script that I use to generate
124 HTML has been updated to handle .nf/.fi and to complain if it encounters
125 .br or .in.
126
127 4. Updated comments in configure.ac that get placed in config.h.in and also
128 arranged for config.h to be included in the distribution, with the name
129 config.h.generic, for the benefit of those who have to compile without
130 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
131
132 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
133 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
134 makevp.bat for the current PCRE, using the additional files
135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
136
137 6. A Windows user reported a minor discrepancy with test 2, which turned out
138 to be caused by a trailing space on an input line that had got lost in his
139 copy. The trailing space was an accident, so I've just removed it.
140
141 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
142 that is needed.
143
144 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
145 as "const" (a) because they are and (b) because it helps the PHP
146 maintainers who have recently made a script to detect big data structures
147 in the php code that should be moved to the .rodata section. I remembered
148 to update Builducptable as well, so it won't revert if ucptable.h is ever
149 re-created.
150
151 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
152 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
153 order to be able to cut out the UTF-8 tables in the latter when UTF-8
154 support is not required. This saves 1.5-2K of code, which is important in
155 some applications.
156
157 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
158 so as not to refer to the tables, even though these functions will never be
159 called when UTF-8 support is disabled. Otherwise there are problems with a
160 shared library.
161
162 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
163
164 (a) It was defining its arguments as char * instead of void *.
165
166 (b) It was assuming that all moves were upwards in memory; this was true
167 a long time ago when I wrote it, but is no longer the case.
168
169 The emulated memove() is provided for those environments that have neither
170 memmove() nor bcopy(). I didn't think anyone used it these days, but that
171 is clearly not the case, as these two bugs were recently reported.
172
173 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
174 and Detrail to create the HTML documentation, the .txt form of the man
175 pages, and it removes trailing spaces from listed files. It also creates
176 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
177 case, it wraps all the #defines with #ifndefs. This script should be run
178 before "make dist".
179
180 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
181 with Unicode property support.
182
183 (a) For a maximizing quantifier, if the two different cases of the
184 character were of different lengths in their UTF-8 codings (there are
185 some cases like this - I found 11), and the matching function had to
186 back up over a mixture of the two cases, it incorrectly assumed they
187 were both the same length.
188
189 (b) When PCRE was configured to use the heap rather than the stack for
190 recursion during matching, it was not correctly preserving the data for
191 the other case of a UTF-8 character when checking ahead for a match
192 while processing a minimizing repeat. If the check also involved
193 matching a wide character, but failed, corruption could cause an
194 erroneous result when trying to check for a repeat of the original
195 character.
196
197 13. Some tidying changes to the testing mechanism:
198
199 (a) The RunTest script now detects the internal link size and whether there
200 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
201 values substituted by "configure". (The RunGrepTest script already did
202 this for UTF-8.) The configure.ac script no longer substitutes the
203 relevant variables.
204
205 (b) The debugging options /B and /D in pcretest show the compiled bytecode
206 with length and offset values. This means that the output is different
207 for different internal link sizes. Test 2 is skipped for link sizes
208 other than 2 because of this, bypassing the problem. Unfortunately,
209 there was also a test in test 3 (the locale tests) that used /B and
210 failed for link sizes other than 2. Rather than cut the whole test out,
211 I have added a new /Z option to pcretest that replaces the length and
212 offset values with spaces. This is now used to make test 3 independent
213 of link size. (Test 2 will be tidied up later.)
214
215 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
216 segmentation fault instead of returning the appropriate error message.
217
218 15. In multiline mode when the newline sequence was set to "any", the pattern
219 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
220 This doesn't seem right; it now treats the CRLF combination as the line
221 ending, and so does not match in that case. It's only a pattern such as ^$
222 that would hit this one: something like ^ABC$ would have failed after \r
223 and then tried again after \r\n.
224
225 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
226 in an attempt to make files that differ only in their line terminators
227 compare equal. This works on Linux.
228
229 17. Under certain error circumstances pcregrep might try to free random memory
230 as it exited. This is now fixed, thanks to valgrind.
231
232 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
233 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
234 was because its rules for how to advance for /g after matching an empty
235 string at the end of a line did not allow for this case. They now check for
236 it specially.
237
238 20. pcretest is supposed to handle patterns and data of any length, by
239 extending its buffers when necessary. It was getting this wrong when the
240 buffer for a data line had to be extended.
241
242 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
243 CRLF as a newline sequence.
244
245 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
246 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
247 I have nevertheless tidied it up.
248
249 23. Added some casts to kill warnings from HP-UX ia64 compiler.
250
251 24. Added a man page for pcre-config.
252
253
254 Version 7.0 19-Dec-06
255 ---------------------
256
257 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
258 moving to gcc 4.1.1.
259
260 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
261 sys/time.h, which is documented as needed for this function. It doesn't
262 seem to matter on Linux, but it showed up on some releases of OS X.
263
264 3. It seems that there are systems where bytes whose values are greater than
265 127 match isprint() in the "C" locale. The "C" locale should be the
266 default when a C program starts up. In most systems, only ASCII printing
267 characters match isprint(). This difference caused the output from pcretest
268 to vary, making some of the tests fail. I have changed pcretest so that:
269
270 (a) When it is outputting text in the compiled version of a pattern, bytes
271 other than 32-126 are always shown as hex escapes.
272
273 (b) When it is outputting text that is a matched part of a subject string,
274 it does the same, unless a different locale has been set for the match
275 (using the /L modifier). In this case, it uses isprint() to decide.
276
277 4. Fixed a major bug that caused incorrect computation of the amount of memory
278 required for a compiled pattern when options that changed within the
279 pattern affected the logic of the preliminary scan that determines the
280 length. The relevant options are -x, and -i in UTF-8 mode. The result was
281 that the computed length was too small. The symptoms of this bug were
282 either the PCRE error "internal error: code overflow" from pcre_compile(),
283 or a glibc crash with a message such as "pcretest: free(): invalid next
284 size (fast)". Examples of patterns that provoked this bug (shown in
285 pcretest format) are:
286
287 /(?-x: )/x
288 /(?x)(?-x: \s*#\s*)/
289 /((?i)[\x{c0}])/8
290 /(?i:[\x{c0}])/8
291
292 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
293 is now done differently.
294
295 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
296 wrapper classes; (b) implement a new function in the C++ scanner that is
297 more efficient than the old way of doing things because it avoids levels of
298 recursion in the regex matching; (c) add a paragraph to the documentation
299 for the FullMatch() function.
300
301 6. The escape sequence \n was being treated as whatever was defined as
302 "newline". Not only was this contrary to the documentation, which states
303 that \n is character 10 (hex 0A), but it also went horribly wrong when
304 "newline" was defined as CRLF. This has been fixed.
305
306 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
307 was being set to -1 for the "end of line" case (supposedly a value that no
308 character can have). Though this value is never used (the check for end of
309 line is "zero bytes in current character"), it caused compiler complaints.
310 I've changed it to 0xffffffff.
311
312 8. In pcre_version.c, the version string was being built by a sequence of
313 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
314 string (as it is for production releases) called a macro with an empty
315 argument. The C standard says the result of this is undefined. The gcc
316 compiler treats it as an empty string (which was what was wanted) but it is
317 reported that Visual C gives an error. The source has been hacked around to
318 avoid this problem.
319
320 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
321 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
322 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
323 of them did).
324
325 10. Originally, pcretest opened its input and output without "b"; then I was
326 told that "b" was needed in some environments, so it was added for release
327 5.0 to both the input and output. (It makes no difference on Unix-like
328 systems.) Later I was told that it is wrong for the input on Windows. I've
329 now abstracted the modes into two macros, to make it easier to fiddle with
330 them, and removed "b" from the input mode under Windows.
331
332 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
333
334 12. Added -help and --help to pcretest as an official way of being reminded
335 of the options.
336
337 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
338 and pcrecpp.cc because they annoy compilers at high warning levels.
339
340 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
341
342 15. Fixed an occurrence of == in configure.ac that should have been = (shell
343 scripts are not C programs :-) and which was not noticed because it works
344 on Linux.
345
346 16. pcretest is supposed to handle any length of pattern and data line (as one
347 line or as a continued sequence of lines) by extending its input buffer if
348 necessary. This feature was broken for very long pattern lines, leading to
349 a string of junk being passed to pcre_compile() if the pattern was longer
350 than about 50K.
351
352 17. I have done a major re-factoring of the way pcre_compile() computes the
353 amount of memory needed for a compiled pattern. Previously, there was code
354 that made a preliminary scan of the pattern in order to do this. That was
355 OK when PCRE was new, but as the facilities have expanded, it has become
356 harder and harder to keep it in step with the real compile phase, and there
357 have been a number of bugs (see for example, 4 above). I have now found a
358 cunning way of running the real compile function in a "fake" mode that
359 enables it to compute how much memory it would need, while actually only
360 ever using a few hundred bytes of working memory and without too many
361 tests of the mode. This should make future maintenance and development
362 easier. A side effect of this work is that the limit of 200 on the nesting
363 depth of parentheses has been removed (though this was never a serious
364 limitation, I suspect). However, there is a downside: pcre_compile() now
365 runs more slowly than before (30% or more, depending on the pattern). I
366 hope this isn't a big issue. There is no effect on runtime performance.
367
368 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
369 newline (only possible for the last line of a file) and it was a
370 pattern that set a locale (followed by /Lsomething), pcretest crashed.
371
372 19. Added additional timing features to pcretest. (1) The -tm option now times
373 matching only, not compiling. (2) Both -t and -tm can be followed, as a
374 separate command line item, by a number that specifies the number of
375 repeats to use when timing. The default is 50000; this gives better
376 precision, but takes uncomfortably long for very large patterns.
377
378 20. Extended pcre_study() to be more clever in cases where a branch of a
379 subpattern has no definite first character. For example, (a*|b*)[cd] would
380 previously give no result from pcre_study(). Now it recognizes that the
381 first character must be a, b, c, or d.
382
383 21. There was an incorrect error "recursive call could loop indefinitely" if
384 a subpattern (or the entire pattern) that was being tested for matching an
385 empty string contained only one non-empty item after a nested subpattern.
386 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
387 incorrectly, because the \d was being skipped in the check.
388
389 22. The pcretest program now has a new pattern option /B and a command line
390 option -b, which is equivalent to adding /B to every pattern. This causes
391 it to show the compiled bytecode, without the additional information that
392 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
393 is the same as /B/I).
394
395 23. A new optimization is now able automatically to treat some sequences such
396 as a*b as a*+b. More specifically, if something simple (such as a character
397 or a simple class like \d) has an unlimited quantifier, and is followed by
398 something that cannot possibly match the quantified thing, the quantifier
399 is automatically "possessified".
400
401 24. A recursive reference to a subpattern whose number was greater than 39
402 went wrong under certain circumstances in UTF-8 mode. This bug could also
403 have affected the operation of pcre_study().
404
405 25. Realized that a little bit of performance could be had by replacing
406 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
407
408 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
409
410 27. Possessive quantifiers such as a++ were previously implemented by turning
411 them into atomic groups such as ($>a+). Now they have their own opcodes,
412 which improves performance. This includes the automatically created ones
413 from 23 above.
414
415 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
416 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
417 the first matched character to be a colon. This applied both to named and
418 numbered groups.
419
420 29. The ucpinternal.h header file was missing its idempotency #ifdef.
421
422 30. I was sent a "project" file called libpcre.a.dev which I understand makes
423 building PCRE on Windows easier, so I have included it in the distribution.
424
425 31. There is now a check in pcretest against a ridiculously large number being
426 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
427 loop, the loop is abandoned.
428
429 32. Forward references to subpatterns in conditions such as (?(2)...) where
430 subpattern 2 is defined later cause pcre_compile() to search forwards in
431 the pattern for the relevant set of parentheses. This search went wrong
432 when there were unescaped parentheses in a character class, parentheses
433 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
434
435 33. "Subroutine" calls and backreferences were previously restricted to
436 referencing subpatterns earlier in the regex. This restriction has now
437 been removed.
438
439 34. Added a number of extra features that are going to be in Perl 5.10. On the
440 whole, these are just syntactic alternatives for features that PCRE had
441 previously implemented using the Python syntax or my own invention. The
442 other formats are all retained for compatibility.
443
444 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
445 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
446 also .NET compatible.
447
448 (b) A recursion or subroutine call to a named group can now be defined as
449 (?&name) as well as (?P>name).
450
451 (c) A backreference to a named group can now be defined as \k<name> or
452 \k'name' as well as (?P=name). The new forms, as well as being in Perl
453 5.10, are also .NET compatible.
454
455 (d) A conditional reference to a named group can now use the syntax
456 (?(<name>) or (?('name') as well as (?(name).
457
458 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
459 groups (named and numbered) that are never evaluated inline, but can be
460 called as "subroutines" from elsewhere. In effect, the DEFINE condition
461 is always false. There may be only one alternative in such a group.
462
463 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
464 as the simple (?(R). The condition is true only if the most recent
465 recursion is that of the given number or name. It does not search out
466 through the entire recursion stack.
467
468 (g) The escape \gN or \g{N} has been added, where N is a positive or
469 negative number, specifying an absolute or relative reference.
470
471 35. Tidied to get rid of some further signed/unsigned compiler warnings and
472 some "unreachable code" warnings.
473
474 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
475 things, this adds five new scripts.
476
477 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
478 There were also incompatibilities regarding the handling of \Q..\E inside
479 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
480 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
481
482 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
483 matches an empty string, and forcibly breaks the loop. There were bugs in
484 this code in non-simple cases. For a pattern such as ^(a()*)* matched
485 against aaaa the result was just "a" rather than "aaaa", for example. Two
486 separate and independent bugs (that affected different cases) have been
487 fixed.
488
489 39. Refactored the code to abolish the use of different opcodes for small
490 capturing bracket numbers. This is a tidy that I avoided doing when I
491 removed the limit on the number of capturing brackets for 3.5 back in 2001.
492 The new approach is not only tidier, it makes it possible to reduce the
493 memory needed to fix the previous bug (38).
494
495 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
496 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
497 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
498 mode.
499
500 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
501 report.
502
503 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
504 copy construction and assignment in the C++ wrapper.
505
506 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
507 couple of bugs that could have given wrong results in the "--newline=crlf"
508 case.
509
510 44. Added a number of casts and did some reorganization of signed/unsigned int
511 variables following suggestions from Dair Grant. Also renamed the variable
512 "this" as "item" because it is a C++ keyword.
513
514 45. Arranged for dftables to add
515
516 #include "pcre_internal.h"
517
518 to pcre_chartables.c because without it, gcc 4.x may remove the array
519 definition from the final binary if PCRE is built into a static library and
520 dead code stripping is activated.
521
522 46. For an unanchored pattern, if a match attempt fails at the start of a
523 newline sequence, and the newline setting is CRLF or ANY, and the next two
524 characters are CRLF, advance by two characters instead of one.
525
526
527 Version 6.7 04-Jul-06
528 ---------------------
529
530 1. In order to handle tests when input lines are enormously long, pcretest has
531 been re-factored so that it automatically extends its buffers when
532 necessary. The code is crude, but this _is_ just a test program. The
533 default size has been increased from 32K to 50K.
534
535 2. The code in pcre_study() was using the value of the re argument before
536 testing it for NULL. (Of course, in any sensible call of the function, it
537 won't be NULL.)
538
539 3. The memmove() emulation function in pcre_internal.h, which is used on
540 systems that lack both memmove() and bcopy() - that is, hardly ever -
541 was missing a "static" storage class specifier.
542
543 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
544 containing an extended class (one that cannot be represented by a bitmap
545 because it contains high-valued characters or Unicode property items, e.g.
546 [\pZ]). Almost always one would set UTF-8 mode when processing such a
547 pattern, but PCRE should not loop if you do not (it no longer does).
548 [Detail: two cases were found: (a) a repeated subpattern containing an
549 extended class; (b) a recursive reference to a subpattern that followed a
550 previous extended class. It wasn't skipping over the extended class
551 correctly when UTF-8 mode was not set.]
552
553 5. A negated single-character class was not being recognized as fixed-length
554 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
555 compile error "lookbehind assertion is not fixed length".
556
557 6. The RunPerlTest auxiliary script was showing an unexpected difference
558 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
559 write a Perl script that can interpret lines of an input file either as
560 byte characters or as UTF-8, which is what "perltest" was being required to
561 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
562 can't do is switch easily at run time between having the "use utf8;" pragma
563 or not. In the end, I fudged it by using the RunPerlTest script to insert
564 "use utf8;" explicitly for the UTF-8 tests.
565
566 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
567 the end of the subject string, contrary to the documentation and to what
568 Perl does. This was true of both matching functions. Now it matches only at
569 the start of the subject and immediately after *internal* newlines.
570
571 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
572 a pointer to an int instead of a pointer to an unsigned long int. This
573 caused problems on 64-bit systems.
574
575 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
576 instance of the 'standard' template library not being so standard".
577
578 10. There was no check on the number of named subpatterns nor the maximum
579 length of a subpattern name. The product of these values is used to compute
580 the size of the memory block for a compiled pattern. By supplying a very
581 long subpattern name and a large number of named subpatterns, the size
582 computation could be caused to overflow. This is now prevented by limiting
583 the length of names to 32 characters, and the number of named subpatterns
584 to 10,000.
585
586 11. Subpatterns that are repeated with specific counts have to be replicated in
587 the compiled pattern. The size of memory for this was computed from the
588 length of the subpattern and the repeat count. The latter is limited to
589 65535, but there was no limit on the former, meaning that integer overflow
590 could in principle occur. The compiled length of a repeated subpattern is
591 now limited to 30,000 bytes in order to prevent this.
592
593 12. Added the optional facility to have named substrings with the same name.
594
595 13. Added the ability to use a named substring as a condition, using the
596 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
597 are numbers (not recommended). Forward references are permitted.
598
599 14. Added forward references in named backreferences (if you see what I mean).
600
601 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
602 pattern could run off the end of the subject. For example, the pattern
603 "(?s)(.{1,5})"8 did this with the subject "ab".
604
605 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
606 PCRE_CASELESS was set when matching characters that were quantified with ?
607 or *.
608
609 17. A character class other than a single negated character that had a minimum
610 but no maximum quantifier - for example [ab]{6,} - was not handled
611 correctly by pce_dfa_exec(). It would match only one character.
612
613 18. A valid (though odd) pattern that looked like a POSIX character
614 class but used an invalid character after [ (for example [[,abc,]]) caused
615 pcre_compile() to give the error "Failed: internal error: code overflow" or
616 in some cases to crash with a glibc free() error. This could even happen if
617 the pattern terminated after [[ but there just happened to be a sequence of
618 letters, a binary zero, and a closing ] in the memory that followed.
619
620 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
621 over the years. Originally (before any Unicode support), just the bottom 8
622 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
623 output from "man perlunicode" includes this:
624
625 The regular expression compiler produces polymorphic opcodes. That
626 is, the pattern adapts to the data and automatically switches to
627 the Unicode character scheme when presented with Unicode data--or
628 instead uses a traditional byte scheme when presented with byte
629 data.
630
631 Sadly, a wide octal escape does not cause a switch, and in a string with
632 no other multibyte characters, these octal escapes are treated as before.
633 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
634 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
635 Unicode string.
636
637 I have not perpetrated such confusion in PCRE. Up till now, it took just
638 the bottom 8 bits, as in old Perl. I have now made octal escapes with
639 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
640 translate to the appropriate multibyte character.
641
642 29. Applied some refactoring to reduce the number of warnings from Microsoft
643 and Borland compilers. This has included removing the fudge introduced
644 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
645 a warning about an unused variable.
646
647 21. PCRE has not included VT (character 0x0b) in the set of whitespace
648 characters since release 4.0, because Perl (from release 5.004) does not.
649 [Or at least, is documented not to: some releases seem to be in conflict
650 with the documentation.] However, when a pattern was studied with
651 pcre_study() and all its branches started with \s, PCRE still included VT
652 as a possible starting character. Of course, this did no harm; it just
653 caused an unnecessary match attempt.
654
655 22. Removed a now-redundant internal flag bit that recorded the fact that case
656 dependency changed within the pattern. This was once needed for "required
657 byte" processing, but is no longer used. This recovers a now-scarce options
658 bit. Also moved the least significant internal flag bit to the most-
659 significant bit of the word, which was not previously used (hangover from
660 the days when it was an int rather than a uint) to free up another bit for
661 the future.
662
663 23. Added support for CRLF line endings as well as CR and LF. As well as the
664 default being selectable at build time, it can now be changed at runtime
665 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
666 specify that it is scanning data with non-default line endings.
667
668 24. Changed the definition of CXXLINK to make it agree with the definition of
669 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
670
671 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
672 recursions. This makes a big different to stack usage for some patterns.
673
674 26. If a subpattern containing a named recursion or subroutine reference such
675 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
676 the space required for the compiled pattern went wrong and gave too small a
677 value. Depending on the environment, this could lead to "Failed: internal
678 error: code overflow at offset 49" or "glibc detected double free or
679 corruption" errors.
680
681 27. Applied patches from Google (a) to support the new newline modes and (b) to
682 advance over multibyte UTF-8 characters in GlobalReplace.
683
684 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
685 difference for some implementation of PCRE in some Windows version.
686
687 29. Added some extra testing facilities to pcretest:
688
689 \q<number> in a data line sets the "match limit" value
690 \Q<number> in a data line sets the "match recursion limt" value
691 -S <number> sets the stack size, where <number> is in megabytes
692
693 The -S option isn't available for Windows.
694
695
696 Version 6.6 06-Feb-06
697 ---------------------
698
699 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
700 in pcreposix.h. I have copied the definition from pcre.h.
701
702 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
703 because pcre.h is no longer a built file.
704
705 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
706 not normally included in the compiled code.
707
708
709 Version 6.5 01-Feb-06
710 ---------------------
711
712 1. When using the partial match feature with pcre_dfa_exec(), it was not
713 anchoring the second and subsequent partial matches at the new starting
714 point. This could lead to incorrect results. For example, with the pattern
715 /1234/, partially matching against "123" and then "a4" gave a match.
716
717 2. Changes to pcregrep:
718
719 (a) All non-match returns from pcre_exec() were being treated as failures
720 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
721 error message is output. Some extra information is given for the
722 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
723 probably the only errors that are likely to be caused by users (by
724 specifying a regex that has nested indefinite repeats, for instance).
725 If there are more than 20 of these errors, pcregrep is abandoned.
726
727 (b) A binary zero was treated as data while matching, but terminated the
728 output line if it was written out. This has been fixed: binary zeroes
729 are now no different to any other data bytes.
730
731 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
732 used to set a locale for matching. The --locale=xxxx long option has
733 been added (no short equivalent) to specify a locale explicitly on the
734 pcregrep command, overriding the environment variables.
735
736 (d) When -B was used with -n, some line numbers in the output were one less
737 than they should have been.
738
739 (e) Added the -o (--only-matching) option.
740
741 (f) If -A or -C was used with -c (count only), some lines of context were
742 accidentally printed for the final match.
743
744 (g) Added the -H (--with-filename) option.
745
746 (h) The combination of options -rh failed to suppress file names for files
747 that were found from directory arguments.
748
749 (i) Added the -D (--devices) and -d (--directories) options.
750
751 (j) Added the -F (--fixed-strings) option.
752
753 (k) Allow "-" to be used as a file name for -f as well as for a data file.
754
755 (l) Added the --colo(u)r option.
756
757 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
758 is not present by default.
759
760 3. A nasty bug was discovered in the handling of recursive patterns, that is,
761 items such as (?R) or (?1), when the recursion could match a number of
762 alternatives. If it matched one of the alternatives, but subsequently,
763 outside the recursion, there was a failure, the code tried to back up into
764 the recursion. However, because of the way PCRE is implemented, this is not
765 possible, and the result was an incorrect result from the match.
766
767 In order to prevent this happening, the specification of recursion has
768 been changed so that all such subpatterns are automatically treated as
769 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
770
771 4. I had overlooked the fact that, in some locales, there are characters for
772 which isalpha() is true but neither isupper() nor islower() are true. In
773 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
774 and ordfeminine) are like this. This affected the treatment of \w and \W
775 when they appeared in character classes, but not when they appeared outside
776 a character class. The bit map for "word" characters is now created
777 separately from the results of isalnum() instead of just taking it from the
778 upper, lower, and digit maps. (Plus the underscore character, of course.)
779
780 5. The above bug also affected the handling of POSIX character classes such as
781 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
782 permanent tables. Instead, the bit maps for such a class were previously
783 created as the appropriate unions of the upper, lower, and digit bitmaps.
784 Now they are created by subtraction from the [[:word:]] class, which has
785 its own bitmap.
786
787 6. The [[:blank:]] character class matches horizontal, but not vertical space.
788 It is created by subtracting the vertical space characters (\x09, \x0a,
789 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
790 subtraction was done in the overall bitmap for a character class, meaning
791 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
792 be recognized. This bug has been fixed.
793
794 7. Patches from the folks at Google:
795
796 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
797 real life, but is still worth protecting against".
798
799 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
800 regular expressions".
801
802 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
803 have it.
804
805 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
806 "configure" and the latter not, in order to fix a problem somebody had
807 with compiling the Arg class on HP-UX.
808
809 (e) Improve the error-handling of the C++ wrapper a little bit.
810
811 (f) New tests for checking recursion limiting.
812
813 8. The pcre_memmove() function, which is used only if the environment does not
814 have a standard memmove() function (and is therefore rarely compiled),
815 contained two bugs: (a) use of int instead of size_t, and (b) it was not
816 returning a result (though PCRE never actually uses the result).
817
818 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
819 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
820 returned instead of calling malloc() with an overflowing number that would
821 most likely cause subsequent chaos.
822
823 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
824
825 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
826 with this option is matched, the nmatch and pmatch options of regexec() are
827 ignored.
828
829 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
830 provided in case anyone wants to the the POSIX interface with UTF-8
831 strings.
832
833 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
834 C++ linking (needed for some HP-UX environments).
835
836 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
837 (unused parameter) and in the pcre_printint() function (omitted "default"
838 switch label when the default is to do nothing).
839
840 15. Added some code to make it possible, when PCRE is compiled as a C++
841 library, to replace subject pointers for pcre_exec() with a smart pointer
842 class, thus making it possible to process discontinuous strings.
843
844 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
845 much the same function. They were added by different people who were trying
846 to make PCRE easy to compile on non-Unix systems. It has been suggested
847 that PCRE_EXPORT be abolished now that there is more automatic apparatus
848 for compiling on Windows systems. I have therefore replaced it with
849 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
850 defaults to "extern" for C or "extern C" for C++, which works fine on
851 Unix-like systems. It is now possible to override the value of PCRE_DATA_
852 SCOPE with something explicit in config.h. In addition:
853
854 (a) pcreposix.h still had just "extern" instead of either of these macros;
855 I have replaced it with PCRE_DATA_SCOPE.
856
857 (b) Functions such as _pcre_xclass(), which are internal to the library,
858 but external in the C sense, all had PCRE_EXPORT in their definitions.
859 This is apparently wrong for the Windows case, so I have removed it.
860 (It makes no difference on Unix-like systems.)
861
862 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
863 of recursive calls to match(). This is different to MATCH_LIMIT because
864 that limits the total number of calls to match(), not all of which increase
865 the depth of recursion. Limiting the recursion depth limits the amount of
866 stack (or heap if NO_RECURSE is set) that is used. The default can be set
867 when PCRE is compiled, and changed at run time. A patch from Google adds
868 this functionality to the C++ interface.
869
870 18. Changes to the handling of Unicode character properties:
871
872 (a) Updated the table to Unicode 4.1.0.
873
874 (b) Recognize characters that are not in the table as "Cn" (undefined).
875
876 (c) I revised the way the table is implemented to a much improved format
877 which includes recognition of ranges. It now supports the ranges that
878 are defined in UnicodeData.txt, and it also amalgamates other
879 characters into ranges. This has reduced the number of entries in the
880 table from around 16,000 to around 3,000, thus reducing its size
881 considerably. I realized I did not need to use a tree structure after
882 all - a binary chop search is just as efficient. Having reduced the
883 number of entries, I extended their size from 6 bytes to 8 bytes to
884 allow for more data.
885
886 (d) Added support for Unicode script names via properties such as \p{Han}.
887
888 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
889 matching that character.
890
891 20. When matching a repeated Unicode property with a minimum greater than zero,
892 (for example \pL{2,}), PCRE could look past the end of the subject if it
893 reached it while seeking the minimum number of characters. This could
894 happen only if some of the characters were more than one byte long, because
895 there is a check for at least the minimum number of bytes.
896
897 21. Refactored the implementation of \p and \P so as to be more general, to
898 allow for more different types of property in future. This has changed the
899 compiled form incompatibly. Anybody with saved compiled patterns that use
900 \p or \P will have to recompile them.
901
902 22. Added "Any" and "L&" to the supported property types.
903
904 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
905 but give a compile time error if the value is greater than 0xff.
906
907 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
908 accidentally not being installed or uninstalled.
909
910 25. The pcre.h file was built from pcre.h.in, but the only changes that were
911 made were to insert the current release number. This seemed silly, because
912 it made things harder for people building PCRE on systems that don't run
913 "configure". I have turned pcre.h into a distributed file, no longer built
914 by "configure", with the version identification directly included. There is
915 no longer a pcre.h.in file.
916
917 However, this change necessitated a change to the pcre-config script as
918 well. It is built from pcre-config.in, and one of the substitutions was the
919 release number. I have updated configure.ac so that ./configure now finds
920 the release number by grepping pcre.h.
921
922 26. Added the ability to run the tests under valgrind.
923
924
925 Version 6.4 05-Sep-05
926 ---------------------
927
928 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
929 "--" to be printed when multiple files were scanned, even when none of the
930 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
931 consider it to be a bug, and have restored the previous behaviour.
932
933 2. A couple of code tidies to get rid of compiler warnings.
934
935 3. The pcretest program used to cheat by referring to symbols in the library
936 whose names begin with _pcre_. These are internal symbols that are not
937 really supposed to be visible externally, and in some environments it is
938 possible to suppress them. The cheating is now confined to including
939 certain files from the library's source, which is a bit cleaner.
940
941 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
942 file's purpose clearer.
943
944 5. Reorganized pcre_ucp_findchar().
945
946
947 Version 6.3 15-Aug-05
948 ---------------------
949
950 1. The file libpcre.pc.in did not have general read permission in the tarball.
951
952 2. There were some problems when building without C++ support:
953
954 (a) If C++ support was not built, "make install" and "make test" still
955 tried to test it.
956
957 (b) There were problems when the value of CXX was explicitly set. Some
958 changes have been made to try to fix these, and ...
959
960 (c) --disable-cpp can now be used to explicitly disable C++ support.
961
962 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
963 backslash in a target when C++ was disabled. This confuses some
964 versions of "make", apparently. Using an intermediate variable solves
965 this. (Same for CPP_LOBJ.)
966
967 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
968 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
969 necessary on certain architectures.
970
971 4. Added a setting of -export-symbols-regex to the link command to remove
972 those symbols that are exported in the C sense, but actually are local
973 within the library, and not documented. Their names all begin with
974 "_pcre_". This is not a perfect job, because (a) we have to except some
975 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
976 available (and never for static libraries). I have made a note to try to
977 find a way round (a) in the future.
978
979
980 Version 6.2 01-Aug-05
981 ---------------------
982
983 1. There was no test for integer overflow of quantifier values. A construction
984 such as {1111111111111111} would give undefined results. What is worse, if
985 a minimum quantifier for a parenthesized subpattern overflowed and became
986 negative, the calculation of the memory size went wrong. This could have
987 led to memory overwriting.
988
989 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
990
991 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
992 operating environments where this matters.
993
994 4. Applied Giuseppe Maxia's patch to add additional features for controlling
995 PCRE options from within the C++ wrapper.
996
997 5. Named capturing subpatterns were not being correctly counted when a pattern
998 was compiled. This caused two problems: (a) If there were more than 100
999 such subpatterns, the calculation of the memory needed for the whole
1000 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1001 back references of the form \12, where the number was greater than 9, were
1002 not recognized as back references, even though there were sufficient
1003 previous subpatterns.
1004
1005 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1006 versions of gcc, e.g. 2.95.4.
1007
1008
1009 Version 6.1 21-Jun-05
1010 ---------------------
1011
1012 1. There was one reference to the variable "posix" in pcretest.c that was not
1013 surrounded by "#if !defined NOPOSIX".
1014
1015 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1016 the cross-check on the old pcre_info() function, for the benefit of the
1017 cut-down version of PCRE that is currently imported into Exim.
1018
1019 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1020 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1021 patterns that start (?i) but I don't think that matters. The use of (?i) is
1022 just an example; this all applies to the other options as well.
1023
1024 4. Since libtool seems to echo the compile commands it is issuing, the output
1025 from "make" can be reduced a bit by putting "@" in front of each libtool
1026 compile command.
1027
1028 5. Patch from the folks at Google for configure.in to be a bit more thorough
1029 in checking for a suitable C++ installation before trying to compile the
1030 C++ stuff. This should fix a reported problem when a compiler was present,
1031 but no suitable headers.
1032
1033 6. The man pages all had just "PCRE" as their title. I have changed them to
1034 be the relevant file name. I have also arranged that these names are
1035 retained in the file doc/pcre.txt, which is a concatenation in text format
1036 of all the man pages except the little individual ones for each function.
1037
1038 7. The NON-UNIX-USE file had not been updated for the different set of source
1039 files that come with release 6. I also added a few comments about the C++
1040 wrapper.
1041
1042
1043 Version 6.0 07-Jun-05
1044 ---------------------
1045
1046 1. Some minor internal re-organization to help with my DFA experiments.
1047
1048 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1049 didn't matter for the library itself when fully configured, but did matter
1050 when compiling without UCP support, or within Exim, where the ucp files are
1051 not imported.
1052
1053 3. Refactoring of the library code to split up the various functions into
1054 different source modules. The addition of the new DFA matching code (see
1055 below) to a single monolithic source would have made it really too
1056 unwieldy, quite apart from causing all the code to be include in a
1057 statically linked application, when only some functions are used. This is
1058 relevant even without the DFA addition now that patterns can be compiled in
1059 one application and matched in another.
1060
1061 The downside of splitting up is that there have to be some external
1062 functions and data tables that are used internally in different modules of
1063 the library but which are not part of the API. These have all had their
1064 names changed to start with "_pcre_" so that they are unlikely to clash
1065 with other external names.
1066
1067 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1068 a different (DFA) algorithm. Although it is slower than the original
1069 function, it does have some advantages for certain types of matching
1070 problem.
1071
1072 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1073 including restarting after a partial match.
1074
1075 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1076 defined when compiling for Windows was sent to me. I have put it into the
1077 code, though I have no means of testing or verifying it.
1078
1079 7. Added the pcre_refcount() auxiliary function.
1080
1081 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1082 match before or at the first newline in the subject string. In pcretest,
1083 the /f option on a pattern can be used to set this.
1084
1085 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1086 would behave wrongly. This has been present in PCRE since release 4.0.
1087
1088 10. A number of changes to the pcregrep command:
1089
1090 (a) Refactored how -x works; insert ^(...)$ instead of setting
1091 PCRE_ANCHORED and checking the length, in preparation for adding
1092 something similar for -w.
1093
1094 (b) Added the -w (match as a word) option.
1095
1096 (c) Refactored the way lines are read and buffered so as to have more
1097 than one at a time available.
1098
1099 (d) Implemented a pcregrep test script.
1100
1101 (e) Added the -M (multiline match) option. This allows patterns to match
1102 over several lines of the subject. The buffering ensures that at least
1103 8K, or the rest of the document (whichever is the shorter) is available
1104 for matching (and similarly the previous 8K for lookbehind assertions).
1105
1106 (f) Changed the --help output so that it now says
1107
1108 -w, --word-regex(p)
1109
1110 instead of two lines, one with "regex" and the other with "regexp"
1111 because that confused at least one person since the short forms are the
1112 same. (This required a bit of code, as the output is generated
1113 automatically from a table. It wasn't just a text change.)
1114
1115 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1116 option but starts with a hyphen. Could be a pattern or a path name
1117 starting with a hyphen, for instance.
1118
1119 (h) "-" can be given as a file name to represent stdin.
1120
1121 (i) When file names are being printed, "(standard input)" is used for
1122 the standard input, for compatibility with GNU grep. Previously
1123 "<stdin>" was used.
1124
1125 (j) The option --label=xxx can be used to supply a name to be used for
1126 stdin when file names are being printed. There is no short form.
1127
1128 (k) Re-factored the options decoding logic because we are going to add
1129 two more options that take data. Such options can now be given in four
1130 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1131
1132 (l) Added the -A, -B, and -C options for requesting that lines of context
1133 around matches be printed.
1134
1135 (m) Added the -L option to print the names of files that do not contain
1136 any matching lines, that is, the complement of -l.
1137
1138 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1139 continue to scan other files.
1140
1141 (o) The -s option was incorrectly implemented. For compatibility with other
1142 greps, it now suppresses the error message for a non-existent or non-
1143 accessible file (but not the return code). There is a new option called
1144 -q that suppresses the output of matching lines, which was what -s was
1145 previously doing.
1146
1147 (p) Added --include and --exclude options to specify files for inclusion
1148 and exclusion when recursing.
1149
1150 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1151 Hopefully, it now does.
1152
1153 12. Missing cast in pcre_study().
1154
1155 13. Added an "uninstall" target to the makefile.
1156
1157 14. Replaced "extern" in the function prototypes in Makefile.in with
1158 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1159 world, but is set differently for Windows.
1160
1161 15. Added a second compiling function called pcre_compile2(). The only
1162 difference is that it has an extra argument, which is a pointer to an
1163 integer error code. When there is a compile-time failure, this is set
1164 non-zero, in addition to the error test pointer being set to point to an
1165 error message. The new argument may be NULL if no error number is required
1166 (but then you may as well call pcre_compile(), which is now just a
1167 wrapper). This facility is provided because some applications need a
1168 numeric error indication, but it has also enabled me to tidy up the way
1169 compile-time errors are handled in the POSIX wrapper.
1170
1171 16. Added VPATH=.libs to the makefile; this should help when building with one
1172 prefix path and installing with another. (Or so I'm told by someone who
1173 knows more about this stuff than I do.)
1174
1175 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1176 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1177 match everything, including newlines. This is not POSIX-compatible, but
1178 somebody wanted the feature. From pcretest it can be activated by using
1179 both the P and the s flags.
1180
1181 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1182
1183 19. libpcre.pc was being incorrectly installed as executable.
1184
1185 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1186 it now also looks for '\r' so that it will work unmodified on Windows.
1187
1188 21. Added Google's contributed C++ wrapper to the distribution.
1189
1190 22. Added some untidy missing memory free() calls in pcretest, to keep
1191 Electric Fence happy when testing.
1192
1193
1194
1195 Version 5.0 13-Sep-04
1196 ---------------------
1197
1198 1. Internal change: literal characters are no longer packed up into items
1199 containing multiple characters in a single byte-string. Each character
1200 is now matched using a separate opcode. However, there may be more than one
1201 byte in the character in UTF-8 mode.
1202
1203 2. The pcre_callout_block structure has two new fields: pattern_position and
1204 next_item_length. These contain the offset in the pattern to the next match
1205 item, and its length, respectively.
1206
1207 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1208 insertion of callouts before each pattern item. Added the /C option to
1209 pcretest to make use of this.
1210
1211 4. On the advice of a Windows user, the lines
1212
1213 #if defined(_WIN32) || defined(WIN32)
1214 _setmode( _fileno( stdout ), 0x8000 );
1215 #endif /* defined(_WIN32) || defined(WIN32) */
1216
1217 have been added to the source of pcretest. This apparently does useful
1218 magic in relation to line terminators.
1219
1220 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1221 for the benefit of those environments where the "b" makes a difference.
1222
1223 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1224 to know about it. I have put a hack into configure.in that adds in code
1225 to set GCC=yes if CC=icc. This seems to end up at a point in the
1226 generated configure script that is early enough to affect the setting of
1227 compiler options, which is what is needed, but I have no means of testing
1228 whether it really works. (The user who reported this had patched the
1229 generated configure script, which of course I cannot do.)
1230
1231 LATER: After change 22 below (new libtool files), the configure script
1232 seems to know about icc (and also ecc). Therefore, I have commented out
1233 this hack in configure.in.
1234
1235 7. Added support for pkg-config (2 patches were sent in).
1236
1237 8. Negated POSIX character classes that used a combination of internal tables
1238 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1239 [[:^ascii]]. Typically, they would match almost any characters. The other
1240 POSIX classes were not broken in this way.
1241
1242 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1243 to find the match, as PCRE was deluded into thinking that the match had to
1244 start at the start point or following a newline. The same bug applied to
1245 patterns with negative forward assertions or any backward assertions
1246 preceding ".*" at the start, unless the pattern required a fixed first
1247 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1248
1249 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1250 starting at the last subject character, bytes beyond the end of the subject
1251 string were read.
1252
1253 11. Renamed the variable "class" as "classbits" to make life easier for C++
1254 users. (Previously there was a macro definition, but it apparently wasn't
1255 enough.)
1256
1257 12. Added the new field "tables" to the extra data so that tables can be passed
1258 in at exec time, or the internal tables can be re-selected. This allows
1259 a compiled regex to be saved and re-used at a later time by a different
1260 program that might have everything at different addresses.
1261
1262 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1263 -R library as well as a -L library.
1264
1265 14. The debugging options of pcretest (-d on the command line or D on a
1266 pattern) showed incorrect output for anything following an extended class
1267 that contained multibyte characters and which was followed by a quantifier.
1268
1269 15. Added optional support for general category Unicode character properties
1270 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1271 support. It adds about 90K to the size of the library. The meanings of the
1272 inbuilt class escapes such as \d and \s have NOT been changed.
1273
1274 16. Updated pcredemo.c to include calls to free() to release the memory for the
1275 compiled pattern.
1276
1277 17. The generated file chartables.c was being created in the source directory
1278 instead of in the building directory. This caused the build to fail if the
1279 source directory was different from the building directory, and was
1280 read-only.
1281
1282 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1283 file. No doubt somebody will tell me if they don't make sense... Also added
1284 Dan Mooney's comments about building on OpenVMS.
1285
1286 19. Added support for partial matching via the PCRE_PARTIAL option for
1287 pcre_exec() and the \P data escape in pcretest.
1288
1289 20. Extended pcretest with 3 new pattern features:
1290
1291 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1292 write the compiled pattern to the file whose name is "rest-of-line".
1293 This is a straight binary dump of the data, with the saved pointer to
1294 the character tables forced to be NULL. The study data, if any, is
1295 written too. After writing, pcretest reads a new pattern.
1296
1297 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1298 compiled pattern from the given file. There must not be any
1299 occurrences of "<" in the file name (pretty unlikely); if there are,
1300 pcretest will instead treat the initial "<" as a pattern delimiter.
1301 After reading in the pattern, pcretest goes on to read data lines as
1302 usual.
1303
1304 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1305 and 16-bit fields in a compiled pattern, to simulate a pattern that
1306 was compiled on a host of opposite endianness.
1307
1308 21. The pcre-exec() function can now cope with patterns that were compiled on
1309 hosts of opposite endianness, with this restriction:
1310
1311 As for any compiled expression that is saved and used later, the tables
1312 pointer field cannot be preserved; the extra_data field in the arguments
1313 to pcre_exec() should be used to pass in a tables address if a value
1314 other than the default internal tables were used at compile time.
1315
1316 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1317 now diagnosed as an error. Previously, most of the time, a negative number
1318 would have been treated as zero, but if in addition "ovector" was passed as
1319 NULL, a crash could occur.
1320
1321 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1322 new versions from the libtool 1.5 distribution (the last one is a copy of
1323 a file called libtool.m4). This seems to have fixed the need to patch
1324 "configure" to support Darwin 1.3 (which I used to do). However, I still
1325 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1326 workstation).
1327
1328 24. Changed the PCRE licence to be the more standard "BSD" licence.
1329
1330
1331 Version 4.5 01-Dec-03
1332 ---------------------
1333
1334 1. There has been some re-arrangement of the code for the match() function so
1335 that it can be compiled in a version that does not call itself recursively.
1336 Instead, it keeps those local variables that need separate instances for
1337 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1338 needs to "recurse". Keeping track of where control must go is done by means
1339 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1340 hide most of the details from the main code, and operates only if
1341 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1342 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1343 operating.
1344
1345 To make it easier for callers to provide specially tailored get/free
1346 functions for this usage, two new functions, pcre_stack_malloc, and
1347 pcre_stack_free, are used. They are always called in strict stacking order,
1348 and the size of block requested is always the same.
1349
1350 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1351 PCRE has been compiled to use the stack or the heap for recursion. The
1352 -C option of pcretest uses this to show which version is compiled.
1353
1354 A new data escape \S, is added to pcretest; it causes the amounts of store
1355 obtained and freed by both kinds of malloc/free at match time to be added
1356 to the output.
1357
1358 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1359 what's available on my current Linux desktop machine.
1360
1361 3. When matching a UTF-8 string, the test for a valid string at the start has
1362 been extended. If start_offset is not zero, PCRE now checks that it points
1363 to a byte that is the start of a UTF-8 character. If not, it returns
1364 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1365 this is necessary because there may be backward assertions in the pattern.
1366 When matching the same subject several times, it may save resources to use
1367 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1368
1369 4. The code for checking the validity of UTF-8 strings has been tightened so
1370 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1371 containing "overlong sequences".
1372
1373 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1374 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1375 should have been "&", but it just so happened that all the cases this let
1376 through by mistake were picked up later in the function.
1377
1378 6. I had used a variable called "isblank" - this is a C99 function, causing
1379 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1380
1381 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1382 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1383 so the version is shown; (c) stop "make test" echoing "./RunTest".
1384
1385 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1386
1387 9. The prototype for memmove() for systems that don't have it was using
1388 size_t, but the inclusion of the header that defines size_t was later. I've
1389 moved the #includes for the C headers earlier to avoid this.
1390
1391 10. Added some adjustments to the code to make it easier to compiler on certain
1392 special systems:
1393
1394 (a) Some "const" qualifiers were missing.
1395 (b) Added the macro EXPORT before all exported functions; by default this
1396 is defined to be empty.
1397 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1398 that it reads its output file name as an argument instead of writing
1399 to the standard output and assuming this can be redirected.
1400
1401 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1402 class containing characters with values greater than 255, PCRE compilation
1403 went into a loop.
1404
1405 12. A recursive reference to a subpattern that was within another subpattern
1406 that had a minimum quantifier of zero caused PCRE to crash. For example,
1407 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1408 recursion. If the recursively-called subpattern itself had a zero repeat,
1409 that was OK.
1410
1411 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1412 buffer into which it was copied (for escape processing) was still set at
1413 1024, so long lines caused crashes.
1414
1415 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1416 "internal error: code overflow...". This applied to any character class
1417 that was followed by a possessive quantifier.
1418
1419 15. Modified the Makefile to add libpcre.la as a prerequisite for
1420 libpcreposix.la because I was told this is needed for a parallel build to
1421 work.
1422
1423 16. If a pattern that contained .* following optional items at the start was
1424 studied, the wrong optimizing data was generated, leading to matching
1425 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1426 matching string must start with a or b or c. The correct conclusion for
1427 this pattern is that a match can start with any character.
1428
1429
1430 Version 4.4 13-Aug-03
1431 ---------------------
1432
1433 1. In UTF-8 mode, a character class containing characters with values between
1434 127 and 255 was not handled correctly if the compiled pattern was studied.
1435 In fixing this, I have also improved the studying algorithm for such
1436 classes (slightly).
1437
1438 2. Three internal functions had redundant arguments passed to them. Removal
1439 might give a very teeny performance improvement.
1440
1441 3. Documentation bug: the value of the capture_top field in a callout is *one
1442 more than* the number of the hightest numbered captured substring.
1443
1444 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1445 in incorrectly linking with a previously installed version. They now link
1446 explicitly with libpcre.la.
1447
1448 5. configure.in no longer needs to recognize Cygwin specially.
1449
1450 6. A problem in pcre.in for Windows platforms is fixed.
1451
1452 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1453 pcretest, it used to include the size of the study block as part of its
1454 output. Unfortunately, the structure contains a field that has a different
1455 size on different hardware architectures. This meant that the tests that
1456 showed this size failed. As the block is currently always of a fixed size,
1457 this information isn't actually particularly useful in pcretest output, so
1458 I have just removed it.
1459
1460 8. Three pre-processor statements accidentally did not start in column 1.
1461 Sadly, there are *still* compilers around that complain, even though
1462 standard C has not required this for well over a decade. Sigh.
1463
1464 9. In pcretest, the code for checking callouts passed small integers in the
1465 callout_data field, which is a void * field. However, some picky compilers
1466 complained about the casts involved for this on 64-bit systems. Now
1467 pcretest passes the address of the small integer instead, which should get
1468 rid of the warnings.
1469
1470 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1471 both compile and run time, and gives an error if an invalid UTF-8 sequence
1472 is found. There is a option for disabling this check in cases where the
1473 string is known to be correct and/or the maximum performance is wanted.
1474
1475 11. In response to a bug report, I changed one line in Makefile.in from
1476
1477 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1478 to
1479 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1480
1481 to look similar to other lines, but I have no way of telling whether this
1482 is the right thing to do, as I do not use Windows. No doubt I'll get told
1483 if it's wrong...
1484
1485
1486 Version 4.3 21-May-03
1487 ---------------------
1488
1489 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1490 Makefile.
1491
1492 2. Some refactoring to improve the quality of the code:
1493
1494 (i) The utf8_table... variables are now declared "const".
1495
1496 (ii) The code for \cx, which used the "case flipping" table to upper case
1497 lower case letters, now just substracts 32. This is ASCII-specific,
1498 but the whole concept of \cx is ASCII-specific, so it seems
1499 reasonable.
1500
1501 (iii) PCRE was using its character types table to recognize decimal and
1502 hexadecimal digits in the pattern. This is silly, because it handles
1503 only 0-9, a-f, and A-F, but the character types table is locale-
1504 specific, which means strange things might happen. A private
1505 table is now used for this - though it costs 256 bytes, a table is
1506 much faster than multiple explicit tests. Of course, the standard
1507 character types table is still used for matching digits in subject
1508 strings against \d.
1509
1510 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1511 ending in _t are). So I've renamed it as ESC_tee.
1512
1513 3. The first argument for regexec() in the POSIX wrapper should have been
1514 defined as "const".
1515
1516 4. Changed pcretest to use malloc() for its buffers so that they can be
1517 Electric Fenced for debugging.
1518
1519 5. There were several places in the code where, in UTF-8 mode, PCRE would try
1520 to read one or more bytes before the start of the subject string. Often this
1521 had no effect on PCRE's behaviour, but in some circumstances it could
1522 provoke a segmentation fault.
1523
1524 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1525 to try to read one or more bytes before the start of the subject string.
1526
1527 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1528 UTF-8 support could misbehave in various ways if the subject string
1529 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1530 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1531 back over UTF-8 characters.)
1532
1533
1534 Version 4.2 14-Apr-03
1535 ---------------------
1536
1537 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1538
1539 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1540 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1541 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1542 [WIN_PREFIX]: new variable, "cyg" for Cygwin
1543 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1544 and BUILD_EXEEXT
1545 Note: automatic setting of the BUILD variables is not yet working
1546 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1547 compile-time but not at link-time
1548 [LINK]: use for linking executables only
1549 make different versions for Windows and non-Windows
1550 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1551 libraries
1552 [LINK_FOR_BUILD]: new variable
1553 [OBJEXT]: use throughout
1554 [EXEEXT]: use throughout
1555 <winshared>: new target
1556 <wininstall>: new target
1557 <dftables.o>: use native compiler
1558 <dftables>: use native linker
1559 <install>: handle Windows platform correctly
1560 <clean>: ditto
1561 <check>: ditto
1562 copy DLL to top builddir before testing
1563
1564 As part of these changes, -no-undefined was removed again. This was reported
1565 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1566 in any case.
1567
1568 3. Some tidies to get rid of compiler warnings:
1569
1570 . In the match_data structure, match_limit was an unsigned long int, whereas
1571 match_call_count was an int. I've made them both unsigned long ints.
1572
1573 . In pcretest the fact that a const uschar * doesn't automatically cast to
1574 a void * provoked a warning.
1575
1576 . Turning on some more compiler warnings threw up some "shadow" variables
1577 and a few more missing casts.
1578
1579 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1580 option, a class that contained a single character with a value between 128
1581 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1582
1583 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1584 option, a class that contained several characters, but with at least one
1585 whose value was between 128 and 255 caused PCRE to crash.
1586
1587
1588 Version 4.1 12-Mar-03
1589 ---------------------
1590
1591 1. Compiling with gcc -pedantic found a couple of places where casts were
1592 needed, and a string in dftables.c that was longer than standard compilers are
1593 required to support.
1594
1595 2. Compiling with Sun's compiler found a few more places where the code could
1596 be tidied up in order to avoid warnings.
1597
1598 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1599 first of these names is deprecated in the latest Autoconf in favour of the name
1600 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1601 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1602 analogy I have changed it to CFLAGS_FOR_BUILD.
1603
1604 4. Added -no-undefined to the linking command in the Makefile, because this is
1605 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1606 linking step for the pcreposix library.
1607
1608 5. PCRE was failing to diagnose the case of two named groups with the same
1609 name.
1610
1611 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1612 literal character that is needed in the subject for a match, and scans along to
1613 ensure that it is present before embarking on the full matching process. This
1614 saves time in cases of nested unlimited repeats that are never going to match.
1615 Problem: the scan can take a lot of time if the subject is very long (e.g.
1616 megabytes), thus penalizing straightforward matches. It is now done only if the
1617 amount of subject to be scanned is less than 1000 bytes.
1618
1619 7. A lesser problem with the same optimization is that it was recording the
1620 first character of an anchored pattern as "needed", thus provoking a search
1621 right along the subject, even when the first match of the pattern was going to
1622 fail. The "needed" character is now not set for anchored patterns, unless it
1623 follows something in the pattern that is of non-fixed length. Thus, it still
1624 fulfils its original purpose of finding quick non-matches in cases of nested
1625 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1626
1627
1628 Version 4.0 17-Feb-03
1629 ---------------------
1630
1631 1. If a comment in an extended regex that started immediately after a meta-item
1632 extended to the end of string, PCRE compiled incorrect data. This could lead to
1633 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1634
1635 2. Moved to autoconf 2.53 and libtool 1.4.2.
1636
1637 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1638 the special perltest8 script is no longer needed - all the tests can be run
1639 from a single perltest script.
1640
1641 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1642 by \s. It has now been removed in PCRE. This means it isn't recognized as
1643 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1644 class [:space:] *does* include VT, thereby creating a mess.
1645
1646 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1647 space and tab.
1648
1649 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1650 its new features into the main test script, reducing the number of scripts.
1651
1652 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1653 were backward compatible, and made the (?i) apply to the whole pattern, as if
1654 /i were given. Now it behaves more logically, and applies the option setting
1655 only to what follows. PCRE has been changed to follow suit. However, if it
1656 finds options settings right at the start of the pattern, it extracts them into
1657 the global options, as before. Thus, they show up in the info data.
1658
1659 8. Added support for the \Q...\E escape sequence. Characters in between are
1660 treated as literals. This is slightly different from Perl in that $ and @ are
1661 also handled as literals inside the quotes. In Perl, they will cause variable
1662 interpolation. Note the following examples:
1663
1664 Pattern PCRE matches Perl matches
1665
1666 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
1667 \Qabc\$xyz\E abc\$xyz abc\$xyz
1668 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
1669
1670 For compatibility with Perl, \Q...\E sequences are recognized inside character
1671 classes as well as outside them.
1672
1673 9. Re-organized 3 code statements in pcretest to avoid "overflow in
1674 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1675 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1676 signed/unsigned warnings.
1677
1678 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1679 option for pcretest, so I've replaced it by a simple function that does just
1680 that job.
1681
1682 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1683 "pcregrep -".
1684
1685 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1686 Java package. This provides some syntactic sugar for simple cases of what my
1687 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1688 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1689 item, you can use this simplified notation. Note that only makes sense with
1690 greedy quantifiers. Consequently, the use of the possessive quantifier forces
1691 greediness, whatever the setting of the PCRE_UNGREEDY option.
1692
1693 13. A change of greediness default within a pattern was not taking effect at
1694 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1695 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
1696 was abstracted outside.
1697
1698 14. PCRE now supports the \G assertion. It is true when the current matching
1699 position is at the start point of the match. This differs from \A when the
1700 starting offset is non-zero. Used with the /g option of pcretest (or similar
1701 code), it works in the same way as it does for Perl's /g option. If all
1702 alternatives of a regex begin with \G, the expression is anchored to the start
1703 match position, and the "anchored" flag is set in the compiled expression.
1704
1705 15. Some bugs concerning the handling of certain option changes within patterns
1706 have been fixed. These applied to options other than (?ims). For example,
1707 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
1708 been the other way round. Some of this was related to change 7 above.
1709
1710 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
1711 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
1712 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
1713 POSIX classes only within a class (e.g. /[[:alpha:]]/).
1714
1715 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
1716 mode. Unlike ".", it always matches newline, whatever the setting of
1717 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
1718 assertions. Perl allows it, but it doesn't (in general) work because it can't
1719 calculate the length of the lookbehind. At least, that's the case for Perl
1720 5.8.0 - I've been told they are going to document that it doesn't work in
1721 future.
1722
1723 18. Added an error diagnosis for escapes that PCRE does not support: these are
1724 \L, \l, \N, \P, \p, \U, \u, and \X.
1725
1726 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
1727 reading past the end of the pattern in cases such as /[abcd/.
1728
1729 20. PCRE was getting more memory than necessary for patterns with classes that
1730 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
1731
1732 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
1733 compiling PCRE for use with Virtual Pascal.
1734
1735 22. Small fix to the Makefile to make it work properly if the build is done
1736 outside the source tree.
1737
1738 23. Added a new extension: a condition to go with recursion. If a conditional
1739 subpattern starts with (?(R) the "true" branch is used if recursion has
1740 happened, whereas the "false" branch is used only at the top level.
1741
1742 24. When there was a very long string of literal characters (over 255 bytes
1743 without UTF support, over 250 bytes with UTF support), the computation of how
1744 much memory was required could be incorrect, leading to segfaults or other
1745 strange effects.
1746
1747 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
1748 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
1749 there was a subsequent back reference to those brackets. This meant that, for
1750 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
1751 possible to check for precisely this case. All we can do is abandon the
1752 optimization if .* occurs inside capturing brackets when there are any back
1753 references whatsoever. (See below for a better fix that came later.)
1754
1755 26. The handling of the optimization for finding the first character of a
1756 non-anchored pattern, and for finding a character that is required later in the
1757 match were failing in some cases. This didn't break the matching; it just
1758 failed to optimize when it could. The way this is done has been re-implemented.
1759
1760 27. Fixed typo in error message for invalid (?R item (it said "(?p").
1761
1762 28. Added a new feature that provides some of the functionality that Perl
1763 provides with (?{...}). The facility is termed a "callout". The way it is done
1764 in PCRE is for the caller to provide an optional function, by setting
1765 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
1766 global variable. By default it is unset, which disables all calling out. To get
1767 the function called, the regex must include (?C) at appropriate points. This
1768 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
1769 This provides a means of identifying different callout points. When PCRE
1770 reaches such a point in the regex, if pcre_callout has been set, the external
1771 function is called. It is provided with data in a structure called
1772 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
1773 matching continues; if it returns a non-zero value, the match at the current
1774 point fails. However, backtracking will occur if possible. [This was changed
1775 later and other features added - see item 49 below.]
1776
1777 29. pcretest is upgraded to test the callout functionality. It provides a
1778 callout function that displays information. By default, it shows the start of
1779 the match and the current position in the text. There are some new data escapes
1780 to vary what happens:
1781
1782 \C+ in addition, show current contents of captured substrings
1783 \C- do not supply a callout function
1784 \C!n return 1 when callout number n is reached
1785 \C!n!m return 1 when callout number n is reached for the mth time
1786
1787 30. If pcregrep was called with the -l option and just a single file name, it
1788 output "<stdin>" if a match was found, instead of the file name.
1789
1790 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
1791 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
1792 pcre_exec(). This saves a malloc/free per call. The default value of
1793 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
1794 when configuring.
1795
1796 32. The default maximum size of a compiled pattern is 64K. There have been a
1797 few cases of people hitting this limit. The code now uses macros to handle the
1798 storing of links as offsets within the compiled pattern. It defaults to 2-byte
1799 links, but this can be changed to 3 or 4 bytes by --with-link-size when
1800 configuring. Tests 2 and 5 work only with 2-byte links because they output
1801 debugging information about compiled patterns.
1802
1803 33. Internal code re-arrangements:
1804
1805 (a) Moved the debugging function for printing out a compiled regex into
1806 its own source file (printint.c) and used #include to pull it into
1807 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
1808 separate copies.
1809
1810 (b) Defined the list of op-code names for debugging as a macro in
1811 internal.h so that it is next to the definition of the opcodes.
1812
1813 (c) Defined a table of op-code lengths for simpler skipping along compiled
1814 code. This is again a macro in internal.h so that it is next to the
1815 definition of the opcodes.
1816
1817 34. Added support for recursive calls to individual subpatterns, along the
1818 lines of Robin Houston's patch (but implemented somewhat differently).
1819
1820 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
1821 allow it to read and process whole directories in Win32. This code was
1822 contributed by Lionel Fourquaux; it has not been tested by me.
1823
1824 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
1825 used to name a group. Names consist of alphanumerics and underscores, and must
1826 be unique. Back references use the syntax (?P=name) and recursive calls use
1827 (?P>name) which is a PCRE extension to the Python extension. Groups still have
1828 numbers. The function pcre_fullinfo() can be used after compilation to extract
1829 a name/number map. There are three relevant calls:
1830
1831 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
1832 PCRE_INFO_NAMECOUNT yields the number of entries
1833 PCRE_INFO_NAMETABLE yields a pointer to the map.
1834
1835 The map is a vector of fixed-size entries. The size of each entry depends on
1836 the length of the longest name used. The first two bytes of each entry are the
1837 group number, most significant byte first. There follows the corresponding
1838 name, zero terminated. The names are in alphabetical order.
1839
1840 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
1841 case instead of 255. Making it the same both with and without UTF-8 support
1842 means that the same test output works with both.
1843
1844 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
1845 calling malloc() with a zero argument.
1846
1847 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
1848 optimization. I've improved things by keeping a bitmap of backreferences with
1849 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
1850 fact referenced, the optimization can be applied. It is unlikely that a
1851 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
1852 the match to follow \n) will appear inside brackets with a number greater than
1853 31, but if it does, any back reference > 31 suppresses the optimization.
1854
1855 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
1856 of disabling numbered capturing parentheses. Any opening parenthesis that is
1857 not followed by ? behaves as if it were followed by ?: but named parentheses
1858 can still be used for capturing (and they will acquire numbers in the usual
1859 way).
1860
1861 41. Redesigned the return codes from the match() function into yes/no/error so
1862 that errors can be passed back from deep inside the nested calls. A malloc
1863 failure while inside a recursive subpattern call now causes the
1864 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
1865
1866 42. It is now possible to set a limit on the number of times the match()
1867 function is called in a call to pcre_exec(). This facility makes it possible to
1868 limit the amount of recursion and backtracking, though not in a directly
1869 obvious way, because the match() function is used in a number of different
1870 circumstances. The count starts from zero for each position in the subject
1871 string (for non-anchored patterns). The default limit is, for compatibility, a
1872 large number, namely 10 000 000. You can change this in two ways:
1873
1874 (a) When configuring PCRE before making, you can use --with-match-limit=n
1875 to set a default value for the compiled library.
1876
1877 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
1878 a different value is set. See 45 below.
1879
1880 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
1881
1882 43. Added a new function pcre_config(int, void *) to enable run-time extraction
1883 of things that can be changed at compile time. The first argument specifies
1884 what is wanted and the second points to where the information is to be placed.
1885 The current list of available information is:
1886
1887 PCRE_CONFIG_UTF8
1888
1889 The output is an integer that is set to one if UTF-8 support is available;
1890 otherwise it is set to zero.
1891
1892 PCRE_CONFIG_NEWLINE
1893
1894 The output is an integer that it set to the value of the code that is used for
1895 newline. It is either LF (10) or CR (13).
1896
1897 PCRE_CONFIG_LINK_SIZE
1898
1899 The output is an integer that contains the number of bytes used for internal
1900 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
1901
1902 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
1903
1904 The output is an integer that contains the threshold above which the POSIX
1905 interface uses malloc() for output vectors. See item 31 above.
1906
1907 PCRE_CONFIG_MATCH_LIMIT
1908
1909 The output is an unsigned integer that contains the default limit of the number
1910 of match() calls in a pcre_exec() execution. See 42 above.
1911
1912 44. pcretest has been upgraded by the addition of the -C option. This causes it
1913 to extract all the available output from the new pcre_config() function, and to
1914 output it. The program then exits immediately.
1915
1916 45. A need has arisen to pass over additional data with calls to pcre_exec() in
1917 order to support additional features. One way would have been to define
1918 pcre_exec2() (for example) with extra arguments, but this would not have been
1919 extensible, and would also have required all calls to the original function to
1920 be mapped to the new one. Instead, I have chosen to extend the mechanism that
1921 is used for passing in "extra" data from pcre_study().
1922
1923 The pcre_extra structure is now exposed and defined in pcre.h. It currently
1924 contains the following fields:
1925
1926 flags a bitmap indicating which of the following fields are set
1927 study_data opaque data from pcre_study()
1928 match_limit a way of specifying a limit on match() calls for a specific
1929 call to pcre_exec()
1930 callout_data data for callouts (see 49 below)
1931
1932 The flag bits are also defined in pcre.h, and are
1933
1934 PCRE_EXTRA_STUDY_DATA
1935 PCRE_EXTRA_MATCH_LIMIT
1936 PCRE_EXTRA_CALLOUT_DATA
1937
1938 The pcre_study() function now returns one of these new pcre_extra blocks, with
1939 the actual study data pointed to by the study_data field, and the
1940 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
1941 before. That is, this change is entirely upwards-compatible and requires no
1942 change to existing code.
1943
1944 If you want to pass in additional data to pcre_exec(), you can either place it
1945 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
1946 block.
1947
1948 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
1949 data string contains the escape sequence \M, pcretest calls pcre_exec() several
1950 times with different match limits, until it finds the minimum value needed for
1951 pcre_exec() to complete. The value is then output. This can be instructive; for
1952 most simple matches the number is quite small, but for pathological cases it
1953 gets very large very quickly.
1954
1955 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
1956 returns the size of the data block pointed to by the study_data field in a
1957 pcre_extra block, that is, the value that was passed as the argument to
1958 pcre_malloc() when PCRE was getting memory in which to place the information
1959 created by pcre_study(). The fourth argument should point to a size_t variable.
1960 pcretest has been extended so that this information is shown after a successful
1961 pcre_study() call when information about the compiled regex is being displayed.
1962
1963 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
1964 because what follows is always an absolute path. (Later: it turns out that this
1965 is more than cosmetic for MinGW, because it doesn't like empty path
1966 components.)
1967
1968 49. Some changes have been made to the callout feature (see 28 above):
1969
1970 (i) A callout function now has three choices for what it returns:
1971
1972 0 => success, carry on matching
1973 > 0 => failure at this point, but backtrack if possible
1974 < 0 => serious error, return this value from pcre_exec()
1975
1976 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
1977 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
1978 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
1979 use by callout functions. It will never be used by PCRE itself.
1980
1981 (ii) The pcre_extra structure (see 45 above) has a void * field called
1982 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
1983 pcre_callout_block structure has a field of the same name. The contents of
1984 the field passed in the pcre_extra structure are passed to the callout
1985 function in the corresponding field in the callout block. This makes it
1986 easier to use the same callout-containing regex from multiple threads. For
1987 testing, the pcretest program has a new data escape
1988
1989 \C*n pass the number n (may be negative) as callout_data
1990
1991 If the callout function in pcretest receives a non-zero value as
1992 callout_data, it returns that value.
1993
1994 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
1995 there were some redundant $(CFLAGS) in commands that are now specified as
1996 $(LINK), which already includes $(CFLAGS).
1997
1998 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
1999 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2000 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2001 one-byte characters throughout. Note that case-insensitive matching applies
2002 only to characters whose values are less than 256. PCRE doesn't support the
2003 notion of cases for higher-valued characters.
2004
2005 (i) A character class whose characters are all within 0-255 is handled as
2006 a bit map, and the map is inverted for negative classes. Previously, a
2007 character > 255 always failed to match such a class; however it should
2008 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2009
2010 (ii) A negated character class with a single character < 255 is coded as
2011 "not this character" (OP_NOT). This wasn't working properly when the test
2012 character was multibyte, either singly or repeated.
2013
2014 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2015 mode, for example: \x{100}{2,3}.
2016
2017 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2018 singly or repeated) now correctly test multibyte characters. However,
2019 PCRE doesn't recognize any characters with values greater than 255 as
2020 digits, spaces, or word characters. Such characters always match \D, \S,
2021 and \W, and never match \d, \s, or \w.
2022
2023 (v) Classes may now contain characters and character ranges with values
2024 greater than 255. For example: [ab\x{100}-\x{400}].
2025
2026 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2027 PCRE in UTF-8 mode.
2028
2029 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2030 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2031 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2032 value.)
2033
2034 53. The single man page has become too large. I have therefore split it up into
2035 a number of separate man pages. These also give rise to individual HTML pages;
2036 these are now put in a separate directory, and there is an index.html page that
2037 lists them all. Some hyperlinking between the pages has been installed.
2038
2039 54. Added convenience functions for handling named capturing parentheses.
2040
2041 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2042 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2043 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2044 are faulted.
2045
2046 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2047 calling configure. These values are used when compiling the dftables.c program
2048 which is run to generate the source of the default character tables. They
2049 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2050 you will need to set these values.
2051
2052 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2053
2054
2055 Version 3.9 02-Jan-02
2056 ---------------------
2057
2058 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2059
2060 2. If --disable-static was given, the building process failed when trying to
2061 build pcretest and pcregrep. (For some reason it was using libtool to compile
2062 them, which is not right, as they aren't part of the library.)
2063
2064
2065 Version 3.8 18-Dec-01
2066 ---------------------
2067
2068 1. The experimental UTF-8 code was completely screwed up. It was packing the
2069 bytes in the wrong order. How dumb can you get?
2070
2071
2072 Version 3.7 29-Oct-01
2073 ---------------------
2074
2075 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2076 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2077 this didn't happen under Solaris 8, where I normally test things.
2078
2079 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2080 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2081 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2082 this fix an hour or so after the initial 3.7 release.)
2083
2084
2085 Version 3.6 23-Oct-01
2086 ---------------------
2087
2088 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2089 offsets passed as NULL with zero offset count.
2090
2091 2. The config.guess and config.sub files had not been updated when I moved to
2092 the latest autoconf.
2093
2094
2095 Version 3.5 15-Aug-01
2096 ---------------------
2097
2098 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2099 had been forgotten.
2100
2101 2. By using declared but undefined structures, we can avoid using "void"
2102 definitions in pcre.h while keeping the internal definitions of the structures
2103 private.
2104
2105 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2106 user point of view, this means that both static and shared libraries are built
2107 by default, but this can be individually controlled. More of the work of
2108 handling this static/shared cases is now inside libtool instead of PCRE's make
2109 file.
2110
2111 4. The pcretest utility is now installed along with pcregrep because it is
2112 useful for users (to test regexs) and by doing this, it automatically gets
2113 relinked by libtool. The documentation has been turned into a man page, so
2114 there are now .1, .txt, and .html versions in /doc.
2115
2116 5. Upgrades to pcregrep:
2117 (i) Added long-form option names like gnu grep.
2118 (ii) Added --help to list all options with an explanatory phrase.
2119 (iii) Added -r, --recursive to recurse into sub-directories.
2120 (iv) Added -f, --file to read patterns from a file.
2121
2122 6. pcre_exec() was referring to its "code" argument before testing that
2123 argument for NULL (and giving an error if it was NULL).
2124
2125 7. Upgraded Makefile.in to allow for compiling in a different directory from
2126 the source directory.
2127
2128 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2129 options bits, the pointer it was passed was to an int instead of to an unsigned
2130 long int. This mattered only on 64-bit systems.
2131
2132 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2133 generated) instead of pcre.in, which it its source. Also made the same change
2134 in several of the .c files.
2135
2136 10. A new release of gcc defines printf() as a macro, which broke pcretest
2137 because it had an ifdef in the middle of a string argument for printf(). Fixed
2138 by using separate calls to printf().
2139
2140 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2141 script, to force use of CR or LF instead of \n in the source. On non-Unix
2142 systems, the value can be set in config.h.
2143
2144 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2145 absolute limit. Changed the text of the error message to make this clear, and
2146 likewise updated the man page.
2147
2148 13. The limit of 99 on the number of capturing subpatterns has been removed.
2149 The new limit is 65535, which I hope will not be a "real" limit.
2150
2151
2152 Version 3.4 22-Aug-00
2153 ---------------------
2154
2155 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2156
2157 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2158
2159
2160 Version 3.3 01-Aug-00
2161 ---------------------
2162
2163 1. If an octal character was given, but the value was greater than \377, it
2164 was not getting masked to the least significant bits, as documented. This could
2165 lead to crashes in some systems.
2166
2167 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2168 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2169
2170 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2171 These just pass their arguments on to (pcre_free)(), but they are provided
2172 because some uses of PCRE bind it to non-C systems that can call its functions,
2173 but cannot call free() or pcre_free() directly.
2174
2175 4. Add "make test" as a synonym for "make check". Corrected some comments in
2176 the Makefile.
2177
2178 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2179 Makefile.
2180
2181 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2182 command called pgrep for grepping around the active processes.
2183
2184 7. Added the beginnings of support for UTF-8 character strings.
2185
2186 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2187 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2188 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2189 out for the ar command.)
2190
2191
2192 Version 3.2 12-May-00
2193 ---------------------
2194
2195 This is purely a bug fixing release.
2196
2197 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2198 of ZA. This was just one example of several cases that could provoke this bug,
2199 which was introduced by change 9 of version 2.00. The code for breaking
2200 infinite loops after an iteration that matches an empty string was't working
2201 correctly.
2202
2203 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2204 when matched against abbab (for example). After matching an empty string, it
2205 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2206 caused it to match further down the string than it should.
2207
2208 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2209 was there because it doesn't seem to be needed, and it causes trouble on some
2210 systems, as it is not a Standard C header. It has been removed.
2211
2212 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2213 were reported on the Macintosh. The changes were from
2214
2215 while ((c = *(++ptr)) != 0 && c != '\n');
2216 to
2217 while ((c = *(++ptr)) != 0 && c != '\n') ;
2218
2219 Totally extraordinary, but if that's what it takes...
2220
2221 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2222 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2223 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2224 assumes the way PCRE uses memmove() (always moving upwards).
2225
2226 6. PCRE is being used in one environment where strchr() is not available. There
2227 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2228 faster code anyway.
2229
2230
2231 Version 3.1 09-Feb-00
2232 ---------------------
2233
2234 The only change in this release is the fixing of some bugs in Makefile.in for
2235 the "install" target:
2236
2237 (1) It was failing to install pcreposix.h.
2238
2239 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2240
2241
2242 Version 3.0 01-Feb-00
2243 ---------------------
2244
2245 1. Add support for the /+ modifier to perltest (to output $` like it does in
2246 pcretest).
2247
2248 2. Add support for the /g modifier to perltest.
2249
2250 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2251 matches null strings.
2252
2253 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2254 pattern. Perl treats empty patterns specially - it reuses the most recent
2255 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2256 effect.
2257
2258 5. The POSIX interface was broken in that it was just handing over the POSIX
2259 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2260 required a bigger vector, with some working space on the end. This means that
2261 the POSIX wrapper now has to get and free some memory, and copy the results.
2262
2263 6. Added some simple autoconf support, placing the test data and the
2264 documentation in separate directories, re-organizing some of the
2265 information files, and making it build pcre-config (a GNU standard). Also added
2266 libtool support for building PCRE as a shared library, which is now the
2267 default.
2268
2269 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2270 09 are not valid octal constants. Single digits will be used for minor values
2271 less than 10.
2272
2273 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2274 existing programs that set these in the POSIX interface can use PCRE without
2275 modification.
2276
2277 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2278 return all that pcre_info() returns, plus additional data. The pcre_info()
2279 function is retained for compatibility, but is considered to be obsolete.
2280
2281 10. Added experimental recursion feature (?R) to handle one common case that
2282 Perl 5.6 will be able to do with (?p{...}).
2283
2284 11. Added support for POSIX character classes like [:alpha:], which Perl is
2285 adopting.
2286
2287
2288 Version 2.08 31-Aug-99
2289 ----------------------
2290
2291 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2292 trying to match at the startoffset position, but instead was moving forward to
2293 the next newline as if a previous match had failed.
2294
2295 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2296 and could get into a loop if a null string was matched other than at the start
2297 of the subject.
2298
2299 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2300 be distinguished at compile time, and for completeness also added PCRE_DATE.
2301
2302 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2303 in GnuWin32 environments.
2304
2305
2306 Version 2.07 29-Jul-99
2307 ----------------------
2308
2309 1. The documentation is now supplied in plain text form and HTML as well as in
2310 the form of man page sources.
2311
2312 2. C++ compilers don't like assigning (void *) values to other pointer types.
2313 In particular this affects malloc(). Although there is no problem in Standard
2314 C, I've put in casts to keep C++ compilers happy.
2315
2316 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2317 should be (const char *).
2318
2319 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2320 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2321 However, I haven't made this a standard facility. The documentation doesn't
2322 mention it, and the Makefile doesn't support it.
2323
2324 5. The Makefile now contains an "install" target, with editable destinations at
2325 the top of the file. The pcretest program is not installed.
2326
2327 6. pgrep -V now gives the PCRE version number and date.
2328
2329 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2330 causing the entire string to be ignored, instead of just the last character.
2331
2332 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2333 non-matching string, it can take a very, very long time, even for strings of
2334 quite modest length, because of the nested recursion. PCRE now does better in
2335 some of these cases. It does this by remembering the last required literal
2336 character in the pattern, and pre-searching the subject to ensure it is present
2337 before running the real match. In other words, it applies a heuristic to detect
2338 some types of certain failure quickly, and in the above example, if presented
2339 with a string that has no trailing " it gives "no match" very quickly.
2340
2341 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2342 other alternatives are tried instead.
2343
2344
2345 Version 2.06 09-Jun-99
2346 ----------------------
2347
2348 1. Change pcretest's output for amount of store used to show just the code
2349 space, because the remainder (the data block) varies in size between 32-bit and
2350 64-bit systems.
2351
2352 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2353 start matching at. This allows lookbehinds to work when searching for multiple
2354 occurrences in a string.
2355
2356 3. Added additional options to pcretest for testing multiple occurrences:
2357
2358 /+ outputs the rest of the string that follows a match
2359 /g loops for multiple occurrences, using the new startoffset argument
2360 /G loops for multiple occurrences by passing an incremented pointer
2361
2362 4. PCRE wasn't doing the "first character" optimization for patterns starting
2363 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2364 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2365 the letter 'x'. On long subject strings, this gives a significant speed-up.
2366
2367
2368 Version 2.05 21-Apr-99
2369 ----------------------
2370
2371 1. Changed the type of magic_number from int to long int so that it works
2372 properly on 16-bit systems.
2373
2374 2. Fixed a bug which caused patterns starting with .* not to work correctly
2375 when the subject string contained newline characters. PCRE was assuming
2376 anchoring for such patterns in all cases, which is not correct because .* will
2377 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2378 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2379 must be retried after every newline in the subject.
2380
2381
2382 Version 2.04 18-Feb-99
2383 ----------------------
2384
2385 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2386 computation of the store needed to hold the pattern was incorrect (too large).
2387 If such patterns were nested a few deep, this could multiply and become a real
2388 problem.
2389
2390 2. Added /M option to pcretest to show the memory requirement of a specific
2391 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2392
2393 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2394 compiled in such a way that the backtracking after subsequent failure was
2395 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2396 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2397
2398
2399 Version 2.03 02-Feb-99
2400 ----------------------
2401
2402 1. Fixed typo and small mistake in man page.
2403
2404 2. Added 4th condition (GPL supersedes if conflict) and created separate
2405 LICENCE file containing the conditions.
2406
2407 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2408 Perl, that is the internal \ allows the delimiter to be included in the
2409 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2410 the final delimiter, add \ to the end of the pattern (to test the error).
2411
2412 4. Added the convenience functions for extracting substrings after a successful
2413 match. Updated pcretest to make it able to test these functions.
2414
2415
2416 Version 2.02 14-Jan-99
2417 ----------------------
2418
2419 1. Initialized the working variables associated with each extraction so that
2420 their saving and restoring doesn't refer to uninitialized store.
2421
2422 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2423 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2424 fix the problem.
2425
2426 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2427 calls, and wasn't printing the correct value for compiling calls. Increased the
2428 default value of LOOPREPEAT, and the number of significant figures in the
2429 times.
2430
2431 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2432
2433 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2434 a building problem on Windows NT with a FAT file system.
2435
2436
2437 Version 2.01 21-Oct-98
2438 ----------------------
2439
2440 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2441 to character tables built by pcre_maketables() in the current locale. If NULL
2442 is passed, the default tables are used.
2443
2444
2445 Version 2.00 24-Sep-98
2446 ----------------------
2447
2448 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2449 it any more.
2450
2451 2. Allow quantification of (?>) groups, and make it work correctly.
2452
2453 3. The first character computation wasn't working for (?>) groups.
2454
2455 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2456 end of the subject) and add 5.005's \z, which really does match only at the
2457 very end of the subject.
2458
2459 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2460
2461 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2462 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2463 localized options. All options to pcre_study() were also removed.
2464
2465 7. Add other new features from 5.005:
2466
2467 $(?<= positive lookbehind
2468 $(?<! negative lookbehind
2469 (?imsx-imsx) added the unsetting capability
2470 such a setting is global if at outer level; local otherwise
2471 (?imsx-imsx:) non-capturing groups with option setting
2472 (?(cond)re|re) conditional pattern matching
2473
2474 A backreference to itself in a repeated group matches the previous
2475 captured string.
2476
2477 8. General tidying up of studying (both automatic and via "study")
2478 consequential on the addition of new assertions.
2479
2480 9. As in 5.005, unlimited repeated groups that could match an empty substring
2481 are no longer faulted at compile time. Instead, the loop is forcibly broken at
2482 runtime if any iteration does actually match an empty substring.
2483
2484 10. Include the RunTest script in the distribution.
2485
2486 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2487 discrepancies, some of which were old and were also with respect to 5.004. They
2488 have now been fixed.
2489
2490
2491 Version 1.09 28-Apr-98
2492 ----------------------
2493
2494 1. A negated single character class followed by a quantifier with a minimum
2495 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2496 program crashes, or just wrong answers. This did not apply to negated classes
2497 containing more than one character, or to minima other than one.
2498
2499
2500 Version 1.08 27-Mar-98
2501 ----------------------
2502
2503 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2504
2505 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2506 latter must appear before anything that relies on it in the pattern.
2507
2508
2509 Version 1.07 16-Feb-98
2510 ----------------------
2511
2512 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2513 repeat of a potentially empty string).
2514
2515
2516 Version 1.06 23-Jan-98
2517 ----------------------
2518
2519 1. Added Markus Oberhumer's little patches for C++.
2520
2521 2. Literal strings longer than 255 characters were broken.
2522
2523
2524 Version 1.05 23-Dec-97
2525 ----------------------
2526
2527 1. Negated character classes containing more than one character were failing if
2528 PCRE_CASELESS was set at run time.
2529
2530
2531 Version 1.04 19-Dec-97
2532 ----------------------
2533
2534 1. Corrected the man page, where some "const" qualifiers had been omitted.
2535
2536 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2537 input syntax.
2538
2539 3. Fixed memory leak which occurred when a regex with back references was
2540 matched with an offsets vector that wasn't big enough. The temporary memory
2541 that is used in this case wasn't being freed if the match failed.
2542
2543 4. Tidied pcretest to ensure it frees memory that it gets.
2544
2545 5. Temporary memory was being obtained in the case where the passed offsets
2546 vector was exactly big enough.
2547
2548 6. Corrected definition of offsetof() from change 5 below.
2549
2550 7. I had screwed up change 6 below and broken the rules for the use of
2551 setjmp(). Now fixed.
2552
2553
2554 Version 1.03 18-Dec-97
2555 ----------------------
2556
2557 1. A erroneous regex with a missing opening parenthesis was correctly
2558 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2559 on some systems.
2560
2561 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2562 it was reported that one broken compiler failed on the former because "code" is
2563 also an independent variable.
2564
2565 3. The erroneous regex a[]b caused an array overrun reference.
2566
2567 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2568 fail on data ending with that character. (It was going on too far, and checking
2569 the next character, typically a binary zero.) This was specific to the
2570 optimized code for single-character negative classes.
2571
2572 5. Added a contributed patch from the TIN world which does the following:
2573
2574 + Add an undef for memmove, in case the the system defines a macro for it.
2575
2576 + Add a definition of offsetof(), in case there isn't one. (I don't know
2577 the reason behind this - offsetof() is part of the ANSI standard - but
2578 it does no harm).
2579
2580 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2581 most of the places where whitespace preceded '#'. I have given up and
2582 allowed the remaining 2 cases to be at the margin.
2583
2584 + Rename some variables in pcre to eliminate shadowing. This seems very
2585 pedantic, but does no harm, of course.
2586
2587 6. Moved the call to setjmp() into its own function, to get rid of warnings
2588 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2589
2590 7. Constructs such as \d{8,} were compiling into the equivalent of
2591 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2592 outcome, but in this particular case used more store than had been allocated,
2593 which caused the bug to be discovered because it threw up an internal error.
2594
2595 8. The debugging code in both pcre and pcretest for outputting the compiled
2596 form of a regex was going wrong in the case of back references followed by
2597 curly-bracketed repeats.
2598
2599
2600 Version 1.02 12-Dec-97
2601 ----------------------
2602
2603 1. Typos in pcre.3 and comments in the source fixed.
2604
2605 2. Applied a contributed patch to get rid of places where it used to remove
2606 'const' from variables, and fixed some signed/unsigned and uninitialized
2607 variable warnings.
2608
2609 3. Added the "runtest" target to Makefile.
2610
2611 4. Set default compiler flag to -O2 rather than just -O.
2612
2613
2614 Version 1.01 19-Nov-97
2615 ----------------------
2616
2617 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2618 like /([ab]*)*/, that is, for classes with more than one character in them.
2619
2620 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2621 as /((?>a*))*/ (a PCRE_EXTRA facility).
2622
2623
2624 Version 1.00 18-Nov-97
2625 ----------------------
2626
2627 1. Added compile-time macros to support systems such as SunOS4 which don't have
2628 memmove() or strerror() but have other things that can be used instead.
2629
2630 2. Arranged that "make clean" removes the executables.
2631
2632
2633 Version 0.99 27-Oct-97
2634 ----------------------
2635
2636 1. Fixed bug in code for optimizing classes with only one character. It was
2637 initializing a 32-byte map regardless, which could cause it to run off the end
2638 of the memory it had got.
2639
2640 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
2641
2642
2643 Version 0.98 22-Oct-97
2644 ----------------------
2645
2646 1. Fixed bug in code for handling temporary memory usage when there are more
2647 back references than supplied space in the ovector. This could cause segfaults.
2648
2649
2650 Version 0.97 21-Oct-97
2651 ----------------------
2652
2653 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
2654
2655 2. Optimized negated single characters not to use a bit map.
2656
2657 3. Brought error texts together as macro definitions; clarified some of them;
2658 fixed one that was wrong - it said "range out of order" when it meant "invalid
2659 escape sequence".
2660
2661 4. Changed some char * arguments to const char *.
2662
2663 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
2664
2665 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
2666 pcretest.
2667
2668
2669 Version 0.96 16-Oct-97
2670 ----------------------
2671
2672 1. Added a simple "pgrep" utility to the distribution.
2673
2674 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
2675 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
2676 where "ddd" means "one or more decimal digits".
2677
2678 3. Fixed serious bug. If a pattern had a back reference, but the call to
2679 pcre_exec() didn't supply a large enough ovector to record the related
2680 identifying subpattern, the match always failed. PCRE now remembers the number
2681 of the largest back reference, and gets some temporary memory in which to save
2682 the offsets during matching if necessary, in order to ensure that
2683 backreferences always work.
2684
2685 4. Increased the compatibility with Perl in a number of ways:
2686
2687 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
2688 to request this handling. The option can be set at compile or exec time.
2689
2690 (b) $ matches before a terminating newline by default; an option
2691 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
2692 mode). The option can be set at compile or exec time.
2693
2694 (c) The handling of \ followed by a digit other than 0 is now supposed to be
2695 the same as Perl's. If the decimal number it represents is less than 10
2696 or there aren't that many previous left capturing parentheses, an octal
2697 escape is read. Inside a character class, it's always an octal escape,
2698 even if it is a single digit.
2699
2700 (d) An escaped but undefined alphabetic character is taken as a literal,
2701 unless PCRE_EXTRA is set. Currently this just reserves the remaining
2702 escapes.
2703
2704 (e) {0} is now permitted. (The previous item is removed from the compiled
2705 pattern).
2706
2707 5. Changed all the names of code files so that the basic parts are no longer
2708 than 10 characters, and abolished the teeny "globals.c" file.
2709
2710 6. Changed the handling of character classes; they are now done with a 32-byte
2711 bit map always.
2712
2713 7. Added the -d and /D options to pcretest to make it possible to look at the
2714 internals of compilation without having to recompile pcre.
2715
2716
2717 Version 0.95 23-Sep-97
2718 ----------------------
2719
2720 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
2721 \x20 at the start of a run of normal characters. These were being treated as
2722 real characters, instead of the source characters being re-checked.
2723
2724
2725 Version 0.94 18-Sep-97
2726 ----------------------
2727
2728 1. The functions are now thread-safe, with the caveat that the global variables
2729 containing pointers to malloc() and free() or alternative functions are the
2730 same for all threads.
2731
2732 2. Get pcre_study() to generate a bitmap of initial characters for non-
2733 anchored patterns when this is possible, and use it if passed to pcre_exec().
2734
2735
2736 Version 0.93 15-Sep-97
2737 ----------------------
2738
2739 1. /(b)|(:+)/ was computing an incorrect first character.
2740
2741 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
2742 but not actually doing anything yet.
2743
2744 3. Treat "-" characters in classes that cannot be part of ranges as literals,
2745 as Perl does (e.g. [-az] or [az-]).
2746
2747 4. Set the anchored flag if a branch starts with .* or .*? because that tests
2748 all possible positions.
2749
2750 5. Split up into different modules to avoid including unneeded functions in a
2751 compiled binary. However, compile and exec are still in one module. The "study"
2752 function is split off.
2753
2754 6. The character tables are now in a separate module whose source is generated
2755 by an auxiliary program - but can then be edited by hand if required. There are
2756 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
2757 toupper() in the code.
2758
2759 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
2760 make them global. Abolish the function for setting them, as the caller can now
2761 set them directly.
2762
2763
2764 Version 0.92 11-Sep-97
2765 ----------------------
2766
2767 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
2768 (e.g. /a{1,3}/) was broken (I mis-optimized it).
2769
2770 2. Caseless matching was not working in character classes if the characters in
2771 the pattern were in upper case.
2772
2773 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
2774
2775 4. Make PCRE_ANCHORED public and accept as a compile option.
2776
2777 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
2778 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
2779 pass them.
2780
2781 6. Give an error if bad option bits passed at compile or run time.
2782
2783 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
2784 pcretest to cause it to pass that flag.
2785
2786 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
2787 options, and the first character, if set.
2788
2789 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
2790
2791
2792 Version 0.91 10-Sep-97
2793 ----------------------
2794
2795 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
2796 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
2797
2798 2. PCRE was looping on encountering an indefinitely repeated back reference to
2799 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
2800 Perl does - treats the match as successful.
2801
2802 ****

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