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1 ChangeLog for PCRE
2 ------------------
3
4
5 Version 2.08 31-Aug-99
6 ----------------------
7
8 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
9 trying to match at the startoffset position, but instead was moving forward to
10 the next newline as if a previous match had failed.
11
12 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
13 and could get into a loop if a null string was matched other than at the start
14 of the subject.
15
16 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
17 be distinguished at compile time, and for completeness also added PCRE_DATE.
18
19 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
20 in GnuWin32 environments.
21
22
23 Version 2.07 29-Jul-99
24 ----------------------
25
26 1. The documentation is now supplied in plain text form and HTML as well as in
27 the form of man page sources.
28
29 2. C++ compilers don't like assigning (void *) values to other pointer types.
30 In particular this affects malloc(). Although there is no problem in Standard
31 C, I've put in casts to keep C++ compilers happy.
32
33 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
34 should be (const char *).
35
36 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
37 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
38 However, I haven't made this a standard facility. The documentation doesn't
39 mention it, and the Makefile doesn't support it.
40
41 5. The Makefile now contains an "install" target, with editable destinations at
42 the top of the file. The pcretest program is not installed.
43
44 6. pgrep -V now gives the PCRE version number and date.
45
46 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
47 causing the entire string to be ignored, instead of just the last character.
48
49 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
50 non-matching string, it can take a very, very long time, even for strings of
51 quite modest length, because of the nested recursion. PCRE now does better in
52 some of these cases. It does this by remembering the last required literal
53 character in the pattern, and pre-searching the subject to ensure it is present
54 before running the real match. In other words, it applies a heuristic to detect
55 some types of certain failure quickly, and in the above example, if presented
56 with a string that has no trailing " it gives "no match" very quickly.
57
58 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
59 other alternatives are tried instead.
60
61
62 Version 2.06 09-Jun-99
63 ----------------------
64
65 1. Change pcretest's output for amount of store used to show just the code
66 space, because the remainder (the data block) varies in size between 32-bit and
67 64-bit systems.
68
69 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
70 start matching at. This allows lookbehinds to work when searching for multiple
71 occurrences in a string.
72
73 3. Added additional options to pcretest for testing multiple occurrences:
74
75 /+ outputs the rest of the string that follows a match
76 /g loops for multiple occurrences, using the new startoffset argument
77 /G loops for multiple occurrences by passing an incremented pointer
78
79 4. PCRE wasn't doing the "first character" optimization for patterns starting
80 with \b or \B, though it was doing it for other lookbehind assertions. That is,
81 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
82 the letter 'x'. On long subject strings, this gives a significant speed-up.
83
84
85 Version 2.05 21-Apr-99
86 ----------------------
87
88 1. Changed the type of magic_number from int to long int so that it works
89 properly on 16-bit systems.
90
91 2. Fixed a bug which caused patterns starting with .* not to work correctly
92 when the subject string contained newline characters. PCRE was assuming
93 anchoring for such patterns in all cases, which is not correct because .* will
94 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
95 DOTALL is set at top level; otherwise it knows that patterns starting with .*
96 must be retried after every newline in the subject.
97
98
99 Version 2.04 18-Feb-99
100 ----------------------
101
102 1. For parenthesized subpatterns with repeats whose minimum was zero, the
103 computation of the store needed to hold the pattern was incorrect (too large).
104 If such patterns were nested a few deep, this could multiply and become a real
105 problem.
106
107 2. Added /M option to pcretest to show the memory requirement of a specific
108 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
109
110 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
111 compiled in such a way that the backtracking after subsequent failure was
112 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
113 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
114
115
116 Version 2.03 02-Feb-99
117 ----------------------
118
119 1. Fixed typo and small mistake in man page.
120
121 2. Added 4th condition (GPL supersedes if conflict) and created separate
122 LICENCE file containing the conditions.
123
124 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
125 Perl, that is the internal \ allows the delimiter to be included in the
126 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
127 the final delimiter, add \ to the end of the pattern (to test the error).
128
129 4. Added the convenience functions for extracting substrings after a successful
130 match. Updated pcretest to make it able to test these functions.
131
132
133 Version 2.02 14-Jan-99
134 ----------------------
135
136 1. Initialized the working variables associated with each extraction so that
137 their saving and restoring doesn't refer to uninitialized store.
138
139 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
140 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
141 fix the problem.
142
143 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
144 calls, and wasn't printing the correct value for compiling calls. Increased the
145 default value of LOOPREPEAT, and the number of significant figures in the
146 times.
147
148 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
149
150 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
151 a building problem on Windows NT with a FAT file system.
152
153
154 Version 2.01 21-Oct-98
155 ----------------------
156
157 1. Changed the API for pcre_compile() to allow for the provision of a pointer
158 to character tables built by pcre_maketables() in the current locale. If NULL
159 is passed, the default tables are used.
160
161
162 Version 2.00 24-Sep-98
163 ----------------------
164
165 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
166 it any more.
167
168 2. Allow quantification of (?>) groups, and make it work correctly.
169
170 3. The first character computation wasn't working for (?>) groups.
171
172 4. Correct the implementation of \Z (it is permitted to match on the \n at the
173 end of the subject) and add 5.005's \z, which really does match only at the
174 very end of the subject.
175
176 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
177
178 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
179 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
180 localized options. All options to pcre_study() were also removed.
181
182 7. Add other new features from 5.005:
183
184 $(?<= positive lookbehind
185 $(?<! negative lookbehind
186 (?imsx-imsx) added the unsetting capability
187 such a setting is global if at outer level; local otherwise
188 (?imsx-imsx:) non-capturing groups with option setting
189 (?(cond)re|re) conditional pattern matching
190
191 A backreference to itself in a repeated group matches the previous
192 captured string.
193
194 8. General tidying up of studying (both automatic and via "study")
195 consequential on the addition of new assertions.
196
197 9. As in 5.005, unlimited repeated groups that could match an empty substring
198 are no longer faulted at compile time. Instead, the loop is forcibly broken at
199 runtime if any iteration does actually match an empty substring.
200
201 10. Include the RunTest script in the distribution.
202
203 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
204 discrepancies, some of which were old and were also with respect to 5.004. They
205 have now been fixed.
206
207
208 Version 1.09 28-Apr-98
209 ----------------------
210
211 1. A negated single character class followed by a quantifier with a minimum
212 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
213 program crashes, or just wrong answers. This did not apply to negated classes
214 containing more than one character, or to minima other than one.
215
216
217 Version 1.08 27-Mar-98
218 ----------------------
219
220 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
221
222 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
223 latter must appear before anything that relies on it in the pattern.
224
225
226 Version 1.07 16-Feb-98
227 ----------------------
228
229 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
230 repeat of a potentially empty string).
231
232
233 Version 1.06 23-Jan-98
234 ----------------------
235
236 1. Added Markus Oberhumer's little patches for C++.
237
238 2. Literal strings longer than 255 characters were broken.
239
240
241 Version 1.05 23-Dec-97
242 ----------------------
243
244 1. Negated character classes containing more than one character were failing if
245 PCRE_CASELESS was set at run time.
246
247
248 Version 1.04 19-Dec-97
249 ----------------------
250
251 1. Corrected the man page, where some "const" qualifiers had been omitted.
252
253 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
254 input syntax.
255
256 3. Fixed memory leak which occurred when a regex with back references was
257 matched with an offsets vector that wasn't big enough. The temporary memory
258 that is used in this case wasn't being freed if the match failed.
259
260 4. Tidied pcretest to ensure it frees memory that it gets.
261
262 5. Temporary memory was being obtained in the case where the passed offsets
263 vector was exactly big enough.
264
265 6. Corrected definition of offsetof() from change 5 below.
266
267 7. I had screwed up change 6 below and broken the rules for the use of
268 setjmp(). Now fixed.
269
270
271 Version 1.03 18-Dec-97
272 ----------------------
273
274 1. A erroneous regex with a missing opening parenthesis was correctly
275 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
276 on some systems.
277
278 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
279 it was reported that one broken compiler failed on the former because "code" is
280 also an independent variable.
281
282 3. The erroneous regex a[]b caused an array overrun reference.
283
284 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
285 fail on data ending with that character. (It was going on too far, and checking
286 the next character, typically a binary zero.) This was specific to the
287 optimized code for single-character negative classes.
288
289 5. Added a contributed patch from the TIN world which does the following:
290
291 + Add an undef for memmove, in case the the system defines a macro for it.
292
293 + Add a definition of offsetof(), in case there isn't one. (I don't know
294 the reason behind this - offsetof() is part of the ANSI standard - but
295 it does no harm).
296
297 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
298 most of the places where whitespace preceded '#'. I have given up and
299 allowed the remaining 2 cases to be at the margin.
300
301 + Rename some variables in pcre to eliminate shadowing. This seems very
302 pedantic, but does no harm, of course.
303
304 6. Moved the call to setjmp() into its own function, to get rid of warnings
305 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
306
307 7. Constructs such as \d{8,} were compiling into the equivalent of
308 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
309 outcome, but in this particular case used more store than had been allocated,
310 which caused the bug to be discovered because it threw up an internal error.
311
312 8. The debugging code in both pcre and pcretest for outputting the compiled
313 form of a regex was going wrong in the case of back references followed by
314 curly-bracketed repeats.
315
316
317 Version 1.02 12-Dec-97
318 ----------------------
319
320 1. Typos in pcre.3 and comments in the source fixed.
321
322 2. Applied a contributed patch to get rid of places where it used to remove
323 'const' from variables, and fixed some signed/unsigned and uninitialized
324 variable warnings.
325
326 3. Added the "runtest" target to Makefile.
327
328 4. Set default compiler flag to -O2 rather than just -O.
329
330
331 Version 1.01 19-Nov-97
332 ----------------------
333
334 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
335 like /([ab]*)*/, that is, for classes with more than one character in them.
336
337 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
338 as /((?>a*))*/ (a PCRE_EXTRA facility).
339
340
341 Version 1.00 18-Nov-97
342 ----------------------
343
344 1. Added compile-time macros to support systems such as SunOS4 which don't have
345 memmove() or strerror() but have other things that can be used instead.
346
347 2. Arranged that "make clean" removes the executables.
348
349
350 Version 0.99 27-Oct-97
351 ----------------------
352
353 1. Fixed bug in code for optimizing classes with only one character. It was
354 initializing a 32-byte map regardless, which could cause it to run off the end
355 of the memory it had got.
356
357 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
358
359
360 Version 0.98 22-Oct-97
361 ----------------------
362
363 1. Fixed bug in code for handling temporary memory usage when there are more
364 back references than supplied space in the ovector. This could cause segfaults.
365
366
367 Version 0.97 21-Oct-97
368 ----------------------
369
370 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
371
372 2. Optimized negated single characters not to use a bit map.
373
374 3. Brought error texts together as macro definitions; clarified some of them;
375 fixed one that was wrong - it said "range out of order" when it meant "invalid
376 escape sequence".
377
378 4. Changed some char * arguments to const char *.
379
380 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
381
382 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
383 pcretest.
384
385
386 Version 0.96 16-Oct-97
387 ----------------------
388
389 1. Added a simple "pgrep" utility to the distribution.
390
391 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
392 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
393 where "ddd" means "one or more decimal digits".
394
395 3. Fixed serious bug. If a pattern had a back reference, but the call to
396 pcre_exec() didn't supply a large enough ovector to record the related
397 identifying subpattern, the match always failed. PCRE now remembers the number
398 of the largest back reference, and gets some temporary memory in which to save
399 the offsets during matching if necessary, in order to ensure that
400 backreferences always work.
401
402 4. Increased the compatibility with Perl in a number of ways:
403
404 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
405 to request this handling. The option can be set at compile or exec time.
406
407 (b) $ matches before a terminating newline by default; an option
408 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
409 mode). The option can be set at compile or exec time.
410
411 (c) The handling of \ followed by a digit other than 0 is now supposed to be
412 the same as Perl's. If the decimal number it represents is less than 10
413 or there aren't that many previous left capturing parentheses, an octal
414 escape is read. Inside a character class, it's always an octal escape,
415 even if it is a single digit.
416
417 (d) An escaped but undefined alphabetic character is taken as a literal,
418 unless PCRE_EXTRA is set. Currently this just reserves the remaining
419 escapes.
420
421 (e) {0} is now permitted. (The previous item is removed from the compiled
422 pattern).
423
424 5. Changed all the names of code files so that the basic parts are no longer
425 than 10 characters, and abolished the teeny "globals.c" file.
426
427 6. Changed the handling of character classes; they are now done with a 32-byte
428 bit map always.
429
430 7. Added the -d and /D options to pcretest to make it possible to look at the
431 internals of compilation without having to recompile pcre.
432
433
434 Version 0.95 23-Sep-97
435 ----------------------
436
437 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
438 \x20 at the start of a run of normal characters. These were being treated as
439 real characters, instead of the source characters being re-checked.
440
441
442 Version 0.94 18-Sep-97
443 ----------------------
444
445 1. The functions are now thread-safe, with the caveat that the global variables
446 containing pointers to malloc() and free() or alternative functions are the
447 same for all threads.
448
449 2. Get pcre_study() to generate a bitmap of initial characters for non-
450 anchored patterns when this is possible, and use it if passed to pcre_exec().
451
452
453 Version 0.93 15-Sep-97
454 ----------------------
455
456 1. /(b)|(:+)/ was computing an incorrect first character.
457
458 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
459 but not actually doing anything yet.
460
461 3. Treat "-" characters in classes that cannot be part of ranges as literals,
462 as Perl does (e.g. [-az] or [az-]).
463
464 4. Set the anchored flag if a branch starts with .* or .*? because that tests
465 all possible positions.
466
467 5. Split up into different modules to avoid including unneeded functions in a
468 compiled binary. However, compile and exec are still in one module. The "study"
469 function is split off.
470
471 6. The character tables are now in a separate module whose source is generated
472 by an auxiliary program - but can then be edited by hand if required. There are
473 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
474 toupper() in the code.
475
476 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
477 make them global. Abolish the function for setting them, as the caller can now
478 set them directly.
479
480
481 Version 0.92 11-Sep-97
482 ----------------------
483
484 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
485 (e.g. /a{1,3}/) was broken (I mis-optimized it).
486
487 2. Caseless matching was not working in character classes if the characters in
488 the pattern were in upper case.
489
490 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
491
492 4. Make PCRE_ANCHORED public and accept as a compile option.
493
494 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
495 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
496 pass them.
497
498 6. Give an error if bad option bits passed at compile or run time.
499
500 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
501 pcretest to cause it to pass that flag.
502
503 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
504 options, and the first character, if set.
505
506 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
507
508
509 Version 0.91 10-Sep-97
510 ----------------------
511
512 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
513 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
514
515 2. PCRE was looping on encountering an indefinitely repeated back reference to
516 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
517 Perl does - treats the match as successful.
518
519 ****

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