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Revision 324 - (hide annotations) (download)
Fri Mar 7 19:48:32 2008 UTC (7 years, 1 month ago) by ph10
File size: 151973 byte(s)
Fix bugs with --include and --exclude in pcregrep.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 321 Version 7.7 05-Mar-08
5     ---------------------
7     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
8     a string to a long long, pretend we don't even have a long long." This is
9     done by checking for the strtoq, strtoll, and _strtoi64 functions.
10 ph10 322
11     2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
12     pre-7.6 versions, which defined a global no_arg variable instead of putting
13     it in the RE class.
14 ph10 323
15     3. Remove a line of dead code, identified by coverity and reported by Nuno
16     Lopes.
17 ph10 324
18     4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
19 ph10 321
20 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
21     of files, instead of just to the final components.
23     (2) If there was more than one level of directory, the subdirectories were
24     skipped unless they satisfied the include/exclude conditions. This is
25     inconsistent with GNU grep (and could even be seen as contrary to the
26     pcregrep specification - which I improved to make it absolutely clear).
27     The action now is always to scan all levels of directory, and just
28     apply the include/exclude patterns to regular files.
29 ph10 321
30 ph10 324
31 ph10 319 Version 7.6 28-Jan-08
32 ph10 300 ---------------------
34 ph10 302 1. A character class containing a very large number of characters with
35     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
36     overflow.
37 ph10 309
38     2. Patch to cut out the "long long" test in pcrecpp_unittest when
39     HAVE_LONG_LONG is not defined.
41 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
42 ph10 304 bring them up to date and include new features. This patch includes:
43 ph10 309
44 ph10 304 - Fixed PH's badly added libz and libbz2 support.
45     - Fixed a problem with static linking.
46 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
47 ph10 304 - Fixed dftables problem and added an option.
48     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
50     - Added readline support for pcretest.
51 ph10 309 - Added an listing of the option settings after cmake has run.
53 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
54     "pcre.dll" under mingw when using Configure/Make. I added stuff to
55     Makefile.am that cause it to include this special target, without
56     affecting anything else. Note that the same mingw target plus all
57     the other distribution libraries and programs are now supported
58     when configuring with CMake (see 6 below) instead of with
59     Configure/Make.
60 ph10 309
61 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
62     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
63 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
64     solves the problem, but it does no harm.
65 ph10 313
66 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
67 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
68 ph10 314 with CMake, and also correct the comment about stack recursion.
69 ph10 313
70 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
71 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
72     of a program that users should build themselves after PCRE is installed, so
73     building it automatically is not really right. What is more, it gave
74 ph10 312 trouble in some build environments.
75 ph10 300
76 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
77 ph10 308
78 ph10 319
79 ph10 298 Version 7.5 10-Jan-08
80 ph10 263 ---------------------
82     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
83     values in parens when parsing an RE using the C++ wrapper."
84 ph10 286
85 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
86     Characters greater than 255 were excluded from the class instead of being
87     included.
88 ph10 286
89     3. The same bug as (2) above applied to negated POSIX classes such as
90 ph10 265 [:^space:].
91 ph10 286
92 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
93     defined or documented. It seems to have been a typo for PCRE_STATIC, so
94 ph10 286 I have changed it.
96 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
97 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
98     first named subpattern whose name started with "a" (in other words, the
99 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
100     expected" is now given for (?&) (a zero-length name), and this patch also
101     makes it give the same error for \k'' (previously it complained that that
102     was a reference to a non-existent subpattern).
103 ph10 286
104 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
105 ph10 286 this is right because (?- can be followed by option settings as well as by
106 ph10 269 digits. I have, however, made the messages clearer.
107 ph10 286
108 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
109     than the number used in the conditional) now cause a compile-time error.
110     This is actually not compatible with Perl, which accepts such patterns, but
111     treats the conditional as always being FALSE (as PCRE used to), but it
112     seems to me that giving a diagnostic is better.
113 ph10 286
114 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
115 ph10 275 and messages.
116 ph10 286
117     9. Fix two occurrences of "backslash" in comments that should have been
118     "backspace".
120     10. Remove two redundant lines of code that can never be obeyed (their function
121     was moved elsewhere).
123     11. The program that makes PCRE's Unicode character property table had a bug
124     which caused it to generate incorrect table entries for sequences of
125 ph10 277 characters that have the same character type, but are in different scripts.
126 ph10 286 It amalgamated them into a single range, with the script of the first of
127 ph10 277 them. In other words, some characters were in the wrong script. There were
128     thirteen such cases, affecting characters in the following ranges:
129 ph10 286
130 ph10 277 U+002b0 - U+002c1
131     U+0060c - U+0060d
132 ph10 286 U+0061e - U+00612
133 ph10 277 U+0064b - U+0065e
134     U+0074d - U+0076d
135     U+01800 - U+01805
136     U+01d00 - U+01d77
137     U+01d9b - U+01dbf
138     U+0200b - U+0200f
139     U+030fc - U+030fe
140     U+03260 - U+0327f
141     U+0fb46 - U+0fbb1
142     U+10450 - U+1049d
143 ph10 286
144 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
145     compatible with GNU grep in that, if there was more than one match in a
146     line, it showed only the first of them. It now behaves in the same way as
147     GNU grep.
148 ph10 286
149     13. If the -o and -v options were combined for pcregrep, it printed a blank
150     line for every non-matching line. GNU grep prints nothing, and pcregrep now
151     does the same. The return code can be used to tell if there were any
152     non-matching lines.
154 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
156     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
157 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
158 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
159     and both kinds of lookbehind were skipped).
161 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
162 ph10 284 inclusion of <windows.h> to before rather than after the definition of
163     INVALID_FILE_ATTRIBUTES (patch from David Byron).
164 ph10 263
165 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
166 ph10 286 character property caused pcre_compile() to compile bad code, which led at
167     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
168     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
169     caused the error; without that there was no problem.
170 ph10 263
171 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
172 ph10 286
173 ph10 289 19. Added --enable-pcretest-libreadline.
174 ph10 286
175 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
176 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
177 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
178     later patch that removed the other one (the right fix) and added unit tests
179     that check the return values (which was not done before).
180 ph10 292
181 ph10 291 21. Several CMake things:
182 ph10 287
183 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
184 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
185 ph10 288
186 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
187     linked with the newly-built libraries, not previously installed ones.
188 ph10 291
190 ph10 298
191     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
192     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
193     UTF-8 newline character). The key issue is that the pattern starts .*;
194     this means that the match must be either at the beginning, or after a
195     newline. The bug was in the code for advancing after a failed match and
196     checking that the new position followed a newline. It was not taking
197 ph10 294 account of UTF-8 characters correctly.
198 ph10 298
199     23. PCRE was behaving differently from Perl in the way it recognized POSIX
200     character classes. PCRE was not treating the sequence [:...:] as a
201     character class unless the ... were all letters. Perl, however, seems to
202     allow any characters between [: and :], though of course it rejects as
203     unknown any "names" that contain non-letters, because all the known class
204     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
205     for example, whereas PCRE did not - it did not recognize a POSIX character
206     class. This seemed a bit dangerous, so the code has been changed to be
207     closer to Perl. The behaviour is not identical to Perl, because PCRE will
208     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
209     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
210     Perl does, and where it didn't before.
212 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
213     Windows environments %n is disabled by default.
214 ph10 292
216 ph10 260 Version 7.4 21-Sep-07
217 ph10 230 ---------------------
219     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
220 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
221     LF". That isn't really right - the whole point of the change was to try to
222     help when there was an actual mention of one of the two characters. So now
223     the change happens only if \r or \n (or a literal CR or LF) character is
224 ph10 230 encountered.
225 ph10 231
226     2. The 32-bit options word was also used for 6 internal flags, but the numbers
227     of both had grown to the point where there were only 3 bits left.
228     Fortunately, there was spare space in the data structure, and so I have
229     moved the internal flags into a new 16-bit field to free up more option
230 ph10 230 bits.
231 ph10 231
232     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
233     but did not set the internal JCHANGED flag - either of these is enough to
234     control the way the "get" function works - but the PCRE_INFO_JCHANGED
235     facility is supposed to tell if (?J) was ever used, so now (?J) at the
236 ph10 230 start sets both bits.
238 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
239     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
240 ph10 230
241 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
243     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
244 ph10 233 compatibility, even though it is no longer used.
245 ph10 243
246     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
247 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
248 ph10 259 windows.h file is present (where different names are used). [This was
249 ph10 257 reversed later after testing - see 16 below.]
250 ph10 243
251     8. Changed all #include <config.h> to #include "config.h". There were also
252 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
253 ph10 243
254 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
255 ph10 243 sequence off the lines that it output.
257     10. It was pointed out to me that arrays of string pointers cause lots of
258     relocations when a shared library is dynamically loaded. A technique of
259     using a single long string with a table of offsets can drastically reduce
260     these. I have refactored PCRE in four places to do this. The result is
261 ph10 240 dramatic:
262 ph10 243
263 ph10 240 Originally: 290
264     After changing UCP table: 187
265 ph10 243 After changing error message table: 43
266 ph10 240 After changing table of "verbs" 36
267     After changing table of Posix names 22
268 ph10 243
269 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
270 ph10 247
271 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
272 ph10 247 unicode-properties was also set.
274 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
275 ph10 231
276 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
277     checked only for CRLF.
278 ph10 233
279 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
281 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
282 ph10 253
283 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
284 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
285     entirely. This removes changes made in 7 above.
286 ph10 256
287 ph10 261 17. The CMake files have been updated, and there is now more information about
288     building with CMake in the NON-UNIX-USE document.
289 ph10 257
290 ph10 261
291 ph10 228 Version 7.3 28-Aug-07
292 ph10 157 ---------------------
294 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
295     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
296     brackets there is not right, since it causes compilers to look for an
297     installed pcre.h, not the version that is in the source that is being
298     compiled (which of course may be different). I have changed it back to:
299 ph10 197
300 ph10 189 #include "pcre.h"
301 ph10 197
302     I have a vague recollection that the change was concerned with compiling in
303     different directories, but in the new build system, that is taken care of
304     by the VPATH setting the Makefile.
306 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
307     when the subject happened to end in the byte 0x85 (e.g. if the last
308     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
309     characters but of course it shouldn't be taken as a newline when it is part
310     of another character. The bug was that, for an unlimited repeat of . in
311     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
312     characters when looking for a newline.
313 ph10 197
314     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
316     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
317     in debug output.
319 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
320     long printing in the pcrecpp unittest when running under MinGW.
321 ph10 189
322 ph10 197 6. ESC_K was left out of the EBCDIC table.
323 ph10 189
324 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
325     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
326     limit also applies to "virtual nesting" when a pattern is recursive, and in
327     this case 1000 isn't so big. I have been able to remove this limit at the
328     expense of backing off one optimization in certain circumstances. Normally,
329     when pcre_exec() would call its internal match() function recursively and
330     immediately return the result unconditionally, it uses a "tail recursion"
331     feature to save stack. However, when a subpattern that can match an empty
332     string has an unlimited repetition quantifier, it no longer makes this
333     optimization. That gives it a stack frame in which to save the data for
334     checking that an empty string has been matched. Previously this was taken
335     from the 1000-entry workspace that had been reserved. So now there is no
336     explicit limit, but more stack is used.
337 ph10 189
338 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
339     syntax that is required for Windows, and which was going wrong for the
340     pcreposix and pcrecpp parts of the library. These were overlooked when this
341     problem was solved for the main library.
342 ph10 197
343 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
344     the size of patterns that contain repeated groups with explicit upper
345     limits. As the maximum quantifier is 65535, the maximum group length was
346     set at 30,000 so that the product of these two numbers did not overflow a
347     32-bit integer. However, it turns out that people want to use groups that
348     are longer than 30,000 bytes (though not repeat them that many times).
349     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
350     made it possible to implement the integer overflow checks in a much more
351     dynamic way, which I have now done. The artificial limitation on group
352     length has been removed - we now have only the limit on the total length of
353     the compiled pattern, which depends on the LINK_SIZE setting.
354 ph10 208
355     10. Fixed a bug in the documentation for get/copy named substring when
356     duplicate names are permitted. If none of the named substrings are set, the
357     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
358     empty string.
360     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
361     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
362     because the ] is interpreted as the first data character and the
363     terminating ] is not found. PCRE has been made compatible with Perl in this
364     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
365     cause memory overwriting.
367 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
368     string has been matched (to stop an infinite loop). It was not recognizing
369 ph10 208 a conditional subpattern that could match an empty string if that
370 ph10 206 subpattern was within another subpattern. For example, it looped when
371 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
372 ph10 206 condition was not nested. This bug has been fixed.
373 ph10 208
374 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
375     past the start of the subject in the presence of bytes with the top bit
376     set, for example "\x8aBCD".
377 ph10 211
378 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
379     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
380 ph10 200
381 ph10 211 14. Optimized (?!) to (*FAIL).
382 ph10 202
383 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
384     This restricts code points to be within the range 0 to 0x10FFFF, excluding
385     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
386     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
387     does: it's just the validity check that is more restrictive.
388 ph10 220
389     16. Inserted checks for integer overflows during escape sequence (backslash)
390     processing, and also fixed erroneous offset values for syntax errors during
391     backslash processing.
393 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
394 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
396 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
397     caused an overrun.
398 ph10 220
399     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
400     something other than just ASCII characters) inside a group that had an
401     unlimited repeat caused a loop at compile time (while checking to see
402     whether the group could match an empty string).
404 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
405     [\P{Any}] did so. (Error in the code for printing property names.)
406 ph10 210
407 ph10 220 21. An orphan \E inside a character class could cause a crash.
409     22. A repeated capturing bracket such as (A)? could cause a wild memory
410 ph10 218 reference during compilation.
411 ph10 220
412     23. There are several functions in pcre_compile() that scan along a compiled
413     expression for various reasons (e.g. to see if it's fixed length for look
414 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
415 ph10 220 present in the pattern. These operators have additional parameters compared
416     with \d, etc, and these were not being taken into account when moving along
417 ph10 218 the compiled data. Specifically:
418 ph10 220
419     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
420     length.
422     (b) An item such as \pL+ within a repeated group could cause crashes or
423 ph10 218 loops.
424 ph10 220
425 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
426 ph10 220 "reference to non-existent subpattern" error.
428 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
430 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
431 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
432 ph10 211
433 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
434 ph10 218
435 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
436 ph10 223 character were causing crashes (broken optimization).
437 ph10 227
438 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
439 ph10 227 \p or \P) caused a compile-time loop.
441 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
442     break. For example, the unstudied pattern [\r\n]A does not match the string
443     "\r\nA" because change 7.0/46 below moves the current point on by two
444     characters after failing to match at the start. However, the pattern \nA
445 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
446     the same is true. There doesn't seem any very clean way out of this, but
447     what I have chosen to do makes the common cases work: PCRE now takes note
448     of whether there can be an explicit match for \r or \n anywhere in the
449     pattern, and if so, 7.0/46 no longer applies. As part of this change,
450     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
451     pattern has explicit CR or LF references.
452 ph10 222
453 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
454 ph10 223
455 ph10 227
456 ph10 189 Version 7.2 19-Jun-07
457     ---------------------
459 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
460     which is apparently normally available under Windows.
461 ph10 159
462     2. Re-jig the pcregrep tests with different newline settings in an attempt
463     to make them independent of the local environment's newline setting.
464 ph10 157
465 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
466 ph10 165
467 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
468     was not 2, because the output contained actual offsets. The recent new
469 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
470     usable with all link sizes.
472 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
473     stack recursion. This gives a massive performance boost under BSD, but just
474 ph10 165 a small improvement under Linux. However, it saves one field in the frame
475 ph10 164 in all cases.
476 ph10 172
477 ph10 166 6. Added more features from the forthcoming Perl 5.10:
478 ph10 172
479 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
480     recursion call. It refers to the nth most recently opened parentheses.
481 ph10 172
482 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
483 ph10 172 to be opened parentheses.
485     (c) Conditions that refer to capturing parentheses can be specified
486 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
487 ph10 172
488 ph10 168 (d) \K resets the start of the current match so that everything before
489 ph10 172 is not part of it.
491 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
492 ph10 172
493 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
494 ph10 172 reference syntax.
495 ph10 182
496 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
497 ph10 182 alternative starts with the same number.
498 ph10 172
499 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
501 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
504     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
505     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
506 ph10 170 for detecting groups that can match an empty string.
507 ph10 159
508 ph10 172 9. A pattern with a very large number of alternatives (more than several
509     hundred) was running out of internal workspace during the pre-compile
510     phase, where pcre_compile() figures out how much memory will be needed. A
511     bit of new cunning has reduced the workspace needed for groups with
512     alternatives. The 1000-alternative test pattern now uses 12 bytes of
513     workspace instead of running out of the 4096 that are available.
514 ph10 182
515 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
516 ph10 172
517 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
518     The report of the bug said:
519 ph10 182
520 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
521     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
522 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
523 ph10 185
524 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
525 ph10 185 it matched the wrong number of bytes.
526 ph10 172
527 ph10 179
528 ph10 155 Version 7.1 24-Apr-07
529 ph10 98 ---------------------
531 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
532 ph10 122 that is more "standard", making use of automake and other Autotools. There
533 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
534     on this.
535 ph10 111
536     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
537     for recursive directory scanning broke on some systems because the files
538     are not scanned in any specific order and on different systems the order
539     was different. A call to "sort" has been inserted into RunGrepTest for the
540     approprate test as a short-term fix. In the longer term there may be an
541 ph10 100 alternative.
542 ph10 111
543 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
544 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
545     people do their own conversions for various reasons). The problems
546     concerned the use of low-level troff macros .br and .in. I have therefore
547     removed all such uses from the man pages (some were redundant, some could
548 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
549     HTML has been updated to handle .nf/.fi and to complain if it encounters
550     .br or .in.
551 ph10 111
552 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
553 ph10 123 arranged for config.h to be included in the distribution, with the name
554 ph10 111 config.h.generic, for the benefit of those who have to compile without
555     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
557     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
558     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
559 ph10 127 makevp.bat for the current PCRE, using the additional files
560 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
561 ph10 111
562     6. A Windows user reported a minor discrepancy with test 2, which turned out
563     to be caused by a trailing space on an input line that had got lost in his
564 ph10 102 copy. The trailing space was an accident, so I've just removed it.
565 ph10 111
566 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
567 ph10 111 that is needed.
569 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
570     as "const" (a) because they are and (b) because it helps the PHP
571     maintainers who have recently made a script to detect big data structures
572 ph10 111 in the php code that should be moved to the .rodata section. I remembered
573     to update Builducptable as well, so it won't revert if ucptable.h is ever
574 ph10 105 re-created.
575 ph10 111
576     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
577 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
578 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
579     support is not required. This saves 1.5-2K of code, which is important in
580 ph10 107 some applications.
581 ph10 111
582 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
583 ph10 111 so as not to refer to the tables, even though these functions will never be
584     called when UTF-8 support is disabled. Otherwise there are problems with a
585     shared library.
587 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
589     (a) It was defining its arguments as char * instead of void *.
591 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
592     a long time ago when I wrote it, but is no longer the case.
594 ph10 118 The emulated memove() is provided for those environments that have neither
595 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
596 ph10 118 is clearly not the case, as these two bugs were recently reported.
597 ph10 123
598 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
599 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
600     pages, and it removes trailing spaces from listed files. It also creates
601     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
602     case, it wraps all the #defines with #ifndefs. This script should be run
603 ph10 111 before "make dist".
604 ph10 123
605 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
606     with Unicode property support.
607 ph10 123
608     (a) For a maximizing quantifier, if the two different cases of the
609     character were of different lengths in their UTF-8 codings (there are
610     some cases like this - I found 11), and the matching function had to
611 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
612     were both the same length.
613 ph10 123
614     (b) When PCRE was configured to use the heap rather than the stack for
615     recursion during matching, it was not correctly preserving the data for
616     the other case of a UTF-8 character when checking ahead for a match
617     while processing a minimizing repeat. If the check also involved
618 ph10 115 matching a wide character, but failed, corruption could cause an
619     erroneous result when trying to check for a repeat of the original
620     character.
621 ph10 123
622 ph10 116 13. Some tidying changes to the testing mechanism:
623 ph10 98
624 ph10 116 (a) The RunTest script now detects the internal link size and whether there
625     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
626 ph10 123 values substituted by "configure". (The RunGrepTest script already did
627     this for UTF-8.) The configure.ac script no longer substitutes the
628     relevant variables.
630 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
631     with length and offset values. This means that the output is different
632     for different internal link sizes. Test 2 is skipped for link sizes
633     other than 2 because of this, bypassing the problem. Unfortunately,
634     there was also a test in test 3 (the locale tests) that used /B and
635 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
636     I have added a new /Z option to pcretest that replaces the length and
637     offset values with spaces. This is now used to make test 3 independent
638 ph10 122 of link size. (Test 2 will be tidied up later.)
639 ph10 123
640     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
641 ph10 122 segmentation fault instead of returning the appropriate error message.
642 ph10 134
643 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
644 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
645     This doesn't seem right; it now treats the CRLF combination as the line
646     ending, and so does not match in that case. It's only a pattern such as ^$
647     that would hit this one: something like ^ABC$ would have failed after \r
648     and then tried again after \r\n.
650 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
651 ph10 134 in an attempt to make files that differ only in their line terminators
652     compare equal. This works on Linux.
653 ph10 142
654 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
655     as it exited. This is now fixed, thanks to valgrind.
656 ph10 142
657 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
658 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
659     was because its rules for how to advance for /g after matching an empty
660 ph10 143 string at the end of a line did not allow for this case. They now check for
661     it specially.
662 ph10 150
663     20. pcretest is supposed to handle patterns and data of any length, by
664     extending its buffers when necessary. It was getting this wrong when the
665 ph10 147 buffer for a data line had to be extended.
666 ph10 150
667 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
668 ph10 150 CRLF as a newline sequence.
669 ph10 152
670 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
671 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
672     I have nevertheless tidied it up.
673 ph10 111
674 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
675 ph10 123
676 ph10 153 24. Added a man page for pcre-config.
677 ph10 152
678 ph10 153
679 nigel 93 Version 7.0 19-Dec-06
680     ---------------------
682     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
683     moving to gcc 4.1.1.
685     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
686     sys/time.h, which is documented as needed for this function. It doesn't
687     seem to matter on Linux, but it showed up on some releases of OS X.
689     3. It seems that there are systems where bytes whose values are greater than
690     127 match isprint() in the "C" locale. The "C" locale should be the
691     default when a C program starts up. In most systems, only ASCII printing
692     characters match isprint(). This difference caused the output from pcretest
693     to vary, making some of the tests fail. I have changed pcretest so that:
695     (a) When it is outputting text in the compiled version of a pattern, bytes
696     other than 32-126 are always shown as hex escapes.
698     (b) When it is outputting text that is a matched part of a subject string,
699     it does the same, unless a different locale has been set for the match
700     (using the /L modifier). In this case, it uses isprint() to decide.
702     4. Fixed a major bug that caused incorrect computation of the amount of memory
703     required for a compiled pattern when options that changed within the
704     pattern affected the logic of the preliminary scan that determines the
705     length. The relevant options are -x, and -i in UTF-8 mode. The result was
706     that the computed length was too small. The symptoms of this bug were
707     either the PCRE error "internal error: code overflow" from pcre_compile(),
708     or a glibc crash with a message such as "pcretest: free(): invalid next
709     size (fast)". Examples of patterns that provoked this bug (shown in
710     pcretest format) are:
712     /(?-x: )/x
713     /(?x)(?-x: \s*#\s*)/
714     /((?i)[\x{c0}])/8
715     /(?i:[\x{c0}])/8
717     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
718     is now done differently.
720     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
721     wrapper classes; (b) implement a new function in the C++ scanner that is
722     more efficient than the old way of doing things because it avoids levels of
723     recursion in the regex matching; (c) add a paragraph to the documentation
724     for the FullMatch() function.
726     6. The escape sequence \n was being treated as whatever was defined as
727     "newline". Not only was this contrary to the documentation, which states
728     that \n is character 10 (hex 0A), but it also went horribly wrong when
729     "newline" was defined as CRLF. This has been fixed.
731     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
732     was being set to -1 for the "end of line" case (supposedly a value that no
733     character can have). Though this value is never used (the check for end of
734     line is "zero bytes in current character"), it caused compiler complaints.
735     I've changed it to 0xffffffff.
737     8. In pcre_version.c, the version string was being built by a sequence of
738     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
739     string (as it is for production releases) called a macro with an empty
740     argument. The C standard says the result of this is undefined. The gcc
741     compiler treats it as an empty string (which was what was wanted) but it is
742     reported that Visual C gives an error. The source has been hacked around to
743     avoid this problem.
745     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
746     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
747     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
748     of them did).
750     10. Originally, pcretest opened its input and output without "b"; then I was
751     told that "b" was needed in some environments, so it was added for release
752     5.0 to both the input and output. (It makes no difference on Unix-like
753     systems.) Later I was told that it is wrong for the input on Windows. I've
754     now abstracted the modes into two macros, to make it easier to fiddle with
755     them, and removed "b" from the input mode under Windows.
757     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
759     12. Added -help and --help to pcretest as an official way of being reminded
760     of the options.
762     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
763     and pcrecpp.cc because they annoy compilers at high warning levels.
765     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
767     15. Fixed an occurrence of == in configure.ac that should have been = (shell
768     scripts are not C programs :-) and which was not noticed because it works
769     on Linux.
771     16. pcretest is supposed to handle any length of pattern and data line (as one
772     line or as a continued sequence of lines) by extending its input buffer if
773     necessary. This feature was broken for very long pattern lines, leading to
774     a string of junk being passed to pcre_compile() if the pattern was longer
775     than about 50K.
777     17. I have done a major re-factoring of the way pcre_compile() computes the
778     amount of memory needed for a compiled pattern. Previously, there was code
779     that made a preliminary scan of the pattern in order to do this. That was
780     OK when PCRE was new, but as the facilities have expanded, it has become
781     harder and harder to keep it in step with the real compile phase, and there
782     have been a number of bugs (see for example, 4 above). I have now found a
783     cunning way of running the real compile function in a "fake" mode that
784     enables it to compute how much memory it would need, while actually only
785     ever using a few hundred bytes of working memory and without too many
786     tests of the mode. This should make future maintenance and development
787     easier. A side effect of this work is that the limit of 200 on the nesting
788     depth of parentheses has been removed (though this was never a serious
789     limitation, I suspect). However, there is a downside: pcre_compile() now
790     runs more slowly than before (30% or more, depending on the pattern). I
791     hope this isn't a big issue. There is no effect on runtime performance.
793     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
794     newline (only possible for the last line of a file) and it was a
795     pattern that set a locale (followed by /Lsomething), pcretest crashed.
797     19. Added additional timing features to pcretest. (1) The -tm option now times
798     matching only, not compiling. (2) Both -t and -tm can be followed, as a
799     separate command line item, by a number that specifies the number of
800     repeats to use when timing. The default is 50000; this gives better
801     precision, but takes uncomfortably long for very large patterns.
803     20. Extended pcre_study() to be more clever in cases where a branch of a
804     subpattern has no definite first character. For example, (a*|b*)[cd] would
805     previously give no result from pcre_study(). Now it recognizes that the
806     first character must be a, b, c, or d.
808     21. There was an incorrect error "recursive call could loop indefinitely" if
809     a subpattern (or the entire pattern) that was being tested for matching an
810     empty string contained only one non-empty item after a nested subpattern.
811     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
812     incorrectly, because the \d was being skipped in the check.
814     22. The pcretest program now has a new pattern option /B and a command line
815     option -b, which is equivalent to adding /B to every pattern. This causes
816     it to show the compiled bytecode, without the additional information that
817     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
818     is the same as /B/I).
820     23. A new optimization is now able automatically to treat some sequences such
821     as a*b as a*+b. More specifically, if something simple (such as a character
822     or a simple class like \d) has an unlimited quantifier, and is followed by
823     something that cannot possibly match the quantified thing, the quantifier
824     is automatically "possessified".
826     24. A recursive reference to a subpattern whose number was greater than 39
827     went wrong under certain circumstances in UTF-8 mode. This bug could also
828     have affected the operation of pcre_study().
830     25. Realized that a little bit of performance could be had by replacing
831     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
833     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
835     27. Possessive quantifiers such as a++ were previously implemented by turning
836     them into atomic groups such as ($>a+). Now they have their own opcodes,
837     which improves performance. This includes the automatically created ones
838     from 23 above.
840     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
841     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
842     the first matched character to be a colon. This applied both to named and
843     numbered groups.
845     29. The ucpinternal.h header file was missing its idempotency #ifdef.
847     30. I was sent a "project" file called libpcre.a.dev which I understand makes
848     building PCRE on Windows easier, so I have included it in the distribution.
850     31. There is now a check in pcretest against a ridiculously large number being
851     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
852     loop, the loop is abandoned.
854     32. Forward references to subpatterns in conditions such as (?(2)...) where
855     subpattern 2 is defined later cause pcre_compile() to search forwards in
856     the pattern for the relevant set of parentheses. This search went wrong
857     when there were unescaped parentheses in a character class, parentheses
858     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
860     33. "Subroutine" calls and backreferences were previously restricted to
861     referencing subpatterns earlier in the regex. This restriction has now
862     been removed.
864     34. Added a number of extra features that are going to be in Perl 5.10. On the
865     whole, these are just syntactic alternatives for features that PCRE had
866     previously implemented using the Python syntax or my own invention. The
867     other formats are all retained for compatibility.
869     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
870     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
871     also .NET compatible.
873     (b) A recursion or subroutine call to a named group can now be defined as
874     (?&name) as well as (?P>name).
876     (c) A backreference to a named group can now be defined as \k<name> or
877     \k'name' as well as (?P=name). The new forms, as well as being in Perl
878     5.10, are also .NET compatible.
880     (d) A conditional reference to a named group can now use the syntax
881     (?(<name>) or (?('name') as well as (?(name).
883     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
884     groups (named and numbered) that are never evaluated inline, but can be
885     called as "subroutines" from elsewhere. In effect, the DEFINE condition
886     is always false. There may be only one alternative in such a group.
888     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
889     as the simple (?(R). The condition is true only if the most recent
890     recursion is that of the given number or name. It does not search out
891     through the entire recursion stack.
893     (g) The escape \gN or \g{N} has been added, where N is a positive or
894     negative number, specifying an absolute or relative reference.
896     35. Tidied to get rid of some further signed/unsigned compiler warnings and
897     some "unreachable code" warnings.
899     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
900     things, this adds five new scripts.
902     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
903     There were also incompatibilities regarding the handling of \Q..\E inside
904     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
905     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
907     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
908     matches an empty string, and forcibly breaks the loop. There were bugs in
909     this code in non-simple cases. For a pattern such as ^(a()*)* matched
910     against aaaa the result was just "a" rather than "aaaa", for example. Two
911     separate and independent bugs (that affected different cases) have been
912     fixed.
914     39. Refactored the code to abolish the use of different opcodes for small
915     capturing bracket numbers. This is a tidy that I avoided doing when I
916     removed the limit on the number of capturing brackets for 3.5 back in 2001.
917     The new approach is not only tidier, it makes it possible to reduce the
918     memory needed to fix the previous bug (38).
920     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
921     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
922     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
923     mode.
925     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
926     report.
928     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
929     copy construction and assignment in the C++ wrapper.
931     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
932     couple of bugs that could have given wrong results in the "--newline=crlf"
933     case.
935     44. Added a number of casts and did some reorganization of signed/unsigned int
936     variables following suggestions from Dair Grant. Also renamed the variable
937     "this" as "item" because it is a C++ keyword.
939     45. Arranged for dftables to add
941     #include "pcre_internal.h"
943     to pcre_chartables.c because without it, gcc 4.x may remove the array
944     definition from the final binary if PCRE is built into a static library and
945     dead code stripping is activated.
947     46. For an unanchored pattern, if a match attempt fails at the start of a
948     newline sequence, and the newline setting is CRLF or ANY, and the next two
949     characters are CRLF, advance by two characters instead of one.
952 nigel 91 Version 6.7 04-Jul-06
953     ---------------------
955     1. In order to handle tests when input lines are enormously long, pcretest has
956     been re-factored so that it automatically extends its buffers when
957     necessary. The code is crude, but this _is_ just a test program. The
958     default size has been increased from 32K to 50K.
960     2. The code in pcre_study() was using the value of the re argument before
961     testing it for NULL. (Of course, in any sensible call of the function, it
962     won't be NULL.)
964     3. The memmove() emulation function in pcre_internal.h, which is used on
965     systems that lack both memmove() and bcopy() - that is, hardly ever -
966     was missing a "static" storage class specifier.
968     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
969     containing an extended class (one that cannot be represented by a bitmap
970     because it contains high-valued characters or Unicode property items, e.g.
971     [\pZ]). Almost always one would set UTF-8 mode when processing such a
972     pattern, but PCRE should not loop if you do not (it no longer does).
973     [Detail: two cases were found: (a) a repeated subpattern containing an
974     extended class; (b) a recursive reference to a subpattern that followed a
975     previous extended class. It wasn't skipping over the extended class
976     correctly when UTF-8 mode was not set.]
978     5. A negated single-character class was not being recognized as fixed-length
979     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
980     compile error "lookbehind assertion is not fixed length".
982     6. The RunPerlTest auxiliary script was showing an unexpected difference
983     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
984     write a Perl script that can interpret lines of an input file either as
985     byte characters or as UTF-8, which is what "perltest" was being required to
986     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
987     can't do is switch easily at run time between having the "use utf8;" pragma
988     or not. In the end, I fudged it by using the RunPerlTest script to insert
989     "use utf8;" explicitly for the UTF-8 tests.
991     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
992     the end of the subject string, contrary to the documentation and to what
993     Perl does. This was true of both matching functions. Now it matches only at
994     the start of the subject and immediately after *internal* newlines.
996     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
997     a pointer to an int instead of a pointer to an unsigned long int. This
998     caused problems on 64-bit systems.
1000     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1001     instance of the 'standard' template library not being so standard".
1003     10. There was no check on the number of named subpatterns nor the maximum
1004     length of a subpattern name. The product of these values is used to compute
1005     the size of the memory block for a compiled pattern. By supplying a very
1006     long subpattern name and a large number of named subpatterns, the size
1007     computation could be caused to overflow. This is now prevented by limiting
1008     the length of names to 32 characters, and the number of named subpatterns
1009     to 10,000.
1011     11. Subpatterns that are repeated with specific counts have to be replicated in
1012     the compiled pattern. The size of memory for this was computed from the
1013     length of the subpattern and the repeat count. The latter is limited to
1014     65535, but there was no limit on the former, meaning that integer overflow
1015     could in principle occur. The compiled length of a repeated subpattern is
1016     now limited to 30,000 bytes in order to prevent this.
1018     12. Added the optional facility to have named substrings with the same name.
1020     13. Added the ability to use a named substring as a condition, using the
1021     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1022     are numbers (not recommended). Forward references are permitted.
1024     14. Added forward references in named backreferences (if you see what I mean).
1026     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1027     pattern could run off the end of the subject. For example, the pattern
1028     "(?s)(.{1,5})"8 did this with the subject "ab".
1030     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1031     PCRE_CASELESS was set when matching characters that were quantified with ?
1032     or *.
1034     17. A character class other than a single negated character that had a minimum
1035     but no maximum quantifier - for example [ab]{6,} - was not handled
1036     correctly by pce_dfa_exec(). It would match only one character.
1038     18. A valid (though odd) pattern that looked like a POSIX character
1039     class but used an invalid character after [ (for example [[,abc,]]) caused
1040     pcre_compile() to give the error "Failed: internal error: code overflow" or
1041     in some cases to crash with a glibc free() error. This could even happen if
1042     the pattern terminated after [[ but there just happened to be a sequence of
1043     letters, a binary zero, and a closing ] in the memory that followed.
1045     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1046     over the years. Originally (before any Unicode support), just the bottom 8
1047     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1048     output from "man perlunicode" includes this:
1050     The regular expression compiler produces polymorphic opcodes. That
1051     is, the pattern adapts to the data and automatically switches to
1052     the Unicode character scheme when presented with Unicode data--or
1053     instead uses a traditional byte scheme when presented with byte
1054     data.
1056     Sadly, a wide octal escape does not cause a switch, and in a string with
1057     no other multibyte characters, these octal escapes are treated as before.
1058     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1059     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1060     Unicode string.
1062     I have not perpetrated such confusion in PCRE. Up till now, it took just
1063     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1064     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1065     translate to the appropriate multibyte character.
1067     29. Applied some refactoring to reduce the number of warnings from Microsoft
1068     and Borland compilers. This has included removing the fudge introduced
1069     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1070     a warning about an unused variable.
1072     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1073     characters since release 4.0, because Perl (from release 5.004) does not.
1074     [Or at least, is documented not to: some releases seem to be in conflict
1075     with the documentation.] However, when a pattern was studied with
1076     pcre_study() and all its branches started with \s, PCRE still included VT
1077     as a possible starting character. Of course, this did no harm; it just
1078     caused an unnecessary match attempt.
1080     22. Removed a now-redundant internal flag bit that recorded the fact that case
1081     dependency changed within the pattern. This was once needed for "required
1082     byte" processing, but is no longer used. This recovers a now-scarce options
1083     bit. Also moved the least significant internal flag bit to the most-
1084     significant bit of the word, which was not previously used (hangover from
1085     the days when it was an int rather than a uint) to free up another bit for
1086     the future.
1088     23. Added support for CRLF line endings as well as CR and LF. As well as the
1089     default being selectable at build time, it can now be changed at runtime
1090     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1091     specify that it is scanning data with non-default line endings.
1093     24. Changed the definition of CXXLINK to make it agree with the definition of
1094     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1096     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1097     recursions. This makes a big different to stack usage for some patterns.
1099     26. If a subpattern containing a named recursion or subroutine reference such
1100     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1101     the space required for the compiled pattern went wrong and gave too small a
1102     value. Depending on the environment, this could lead to "Failed: internal
1103     error: code overflow at offset 49" or "glibc detected double free or
1104     corruption" errors.
1106     27. Applied patches from Google (a) to support the new newline modes and (b) to
1107     advance over multibyte UTF-8 characters in GlobalReplace.
1109     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1110     difference for some implementation of PCRE in some Windows version.
1112     29. Added some extra testing facilities to pcretest:
1114     \q<number> in a data line sets the "match limit" value
1115     \Q<number> in a data line sets the "match recursion limt" value
1116     -S <number> sets the stack size, where <number> is in megabytes
1118     The -S option isn't available for Windows.
1121 nigel 89 Version 6.6 06-Feb-06
1122     ---------------------
1124     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1125     in pcreposix.h. I have copied the definition from pcre.h.
1127     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1128     because pcre.h is no longer a built file.
1130     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1131     not normally included in the compiled code.
1134 nigel 87 Version 6.5 01-Feb-06
1135     ---------------------
1137     1. When using the partial match feature with pcre_dfa_exec(), it was not
1138     anchoring the second and subsequent partial matches at the new starting
1139     point. This could lead to incorrect results. For example, with the pattern
1140     /1234/, partially matching against "123" and then "a4" gave a match.
1142     2. Changes to pcregrep:
1144     (a) All non-match returns from pcre_exec() were being treated as failures
1145     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1146     error message is output. Some extra information is given for the
1148     probably the only errors that are likely to be caused by users (by
1149     specifying a regex that has nested indefinite repeats, for instance).
1150     If there are more than 20 of these errors, pcregrep is abandoned.
1152     (b) A binary zero was treated as data while matching, but terminated the
1153     output line if it was written out. This has been fixed: binary zeroes
1154     are now no different to any other data bytes.
1156     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1157     used to set a locale for matching. The --locale=xxxx long option has
1158     been added (no short equivalent) to specify a locale explicitly on the
1159     pcregrep command, overriding the environment variables.
1161     (d) When -B was used with -n, some line numbers in the output were one less
1162     than they should have been.
1164     (e) Added the -o (--only-matching) option.
1166     (f) If -A or -C was used with -c (count only), some lines of context were
1167     accidentally printed for the final match.
1169     (g) Added the -H (--with-filename) option.
1171     (h) The combination of options -rh failed to suppress file names for files
1172     that were found from directory arguments.
1174     (i) Added the -D (--devices) and -d (--directories) options.
1176     (j) Added the -F (--fixed-strings) option.
1178     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1180     (l) Added the --colo(u)r option.
1182     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1183     is not present by default.
1185     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1186     items such as (?R) or (?1), when the recursion could match a number of
1187     alternatives. If it matched one of the alternatives, but subsequently,
1188     outside the recursion, there was a failure, the code tried to back up into
1189     the recursion. However, because of the way PCRE is implemented, this is not
1190     possible, and the result was an incorrect result from the match.
1192     In order to prevent this happening, the specification of recursion has
1193     been changed so that all such subpatterns are automatically treated as
1194     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1196     4. I had overlooked the fact that, in some locales, there are characters for
1197     which isalpha() is true but neither isupper() nor islower() are true. In
1198     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1199     and ordfeminine) are like this. This affected the treatment of \w and \W
1200     when they appeared in character classes, but not when they appeared outside
1201     a character class. The bit map for "word" characters is now created
1202     separately from the results of isalnum() instead of just taking it from the
1203     upper, lower, and digit maps. (Plus the underscore character, of course.)
1205     5. The above bug also affected the handling of POSIX character classes such as
1206     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1207     permanent tables. Instead, the bit maps for such a class were previously
1208     created as the appropriate unions of the upper, lower, and digit bitmaps.
1209     Now they are created by subtraction from the [[:word:]] class, which has
1210     its own bitmap.
1212     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1213     It is created by subtracting the vertical space characters (\x09, \x0a,
1214     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1215     subtraction was done in the overall bitmap for a character class, meaning
1216     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1217     be recognized. This bug has been fixed.
1219     7. Patches from the folks at Google:
1221     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1222     real life, but is still worth protecting against".
1224     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1225     regular expressions".
1227     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1228     have it.
1230     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1231     "configure" and the latter not, in order to fix a problem somebody had
1232     with compiling the Arg class on HP-UX.
1234     (e) Improve the error-handling of the C++ wrapper a little bit.
1236     (f) New tests for checking recursion limiting.
1238     8. The pcre_memmove() function, which is used only if the environment does not
1239     have a standard memmove() function (and is therefore rarely compiled),
1240     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1241     returning a result (though PCRE never actually uses the result).
1243     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1244     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1245     returned instead of calling malloc() with an overflowing number that would
1246     most likely cause subsequent chaos.
1248     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1250     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1251     with this option is matched, the nmatch and pmatch options of regexec() are
1252     ignored.
1254     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1255     provided in case anyone wants to the the POSIX interface with UTF-8
1256     strings.
1258     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1259     C++ linking (needed for some HP-UX environments).
1261     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1262     (unused parameter) and in the pcre_printint() function (omitted "default"
1263     switch label when the default is to do nothing).
1265     15. Added some code to make it possible, when PCRE is compiled as a C++
1266     library, to replace subject pointers for pcre_exec() with a smart pointer
1267     class, thus making it possible to process discontinuous strings.
1269     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1270     much the same function. They were added by different people who were trying
1271     to make PCRE easy to compile on non-Unix systems. It has been suggested
1272     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1273     for compiling on Windows systems. I have therefore replaced it with
1274     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1275     defaults to "extern" for C or "extern C" for C++, which works fine on
1276     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1277     SCOPE with something explicit in config.h. In addition:
1279     (a) pcreposix.h still had just "extern" instead of either of these macros;
1280     I have replaced it with PCRE_DATA_SCOPE.
1282     (b) Functions such as _pcre_xclass(), which are internal to the library,
1283     but external in the C sense, all had PCRE_EXPORT in their definitions.
1284     This is apparently wrong for the Windows case, so I have removed it.
1285     (It makes no difference on Unix-like systems.)
1287     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1288     of recursive calls to match(). This is different to MATCH_LIMIT because
1289     that limits the total number of calls to match(), not all of which increase
1290     the depth of recursion. Limiting the recursion depth limits the amount of
1291     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1292     when PCRE is compiled, and changed at run time. A patch from Google adds
1293     this functionality to the C++ interface.
1295     18. Changes to the handling of Unicode character properties:
1297     (a) Updated the table to Unicode 4.1.0.
1299     (b) Recognize characters that are not in the table as "Cn" (undefined).
1301     (c) I revised the way the table is implemented to a much improved format
1302     which includes recognition of ranges. It now supports the ranges that
1303     are defined in UnicodeData.txt, and it also amalgamates other
1304     characters into ranges. This has reduced the number of entries in the
1305     table from around 16,000 to around 3,000, thus reducing its size
1306     considerably. I realized I did not need to use a tree structure after
1307     all - a binary chop search is just as efficient. Having reduced the
1308     number of entries, I extended their size from 6 bytes to 8 bytes to
1309     allow for more data.
1311     (d) Added support for Unicode script names via properties such as \p{Han}.
1313     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1314     matching that character.
1316     20. When matching a repeated Unicode property with a minimum greater than zero,
1317     (for example \pL{2,}), PCRE could look past the end of the subject if it
1318     reached it while seeking the minimum number of characters. This could
1319     happen only if some of the characters were more than one byte long, because
1320     there is a check for at least the minimum number of bytes.
1322     21. Refactored the implementation of \p and \P so as to be more general, to
1323     allow for more different types of property in future. This has changed the
1324     compiled form incompatibly. Anybody with saved compiled patterns that use
1325     \p or \P will have to recompile them.
1327     22. Added "Any" and "L&" to the supported property types.
1329     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1330     but give a compile time error if the value is greater than 0xff.
1332     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1333     accidentally not being installed or uninstalled.
1335     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1336     made were to insert the current release number. This seemed silly, because
1337     it made things harder for people building PCRE on systems that don't run
1338     "configure". I have turned pcre.h into a distributed file, no longer built
1339     by "configure", with the version identification directly included. There is
1340     no longer a pcre.h.in file.
1342     However, this change necessitated a change to the pcre-config script as
1343     well. It is built from pcre-config.in, and one of the substitutions was the
1344     release number. I have updated configure.ac so that ./configure now finds
1345     the release number by grepping pcre.h.
1347     26. Added the ability to run the tests under valgrind.
1350 nigel 85 Version 6.4 05-Sep-05
1351     ---------------------
1353     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1354     "--" to be printed when multiple files were scanned, even when none of the
1355     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1356     consider it to be a bug, and have restored the previous behaviour.
1358     2. A couple of code tidies to get rid of compiler warnings.
1360     3. The pcretest program used to cheat by referring to symbols in the library
1361     whose names begin with _pcre_. These are internal symbols that are not
1362     really supposed to be visible externally, and in some environments it is
1363     possible to suppress them. The cheating is now confined to including
1364     certain files from the library's source, which is a bit cleaner.
1366     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1367     file's purpose clearer.
1369     5. Reorganized pcre_ucp_findchar().
1372 nigel 83 Version 6.3 15-Aug-05
1373     ---------------------
1375     1. The file libpcre.pc.in did not have general read permission in the tarball.
1377     2. There were some problems when building without C++ support:
1379     (a) If C++ support was not built, "make install" and "make test" still
1380     tried to test it.
1382     (b) There were problems when the value of CXX was explicitly set. Some
1383     changes have been made to try to fix these, and ...
1385     (c) --disable-cpp can now be used to explicitly disable C++ support.
1387     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1388     backslash in a target when C++ was disabled. This confuses some
1389     versions of "make", apparently. Using an intermediate variable solves
1390     this. (Same for CPP_LOBJ.)
1392     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1393     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1394     necessary on certain architectures.
1396     4. Added a setting of -export-symbols-regex to the link command to remove
1397     those symbols that are exported in the C sense, but actually are local
1398     within the library, and not documented. Their names all begin with
1399     "_pcre_". This is not a perfect job, because (a) we have to except some
1400     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1401     available (and never for static libraries). I have made a note to try to
1402     find a way round (a) in the future.
1405 nigel 81 Version 6.2 01-Aug-05
1406     ---------------------
1408     1. There was no test for integer overflow of quantifier values. A construction
1409     such as {1111111111111111} would give undefined results. What is worse, if
1410     a minimum quantifier for a parenthesized subpattern overflowed and became
1411     negative, the calculation of the memory size went wrong. This could have
1412     led to memory overwriting.
1414     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1416     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1417     operating environments where this matters.
1419     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1420     PCRE options from within the C++ wrapper.
1422     5. Named capturing subpatterns were not being correctly counted when a pattern
1423     was compiled. This caused two problems: (a) If there were more than 100
1424     such subpatterns, the calculation of the memory needed for the whole
1425     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1426     back references of the form \12, where the number was greater than 9, were
1427     not recognized as back references, even though there were sufficient
1428     previous subpatterns.
1430     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1431     versions of gcc, e.g. 2.95.4.
1434 nigel 79 Version 6.1 21-Jun-05
1435     ---------------------
1437     1. There was one reference to the variable "posix" in pcretest.c that was not
1438     surrounded by "#if !defined NOPOSIX".
1440     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1441     the cross-check on the old pcre_info() function, for the benefit of the
1442     cut-down version of PCRE that is currently imported into Exim.
1444     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1445     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1446     patterns that start (?i) but I don't think that matters. The use of (?i) is
1447     just an example; this all applies to the other options as well.
1449     4. Since libtool seems to echo the compile commands it is issuing, the output
1450     from "make" can be reduced a bit by putting "@" in front of each libtool
1451     compile command.
1453     5. Patch from the folks at Google for configure.in to be a bit more thorough
1454     in checking for a suitable C++ installation before trying to compile the
1455     C++ stuff. This should fix a reported problem when a compiler was present,
1456     but no suitable headers.
1458     6. The man pages all had just "PCRE" as their title. I have changed them to
1459     be the relevant file name. I have also arranged that these names are
1460     retained in the file doc/pcre.txt, which is a concatenation in text format
1461     of all the man pages except the little individual ones for each function.
1463     7. The NON-UNIX-USE file had not been updated for the different set of source
1464     files that come with release 6. I also added a few comments about the C++
1465     wrapper.
1468 nigel 77 Version 6.0 07-Jun-05
1469     ---------------------
1471     1. Some minor internal re-organization to help with my DFA experiments.
1473     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1474     didn't matter for the library itself when fully configured, but did matter
1475     when compiling without UCP support, or within Exim, where the ucp files are
1476     not imported.
1478     3. Refactoring of the library code to split up the various functions into
1479     different source modules. The addition of the new DFA matching code (see
1480     below) to a single monolithic source would have made it really too
1481     unwieldy, quite apart from causing all the code to be include in a
1482     statically linked application, when only some functions are used. This is
1483     relevant even without the DFA addition now that patterns can be compiled in
1484     one application and matched in another.
1486     The downside of splitting up is that there have to be some external
1487     functions and data tables that are used internally in different modules of
1488     the library but which are not part of the API. These have all had their
1489     names changed to start with "_pcre_" so that they are unlikely to clash
1490     with other external names.
1492     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1493     a different (DFA) algorithm. Although it is slower than the original
1494     function, it does have some advantages for certain types of matching
1495     problem.
1497     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1498     including restarting after a partial match.
1500     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1501     defined when compiling for Windows was sent to me. I have put it into the
1502     code, though I have no means of testing or verifying it.
1504     7. Added the pcre_refcount() auxiliary function.
1506     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1507     match before or at the first newline in the subject string. In pcretest,
1508     the /f option on a pattern can be used to set this.
1510     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1511     would behave wrongly. This has been present in PCRE since release 4.0.
1513     10. A number of changes to the pcregrep command:
1515     (a) Refactored how -x works; insert ^(...)$ instead of setting
1516     PCRE_ANCHORED and checking the length, in preparation for adding
1517     something similar for -w.
1519     (b) Added the -w (match as a word) option.
1521     (c) Refactored the way lines are read and buffered so as to have more
1522     than one at a time available.
1524     (d) Implemented a pcregrep test script.
1526     (e) Added the -M (multiline match) option. This allows patterns to match
1527     over several lines of the subject. The buffering ensures that at least
1528     8K, or the rest of the document (whichever is the shorter) is available
1529     for matching (and similarly the previous 8K for lookbehind assertions).
1531     (f) Changed the --help output so that it now says
1533     -w, --word-regex(p)
1535     instead of two lines, one with "regex" and the other with "regexp"
1536     because that confused at least one person since the short forms are the
1537     same. (This required a bit of code, as the output is generated
1538     automatically from a table. It wasn't just a text change.)
1540     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1541     option but starts with a hyphen. Could be a pattern or a path name
1542     starting with a hyphen, for instance.
1544     (h) "-" can be given as a file name to represent stdin.
1546     (i) When file names are being printed, "(standard input)" is used for
1547     the standard input, for compatibility with GNU grep. Previously
1548     "<stdin>" was used.
1550     (j) The option --label=xxx can be used to supply a name to be used for
1551     stdin when file names are being printed. There is no short form.
1553     (k) Re-factored the options decoding logic because we are going to add
1554     two more options that take data. Such options can now be given in four
1555     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1557     (l) Added the -A, -B, and -C options for requesting that lines of context
1558     around matches be printed.
1560     (m) Added the -L option to print the names of files that do not contain
1561     any matching lines, that is, the complement of -l.
1563     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1564     continue to scan other files.
1566     (o) The -s option was incorrectly implemented. For compatibility with other
1567     greps, it now suppresses the error message for a non-existent or non-
1568     accessible file (but not the return code). There is a new option called
1569     -q that suppresses the output of matching lines, which was what -s was
1570     previously doing.
1572     (p) Added --include and --exclude options to specify files for inclusion
1573     and exclusion when recursing.
1575     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1576     Hopefully, it now does.
1578     12. Missing cast in pcre_study().
1580     13. Added an "uninstall" target to the makefile.
1582     14. Replaced "extern" in the function prototypes in Makefile.in with
1583     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1584     world, but is set differently for Windows.
1586     15. Added a second compiling function called pcre_compile2(). The only
1587     difference is that it has an extra argument, which is a pointer to an
1588     integer error code. When there is a compile-time failure, this is set
1589     non-zero, in addition to the error test pointer being set to point to an
1590     error message. The new argument may be NULL if no error number is required
1591     (but then you may as well call pcre_compile(), which is now just a
1592     wrapper). This facility is provided because some applications need a
1593     numeric error indication, but it has also enabled me to tidy up the way
1594     compile-time errors are handled in the POSIX wrapper.
1596     16. Added VPATH=.libs to the makefile; this should help when building with one
1597     prefix path and installing with another. (Or so I'm told by someone who
1598     knows more about this stuff than I do.)
1600     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1601     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1602     match everything, including newlines. This is not POSIX-compatible, but
1603     somebody wanted the feature. From pcretest it can be activated by using
1604     both the P and the s flags.
1606     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1608     19. libpcre.pc was being incorrectly installed as executable.
1610     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1611     it now also looks for '\r' so that it will work unmodified on Windows.
1613     21. Added Google's contributed C++ wrapper to the distribution.
1615     22. Added some untidy missing memory free() calls in pcretest, to keep
1616     Electric Fence happy when testing.
1620 nigel 75 Version 5.0 13-Sep-04
1621     ---------------------
1623     1. Internal change: literal characters are no longer packed up into items
1624     containing multiple characters in a single byte-string. Each character
1625     is now matched using a separate opcode. However, there may be more than one
1626     byte in the character in UTF-8 mode.
1628     2. The pcre_callout_block structure has two new fields: pattern_position and
1629     next_item_length. These contain the offset in the pattern to the next match
1630     item, and its length, respectively.
1632     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1633     insertion of callouts before each pattern item. Added the /C option to
1634     pcretest to make use of this.
1636     4. On the advice of a Windows user, the lines
1638     #if defined(_WIN32) || defined(WIN32)
1639     _setmode( _fileno( stdout ), 0x8000 );
1640     #endif /* defined(_WIN32) || defined(WIN32) */
1642     have been added to the source of pcretest. This apparently does useful
1643     magic in relation to line terminators.
1645     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1646     for the benefit of those environments where the "b" makes a difference.
1648     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1649     to know about it. I have put a hack into configure.in that adds in code
1650     to set GCC=yes if CC=icc. This seems to end up at a point in the
1651     generated configure script that is early enough to affect the setting of
1652     compiler options, which is what is needed, but I have no means of testing
1653     whether it really works. (The user who reported this had patched the
1654     generated configure script, which of course I cannot do.)
1656     LATER: After change 22 below (new libtool files), the configure script
1657     seems to know about icc (and also ecc). Therefore, I have commented out
1658     this hack in configure.in.
1660     7. Added support for pkg-config (2 patches were sent in).
1662     8. Negated POSIX character classes that used a combination of internal tables
1663     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1664     [[:^ascii]]. Typically, they would match almost any characters. The other
1665     POSIX classes were not broken in this way.
1667     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1668     to find the match, as PCRE was deluded into thinking that the match had to
1669     start at the start point or following a newline. The same bug applied to
1670     patterns with negative forward assertions or any backward assertions
1671     preceding ".*" at the start, unless the pattern required a fixed first
1672     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1674     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1675     starting at the last subject character, bytes beyond the end of the subject
1676     string were read.
1678     11. Renamed the variable "class" as "classbits" to make life easier for C++
1679     users. (Previously there was a macro definition, but it apparently wasn't
1680     enough.)
1682     12. Added the new field "tables" to the extra data so that tables can be passed
1683     in at exec time, or the internal tables can be re-selected. This allows
1684     a compiled regex to be saved and re-used at a later time by a different
1685     program that might have everything at different addresses.
1687     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1688     -R library as well as a -L library.
1690     14. The debugging options of pcretest (-d on the command line or D on a
1691     pattern) showed incorrect output for anything following an extended class
1692     that contained multibyte characters and which was followed by a quantifier.
1694     15. Added optional support for general category Unicode character properties
1695     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1696     support. It adds about 90K to the size of the library. The meanings of the
1697     inbuilt class escapes such as \d and \s have NOT been changed.
1699     16. Updated pcredemo.c to include calls to free() to release the memory for the
1700     compiled pattern.
1702     17. The generated file chartables.c was being created in the source directory
1703     instead of in the building directory. This caused the build to fail if the
1704     source directory was different from the building directory, and was
1705     read-only.
1707     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1708     file. No doubt somebody will tell me if they don't make sense... Also added
1709     Dan Mooney's comments about building on OpenVMS.
1711     19. Added support for partial matching via the PCRE_PARTIAL option for
1712     pcre_exec() and the \P data escape in pcretest.
1714     20. Extended pcretest with 3 new pattern features:
1716     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1717     write the compiled pattern to the file whose name is "rest-of-line".
1718     This is a straight binary dump of the data, with the saved pointer to
1719     the character tables forced to be NULL. The study data, if any, is
1720     written too. After writing, pcretest reads a new pattern.
1722     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1723     compiled pattern from the given file. There must not be any
1724     occurrences of "<" in the file name (pretty unlikely); if there are,
1725     pcretest will instead treat the initial "<" as a pattern delimiter.
1726     After reading in the pattern, pcretest goes on to read data lines as
1727     usual.
1729     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1730     and 16-bit fields in a compiled pattern, to simulate a pattern that
1731     was compiled on a host of opposite endianness.
1733     21. The pcre-exec() function can now cope with patterns that were compiled on
1734     hosts of opposite endianness, with this restriction:
1736     As for any compiled expression that is saved and used later, the tables
1737     pointer field cannot be preserved; the extra_data field in the arguments
1738     to pcre_exec() should be used to pass in a tables address if a value
1739     other than the default internal tables were used at compile time.
1741     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1742     now diagnosed as an error. Previously, most of the time, a negative number
1743     would have been treated as zero, but if in addition "ovector" was passed as
1744     NULL, a crash could occur.
1746     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1747     new versions from the libtool 1.5 distribution (the last one is a copy of
1748     a file called libtool.m4). This seems to have fixed the need to patch
1749     "configure" to support Darwin 1.3 (which I used to do). However, I still
1750     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1751     workstation).
1753     24. Changed the PCRE licence to be the more standard "BSD" licence.
1756 nigel 73 Version 4.5 01-Dec-03
1757     ---------------------
1759     1. There has been some re-arrangement of the code for the match() function so
1760     that it can be compiled in a version that does not call itself recursively.
1761     Instead, it keeps those local variables that need separate instances for
1762     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1763     needs to "recurse". Keeping track of where control must go is done by means
1764     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1765     hide most of the details from the main code, and operates only if
1766     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1767     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1768     operating.
1770     To make it easier for callers to provide specially tailored get/free
1771     functions for this usage, two new functions, pcre_stack_malloc, and
1772     pcre_stack_free, are used. They are always called in strict stacking order,
1773     and the size of block requested is always the same.
1775     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1776     PCRE has been compiled to use the stack or the heap for recursion. The
1777     -C option of pcretest uses this to show which version is compiled.
1779     A new data escape \S, is added to pcretest; it causes the amounts of store
1780     obtained and freed by both kinds of malloc/free at match time to be added
1781     to the output.
1783     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1784     what's available on my current Linux desktop machine.
1786     3. When matching a UTF-8 string, the test for a valid string at the start has
1787     been extended. If start_offset is not zero, PCRE now checks that it points
1788     to a byte that is the start of a UTF-8 character. If not, it returns
1789     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1790     this is necessary because there may be backward assertions in the pattern.
1791     When matching the same subject several times, it may save resources to use
1792     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1794     4. The code for checking the validity of UTF-8 strings has been tightened so
1795     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1796     containing "overlong sequences".
1798     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1799     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1800     should have been "&", but it just so happened that all the cases this let
1801     through by mistake were picked up later in the function.
1803     6. I had used a variable called "isblank" - this is a C99 function, causing
1804     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1806     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1807     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1808     so the version is shown; (c) stop "make test" echoing "./RunTest".
1810     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1812     9. The prototype for memmove() for systems that don't have it was using
1813     size_t, but the inclusion of the header that defines size_t was later. I've
1814     moved the #includes for the C headers earlier to avoid this.
1816     10. Added some adjustments to the code to make it easier to compiler on certain
1817     special systems:
1819     (a) Some "const" qualifiers were missing.
1820     (b) Added the macro EXPORT before all exported functions; by default this
1821     is defined to be empty.
1822     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1823     that it reads its output file name as an argument instead of writing
1824     to the standard output and assuming this can be redirected.
1826     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1827     class containing characters with values greater than 255, PCRE compilation
1828     went into a loop.
1830     12. A recursive reference to a subpattern that was within another subpattern
1831     that had a minimum quantifier of zero caused PCRE to crash. For example,
1832     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1833     recursion. If the recursively-called subpattern itself had a zero repeat,
1834     that was OK.
1836     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1837     buffer into which it was copied (for escape processing) was still set at
1838     1024, so long lines caused crashes.
1840     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1841     "internal error: code overflow...". This applied to any character class
1842     that was followed by a possessive quantifier.
1844     15. Modified the Makefile to add libpcre.la as a prerequisite for
1845     libpcreposix.la because I was told this is needed for a parallel build to
1846     work.
1848     16. If a pattern that contained .* following optional items at the start was
1849     studied, the wrong optimizing data was generated, leading to matching
1850     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1851     matching string must start with a or b or c. The correct conclusion for
1852     this pattern is that a match can start with any character.
1855 nigel 71 Version 4.4 13-Aug-03
1856     ---------------------
1858     1. In UTF-8 mode, a character class containing characters with values between
1859     127 and 255 was not handled correctly if the compiled pattern was studied.
1860     In fixing this, I have also improved the studying algorithm for such
1861     classes (slightly).
1863     2. Three internal functions had redundant arguments passed to them. Removal
1864     might give a very teeny performance improvement.
1866     3. Documentation bug: the value of the capture_top field in a callout is *one
1867     more than* the number of the hightest numbered captured substring.
1869     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1870     in incorrectly linking with a previously installed version. They now link
1871     explicitly with libpcre.la.
1873     5. configure.in no longer needs to recognize Cygwin specially.
1875     6. A problem in pcre.in for Windows platforms is fixed.
1877     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1878     pcretest, it used to include the size of the study block as part of its
1879     output. Unfortunately, the structure contains a field that has a different
1880     size on different hardware architectures. This meant that the tests that
1881     showed this size failed. As the block is currently always of a fixed size,
1882     this information isn't actually particularly useful in pcretest output, so
1883     I have just removed it.
1885     8. Three pre-processor statements accidentally did not start in column 1.
1886     Sadly, there are *still* compilers around that complain, even though
1887     standard C has not required this for well over a decade. Sigh.
1889     9. In pcretest, the code for checking callouts passed small integers in the
1890     callout_data field, which is a void * field. However, some picky compilers
1891     complained about the casts involved for this on 64-bit systems. Now
1892     pcretest passes the address of the small integer instead, which should get
1893     rid of the warnings.
1895     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1896     both compile and run time, and gives an error if an invalid UTF-8 sequence
1897     is found. There is a option for disabling this check in cases where the
1898     string is known to be correct and/or the maximum performance is wanted.
1900     11. In response to a bug report, I changed one line in Makefile.in from
1902     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1903     to
1904     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1906     to look similar to other lines, but I have no way of telling whether this
1907     is the right thing to do, as I do not use Windows. No doubt I'll get told
1908     if it's wrong...
1911 nigel 69 Version 4.3 21-May-03
1912     ---------------------
1914     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1915     Makefile.
1917     2. Some refactoring to improve the quality of the code:
1919     (i) The utf8_table... variables are now declared "const".
1921     (ii) The code for \cx, which used the "case flipping" table to upper case
1922     lower case letters, now just substracts 32. This is ASCII-specific,
1923     but the whole concept of \cx is ASCII-specific, so it seems
1924     reasonable.
1926     (iii) PCRE was using its character types table to recognize decimal and
1927     hexadecimal digits in the pattern. This is silly, because it handles
1928     only 0-9, a-f, and A-F, but the character types table is locale-
1929     specific, which means strange things might happen. A private
1930     table is now used for this - though it costs 256 bytes, a table is
1931     much faster than multiple explicit tests. Of course, the standard
1932     character types table is still used for matching digits in subject
1933     strings against \d.
1935     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1936     ending in _t are). So I've renamed it as ESC_tee.
1938     3. The first argument for regexec() in the POSIX wrapper should have been
1939     defined as "const".
1941     4. Changed pcretest to use malloc() for its buffers so that they can be
1942     Electric Fenced for debugging.
1944     5. There were several places in the code where, in UTF-8 mode, PCRE would try
1945     to read one or more bytes before the start of the subject string. Often this
1946     had no effect on PCRE's behaviour, but in some circumstances it could
1947     provoke a segmentation fault.
1949     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1950     to try to read one or more bytes before the start of the subject string.
1952     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1953     UTF-8 support could misbehave in various ways if the subject string
1954     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1955     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1956     back over UTF-8 characters.)
1959 nigel 67 Version 4.2 14-Apr-03
1960     ---------------------
1962     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1964     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1965     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1966     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1967     [WIN_PREFIX]: new variable, "cyg" for Cygwin
1968     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1969     and BUILD_EXEEXT
1970     Note: automatic setting of the BUILD variables is not yet working
1971     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1972     compile-time but not at link-time
1973     [LINK]: use for linking executables only
1974     make different versions for Windows and non-Windows
1975     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1976     libraries
1977     [LINK_FOR_BUILD]: new variable
1978     [OBJEXT]: use throughout
1979     [EXEEXT]: use throughout
1980     <winshared>: new target
1981     <wininstall>: new target
1982     <dftables.o>: use native compiler
1983     <dftables>: use native linker
1984     <install>: handle Windows platform correctly
1985     <clean>: ditto
1986     <check>: ditto
1987     copy DLL to top builddir before testing
1989     As part of these changes, -no-undefined was removed again. This was reported
1990     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1991     in any case.
1993     3. Some tidies to get rid of compiler warnings:
1995     . In the match_data structure, match_limit was an unsigned long int, whereas
1996     match_call_count was an int. I've made them both unsigned long ints.
1998     . In pcretest the fact that a const uschar * doesn't automatically cast to
1999     a void * provoked a warning.
2001     . Turning on some more compiler warnings threw up some "shadow" variables
2002     and a few more missing casts.
2004     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2005     option, a class that contained a single character with a value between 128
2006     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2008     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2009     option, a class that contained several characters, but with at least one
2010     whose value was between 128 and 255 caused PCRE to crash.
2013 nigel 65 Version 4.1 12-Mar-03
2014     ---------------------
2015 nigel 63
2016 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2017     needed, and a string in dftables.c that was longer than standard compilers are
2018     required to support.
2020     2. Compiling with Sun's compiler found a few more places where the code could
2021     be tidied up in order to avoid warnings.
2023     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2024     first of these names is deprecated in the latest Autoconf in favour of the name
2025     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2026     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2027     analogy I have changed it to CFLAGS_FOR_BUILD.
2029     4. Added -no-undefined to the linking command in the Makefile, because this is
2030     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2031     linking step for the pcreposix library.
2033     5. PCRE was failing to diagnose the case of two named groups with the same
2034     name.
2036     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2037     literal character that is needed in the subject for a match, and scans along to
2038     ensure that it is present before embarking on the full matching process. This
2039     saves time in cases of nested unlimited repeats that are never going to match.
2040     Problem: the scan can take a lot of time if the subject is very long (e.g.
2041     megabytes), thus penalizing straightforward matches. It is now done only if the
2042     amount of subject to be scanned is less than 1000 bytes.
2044     7. A lesser problem with the same optimization is that it was recording the
2045     first character of an anchored pattern as "needed", thus provoking a search
2046     right along the subject, even when the first match of the pattern was going to
2047     fail. The "needed" character is now not set for anchored patterns, unless it
2048     follows something in the pattern that is of non-fixed length. Thus, it still
2049     fulfils its original purpose of finding quick non-matches in cases of nested
2050     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2053     Version 4.0 17-Feb-03
2054     ---------------------
2056 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2057     extended to the end of string, PCRE compiled incorrect data. This could lead to
2058     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2060     2. Moved to autoconf 2.53 and libtool 1.4.2.
2062     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2063     the special perltest8 script is no longer needed - all the tests can be run
2064     from a single perltest script.
2066     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2067     by \s. It has now been removed in PCRE. This means it isn't recognized as
2068     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2069     class [:space:] *does* include VT, thereby creating a mess.
2071     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2072     space and tab.
2074     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2075     its new features into the main test script, reducing the number of scripts.
2077     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2078     were backward compatible, and made the (?i) apply to the whole pattern, as if
2079     /i were given. Now it behaves more logically, and applies the option setting
2080     only to what follows. PCRE has been changed to follow suit. However, if it
2081     finds options settings right at the start of the pattern, it extracts them into
2082     the global options, as before. Thus, they show up in the info data.
2084     8. Added support for the \Q...\E escape sequence. Characters in between are
2085     treated as literals. This is slightly different from Perl in that $ and @ are
2086     also handled as literals inside the quotes. In Perl, they will cause variable
2087     interpolation. Note the following examples:
2089     Pattern PCRE matches Perl matches
2091     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2092     \Qabc\$xyz\E abc\$xyz abc\$xyz
2093     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2095     For compatibility with Perl, \Q...\E sequences are recognized inside character
2096     classes as well as outside them.
2098     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2099     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2100     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2101     signed/unsigned warnings.
2103     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2104     option for pcretest, so I've replaced it by a simple function that does just
2105     that job.
2107     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2108     "pcregrep -".
2110     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2111     Java package. This provides some syntactic sugar for simple cases of what my
2112     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2113     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2114     item, you can use this simplified notation. Note that only makes sense with
2115     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2116     greediness, whatever the setting of the PCRE_UNGREEDY option.
2118     13. A change of greediness default within a pattern was not taking effect at
2119     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2120     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2121     was abstracted outside.
2123     14. PCRE now supports the \G assertion. It is true when the current matching
2124     position is at the start point of the match. This differs from \A when the
2125     starting offset is non-zero. Used with the /g option of pcretest (or similar
2126     code), it works in the same way as it does for Perl's /g option. If all
2127     alternatives of a regex begin with \G, the expression is anchored to the start
2128     match position, and the "anchored" flag is set in the compiled expression.
2130     15. Some bugs concerning the handling of certain option changes within patterns
2131     have been fixed. These applied to options other than (?ims). For example,
2132     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2133     been the other way round. Some of this was related to change 7 above.
2135     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2136     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2137     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2138     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2140     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2141     mode. Unlike ".", it always matches newline, whatever the setting of
2142     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2143     assertions. Perl allows it, but it doesn't (in general) work because it can't
2144     calculate the length of the lookbehind. At least, that's the case for Perl
2145     5.8.0 - I've been told they are going to document that it doesn't work in
2146     future.
2148     18. Added an error diagnosis for escapes that PCRE does not support: these are
2149     \L, \l, \N, \P, \p, \U, \u, and \X.
2151     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2152     reading past the end of the pattern in cases such as /[abcd/.
2154     20. PCRE was getting more memory than necessary for patterns with classes that
2155     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2157     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2158     compiling PCRE for use with Virtual Pascal.
2160     22. Small fix to the Makefile to make it work properly if the build is done
2161     outside the source tree.
2163     23. Added a new extension: a condition to go with recursion. If a conditional
2164     subpattern starts with (?(R) the "true" branch is used if recursion has
2165     happened, whereas the "false" branch is used only at the top level.
2167     24. When there was a very long string of literal characters (over 255 bytes
2168     without UTF support, over 250 bytes with UTF support), the computation of how
2169     much memory was required could be incorrect, leading to segfaults or other
2170     strange effects.
2172     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2173     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2174     there was a subsequent back reference to those brackets. This meant that, for
2175     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2176     possible to check for precisely this case. All we can do is abandon the
2177     optimization if .* occurs inside capturing brackets when there are any back
2178     references whatsoever. (See below for a better fix that came later.)
2180     26. The handling of the optimization for finding the first character of a
2181     non-anchored pattern, and for finding a character that is required later in the
2182     match were failing in some cases. This didn't break the matching; it just
2183     failed to optimize when it could. The way this is done has been re-implemented.
2185     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2187     28. Added a new feature that provides some of the functionality that Perl
2188     provides with (?{...}). The facility is termed a "callout". The way it is done
2189     in PCRE is for the caller to provide an optional function, by setting
2190     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2191     global variable. By default it is unset, which disables all calling out. To get
2192     the function called, the regex must include (?C) at appropriate points. This
2193     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2194     This provides a means of identifying different callout points. When PCRE
2195     reaches such a point in the regex, if pcre_callout has been set, the external
2196     function is called. It is provided with data in a structure called
2197     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2198     matching continues; if it returns a non-zero value, the match at the current
2199     point fails. However, backtracking will occur if possible. [This was changed
2200     later and other features added - see item 49 below.]
2202     29. pcretest is upgraded to test the callout functionality. It provides a
2203     callout function that displays information. By default, it shows the start of
2204     the match and the current position in the text. There are some new data escapes
2205     to vary what happens:
2207     \C+ in addition, show current contents of captured substrings
2208     \C- do not supply a callout function
2209     \C!n return 1 when callout number n is reached
2210     \C!n!m return 1 when callout number n is reached for the mth time
2212     30. If pcregrep was called with the -l option and just a single file name, it
2213     output "<stdin>" if a match was found, instead of the file name.
2215     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2216     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2217     pcre_exec(). This saves a malloc/free per call. The default value of
2218     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2219     when configuring.
2221     32. The default maximum size of a compiled pattern is 64K. There have been a
2222     few cases of people hitting this limit. The code now uses macros to handle the
2223     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2224     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2225     configuring. Tests 2 and 5 work only with 2-byte links because they output
2226     debugging information about compiled patterns.
2228     33. Internal code re-arrangements:
2230     (a) Moved the debugging function for printing out a compiled regex into
2231     its own source file (printint.c) and used #include to pull it into
2232     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2233     separate copies.
2235     (b) Defined the list of op-code names for debugging as a macro in
2236     internal.h so that it is next to the definition of the opcodes.
2238     (c) Defined a table of op-code lengths for simpler skipping along compiled
2239     code. This is again a macro in internal.h so that it is next to the
2240     definition of the opcodes.
2242     34. Added support for recursive calls to individual subpatterns, along the
2243     lines of Robin Houston's patch (but implemented somewhat differently).
2245     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2246     allow it to read and process whole directories in Win32. This code was
2247     contributed by Lionel Fourquaux; it has not been tested by me.
2249     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2250     used to name a group. Names consist of alphanumerics and underscores, and must
2251     be unique. Back references use the syntax (?P=name) and recursive calls use
2252     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2253     numbers. The function pcre_fullinfo() can be used after compilation to extract
2254     a name/number map. There are three relevant calls:
2256     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2257     PCRE_INFO_NAMECOUNT yields the number of entries
2258     PCRE_INFO_NAMETABLE yields a pointer to the map.
2260     The map is a vector of fixed-size entries. The size of each entry depends on
2261     the length of the longest name used. The first two bytes of each entry are the
2262     group number, most significant byte first. There follows the corresponding
2263     name, zero terminated. The names are in alphabetical order.
2265     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2266     case instead of 255. Making it the same both with and without UTF-8 support
2267     means that the same test output works with both.
2269     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2270     calling malloc() with a zero argument.
2272     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2273     optimization. I've improved things by keeping a bitmap of backreferences with
2274     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2275     fact referenced, the optimization can be applied. It is unlikely that a
2276     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2277     the match to follow \n) will appear inside brackets with a number greater than
2278     31, but if it does, any back reference > 31 suppresses the optimization.
2280     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2281     of disabling numbered capturing parentheses. Any opening parenthesis that is
2282     not followed by ? behaves as if it were followed by ?: but named parentheses
2283     can still be used for capturing (and they will acquire numbers in the usual
2284     way).
2286     41. Redesigned the return codes from the match() function into yes/no/error so
2287     that errors can be passed back from deep inside the nested calls. A malloc
2288     failure while inside a recursive subpattern call now causes the
2289     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2291     42. It is now possible to set a limit on the number of times the match()
2292     function is called in a call to pcre_exec(). This facility makes it possible to
2293     limit the amount of recursion and backtracking, though not in a directly
2294     obvious way, because the match() function is used in a number of different
2295     circumstances. The count starts from zero for each position in the subject
2296     string (for non-anchored patterns). The default limit is, for compatibility, a
2297     large number, namely 10 000 000. You can change this in two ways:
2299     (a) When configuring PCRE before making, you can use --with-match-limit=n
2300     to set a default value for the compiled library.
2302     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2303     a different value is set. See 45 below.
2305     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2307     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2308     of things that can be changed at compile time. The first argument specifies
2309     what is wanted and the second points to where the information is to be placed.
2310     The current list of available information is:
2314     The output is an integer that is set to one if UTF-8 support is available;
2315     otherwise it is set to zero.
2319     The output is an integer that it set to the value of the code that is used for
2320     newline. It is either LF (10) or CR (13).
2324     The output is an integer that contains the number of bytes used for internal
2325     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2329     The output is an integer that contains the threshold above which the POSIX
2330     interface uses malloc() for output vectors. See item 31 above.
2334     The output is an unsigned integer that contains the default limit of the number
2335     of match() calls in a pcre_exec() execution. See 42 above.
2337     44. pcretest has been upgraded by the addition of the -C option. This causes it
2338     to extract all the available output from the new pcre_config() function, and to
2339     output it. The program then exits immediately.
2341     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2342     order to support additional features. One way would have been to define
2343     pcre_exec2() (for example) with extra arguments, but this would not have been
2344     extensible, and would also have required all calls to the original function to
2345     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2346     is used for passing in "extra" data from pcre_study().
2348     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2349     contains the following fields:
2351     flags a bitmap indicating which of the following fields are set
2352     study_data opaque data from pcre_study()
2353     match_limit a way of specifying a limit on match() calls for a specific
2354     call to pcre_exec()
2355     callout_data data for callouts (see 49 below)
2357     The flag bits are also defined in pcre.h, and are
2363     The pcre_study() function now returns one of these new pcre_extra blocks, with
2364     the actual study data pointed to by the study_data field, and the
2365     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2366     before. That is, this change is entirely upwards-compatible and requires no
2367     change to existing code.
2369     If you want to pass in additional data to pcre_exec(), you can either place it
2370     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2371     block.
2373     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2374     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2375     times with different match limits, until it finds the minimum value needed for
2376     pcre_exec() to complete. The value is then output. This can be instructive; for
2377     most simple matches the number is quite small, but for pathological cases it
2378     gets very large very quickly.
2380     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2381     returns the size of the data block pointed to by the study_data field in a
2382     pcre_extra block, that is, the value that was passed as the argument to
2383     pcre_malloc() when PCRE was getting memory in which to place the information
2384     created by pcre_study(). The fourth argument should point to a size_t variable.
2385     pcretest has been extended so that this information is shown after a successful
2386     pcre_study() call when information about the compiled regex is being displayed.
2388     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2389     because what follows is always an absolute path. (Later: it turns out that this
2390     is more than cosmetic for MinGW, because it doesn't like empty path
2391     components.)
2393     49. Some changes have been made to the callout feature (see 28 above):
2395     (i) A callout function now has three choices for what it returns:
2397     0 => success, carry on matching
2398     > 0 => failure at this point, but backtrack if possible
2399     < 0 => serious error, return this value from pcre_exec()
2401     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2402     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2403     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2404     use by callout functions. It will never be used by PCRE itself.
2406     (ii) The pcre_extra structure (see 45 above) has a void * field called
2407     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2408     pcre_callout_block structure has a field of the same name. The contents of
2409     the field passed in the pcre_extra structure are passed to the callout
2410     function in the corresponding field in the callout block. This makes it
2411     easier to use the same callout-containing regex from multiple threads. For
2412     testing, the pcretest program has a new data escape
2414     \C*n pass the number n (may be negative) as callout_data
2416     If the callout function in pcretest receives a non-zero value as
2417     callout_data, it returns that value.
2419     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2420     there were some redundant $(CFLAGS) in commands that are now specified as
2421     $(LINK), which already includes $(CFLAGS).
2423     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2424     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2425     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2426     one-byte characters throughout. Note that case-insensitive matching applies
2427     only to characters whose values are less than 256. PCRE doesn't support the
2428     notion of cases for higher-valued characters.
2430     (i) A character class whose characters are all within 0-255 is handled as
2431     a bit map, and the map is inverted for negative classes. Previously, a
2432     character > 255 always failed to match such a class; however it should
2433     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2435     (ii) A negated character class with a single character < 255 is coded as
2436     "not this character" (OP_NOT). This wasn't working properly when the test
2437     character was multibyte, either singly or repeated.
2439     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2440     mode, for example: \x{100}{2,3}.
2442     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2443     singly or repeated) now correctly test multibyte characters. However,
2444     PCRE doesn't recognize any characters with values greater than 255 as
2445     digits, spaces, or word characters. Such characters always match \D, \S,
2446     and \W, and never match \d, \s, or \w.
2448     (v) Classes may now contain characters and character ranges with values
2449     greater than 255. For example: [ab\x{100}-\x{400}].
2451     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2452     PCRE in UTF-8 mode.
2454     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2455     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2456     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2457     value.)
2459     53. The single man page has become too large. I have therefore split it up into
2460     a number of separate man pages. These also give rise to individual HTML pages;
2461     these are now put in a separate directory, and there is an index.html page that
2462     lists them all. Some hyperlinking between the pages has been installed.
2464     54. Added convenience functions for handling named capturing parentheses.
2466     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2467     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2468     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2469     are faulted.
2471     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2472     calling configure. These values are used when compiling the dftables.c program
2473     which is run to generate the source of the default character tables. They
2474     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2475     you will need to set these values.
2477     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2480     Version 3.9 02-Jan-02
2481 nigel 61 ---------------------
2483     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2485     2. If --disable-static was given, the building process failed when trying to
2486     build pcretest and pcregrep. (For some reason it was using libtool to compile
2487     them, which is not right, as they aren't part of the library.)
2490 nigel 59 Version 3.8 18-Dec-01
2491     ---------------------
2493     1. The experimental UTF-8 code was completely screwed up. It was packing the
2494     bytes in the wrong order. How dumb can you get?
2497 nigel 57 Version 3.7 29-Oct-01
2498     ---------------------
2500     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2501     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2502     this didn't happen under Solaris 8, where I normally test things.
2504 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2505     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2506     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2507     this fix an hour or so after the initial 3.7 release.)
2508 nigel 57
2509 nigel 59
2510 nigel 55 Version 3.6 23-Oct-01
2511     ---------------------
2513     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2514     offsets passed as NULL with zero offset count.
2516     2. The config.guess and config.sub files had not been updated when I moved to
2517     the latest autoconf.
2520 nigel 53 Version 3.5 15-Aug-01
2521     ---------------------
2522 nigel 5
2523 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2524     had been forgotten.
2526     2. By using declared but undefined structures, we can avoid using "void"
2527     definitions in pcre.h while keeping the internal definitions of the structures
2528     private.
2530     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2531     user point of view, this means that both static and shared libraries are built
2532     by default, but this can be individually controlled. More of the work of
2533     handling this static/shared cases is now inside libtool instead of PCRE's make
2534     file.
2536     4. The pcretest utility is now installed along with pcregrep because it is
2537     useful for users (to test regexs) and by doing this, it automatically gets
2538     relinked by libtool. The documentation has been turned into a man page, so
2539     there are now .1, .txt, and .html versions in /doc.
2541     5. Upgrades to pcregrep:
2542     (i) Added long-form option names like gnu grep.
2543     (ii) Added --help to list all options with an explanatory phrase.
2544     (iii) Added -r, --recursive to recurse into sub-directories.
2545     (iv) Added -f, --file to read patterns from a file.
2547     6. pcre_exec() was referring to its "code" argument before testing that
2548     argument for NULL (and giving an error if it was NULL).
2550     7. Upgraded Makefile.in to allow for compiling in a different directory from
2551     the source directory.
2553     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2554     options bits, the pointer it was passed was to an int instead of to an unsigned
2555     long int. This mattered only on 64-bit systems.
2557     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2558     generated) instead of pcre.in, which it its source. Also made the same change
2559     in several of the .c files.
2561     10. A new release of gcc defines printf() as a macro, which broke pcretest
2562     because it had an ifdef in the middle of a string argument for printf(). Fixed
2563     by using separate calls to printf().
2565     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2566     script, to force use of CR or LF instead of \n in the source. On non-Unix
2567     systems, the value can be set in config.h.
2569     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2570     absolute limit. Changed the text of the error message to make this clear, and
2571     likewise updated the man page.
2573     13. The limit of 99 on the number of capturing subpatterns has been removed.
2574     The new limit is 65535, which I hope will not be a "real" limit.
2577 nigel 51 Version 3.4 22-Aug-00
2578     ---------------------
2580     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2582     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2585 nigel 49 Version 3.3 01-Aug-00
2586     ---------------------
2588     1. If an octal character was given, but the value was greater than \377, it
2589     was not getting masked to the least significant bits, as documented. This could
2590     lead to crashes in some systems.
2592     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2593     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2595     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2596     These just pass their arguments on to (pcre_free)(), but they are provided
2597     because some uses of PCRE bind it to non-C systems that can call its functions,
2598     but cannot call free() or pcre_free() directly.
2600     4. Add "make test" as a synonym for "make check". Corrected some comments in
2601     the Makefile.
2603     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2604     Makefile.
2606     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2607     command called pgrep for grepping around the active processes.
2609     7. Added the beginnings of support for UTF-8 character strings.
2611     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2612     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2613     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2614     out for the ar command.)
2617 nigel 47 Version 3.2 12-May-00
2618     ---------------------
2620     This is purely a bug fixing release.
2622     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2623     of ZA. This was just one example of several cases that could provoke this bug,
2624     which was introduced by change 9 of version 2.00. The code for breaking
2625     infinite loops after an iteration that matches an empty string was't working
2626     correctly.
2628     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2629     when matched against abbab (for example). After matching an empty string, it
2630     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2631     caused it to match further down the string than it should.
2633     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2634     was there because it doesn't seem to be needed, and it causes trouble on some
2635     systems, as it is not a Standard C header. It has been removed.
2637     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2638     were reported on the Macintosh. The changes were from
2640     while ((c = *(++ptr)) != 0 && c != '\n');
2641     to
2642     while ((c = *(++ptr)) != 0 && c != '\n') ;
2644     Totally extraordinary, but if that's what it takes...
2646     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2647     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2648     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2649     assumes the way PCRE uses memmove() (always moving upwards).
2651     6. PCRE is being used in one environment where strchr() is not available. There
2652     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2653     faster code anyway.
2656 nigel 45 Version 3.1 09-Feb-00
2657     ---------------------
2659     The only change in this release is the fixing of some bugs in Makefile.in for
2660     the "install" target:
2662     (1) It was failing to install pcreposix.h.
2664     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2667 nigel 43 Version 3.0 01-Feb-00
2668     ---------------------
2669 nigel 41
2670     1. Add support for the /+ modifier to perltest (to output $` like it does in
2671     pcretest).
2673     2. Add support for the /g modifier to perltest.
2675     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2676     matches null strings.
2678     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2679     pattern. Perl treats empty patterns specially - it reuses the most recent
2680     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2681     effect.
2683     5. The POSIX interface was broken in that it was just handing over the POSIX
2684     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2685     required a bigger vector, with some working space on the end. This means that
2686     the POSIX wrapper now has to get and free some memory, and copy the results.
2688 nigel 43 6. Added some simple autoconf support, placing the test data and the
2689     documentation in separate directories, re-organizing some of the
2690     information files, and making it build pcre-config (a GNU standard). Also added
2691     libtool support for building PCRE as a shared library, which is now the
2692     default.
2693 nigel 41
2694 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2695     09 are not valid octal constants. Single digits will be used for minor values
2696     less than 10.
2698     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2699     existing programs that set these in the POSIX interface can use PCRE without
2700     modification.
2702     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2703     return all that pcre_info() returns, plus additional data. The pcre_info()
2704     function is retained for compatibility, but is considered to be obsolete.
2706     10. Added experimental recursion feature (?R) to handle one common case that
2707     Perl 5.6 will be able to do with (?p{...}).
2709     11. Added support for POSIX character classes like [:alpha:], which Perl is
2710     adopting.
2713 nigel 39 Version 2.08 31-Aug-99
2714     ----------------------
2716     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2717     trying to match at the startoffset position, but instead was moving forward to
2718     the next newline as if a previous match had failed.
2720     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2721     and could get into a loop if a null string was matched other than at the start
2722     of the subject.
2724     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2725     be distinguished at compile time, and for completeness also added PCRE_DATE.
2727     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2728     in GnuWin32 environments.
2731 nigel 37 Version 2.07 29-Jul-99
2732     ----------------------
2734     1. The documentation is now supplied in plain text form and HTML as well as in
2735     the form of man page sources.
2737     2. C++ compilers don't like assigning (void *) values to other pointer types.
2738     In particular this affects malloc(). Although there is no problem in Standard
2739     C, I've put in casts to keep C++ compilers happy.
2741     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2742     should be (const char *).
2744     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2745     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2746     However, I haven't made this a standard facility. The documentation doesn't
2747     mention it, and the Makefile doesn't support it.
2749     5. The Makefile now contains an "install" target, with editable destinations at
2750     the top of the file. The pcretest program is not installed.
2752     6. pgrep -V now gives the PCRE version number and date.
2754     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2755     causing the entire string to be ignored, instead of just the last character.
2757     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2758     non-matching string, it can take a very, very long time, even for strings of
2759     quite modest length, because of the nested recursion. PCRE now does better in
2760     some of these cases. It does this by remembering the last required literal
2761     character in the pattern, and pre-searching the subject to ensure it is present
2762     before running the real match. In other words, it applies a heuristic to detect
2763     some types of certain failure quickly, and in the above example, if presented
2764     with a string that has no trailing " it gives "no match" very quickly.
2766     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2767     other alternatives are tried instead.
2770 nigel 35 Version 2.06 09-Jun-99
2771     ----------------------
2773     1. Change pcretest's output for amount of store used to show just the code
2774     space, because the remainder (the data block) varies in size between 32-bit and
2775     64-bit systems.
2777     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2778     start matching at. This allows lookbehinds to work when searching for multiple
2779     occurrences in a string.
2781     3. Added additional options to pcretest for testing multiple occurrences:
2783     /+ outputs the rest of the string that follows a match
2784     /g loops for multiple occurrences, using the new startoffset argument
2785     /G loops for multiple occurrences by passing an incremented pointer
2787     4. PCRE wasn't doing the "first character" optimization for patterns starting
2788     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2789     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2790     the letter 'x'. On long subject strings, this gives a significant speed-up.
2793 nigel 33 Version 2.05 21-Apr-99
2794     ----------------------
2796     1. Changed the type of magic_number from int to long int so that it works
2797     properly on 16-bit systems.
2799     2. Fixed a bug which caused patterns starting with .* not to work correctly
2800     when the subject string contained newline characters. PCRE was assuming
2801     anchoring for such patterns in all cases, which is not correct because .* will
2802     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2803     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2804     must be retried after every newline in the subject.
2807 nigel 31 Version 2.04 18-Feb-99
2808     ----------------------
2810     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2811     computation of the store needed to hold the pattern was incorrect (too large).
2812     If such patterns were nested a few deep, this could multiply and become a real
2813     problem.
2815     2. Added /M option to pcretest to show the memory requirement of a specific
2816     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2818     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2819     compiled in such a way that the backtracking after subsequent failure was
2820     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2821     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2824 nigel 29 Version 2.03 02-Feb-99
2825     ----------------------
2827     1. Fixed typo and small mistake in man page.
2829 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2830     LICENCE file containing the conditions.
2831 nigel 29
2832     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2833     Perl, that is the internal \ allows the delimiter to be included in the
2834     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2835     the final delimiter, add \ to the end of the pattern (to test the error).
2837     4. Added the convenience functions for extracting substrings after a successful
2838     match. Updated pcretest to make it able to test these functions.
2841 nigel 27 Version 2.02 14-Jan-99
2842     ----------------------
2844     1. Initialized the working variables associated with each extraction so that
2845     their saving and restoring doesn't refer to uninitialized store.
2847     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2848     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2849     fix the problem.
2851     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2852     calls, and wasn't printing the correct value for compiling calls. Increased the
2853     default value of LOOPREPEAT, and the number of significant figures in the
2854     times.
2856     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2858     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2859     a building problem on Windows NT with a FAT file system.
2862 nigel 25 Version 2.01 21-Oct-98
2863     ----------------------
2865     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2866     to character tables built by pcre_maketables() in the current locale. If NULL
2867     is passed, the default tables are used.
2870 nigel 23 Version 2.00 24-Sep-98
2871 nigel 21 ----------------------
2873 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2874     it any more.
2876     2. Allow quantification of (?>) groups, and make it work correctly.
2878     3. The first character computation wasn't working for (?>) groups.
2880     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2881     end of the subject) and add 5.005's \z, which really does match only at the
2882     very end of the subject.
2884     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2886     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2887     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2888     localized options. All options to pcre_study() were also removed.
2890     7. Add other new features from 5.005:
2892     $(?<= positive lookbehind
2893     $(?<! negative lookbehind
2894     (?imsx-imsx) added the unsetting capability
2895     such a setting is global if at outer level; local otherwise
2896     (?imsx-imsx:) non-capturing groups with option setting
2897     (?(cond)re|re) conditional pattern matching
2899     A backreference to itself in a repeated group matches the previous
2900     captured string.
2902     8. General tidying up of studying (both automatic and via "study")
2903     consequential on the addition of new assertions.
2905     9. As in 5.005, unlimited repeated groups that could match an empty substring
2906     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2907     runtime if any iteration does actually match an empty substring.
2909     10. Include the RunTest script in the distribution.
2911     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2912     discrepancies, some of which were old and were also with respect to 5.004. They
2913     have now been fixed.
2916     Version 1.09 28-Apr-98
2917     ----------------------
2919 nigel 21 1. A negated single character class followed by a quantifier with a minimum
2920     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2921     program crashes, or just wrong answers. This did not apply to negated classes
2922     containing more than one character, or to minima other than one.
2925 nigel 19 Version 1.08 27-Mar-98
2926     ----------------------
2928     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2930     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2931     latter must appear before anything that relies on it in the pattern.
2934 nigel 17 Version 1.07 16-Feb-98
2935     ----------------------
2937     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2938     repeat of a potentially empty string).
2941 nigel 15 Version 1.06 23-Jan-98
2942     ----------------------
2944     1. Added Markus Oberhumer's little patches for C++.
2946     2. Literal strings longer than 255 characters were broken.
2949 nigel 13 Version 1.05 23-Dec-97
2950     ----------------------
2952     1. Negated character classes containing more than one character were failing if
2953     PCRE_CASELESS was set at run time.
2956 nigel 11 Version 1.04 19-Dec-97
2957     ----------------------
2959     1. Corrected the man page, where some "const" qualifiers had been omitted.
2961     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2962     input syntax.
2964     3. Fixed memory leak which occurred when a regex with back references was
2965     matched with an offsets vector that wasn't big enough. The temporary memory
2966     that is used in this case wasn't being freed if the match failed.
2968     4. Tidied pcretest to ensure it frees memory that it gets.
2970     5. Temporary memory was being obtained in the case where the passed offsets
2971     vector was exactly big enough.
2973     6. Corrected definition of offsetof() from change 5 below.
2975     7. I had screwed up change 6 below and broken the rules for the use of
2976     setjmp(). Now fixed.
2979 nigel 9 Version 1.03 18-Dec-97
2980     ----------------------
2982     1. A erroneous regex with a missing opening parenthesis was correctly
2983     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2984     on some systems.
2986     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2987     it was reported that one broken compiler failed on the former because "code" is
2988     also an independent variable.
2990     3. The erroneous regex a[]b caused an array overrun reference.
2992     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2993     fail on data ending with that character. (It was going on too far, and checking
2994     the next character, typically a binary zero.) This was specific to the
2995     optimized code for single-character negative classes.
2997     5. Added a contributed patch from the TIN world which does the following:
2999     + Add an undef for memmove, in case the the system defines a macro for it.
3001     + Add a definition of offsetof(), in case there isn't one. (I don't know
3002     the reason behind this - offsetof() is part of the ANSI standard - but
3003     it does no harm).
3005     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3006     most of the places where whitespace preceded '#'. I have given up and
3007     allowed the remaining 2 cases to be at the margin.
3009     + Rename some variables in pcre to eliminate shadowing. This seems very
3010     pedantic, but does no harm, of course.
3012     6. Moved the call to setjmp() into its own function, to get rid of warnings
3013     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3015     7. Constructs such as \d{8,} were compiling into the equivalent of
3016 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3017 nigel 9 outcome, but in this particular case used more store than had been allocated,
3018     which caused the bug to be discovered because it threw up an internal error.
3020     8. The debugging code in both pcre and pcretest for outputting the compiled
3021     form of a regex was going wrong in the case of back references followed by
3022     curly-bracketed repeats.
3025 nigel 7 Version 1.02 12-Dec-97
3026     ----------------------
3028     1. Typos in pcre.3 and comments in the source fixed.
3030     2. Applied a contributed patch to get rid of places where it used to remove
3031     'const' from variables, and fixed some signed/unsigned and uninitialized
3032     variable warnings.
3034     3. Added the "runtest" target to Makefile.
3036     4. Set default compiler flag to -O2 rather than just -O.
3039 nigel 5 Version 1.01 19-Nov-97
3040     ----------------------
3042     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3043     like /([ab]*)*/, that is, for classes with more than one character in them.
3045     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3046     as /((?>a*))*/ (a PCRE_EXTRA facility).
3049     Version 1.00 18-Nov-97
3050     ----------------------
3052     1. Added compile-time macros to support systems such as SunOS4 which don't have
3053     memmove() or strerror() but have other things that can be used instead.
3055     2. Arranged that "make clean" removes the executables.
3058 nigel 3 Version 0.99 27-Oct-97
3059     ----------------------
3061     1. Fixed bug in code for optimizing classes with only one character. It was
3062     initializing a 32-byte map regardless, which could cause it to run off the end
3063     of the memory it had got.
3065     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3068     Version 0.98 22-Oct-97
3069     ----------------------
3071     1. Fixed bug in code for handling temporary memory usage when there are more
3072     back references than supplied space in the ovector. This could cause segfaults.
3075     Version 0.97 21-Oct-97
3076     ----------------------
3078     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3080     2. Optimized negated single characters not to use a bit map.
3082     3. Brought error texts together as macro definitions; clarified some of them;
3083     fixed one that was wrong - it said "range out of order" when it meant "invalid
3084     escape sequence".
3086     4. Changed some char * arguments to const char *.
3088     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3090     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3091     pcretest.
3094     Version 0.96 16-Oct-97
3095     ----------------------
3097     1. Added a simple "pgrep" utility to the distribution.
3099     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3100     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3101     where "ddd" means "one or more decimal digits".
3103     3. Fixed serious bug. If a pattern had a back reference, but the call to
3104     pcre_exec() didn't supply a large enough ovector to record the related
3105     identifying subpattern, the match always failed. PCRE now remembers the number
3106     of the largest back reference, and gets some temporary memory in which to save
3107     the offsets during matching if necessary, in order to ensure that
3108     backreferences always work.
3110     4. Increased the compatibility with Perl in a number of ways:
3112     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3113     to request this handling. The option can be set at compile or exec time.
3115     (b) $ matches before a terminating newline by default; an option
3116     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3117     mode). The option can be set at compile or exec time.
3119     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3120     the same as Perl's. If the decimal number it represents is less than 10
3121     or there aren't that many previous left capturing parentheses, an octal
3122     escape is read. Inside a character class, it's always an octal escape,
3123     even if it is a single digit.
3125     (d) An escaped but undefined alphabetic character is taken as a literal,
3126     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3127     escapes.
3129     (e) {0} is now permitted. (The previous item is removed from the compiled
3130     pattern).
3132     5. Changed all the names of code files so that the basic parts are no longer
3133     than 10 characters, and abolished the teeny "globals.c" file.
3135     6. Changed the handling of character classes; they are now done with a 32-byte
3136     bit map always.
3138     7. Added the -d and /D options to pcretest to make it possible to look at the
3139     internals of compilation without having to recompile pcre.
3142     Version 0.95 23-Sep-97
3143     ----------------------
3145     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3146     \x20 at the start of a run of normal characters. These were being treated as
3147     real characters, instead of the source characters being re-checked.
3150     Version 0.94 18-Sep-97
3151     ----------------------
3153     1. The functions are now thread-safe, with the caveat that the global variables
3154     containing pointers to malloc() and free() or alternative functions are the
3155     same for all threads.
3157     2. Get pcre_study() to generate a bitmap of initial characters for non-
3158     anchored patterns when this is possible, and use it if passed to pcre_exec().
3161     Version 0.93 15-Sep-97
3162     ----------------------
3164     1. /(b)|(:+)/ was computing an incorrect first character.
3166     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3167     but not actually doing anything yet.
3169     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3170     as Perl does (e.g. [-az] or [az-]).
3172     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3173     all possible positions.
3175     5. Split up into different modules to avoid including unneeded functions in a
3176     compiled binary. However, compile and exec are still in one module. The "study"
3177     function is split off.
3179     6. The character tables are now in a separate module whose source is generated
3180     by an auxiliary program - but can then be edited by hand if required. There are
3181     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3182     toupper() in the code.
3184     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3185     make them global. Abolish the function for setting them, as the caller can now
3186     set them directly.
3189     Version 0.92 11-Sep-97
3190     ----------------------
3192     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3193     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3195     2. Caseless matching was not working in character classes if the characters in
3196     the pattern were in upper case.
3198     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3200     4. Make PCRE_ANCHORED public and accept as a compile option.
3202     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3203     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3204     pass them.
3206     6. Give an error if bad option bits passed at compile or run time.
3208     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3209     pcretest to cause it to pass that flag.
3211     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3212     options, and the first character, if set.
3214     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3217     Version 0.91 10-Sep-97
3218     ----------------------
3220     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3221     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3223     2. PCRE was looping on encountering an indefinitely repeated back reference to
3224     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3225     Perl does - treats the match as successful.
3227     ****


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