7
1. Internal change: literal characters are no longer packed up into items
8
containing multiple characters in a single byte-string. Each character
9
is now matched using a separate opcode. However, there may be more than one
10
byte in the character in UTF-8 mode.
12
2. The pcre_callout_block structure has two new fields: pattern_position and
13
next_item_length. These contain the offset in the pattern to the next match
14
item, and its length, respectively.
16
3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
17
insertion of callouts before each pattern item. Added the /C option to
18
pcretest to make use of this.
20
4. On the advice of a Windows user, the lines
22
#if defined(_WIN32) || defined(WIN32)
23
_setmode( _fileno( stdout ), 0x8000 );
24
#endif /* defined(_WIN32) || defined(WIN32) */
26
have been added to the source of pcretest. This apparently does useful
27
magic in relation to line terminators.
29
5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
30
for the benefit of those environments where the "b" makes a difference.
32
6. The icc compiler has the same options as gcc, but "configure" doesn't seem
33
to know about it. I have put a hack into configure.in that adds in code
34
to set GCC=yes if CC=icc. This seems to end up at a point in the
35
generated configure script that is early enough to affect the setting of
36
compiler options, which is what is needed, but I have no means of testing
37
whether it really works. (The user who reported this had patched the
38
generated configure script, which of course I cannot do.)
40
LATER: After change 22 below (new libtool files), the configure script
41
seems to know about icc (and also ecc). Therefore, I have commented out
42
this hack in configure.in.
44
7. Added support for pkg-config (2 patches were sent in).
46
8. Negated POSIX character classes that used a combination of internal tables
47
were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
48
[[:^ascii]]. Typically, they would match almost any characters. The other
49
POSIX classes were not broken in this way.
51
9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
52
to find the match, as PCRE was deluded into thinking that the match had to
53
start at the start point or following a newline. The same bug applied to
54
patterns with negative forward assertions or any backward assertions
55
preceding ".*" at the start, unless the pattern required a fixed first
56
character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
58
10. In UTF-8 mode, when moving forwards in the subject after a failed match
59
starting at the last subject character, bytes beyond the end of the subject
62
11. Renamed the variable "class" as "classbits" to make life easier for C++
63
users. (Previously there was a macro definition, but it apparently wasn't
66
12. Added the new field "tables" to the extra data so that tables can be passed
67
in at exec time, or the internal tables can be re-selected. This allows
68
a compiled regex to be saved and re-used at a later time by a different
69
program that might have everything at different addresses.
71
13. Modified the pcre-config script so that, when run on Solaris, it shows a
72
-R library as well as a -L library.
74
14. The debugging options of pcretest (-d on the command line or D on a
75
pattern) showed incorrect output for anything following an extended class
76
that contained multibyte characters and which was followed by a quantifier.
78
15. Added optional support for general category Unicode character properties
79
via the \p, \P, and \X escapes. Unicode property support implies UTF-8
80
support. It adds about 90K to the size of the library. The meanings of the
81
inbuilt class escapes such as \d and \s have NOT been changed.
83
16. Updated pcredemo.c to include calls to free() to release the memory for the
86
17. The generated file chartables.c was being created in the source directory
87
instead of in the building directory. This caused the build to fail if the
88
source directory was different from the building directory, and was
91
18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
92
file. No doubt somebody will tell me if they don't make sense... Also added
93
Dan Mooney's comments about building on OpenVMS.
95
19. Added support for partial matching via the PCRE_PARTIAL option for
96
pcre_exec() and the \P data escape in pcretest.
98
20. Extended pcretest with 3 new pattern features:
100
(i) A pattern option of the form ">rest-of-line" causes pcretest to
101
write the compiled pattern to the file whose name is "rest-of-line".
102
This is a straight binary dump of the data, with the saved pointer to
103
the character tables forced to be NULL. The study data, if any, is
104
written too. After writing, pcretest reads a new pattern.
106
(ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
107
compiled pattern from the given file. There must not be any
108
occurrences of "<" in the file name (pretty unlikely); if there are,
109
pcretest will instead treat the initial "<" as a pattern delimiter.
110
After reading in the pattern, pcretest goes on to read data lines as
113
(iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
114
and 16-bit fields in a compiled pattern, to simulate a pattern that
115
was compiled on a host of opposite endianness.
117
21. The pcre-exec() function can now cope with patterns that were compiled on
118
hosts of opposite endianness, with this restriction:
120
As for any compiled expression that is saved and used later, the tables
121
pointer field cannot be preserved; the extra_data field in the arguments
122
to pcre_exec() should be used to pass in a tables address if a value
123
other than the default internal tables were used at compile time.
125
22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
126
now diagnosed as an error. Previously, most of the time, a negative number
127
would have been treated as zero, but if in addition "ovector" was passed as
128
NULL, a crash could occur.
130
23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
131
new versions from the libtool 1.5 distribution (the last one is a copy of
132
a file called libtool.m4). This seems to have fixed the need to patch
133
"configure" to support Darwin 1.3 (which I used to do). However, I still
134
had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
137
24. Changed the PCRE licence to be the more standard "BSD" licence.
140
Version 4.5 01-Dec-03
141
---------------------
143
1. There has been some re-arrangement of the code for the match() function so
144
that it can be compiled in a version that does not call itself recursively.
145
Instead, it keeps those local variables that need separate instances for
146
each "recursion" in a frame on the heap, and gets/frees frames whenever it
147
needs to "recurse". Keeping track of where control must go is done by means
148
of setjmp/longjmp. The whole thing is implemented by a set of macros that
149
hide most of the details from the main code, and operates only if
150
NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
151
"configure" mechanism, "--disable-stack-for-recursion" turns on this way of
154
To make it easier for callers to provide specially tailored get/free
155
functions for this usage, two new functions, pcre_stack_malloc, and
156
pcre_stack_free, are used. They are always called in strict stacking order,
157
and the size of block requested is always the same.
159
The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
160
PCRE has been compiled to use the stack or the heap for recursion. The
161
-C option of pcretest uses this to show which version is compiled.
163
A new data escape \S, is added to pcretest; it causes the amounts of store
164
obtained and freed by both kinds of malloc/free at match time to be added
167
2. Changed the locale test to use "fr_FR" instead of "fr" because that's
168
what's available on my current Linux desktop machine.
170
3. When matching a UTF-8 string, the test for a valid string at the start has
171
been extended. If start_offset is not zero, PCRE now checks that it points
172
to a byte that is the start of a UTF-8 character. If not, it returns
173
PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
174
this is necessary because there may be backward assertions in the pattern.
175
When matching the same subject several times, it may save resources to use
176
PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
178
4. The code for checking the validity of UTF-8 strings has been tightened so
179
that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
180
containing "overlong sequences".
182
5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
183
I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
184
should have been "&", but it just so happened that all the cases this let
185
through by mistake were picked up later in the function.
187
6. I had used a variable called "isblank" - this is a C99 function, causing
188
some compilers to warn. To avoid this, I renamed it (as "blankclass").
190
7. Cosmetic: (a) only output another newline at the end of pcretest if it is
191
prompting; (b) run "./pcretest /dev/null" at the start of the test script
192
so the version is shown; (c) stop "make test" echoing "./RunTest".
194
8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
196
9. The prototype for memmove() for systems that don't have it was using
197
size_t, but the inclusion of the header that defines size_t was later. I've
198
moved the #includes for the C headers earlier to avoid this.
200
10. Added some adjustments to the code to make it easier to compiler on certain
203
(a) Some "const" qualifiers were missing.
204
(b) Added the macro EXPORT before all exported functions; by default this
205
is defined to be empty.
206
(c) Changed the dftables auxiliary program (that builds chartables.c) so
207
that it reads its output file name as an argument instead of writing
208
to the standard output and assuming this can be redirected.
210
11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
211
class containing characters with values greater than 255, PCRE compilation
214
12. A recursive reference to a subpattern that was within another subpattern
215
that had a minimum quantifier of zero caused PCRE to crash. For example,
216
(x(y(?2))z)? provoked this bug with a subject that got as far as the
217
recursion. If the recursively-called subpattern itself had a zero repeat,
220
13. In pcretest, the buffer for reading a data line was set at 30K, but the
221
buffer into which it was copied (for escape processing) was still set at
222
1024, so long lines caused crashes.
224
14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
225
"internal error: code overflow...". This applied to any character class
226
that was followed by a possessive quantifier.
228
15. Modified the Makefile to add libpcre.la as a prerequisite for
229
libpcreposix.la because I was told this is needed for a parallel build to
232
16. If a pattern that contained .* following optional items at the start was
233
studied, the wrong optimizing data was generated, leading to matching
234
errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
235
matching string must start with a or b or c. The correct conclusion for
236
this pattern is that a match can start with any character.
239
Version 4.4 13-Aug-03
240
---------------------
242
1. In UTF-8 mode, a character class containing characters with values between
243
127 and 255 was not handled correctly if the compiled pattern was studied.
244
In fixing this, I have also improved the studying algorithm for such
247
2. Three internal functions had redundant arguments passed to them. Removal
248
might give a very teeny performance improvement.
250
3. Documentation bug: the value of the capture_top field in a callout is *one
251
more than* the number of the hightest numbered captured substring.
253
4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
254
in incorrectly linking with a previously installed version. They now link
255
explicitly with libpcre.la.
257
5. configure.in no longer needs to recognize Cygwin specially.
259
6. A problem in pcre.in for Windows platforms is fixed.
261
7. If a pattern was successfully studied, and the -d (or /D) flag was given to
262
pcretest, it used to include the size of the study block as part of its
263
output. Unfortunately, the structure contains a field that has a different
264
size on different hardware architectures. This meant that the tests that
265
showed this size failed. As the block is currently always of a fixed size,
266
this information isn't actually particularly useful in pcretest output, so
267
I have just removed it.
269
8. Three pre-processor statements accidentally did not start in column 1.
270
Sadly, there are *still* compilers around that complain, even though
271
standard C has not required this for well over a decade. Sigh.
273
9. In pcretest, the code for checking callouts passed small integers in the
274
callout_data field, which is a void * field. However, some picky compilers
275
complained about the casts involved for this on 64-bit systems. Now
276
pcretest passes the address of the small integer instead, which should get
279
10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
280
both compile and run time, and gives an error if an invalid UTF-8 sequence
281
is found. There is a option for disabling this check in cases where the
282
string is known to be correct and/or the maximum performance is wanted.
284
11. In response to a bug report, I changed one line in Makefile.in from
286
-Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
288
-Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
290
to look similar to other lines, but I have no way of telling whether this
291
is the right thing to do, as I do not use Windows. No doubt I'll get told
295
Version 4.3 21-May-03
296
---------------------
298
1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
301
2. Some refactoring to improve the quality of the code:
303
(i) The utf8_table... variables are now declared "const".
305
(ii) The code for \cx, which used the "case flipping" table to upper case
306
lower case letters, now just substracts 32. This is ASCII-specific,
307
but the whole concept of \cx is ASCII-specific, so it seems
310
(iii) PCRE was using its character types table to recognize decimal and
311
hexadecimal digits in the pattern. This is silly, because it handles
312
only 0-9, a-f, and A-F, but the character types table is locale-
313
specific, which means strange things might happen. A private
314
table is now used for this - though it costs 256 bytes, a table is
315
much faster than multiple explicit tests. Of course, the standard
316
character types table is still used for matching digits in subject
319
(iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
320
ending in _t are). So I've renamed it as ESC_tee.
322
3. The first argument for regexec() in the POSIX wrapper should have been
325
4. Changed pcretest to use malloc() for its buffers so that they can be
326
Electric Fenced for debugging.
328
5. There were several places in the code where, in UTF-8 mode, PCRE would try
329
to read one or more bytes before the start of the subject string. Often this
330
had no effect on PCRE's behaviour, but in some circumstances it could
331
provoke a segmentation fault.
333
6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
334
to try to read one or more bytes before the start of the subject string.
336
7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
337
UTF-8 support could misbehave in various ways if the subject string
338
contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
339
area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
340
back over UTF-8 characters.)
343
Version 4.2 14-Apr-03
344
---------------------
346
1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
348
2. Changes to the building process, supplied by Ronald Landheer-Cieslak
349
[ON_WINDOWS]: new variable, "#" on non-Windows platforms
350
[NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
351
[WIN_PREFIX]: new variable, "cyg" for Cygwin
352
* Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
354
Note: automatic setting of the BUILD variables is not yet working
355
set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
356
compile-time but not at link-time
357
[LINK]: use for linking executables only
358
make different versions for Windows and non-Windows
359
[LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
361
[LINK_FOR_BUILD]: new variable
362
[OBJEXT]: use throughout
363
[EXEEXT]: use throughout
364
<winshared>: new target
365
<wininstall>: new target
366
<dftables.o>: use native compiler
367
<dftables>: use native linker
368
<install>: handle Windows platform correctly
371
copy DLL to top builddir before testing
373
As part of these changes, -no-undefined was removed again. This was reported
374
to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
377
3. Some tidies to get rid of compiler warnings:
379
. In the match_data structure, match_limit was an unsigned long int, whereas
380
match_call_count was an int. I've made them both unsigned long ints.
382
. In pcretest the fact that a const uschar * doesn't automatically cast to
383
a void * provoked a warning.
385
. Turning on some more compiler warnings threw up some "shadow" variables
386
and a few more missing casts.
388
4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
389
option, a class that contained a single character with a value between 128
390
and 255 (e.g. /[\xFF]/) caused PCRE to crash.
392
5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
393
option, a class that contained several characters, but with at least one
394
whose value was between 128 and 255 caused PCRE to crash.
397
Version 4.1 12-Mar-03
398
---------------------
400
1. Compiling with gcc -pedantic found a couple of places where casts were
401
needed, and a string in dftables.c that was longer than standard compilers are
404
2. Compiling with Sun's compiler found a few more places where the code could
405
be tidied up in order to avoid warnings.
407
3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
408
first of these names is deprecated in the latest Autoconf in favour of the name
409
CC_FOR_BUILD, because "host" is typically used to mean the system on which the
410
compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
411
analogy I have changed it to CFLAGS_FOR_BUILD.
413
4. Added -no-undefined to the linking command in the Makefile, because this is
414
apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
415
linking step for the pcreposix library.
417
5. PCRE was failing to diagnose the case of two named groups with the same
420
6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
421
literal character that is needed in the subject for a match, and scans along to
422
ensure that it is present before embarking on the full matching process. This
423
saves time in cases of nested unlimited repeats that are never going to match.
424
Problem: the scan can take a lot of time if the subject is very long (e.g.
425
megabytes), thus penalizing straightforward matches. It is now done only if the
426
amount of subject to be scanned is less than 1000 bytes.
428
7. A lesser problem with the same optimization is that it was recording the
429
first character of an anchored pattern as "needed", thus provoking a search
430
right along the subject, even when the first match of the pattern was going to
431
fail. The "needed" character is now not set for anchored patterns, unless it
432
follows something in the pattern that is of non-fixed length. Thus, it still
433
fulfils its original purpose of finding quick non-matches in cases of nested
434
unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
437
Version 4.0 17-Feb-03
438
---------------------
440
1. If a comment in an extended regex that started immediately after a meta-item
441
extended to the end of string, PCRE compiled incorrect data. This could lead to
442
all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
444
2. Moved to autoconf 2.53 and libtool 1.4.2.
446
3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
447
the special perltest8 script is no longer needed - all the tests can be run
448
from a single perltest script.
450
4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
451
by \s. It has now been removed in PCRE. This means it isn't recognized as
452
whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
453
class [:space:] *does* include VT, thereby creating a mess.
455
5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
458
6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
459
its new features into the main test script, reducing the number of scripts.
461
7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
462
were backward compatible, and made the (?i) apply to the whole pattern, as if
463
/i were given. Now it behaves more logically, and applies the option setting
464
only to what follows. PCRE has been changed to follow suit. However, if it
465
finds options settings right at the start of the pattern, it extracts them into
466
the global options, as before. Thus, they show up in the info data.
468
8. Added support for the \Q...\E escape sequence. Characters in between are
469
treated as literals. This is slightly different from Perl in that $ and @ are
470
also handled as literals inside the quotes. In Perl, they will cause variable
471
interpolation. Note the following examples:
473
Pattern PCRE matches Perl matches
475
\Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
476
\Qabc\$xyz\E abc\$xyz abc\$xyz
477
\Qabc\E\$\Qxyz\E abc$xyz abc$xyz
479
For compatibility with Perl, \Q...\E sequences are recognized inside character
480
classes as well as outside them.
482
9. Re-organized 3 code statements in pcretest to avoid "overflow in
483
floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
484
(size_t) cast to one statement in pcretest and one in pcreposix to avoid
485
signed/unsigned warnings.
487
10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
488
option for pcretest, so I've replaced it by a simple function that does just
491
11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
494
12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
495
Java package. This provides some syntactic sugar for simple cases of what my
496
documentation calls "once-only subpatterns". A pattern such as x*+ is the same
497
as (?>x*). In other words, if what is inside (?>...) is just a single repeated
498
item, you can use this simplified notation. Note that only makes sense with
499
greedy quantifiers. Consequently, the use of the possessive quantifier forces
500
greediness, whatever the setting of the PCRE_UNGREEDY option.
502
13. A change of greediness default within a pattern was not taking effect at
503
the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
504
subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
505
was abstracted outside.
507
14. PCRE now supports the \G assertion. It is true when the current matching
508
position is at the start point of the match. This differs from \A when the
509
starting offset is non-zero. Used with the /g option of pcretest (or similar
510
code), it works in the same way as it does for Perl's /g option. If all
511
alternatives of a regex begin with \G, the expression is anchored to the start
512
match position, and the "anchored" flag is set in the compiled expression.
514
15. Some bugs concerning the handling of certain option changes within patterns
515
have been fixed. These applied to options other than (?ims). For example,
516
"a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
517
been the other way round. Some of this was related to change 7 above.
519
16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
520
features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
521
and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
522
POSIX classes only within a class (e.g. /[[:alpha:]]/).
524
17. Added support for Perl's \C escape. This matches one byte, even in UTF8
525
mode. Unlike ".", it always matches newline, whatever the setting of
526
PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
527
assertions. Perl allows it, but it doesn't (in general) work because it can't
528
calculate the length of the lookbehind. At least, that's the case for Perl
529
5.8.0 - I've been told they are going to document that it doesn't work in
532
18. Added an error diagnosis for escapes that PCRE does not support: these are
533
\L, \l, \N, \P, \p, \U, \u, and \X.
535
19. Although correctly diagnosing a missing ']' in a character class, PCRE was
536
reading past the end of the pattern in cases such as /[abcd/.
538
20. PCRE was getting more memory than necessary for patterns with classes that
539
contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
541
21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
542
compiling PCRE for use with Virtual Pascal.
544
22. Small fix to the Makefile to make it work properly if the build is done
545
outside the source tree.
547
23. Added a new extension: a condition to go with recursion. If a conditional
548
subpattern starts with (?(R) the "true" branch is used if recursion has
549
happened, whereas the "false" branch is used only at the top level.
551
24. When there was a very long string of literal characters (over 255 bytes
552
without UTF support, over 250 bytes with UTF support), the computation of how
553
much memory was required could be incorrect, leading to segfaults or other
556
25. PCRE was incorrectly assuming anchoring (either to start of subject or to
557
start of line for a non-DOTALL pattern) when a pattern started with (.*) and
558
there was a subsequent back reference to those brackets. This meant that, for
559
example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
560
possible to check for precisely this case. All we can do is abandon the
561
optimization if .* occurs inside capturing brackets when there are any back
562
references whatsoever. (See below for a better fix that came later.)
564
26. The handling of the optimization for finding the first character of a
565
non-anchored pattern, and for finding a character that is required later in the
566
match were failing in some cases. This didn't break the matching; it just
567
failed to optimize when it could. The way this is done has been re-implemented.
569
27. Fixed typo in error message for invalid (?R item (it said "(?p").
571
28. Added a new feature that provides some of the functionality that Perl
572
provides with (?{...}). The facility is termed a "callout". The way it is done
573
in PCRE is for the caller to provide an optional function, by setting
574
pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
575
global variable. By default it is unset, which disables all calling out. To get
576
the function called, the regex must include (?C) at appropriate points. This
577
is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
578
This provides a means of identifying different callout points. When PCRE
579
reaches such a point in the regex, if pcre_callout has been set, the external
580
function is called. It is provided with data in a structure called
581
pcre_callout_block, which is defined in pcre.h. If the function returns 0,
582
matching continues; if it returns a non-zero value, the match at the current
583
point fails. However, backtracking will occur if possible. [This was changed
584
later and other features added - see item 49 below.]
586
29. pcretest is upgraded to test the callout functionality. It provides a
587
callout function that displays information. By default, it shows the start of
588
the match and the current position in the text. There are some new data escapes
589
to vary what happens:
591
\C+ in addition, show current contents of captured substrings
592
\C- do not supply a callout function
593
\C!n return 1 when callout number n is reached
594
\C!n!m return 1 when callout number n is reached for the mth time
596
30. If pcregrep was called with the -l option and just a single file name, it
597
output "<stdin>" if a match was found, instead of the file name.
599
31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
600
slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
601
pcre_exec(). This saves a malloc/free per call. The default value of
602
POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
605
32. The default maximum size of a compiled pattern is 64K. There have been a
606
few cases of people hitting this limit. The code now uses macros to handle the
607
storing of links as offsets within the compiled pattern. It defaults to 2-byte
608
links, but this can be changed to 3 or 4 bytes by --with-link-size when
609
configuring. Tests 2 and 5 work only with 2-byte links because they output
610
debugging information about compiled patterns.
612
33. Internal code re-arrangements:
614
(a) Moved the debugging function for printing out a compiled regex into
615
its own source file (printint.c) and used #include to pull it into
616
pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
619
(b) Defined the list of op-code names for debugging as a macro in
620
internal.h so that it is next to the definition of the opcodes.
622
(c) Defined a table of op-code lengths for simpler skipping along compiled
623
code. This is again a macro in internal.h so that it is next to the
624
definition of the opcodes.
626
34. Added support for recursive calls to individual subpatterns, along the
627
lines of Robin Houston's patch (but implemented somewhat differently).
629
35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
630
allow it to read and process whole directories in Win32. This code was
631
contributed by Lionel Fourquaux; it has not been tested by me.
633
36. Added support for named subpatterns. The Python syntax (?P<name>...) is
634
used to name a group. Names consist of alphanumerics and underscores, and must
635
be unique. Back references use the syntax (?P=name) and recursive calls use
636
(?P>name) which is a PCRE extension to the Python extension. Groups still have
637
numbers. The function pcre_fullinfo() can be used after compilation to extract
638
a name/number map. There are three relevant calls:
640
PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
641
PCRE_INFO_NAMECOUNT yields the number of entries
642
PCRE_INFO_NAMETABLE yields a pointer to the map.
644
The map is a vector of fixed-size entries. The size of each entry depends on
645
the length of the longest name used. The first two bytes of each entry are the
646
group number, most significant byte first. There follows the corresponding
647
name, zero terminated. The names are in alphabetical order.
649
37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
650
case instead of 255. Making it the same both with and without UTF-8 support
651
means that the same test output works with both.
653
38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
654
calling malloc() with a zero argument.
656
39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
657
optimization. I've improved things by keeping a bitmap of backreferences with
658
numbers 1-31 so that if .* occurs inside capturing brackets that are not in
659
fact referenced, the optimization can be applied. It is unlikely that a
660
relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
661
the match to follow \n) will appear inside brackets with a number greater than
662
31, but if it does, any back reference > 31 suppresses the optimization.
664
40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
665
of disabling numbered capturing parentheses. Any opening parenthesis that is
666
not followed by ? behaves as if it were followed by ?: but named parentheses
667
can still be used for capturing (and they will acquire numbers in the usual
670
41. Redesigned the return codes from the match() function into yes/no/error so
671
that errors can be passed back from deep inside the nested calls. A malloc
672
failure while inside a recursive subpattern call now causes the
673
PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
675
42. It is now possible to set a limit on the number of times the match()
676
function is called in a call to pcre_exec(). This facility makes it possible to
677
limit the amount of recursion and backtracking, though not in a directly
678
obvious way, because the match() function is used in a number of different
679
circumstances. The count starts from zero for each position in the subject
680
string (for non-anchored patterns). The default limit is, for compatibility, a
681
large number, namely 10 000 000. You can change this in two ways:
683
(a) When configuring PCRE before making, you can use --with-match-limit=n
684
to set a default value for the compiled library.
686
(b) For each call to pcre_exec(), you can pass a pcre_extra block in which
687
a different value is set. See 45 below.
689
If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
691
43. Added a new function pcre_config(int, void *) to enable run-time extraction
692
of things that can be changed at compile time. The first argument specifies
693
what is wanted and the second points to where the information is to be placed.
694
The current list of available information is:
698
The output is an integer that is set to one if UTF-8 support is available;
699
otherwise it is set to zero.
703
The output is an integer that it set to the value of the code that is used for
704
newline. It is either LF (10) or CR (13).
706
PCRE_CONFIG_LINK_SIZE
708
The output is an integer that contains the number of bytes used for internal
709
linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
711
PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
713
The output is an integer that contains the threshold above which the POSIX
714
interface uses malloc() for output vectors. See item 31 above.
716
PCRE_CONFIG_MATCH_LIMIT
718
The output is an unsigned integer that contains the default limit of the number
719
of match() calls in a pcre_exec() execution. See 42 above.
721
44. pcretest has been upgraded by the addition of the -C option. This causes it
722
to extract all the available output from the new pcre_config() function, and to
723
output it. The program then exits immediately.
725
45. A need has arisen to pass over additional data with calls to pcre_exec() in
726
order to support additional features. One way would have been to define
727
pcre_exec2() (for example) with extra arguments, but this would not have been
728
extensible, and would also have required all calls to the original function to
729
be mapped to the new one. Instead, I have chosen to extend the mechanism that
730
is used for passing in "extra" data from pcre_study().
732
The pcre_extra structure is now exposed and defined in pcre.h. It currently
733
contains the following fields:
735
flags a bitmap indicating which of the following fields are set
736
study_data opaque data from pcre_study()
737
match_limit a way of specifying a limit on match() calls for a specific
739
callout_data data for callouts (see 49 below)
741
The flag bits are also defined in pcre.h, and are
743
PCRE_EXTRA_STUDY_DATA
744
PCRE_EXTRA_MATCH_LIMIT
745
PCRE_EXTRA_CALLOUT_DATA
747
The pcre_study() function now returns one of these new pcre_extra blocks, with
748
the actual study data pointed to by the study_data field, and the
749
PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
750
before. That is, this change is entirely upwards-compatible and requires no
751
change to existing code.
753
If you want to pass in additional data to pcre_exec(), you can either place it
754
in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
757
46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
758
data string contains the escape sequence \M, pcretest calls pcre_exec() several
759
times with different match limits, until it finds the minimum value needed for
760
pcre_exec() to complete. The value is then output. This can be instructive; for
761
most simple matches the number is quite small, but for pathological cases it
762
gets very large very quickly.
764
47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
765
returns the size of the data block pointed to by the study_data field in a
766
pcre_extra block, that is, the value that was passed as the argument to
767
pcre_malloc() when PCRE was getting memory in which to place the information
768
created by pcre_study(). The fourth argument should point to a size_t variable.
769
pcretest has been extended so that this information is shown after a successful
770
pcre_study() call when information about the compiled regex is being displayed.
772
48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
773
because what follows is always an absolute path. (Later: it turns out that this
774
is more than cosmetic for MinGW, because it doesn't like empty path
777
49. Some changes have been made to the callout feature (see 28 above):
779
(i) A callout function now has three choices for what it returns:
781
0 => success, carry on matching
782
> 0 => failure at this point, but backtrack if possible
783
< 0 => serious error, return this value from pcre_exec()
785
Negative values should normally be chosen from the set of PCRE_ERROR_xxx
786
values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
787
"match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
788
use by callout functions. It will never be used by PCRE itself.
790
(ii) The pcre_extra structure (see 45 above) has a void * field called
791
callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
792
pcre_callout_block structure has a field of the same name. The contents of
793
the field passed in the pcre_extra structure are passed to the callout
794
function in the corresponding field in the callout block. This makes it
795
easier to use the same callout-containing regex from multiple threads. For
796
testing, the pcretest program has a new data escape
798
\C*n pass the number n (may be negative) as callout_data
800
If the callout function in pcretest receives a non-zero value as
801
callout_data, it returns that value.
803
50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
804
there were some redundant $(CFLAGS) in commands that are now specified as
805
$(LINK), which already includes $(CFLAGS).
807
51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
808
has been compiled with UTF-8 support *and* pcre_compile() has been compiled
809
with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
810
one-byte characters throughout. Note that case-insensitive matching applies
811
only to characters whose values are less than 256. PCRE doesn't support the
812
notion of cases for higher-valued characters.
814
(i) A character class whose characters are all within 0-255 is handled as
815
a bit map, and the map is inverted for negative classes. Previously, a
816
character > 255 always failed to match such a class; however it should
817
match if the class was a negative one (e.g. [^ab]). This has been fixed.
819
(ii) A negated character class with a single character < 255 is coded as
820
"not this character" (OP_NOT). This wasn't working properly when the test
821
character was multibyte, either singly or repeated.
823
(iii) Repeats of multibyte characters are now handled correctly in UTF-8
824
mode, for example: \x{100}{2,3}.
826
(iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
827
singly or repeated) now correctly test multibyte characters. However,
828
PCRE doesn't recognize any characters with values greater than 255 as
829
digits, spaces, or word characters. Such characters always match \D, \S,
830
and \W, and never match \d, \s, or \w.
832
(v) Classes may now contain characters and character ranges with values
833
greater than 255. For example: [ab\x{100}-\x{400}].
835
(vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
838
52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
839
PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
840
retained for backwards compatibility. (Note that LASTLITERAL is also a byte
843
53. The single man page has become too large. I have therefore split it up into
844
a number of separate man pages. These also give rise to individual HTML pages;
845
these are now put in a separate directory, and there is an index.html page that
846
lists them all. Some hyperlinking between the pages has been installed.
848
54. Added convenience functions for handling named capturing parentheses.
850
55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
851
aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
852
true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
855
56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
856
calling configure. These values are used when compiling the dftables.c program
857
which is run to generate the source of the default character tables. They
858
default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
859
you will need to set these values.
861
57. Updated the building process for Windows DLL, as provided by Fred Cox.
864
Version 3.9 02-Jan-02
865
---------------------
867
1. A bit of extraneous text had somehow crept into the pcregrep documentation.
869
2. If --disable-static was given, the building process failed when trying to
870
build pcretest and pcregrep. (For some reason it was using libtool to compile
871
them, which is not right, as they aren't part of the library.)
874
Version 3.8 18-Dec-01
875
---------------------
877
1. The experimental UTF-8 code was completely screwed up. It was packing the
878
bytes in the wrong order. How dumb can you get?
881
Version 3.7 29-Oct-01
882
---------------------
884
1. In updating pcretest to check change 1 of version 3.6, I screwed up.
885
This caused pcretest, when used on the test data, to segfault. Unfortunately,
886
this didn't happen under Solaris 8, where I normally test things.
888
2. The Makefile had to be changed to make it work on BSD systems, where 'make'
889
doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
890
isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
891
this fix an hour or so after the initial 3.7 release.)
894
Version 3.6 23-Oct-01
895
---------------------
897
1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
898
offsets passed as NULL with zero offset count.
900
2. The config.guess and config.sub files had not been updated when I moved to
904
Version 3.5 15-Aug-01
905
---------------------
907
1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
910
2. By using declared but undefined structures, we can avoid using "void"
911
definitions in pcre.h while keeping the internal definitions of the structures
914
3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
915
user point of view, this means that both static and shared libraries are built
916
by default, but this can be individually controlled. More of the work of
917
handling this static/shared cases is now inside libtool instead of PCRE's make
920
4. The pcretest utility is now installed along with pcregrep because it is
921
useful for users (to test regexs) and by doing this, it automatically gets
922
relinked by libtool. The documentation has been turned into a man page, so
923
there are now .1, .txt, and .html versions in /doc.
925
5. Upgrades to pcregrep:
926
(i) Added long-form option names like gnu grep.
927
(ii) Added --help to list all options with an explanatory phrase.
928
(iii) Added -r, --recursive to recurse into sub-directories.
929
(iv) Added -f, --file to read patterns from a file.
931
6. pcre_exec() was referring to its "code" argument before testing that
932
argument for NULL (and giving an error if it was NULL).
934
7. Upgraded Makefile.in to allow for compiling in a different directory from
935
the source directory.
937
8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
938
options bits, the pointer it was passed was to an int instead of to an unsigned
939
long int. This mattered only on 64-bit systems.
941
9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
942
generated) instead of pcre.in, which it its source. Also made the same change
943
in several of the .c files.
945
10. A new release of gcc defines printf() as a macro, which broke pcretest
946
because it had an ifdef in the middle of a string argument for printf(). Fixed
947
by using separate calls to printf().
949
11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
950
script, to force use of CR or LF instead of \n in the source. On non-Unix
951
systems, the value can be set in config.h.
953
12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
954
absolute limit. Changed the text of the error message to make this clear, and
955
likewise updated the man page.
957
13. The limit of 99 on the number of capturing subpatterns has been removed.
958
The new limit is 65535, which I hope will not be a "real" limit.
961
Version 3.4 22-Aug-00
962
---------------------
964
1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
966
2. Diagnose condition (?(0) as an error instead of crashing on matching.
969
Version 3.3 01-Aug-00
970
---------------------
972
1. If an octal character was given, but the value was greater than \377, it
973
was not getting masked to the least significant bits, as documented. This could
974
lead to crashes in some systems.
976
2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
977
the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
979
3. Added the functions pcre_free_substring() and pcre_free_substring_list().
980
These just pass their arguments on to (pcre_free)(), but they are provided
981
because some uses of PCRE bind it to non-C systems that can call its functions,
982
but cannot call free() or pcre_free() directly.
984
4. Add "make test" as a synonym for "make check". Corrected some comments in
987
5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
990
6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
991
command called pgrep for grepping around the active processes.
993
7. Added the beginnings of support for UTF-8 character strings.
995
8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
996
RANLIB to ./ltconfig so that they are used by libtool. I think these are all
997
the relevant ones. (AR is not passed because ./ltconfig does its own figuring
998
out for the ar command.)
1001
Version 3.2 12-May-00
1002
---------------------
1004
This is purely a bug fixing release.
1006
1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
1007
of ZA. This was just one example of several cases that could provoke this bug,
1008
which was introduced by change 9 of version 2.00. The code for breaking
1009
infinite loops after an iteration that matches an empty string was't working
1012
2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
1013
when matched against abbab (for example). After matching an empty string, it
1014
wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
1015
caused it to match further down the string than it should.
1017
3. The code contained an inclusion of sys/types.h. It isn't clear why this
1018
was there because it doesn't seem to be needed, and it causes trouble on some
1019
systems, as it is not a Standard C header. It has been removed.
1021
4. Made 4 silly changes to the source to avoid stupid compiler warnings that
1022
were reported on the Macintosh. The changes were from
1024
while ((c = *(++ptr)) != 0 && c != '\n');
1026
while ((c = *(++ptr)) != 0 && c != '\n') ;
1028
Totally extraordinary, but if that's what it takes...
1030
5. PCRE is being used in one environment where neither memmove() nor bcopy() is
1031
available. Added HAVE_BCOPY and an autoconf test for it; if neither
1032
HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
1033
assumes the way PCRE uses memmove() (always moving upwards).
1035
6. PCRE is being used in one environment where strchr() is not available. There
1036
was only one use in pcre.c, and writing it out to avoid strchr() probably gives
1040
Version 3.2 12-May-00
1041
---------------------
1043
This is purely a bug fixing release.
1045
1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
1046
of ZA. This was just one example of several cases that could provoke this bug,
1047
which was introduced by change 9 of version 2.00. The code for breaking
1048
infinite loops after an iteration that matches an empty string was't working
1051
2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
1052
when matched against abbab (for example). After matching an empty string, it
1053
wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
1054
caused it to match further down the string than it should.
1056
3. The code contained an inclusion of sys/types.h. It isn't clear why this
1057
was there because it doesn't seem to be needed, and it causes trouble on some
1058
systems, as it is not a Standard C header. It has been removed.
1060
4. Made 4 silly changes to the source to avoid stupid compiler warnings that
1061
were reported on the Macintosh. The changes were from
1063
while ((c = *(++ptr)) != 0 && c != '\n');
1065
while ((c = *(++ptr)) != 0 && c != '\n') ;
1067
Totally extraordinary, but if that's what it takes...
1069
5. PCRE is being used in one environment where neither memmove() nor bcopy() is
1070
available. Added HAVE_BCOPY and an autoconf test for it; if neither
1071
HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
1072
assumes the way PCRE uses memmove() (always moving upwards).
1074
6. PCRE is being used in one environment where strchr() is not available. There
1075
was only one use in pcre.c, and writing it out to avoid strchr() probably gives
1079
Version 3.1 09-Feb-00
1080
---------------------
1082
The only change in this release is the fixing of some bugs in Makefile.in for
1083
the "install" target:
1085
(1) It was failing to install pcreposix.h.
1087
(2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
1090
Version 3.0 01-Feb-00
1091
---------------------
1093
1. Add support for the /+ modifier to perltest (to output $` like it does in
1096
2. Add support for the /g modifier to perltest.
1098
3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
1099
matches null strings.
1101
4. Fix perltest so that it doesn't do unwanted things when fed an empty
1102
pattern. Perl treats empty patterns specially - it reuses the most recent
1103
pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
1106
5. The POSIX interface was broken in that it was just handing over the POSIX
1107
captured string vector to pcre_exec(), but (since release 2.00) PCRE has
1108
required a bigger vector, with some working space on the end. This means that
1109
the POSIX wrapper now has to get and free some memory, and copy the results.
1111
6. Added some simple autoconf support, placing the test data and the
1112
documentation in separate directories, re-organizing some of the
1113
information files, and making it build pcre-config (a GNU standard). Also added
1114
libtool support for building PCRE as a shared library, which is now the
1117
7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
1118
09 are not valid octal constants. Single digits will be used for minor values
1121
8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
1122
existing programs that set these in the POSIX interface can use PCRE without
1125
9. Added a new function, pcre_fullinfo() with an extensible interface. It can
1126
return all that pcre_info() returns, plus additional data. The pcre_info()
1127
function is retained for compatibility, but is considered to be obsolete.
1129
10. Added experimental recursion feature (?R) to handle one common case that
1130
Perl 5.6 will be able to do with (?p{...}).
1132
11. Added support for POSIX character classes like [:alpha:], which Perl is
1136
Version 2.08 31-Aug-99
1137
----------------------
1139
1. When startoffset was not zero and the pattern began with ".*", PCRE was not
1140
trying to match at the startoffset position, but instead was moving forward to
1141
the next newline as if a previous match had failed.
1143
2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
1144
and could get into a loop if a null string was matched other than at the start
1147
3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
1148
be distinguished at compile time, and for completeness also added PCRE_DATE.
1150
5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
1151
in GnuWin32 environments.
1154
Version 2.07 29-Jul-99
1155
----------------------
1157
1. The documentation is now supplied in plain text form and HTML as well as in
1158
the form of man page sources.
1160
2. C++ compilers don't like assigning (void *) values to other pointer types.
1161
In particular this affects malloc(). Although there is no problem in Standard
1162
C, I've put in casts to keep C++ compilers happy.
1164
3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
1165
should be (const char *).
1167
4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
1168
be useful for non-Unix systems who don't want to bother with the POSIX stuff.
1169
However, I haven't made this a standard facility. The documentation doesn't
1170
mention it, and the Makefile doesn't support it.
1172
5. The Makefile now contains an "install" target, with editable destinations at
1173
the top of the file. The pcretest program is not installed.
1175
6. pgrep -V now gives the PCRE version number and date.
1177
7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
1178
causing the entire string to be ignored, instead of just the last character.
1180
8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
1181
non-matching string, it can take a very, very long time, even for strings of
1182
quite modest length, because of the nested recursion. PCRE now does better in
1183
some of these cases. It does this by remembering the last required literal
1184
character in the pattern, and pre-searching the subject to ensure it is present
1185
before running the real match. In other words, it applies a heuristic to detect
1186
some types of certain failure quickly, and in the above example, if presented
1187
with a string that has no trailing " it gives "no match" very quickly.
1189
9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
1190
other alternatives are tried instead.
1193
Version 2.06 09-Jun-99
1194
----------------------
1196
1. Change pcretest's output for amount of store used to show just the code
1197
space, because the remainder (the data block) varies in size between 32-bit and
1200
2. Added an extra argument to pcre_exec() to supply an offset in the subject to
1201
start matching at. This allows lookbehinds to work when searching for multiple
1202
occurrences in a string.
1204
3. Added additional options to pcretest for testing multiple occurrences:
1206
/+ outputs the rest of the string that follows a match
1207
/g loops for multiple occurrences, using the new startoffset argument
1208
/G loops for multiple occurrences by passing an incremented pointer
1210
4. PCRE wasn't doing the "first character" optimization for patterns starting
1211
with \b or \B, though it was doing it for other lookbehind assertions. That is,
1212
it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
1213
the letter 'x'. On long subject strings, this gives a significant speed-up.
1216
Version 2.05 21-Apr-99
1217
----------------------
1219
1. Changed the type of magic_number from int to long int so that it works
1220
properly on 16-bit systems.
1222
2. Fixed a bug which caused patterns starting with .* not to work correctly
1223
when the subject string contained newline characters. PCRE was assuming
1224
anchoring for such patterns in all cases, which is not correct because .* will
1225
not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
1226
DOTALL is set at top level; otherwise it knows that patterns starting with .*
1227
must be retried after every newline in the subject.
1230
Version 2.04 18-Feb-99
1231
----------------------
1233
1. For parenthesized subpatterns with repeats whose minimum was zero, the
1234
computation of the store needed to hold the pattern was incorrect (too large).
1235
If such patterns were nested a few deep, this could multiply and become a real
1238
2. Added /M option to pcretest to show the memory requirement of a specific
1239
pattern. Made -m a synonym of -s (which does this globally) for compatibility.
1241
3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
1242
compiled in such a way that the backtracking after subsequent failure was
1243
pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
1244
((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
1247
Version 2.03 02-Feb-99
1248
----------------------
1250
1. Fixed typo and small mistake in man page.
1252
2. Added 4th condition (GPL supersedes if conflict) and created separate
1253
LICENCE file containing the conditions.
1255
3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
1256
Perl, that is the internal \ allows the delimiter to be included in the
1257
pattern. Locked out the use of \ as a delimiter. If \ immediately follows
1258
the final delimiter, add \ to the end of the pattern (to test the error).
1260
4. Added the convenience functions for extracting substrings after a successful
1261
match. Updated pcretest to make it able to test these functions.
1264
Version 2.02 14-Jan-99
1265
----------------------
1267
1. Initialized the working variables associated with each extraction so that
1268
their saving and restoring doesn't refer to uninitialized store.
1270
2. Put dummy code into study.c in order to trick the optimizer of the IBM C
1271
compiler for OS/2 into generating correct code. Apparently IBM isn't going to
1274
3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
1275
calls, and wasn't printing the correct value for compiling calls. Increased the
1276
default value of LOOPREPEAT, and the number of significant figures in the
1279
4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
1281
5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
1282
a building problem on Windows NT with a FAT file system.
1285
Version 2.01 21-Oct-98
1286
----------------------
1288
1. Changed the API for pcre_compile() to allow for the provision of a pointer
1289
to character tables built by pcre_maketables() in the current locale. If NULL
1290
is passed, the default tables are used.
1293
Version 2.00 24-Sep-98
1294
----------------------
1296
1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
1299
2. Allow quantification of (?>) groups, and make it work correctly.
1301
3. The first character computation wasn't working for (?>) groups.
1303
4. Correct the implementation of \Z (it is permitted to match on the \n at the
1304
end of the subject) and add 5.005's \z, which really does match only at the
1305
very end of the subject.
1307
5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
1309
6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
1310
DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
1311
localized options. All options to pcre_study() were also removed.
1313
7. Add other new features from 5.005:
1315
$(?<= positive lookbehind
1316
$(?<! negative lookbehind
1317
(?imsx-imsx) added the unsetting capability
1318
such a setting is global if at outer level; local otherwise
1319
(?imsx-imsx:) non-capturing groups with option setting
1320
(?(cond)re|re) conditional pattern matching
1322
A backreference to itself in a repeated group matches the previous
1325
8. General tidying up of studying (both automatic and via "study")
1326
consequential on the addition of new assertions.
1328
9. As in 5.005, unlimited repeated groups that could match an empty substring
1329
are no longer faulted at compile time. Instead, the loop is forcibly broken at
1330
runtime if any iteration does actually match an empty substring.
1332
10. Include the RunTest script in the distribution.
1334
11. Added tests from the Perl 5.005_02 distribution. This showed up a few
1335
discrepancies, some of which were old and were also with respect to 5.004. They
1336
have now been fixed.
1339
Version 1.09 28-Apr-98
1340
----------------------
1342
1. A negated single character class followed by a quantifier with a minimum
1343
value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
1344
program crashes, or just wrong answers. This did not apply to negated classes
1345
containing more than one character, or to minima other than one.
1348
Version 1.08 27-Mar-98
1349
----------------------
1351
1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
1353
2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
1354
latter must appear before anything that relies on it in the pattern.
1357
Version 1.07 16-Feb-98
1358
----------------------
1360
1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
1361
repeat of a potentially empty string).
1364
Version 1.06 23-Jan-98
1365
----------------------
1367
1. Added Markus Oberhumer's little patches for C++.
1369
2. Literal strings longer than 255 characters were broken.
1372
Version 1.05 23-Dec-97
1373
----------------------
1375
1. Negated character classes containing more than one character were failing if
1376
PCRE_CASELESS was set at run time.
1379
Version 1.04 19-Dec-97
1380
----------------------
1382
1. Corrected the man page, where some "const" qualifiers had been omitted.
1384
2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
1387
3. Fixed memory leak which occurred when a regex with back references was
1388
matched with an offsets vector that wasn't big enough. The temporary memory
1389
that is used in this case wasn't being freed if the match failed.
1391
4. Tidied pcretest to ensure it frees memory that it gets.
1393
5. Temporary memory was being obtained in the case where the passed offsets
1394
vector was exactly big enough.
1396
6. Corrected definition of offsetof() from change 5 below.
1398
7. I had screwed up change 6 below and broken the rules for the use of
1399
setjmp(). Now fixed.
1402
Version 1.03 18-Dec-97
1403
----------------------
1405
1. A erroneous regex with a missing opening parenthesis was correctly
1406
diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
1409
2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
1410
it was reported that one broken compiler failed on the former because "code" is
1411
also an independent variable.
1413
3. The erroneous regex a[]b caused an array overrun reference.
1415
4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
1416
fail on data ending with that character. (It was going on too far, and checking
1417
the next character, typically a binary zero.) This was specific to the
1418
optimized code for single-character negative classes.
1420
5. Added a contributed patch from the TIN world which does the following:
1422
+ Add an undef for memmove, in case the the system defines a macro for it.
1424
+ Add a definition of offsetof(), in case there isn't one. (I don't know
1425
the reason behind this - offsetof() is part of the ANSI standard - but
1428
+ Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
1429
most of the places where whitespace preceded '#'. I have given up and
1430
allowed the remaining 2 cases to be at the margin.
1432
+ Rename some variables in pcre to eliminate shadowing. This seems very
1433
pedantic, but does no harm, of course.
1435
6. Moved the call to setjmp() into its own function, to get rid of warnings
1436
from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
1438
7. Constructs such as \d{8,} were compiling into the equivalent of
1439
\d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
1440
outcome, but in this particular case used more store than had been allocated,
1441
which caused the bug to be discovered because it threw up an internal error.
1443
8. The debugging code in both pcre and pcretest for outputting the compiled
1444
form of a regex was going wrong in the case of back references followed by
1445
curly-bracketed repeats.
1448
Version 1.02 12-Dec-97
1449
----------------------
1451
1. Typos in pcre.3 and comments in the source fixed.
1453
2. Applied a contributed patch to get rid of places where it used to remove
1454
'const' from variables, and fixed some signed/unsigned and uninitialized
1457
3. Added the "runtest" target to Makefile.
1459
4. Set default compiler flag to -O2 rather than just -O.
1462
Version 1.01 19-Nov-97
1463
----------------------
1465
1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
1466
like /([ab]*)*/, that is, for classes with more than one character in them.
1468
2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
1469
as /((?>a*))*/ (a PCRE_EXTRA facility).
1472
Version 1.00 18-Nov-97
1473
----------------------
1475
1. Added compile-time macros to support systems such as SunOS4 which don't have
1476
memmove() or strerror() but have other things that can be used instead.
1478
2. Arranged that "make clean" removes the executables.
1481
Version 0.99 27-Oct-97
1482
----------------------
1484
1. Fixed bug in code for optimizing classes with only one character. It was
1485
initializing a 32-byte map regardless, which could cause it to run off the end
1486
of the memory it had got.
1488
2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
1491
Version 0.98 22-Oct-97
1492
----------------------
1494
1. Fixed bug in code for handling temporary memory usage when there are more
1495
back references than supplied space in the ovector. This could cause segfaults.
1498
Version 0.97 21-Oct-97
1499
----------------------
1501
1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
1503
2. Optimized negated single characters not to use a bit map.
1505
3. Brought error texts together as macro definitions; clarified some of them;
1506
fixed one that was wrong - it said "range out of order" when it meant "invalid
1509
4. Changed some char * arguments to const char *.
1511
5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
1513
6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
1517
Version 0.96 16-Oct-97
1518
----------------------
1520
1. Added a simple "pgrep" utility to the distribution.
1522
2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
1523
unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
1524
where "ddd" means "one or more decimal digits".
1526
3. Fixed serious bug. If a pattern had a back reference, but the call to
1527
pcre_exec() didn't supply a large enough ovector to record the related
1528
identifying subpattern, the match always failed. PCRE now remembers the number
1529
of the largest back reference, and gets some temporary memory in which to save
1530
the offsets during matching if necessary, in order to ensure that
1531
backreferences always work.
1533
4. Increased the compatibility with Perl in a number of ways:
1535
(a) . no longer matches \n by default; an option PCRE_DOTALL is provided
1536
to request this handling. The option can be set at compile or exec time.
1538
(b) $ matches before a terminating newline by default; an option
1539
PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
1540
mode). The option can be set at compile or exec time.
1542
(c) The handling of \ followed by a digit other than 0 is now supposed to be
1543
the same as Perl's. If the decimal number it represents is less than 10
1544
or there aren't that many previous left capturing parentheses, an octal
1545
escape is read. Inside a character class, it's always an octal escape,
1546
even if it is a single digit.
1548
(d) An escaped but undefined alphabetic character is taken as a literal,
1549
unless PCRE_EXTRA is set. Currently this just reserves the remaining
1552
(e) {0} is now permitted. (The previous item is removed from the compiled
1555
5. Changed all the names of code files so that the basic parts are no longer
1556
than 10 characters, and abolished the teeny "globals.c" file.
1558
6. Changed the handling of character classes; they are now done with a 32-byte
1561
7. Added the -d and /D options to pcretest to make it possible to look at the
1562
internals of compilation without having to recompile pcre.
1565
Version 0.95 23-Sep-97
1566
----------------------
1568
1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
1569
\x20 at the start of a run of normal characters. These were being treated as
1570
real characters, instead of the source characters being re-checked.
1573
Version 0.94 18-Sep-97
1574
----------------------
1576
1. The functions are now thread-safe, with the caveat that the global variables
1577
containing pointers to malloc() and free() or alternative functions are the
1578
same for all threads.
1580
2. Get pcre_study() to generate a bitmap of initial characters for non-
1581
anchored patterns when this is possible, and use it if passed to pcre_exec().
1584
Version 0.93 15-Sep-97
1585
----------------------
1587
1. /(b)|(:+)/ was computing an incorrect first character.
1589
2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
1590
but not actually doing anything yet.
1592
3. Treat "-" characters in classes that cannot be part of ranges as literals,
1593
as Perl does (e.g. [-az] or [az-]).
1595
4. Set the anchored flag if a branch starts with .* or .*? because that tests
1596
all possible positions.
1598
5. Split up into different modules to avoid including unneeded functions in a
1599
compiled binary. However, compile and exec are still in one module. The "study"
1600
function is split off.
1602
6. The character tables are now in a separate module whose source is generated
1603
by an auxiliary program - but can then be edited by hand if required. There are
1604
now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
1605
toupper() in the code.
1607
7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
1608
make them global. Abolish the function for setting them, as the caller can now
1612
Version 0.92 11-Sep-97
1613
----------------------
1615
1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
1616
(e.g. /a{1,3}/) was broken (I mis-optimized it).
1618
2. Caseless matching was not working in character classes if the characters in
1619
the pattern were in upper case.
1621
3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
1623
4. Make PCRE_ANCHORED public and accept as a compile option.
1625
5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
1626
PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
1629
6. Give an error if bad option bits passed at compile or run time.
1631
7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
1632
pcretest to cause it to pass that flag.
1634
8. Add pcre_info(), to get the number of identifying subpatterns, the stored
1635
options, and the first character, if set.
1637
9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
1640
Version 0.91 10-Sep-97
1641
----------------------
1643
1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
1644
match the empty string as in /(a*)*/. It was looping and ultimately crashing.
1646
2. PCRE was looping on encountering an indefinitely repeated back reference to
1647
a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
1648
Perl does - treats the match as successful.
added
removed
srclib/pcre/ChangeLog
