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

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