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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    
5    Version 3.0 01-Feb-00
6    ---------------------
7    
8    1. Add support for the /+ modifier to perltest (to output $` like it does in
9    pcretest).
10    
11    2. Add support for the /g modifier to perltest.
12    
13    3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
14    matches null strings.
15    
16    4. Fix perltest so that it doesn't do unwanted things when fed an empty
17    pattern. Perl treats empty patterns specially - it reuses the most recent
18    pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
19    effect.
20    
21    5. The POSIX interface was broken in that it was just handing over the POSIX
22    captured string vector to pcre_exec(), but (since release 2.00) PCRE has
23    required a bigger vector, with some working space on the end. This means that
24    the POSIX wrapper now has to get and free some memory, and copy the results.
25    
26    6. Added some simple autoconf support, placing the test data and the
27    documentation in separate directories, re-organizing some of the
28    information files, and making it build pcre-config (a GNU standard). Also added
29    libtool support for building PCRE as a shared library, which is now the
30    default.
31    
32    7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
33    09 are not valid octal constants. Single digits will be used for minor values
34    less than 10.
35    
36    8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
37    existing programs that set these in the POSIX interface can use PCRE without
38    modification.
39    
40    9. Added a new function, pcre_fullinfo() with an extensible interface. It can
41    return all that pcre_info() returns, plus additional data. The pcre_info()
42    function is retained for compatibility, but is considered to be obsolete.
43    
44    10. Added experimental recursion feature (?R) to handle one common case that
45    Perl 5.6 will be able to do with (?p{...}).
46    
47    11. Added support for POSIX character classes like [:alpha:], which Perl is
48    adopting.
49    
50    
51    Version 2.08 31-Aug-99
52    ----------------------
53    
54    1. When startoffset was not zero and the pattern began with ".*", PCRE was not
55    trying to match at the startoffset position, but instead was moving forward to
56    the next newline as if a previous match had failed.
57    
58    2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
59    and could get into a loop if a null string was matched other than at the start
60    of the subject.
61    
62    3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
63    be distinguished at compile time, and for completeness also added PCRE_DATE.
64    
65    5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
66    in GnuWin32 environments.
67    
68    
69    Version 2.07 29-Jul-99
70    ----------------------
71    
72    1. The documentation is now supplied in plain text form and HTML as well as in
73    the form of man page sources.
74    
75    2. C++ compilers don't like assigning (void *) values to other pointer types.
76    In particular this affects malloc(). Although there is no problem in Standard
77    C, I've put in casts to keep C++ compilers happy.
78    
79    3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
80    should be (const char *).
81    
82    4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
83    be useful for non-Unix systems who don't want to bother with the POSIX stuff.
84    However, I haven't made this a standard facility. The documentation doesn't
85    mention it, and the Makefile doesn't support it.
86    
87    5. The Makefile now contains an "install" target, with editable destinations at
88    the top of the file. The pcretest program is not installed.
89    
90    6. pgrep -V now gives the PCRE version number and date.
91    
92    7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
93    causing the entire string to be ignored, instead of just the last character.
94    
95    8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
96    non-matching string, it can take a very, very long time, even for strings of
97    quite modest length, because of the nested recursion. PCRE now does better in
98    some of these cases. It does this by remembering the last required literal
99    character in the pattern, and pre-searching the subject to ensure it is present
100    before running the real match. In other words, it applies a heuristic to detect
101    some types of certain failure quickly, and in the above example, if presented
102    with a string that has no trailing " it gives "no match" very quickly.
103    
104    9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
105    other alternatives are tried instead.
106    
107    
108    Version 2.06 09-Jun-99
109    ----------------------
110    
111    1. Change pcretest's output for amount of store used to show just the code
112    space, because the remainder (the data block) varies in size between 32-bit and
113    64-bit systems.
114    
115    2. Added an extra argument to pcre_exec() to supply an offset in the subject to
116    start matching at. This allows lookbehinds to work when searching for multiple
117    occurrences in a string.
118    
119    3. Added additional options to pcretest for testing multiple occurrences:
120    
121       /+   outputs the rest of the string that follows a match
122       /g   loops for multiple occurrences, using the new startoffset argument
123       /G   loops for multiple occurrences by passing an incremented pointer
124    
125    4. PCRE wasn't doing the "first character" optimization for patterns starting
126    with \b or \B, though it was doing it for other lookbehind assertions. That is,
127    it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
128    the letter 'x'. On long subject strings, this gives a significant speed-up.
129    
130    
131    Version 2.05 21-Apr-99
132    ----------------------
133    
134    1. Changed the type of magic_number from int to long int so that it works
135    properly on 16-bit systems.
136    
137    2. Fixed a bug which caused patterns starting with .* not to work correctly
138    when the subject string contained newline characters. PCRE was assuming
139    anchoring for such patterns in all cases, which is not correct because .* will
140    not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
141    DOTALL is set at top level; otherwise it knows that patterns starting with .*
142    must be retried after every newline in the subject.
143    
144    
145    Version 2.04 18-Feb-99
146    ----------------------
147    
148    1. For parenthesized subpatterns with repeats whose minimum was zero, the
149    computation of the store needed to hold the pattern was incorrect (too large).
150    If such patterns were nested a few deep, this could multiply and become a real
151    problem.
152    
153    2. Added /M option to pcretest to show the memory requirement of a specific
154    pattern. Made -m a synonym of -s (which does this globally) for compatibility.
155    
156    3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
157    compiled in such a way that the backtracking after subsequent failure was
158    pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
159    ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
160    
161    
162    Version 2.03 02-Feb-99
163    ----------------------
164    
165    1. Fixed typo and small mistake in man page.
166    
167    2. Added 4th condition (GPL supersedes if conflict) and created separate
168    LICENCE file containing the conditions.
169    
170    3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
171    Perl, that is the internal \ allows the delimiter to be included in the
172    pattern. Locked out the use of \ as a delimiter. If \ immediately follows
173    the final delimiter, add \ to the end of the pattern (to test the error).
174    
175    4. Added the convenience functions for extracting substrings after a successful
176    match. Updated pcretest to make it able to test these functions.
177    
178    
179    Version 2.02 14-Jan-99
180    ----------------------
181    
182    1. Initialized the working variables associated with each extraction so that
183    their saving and restoring doesn't refer to uninitialized store.
184    
185    2. Put dummy code into study.c in order to trick the optimizer of the IBM C
186    compiler for OS/2 into generating correct code. Apparently IBM isn't going to
187    fix the problem.
188    
189    3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
190    calls, and wasn't printing the correct value for compiling calls. Increased the
191    default value of LOOPREPEAT, and the number of significant figures in the
192    times.
193    
194    4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
195    
196    5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
197    a building problem on Windows NT with a FAT file system.
198    
199    
200    Version 2.01 21-Oct-98
201    ----------------------
202    
203    1. Changed the API for pcre_compile() to allow for the provision of a pointer
204    to character tables built by pcre_maketables() in the current locale. If NULL
205    is passed, the default tables are used.
206    
207    
208    Version 2.00 24-Sep-98
209    ----------------------
210    
211    1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
212    it any more.
213    
214    2. Allow quantification of (?>) groups, and make it work correctly.
215    
216    3. The first character computation wasn't working for (?>) groups.
217    
218    4. Correct the implementation of \Z (it is permitted to match on the \n at the
219    end of the subject) and add 5.005's \z, which really does match only at the
220    very end of the subject.
221    
222    5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
223    
224    6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
225    DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
226    localized options. All options to pcre_study() were also removed.
227    
228    7. Add other new features from 5.005:
229    
230       $(?<=           positive lookbehind
231       $(?<!           negative lookbehind
232       (?imsx-imsx)    added the unsetting capability
233                       such a setting is global if at outer level; local otherwise
234       (?imsx-imsx:)   non-capturing groups with option setting
235       (?(cond)re|re)  conditional pattern matching
236    
237       A backreference to itself in a repeated group matches the previous
238       captured string.
239    
240    8. General tidying up of studying (both automatic and via "study")
241    consequential on the addition of new assertions.
242    
243    9. As in 5.005, unlimited repeated groups that could match an empty substring
244    are no longer faulted at compile time. Instead, the loop is forcibly broken at
245    runtime if any iteration does actually match an empty substring.
246    
247    10. Include the RunTest script in the distribution.
248    
249    11. Added tests from the Perl 5.005_02 distribution. This showed up a few
250    discrepancies, some of which were old and were also with respect to 5.004. They
251    have now been fixed.
252    
253    
254    Version 1.09 28-Apr-98
255    ----------------------
256    
257    1. A negated single character class followed by a quantifier with a minimum
258    value of one (e.g.  [^x]{1,6}  ) was not compiled correctly. This could lead to
259    program crashes, or just wrong answers. This did not apply to negated classes
260    containing more than one character, or to minima other than one.
261    
262    
263    Version 1.08 27-Mar-98
264    ----------------------
265    
266    1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
267    
268    2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
269    latter must appear before anything that relies on it in the pattern.
270    
271    
272    Version 1.07 16-Feb-98
273    ----------------------
274    
275    1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
276    repeat of a potentially empty string).
277    
278    
279    Version 1.06 23-Jan-98
280    ----------------------
281    
282    1. Added Markus Oberhumer's little patches for C++.
283    
284    2. Literal strings longer than 255 characters were broken.
285    
286    
287    Version 1.05 23-Dec-97
288    ----------------------
289    
290    1. Negated character classes containing more than one character were failing if
291    PCRE_CASELESS was set at run time.
292    
293    
294    Version 1.04 19-Dec-97
295    ----------------------
296    
297    1. Corrected the man page, where some "const" qualifiers had been omitted.
298    
299    2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
300    input syntax.
301    
302    3. Fixed memory leak which occurred when a regex with back references was
303    matched with an offsets vector that wasn't big enough. The temporary memory
304    that is used in this case wasn't being freed if the match failed.
305    
306    4. Tidied pcretest to ensure it frees memory that it gets.
307    
308    5. Temporary memory was being obtained in the case where the passed offsets
309    vector was exactly big enough.
310    
311    6. Corrected definition of offsetof() from change 5 below.
312    
313    7. I had screwed up change 6 below and broken the rules for the use of
314    setjmp(). Now fixed.
315    
316    
317    Version 1.03 18-Dec-97
318    ----------------------
319    
320    1. A erroneous regex with a missing opening parenthesis was correctly
321    diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
322    on some systems.
323    
324    2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
325    it was reported that one broken compiler failed on the former because "code" is
326    also an independent variable.
327    
328    3. The erroneous regex a[]b caused an array overrun reference.
329    
330    4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
331    fail on data ending with that character. (It was going on too far, and checking
332    the next character, typically a binary zero.) This was specific to the
333    optimized code for single-character negative classes.
334    
335    5. Added a contributed patch from the TIN world which does the following:
336    
337      + Add an undef for memmove, in case the the system defines a macro for it.
338    
339      + Add a definition of offsetof(), in case there isn't one. (I don't know
340        the reason behind this - offsetof() is part of the ANSI standard - but
341        it does no harm).
342    
343      + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
344        most of the places where whitespace preceded '#'. I have given up and
345        allowed the remaining 2 cases to be at the margin.
346    
347      + Rename some variables in pcre to eliminate shadowing. This seems very
348        pedantic, but does no harm, of course.
349    
350    6. Moved the call to setjmp() into its own function, to get rid of warnings
351    from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
352    
353    7. Constructs such as \d{8,} were compiling into the equivalent of
354    \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
355    outcome, but in this particular case used more store than had been allocated,
356    which caused the bug to be discovered because it threw up an internal error.
357    
358    8. The debugging code in both pcre and pcretest for outputting the compiled
359    form of a regex was going wrong in the case of back references followed by
360    curly-bracketed repeats.
361    
362    
363    Version 1.02 12-Dec-97
364    ----------------------
365    
366    1. Typos in pcre.3 and comments in the source fixed.
367    
368    2. Applied a contributed patch to get rid of places where it used to remove
369    'const' from variables, and fixed some signed/unsigned and uninitialized
370    variable warnings.
371    
372    3. Added the "runtest" target to Makefile.
373    
374    4. Set default compiler flag to -O2 rather than just -O.
375    
376    
377    Version 1.01 19-Nov-97
378    ----------------------
379    
380    1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
381    like /([ab]*)*/, that is, for classes with more than one character in them.
382    
383    2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
384    as /((?>a*))*/ (a PCRE_EXTRA facility).
385    
386    
387    Version 1.00 18-Nov-97
388    ----------------------
389    
390    1. Added compile-time macros to support systems such as SunOS4 which don't have
391    memmove() or strerror() but have other things that can be used instead.
392    
393    2. Arranged that "make clean" removes the executables.
394    
395    
396  Version 0.99 27-Oct-97  Version 0.99 27-Oct-97
397  ----------------------  ----------------------
398    

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