ChangeLog for PCRE ------------------ Version 3.4 22-Aug-00 --------------------- 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *. 2. Diagnose condition (?(0) as an error instead of crashing on matching. Version 3.3 01-Aug-00 --------------------- 1. If an octal character was given, but the value was greater than \377, it was not getting masked to the least significant bits, as documented. This could lead to crashes in some systems. 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats the hyphen as a literal. PCRE used to give an error; it now behaves like Perl. 3. Added the functions pcre_free_substring() and pcre_free_substring_list(). These just pass their arguments on to (pcre_free)(), but they are provided because some uses of PCRE bind it to non-C systems that can call its functions, but cannot call free() or pcre_free() directly. 4. Add "make test" as a synonym for "make check". Corrected some comments in the Makefile. 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the Makefile. 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a command called pgrep for grepping around the active processes. 7. Added the beginnings of support for UTF-8 character strings. 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and RANLIB to ./ltconfig so that they are used by libtool. I think these are all the relevant ones. (AR is not passed because ./ltconfig does its own figuring out for the ar command.) Version 3.2 12-May-00 --------------------- This is purely a bug fixing release. 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead of ZA. This was just one example of several cases that could provoke this bug, which was introduced by change 9 of version 2.00. The code for breaking infinite loops after an iteration that matches an empty string was't working correctly. 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g when matched against abbab (for example). After matching an empty string, it wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this caused it to match further down the string than it should. 3. The code contained an inclusion of sys/types.h. It isn't clear why this was there because it doesn't seem to be needed, and it causes trouble on some systems, as it is not a Standard C header. It has been removed. 4. Made 4 silly changes to the source to avoid stupid compiler warnings that were reported on the Macintosh. The changes were from while ((c = *(++ptr)) != 0 && c != '\n'); to while ((c = *(++ptr)) != 0 && c != '\n') ; Totally extraordinary, but if that's what it takes... 5. PCRE is being used in one environment where neither memmove() nor bcopy() is available. Added HAVE_BCOPY and an autoconf test for it; if neither HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which assumes the way PCRE uses memmove() (always moving upwards). 6. PCRE is being used in one environment where strchr() is not available. There was only one use in pcre.c, and writing it out to avoid strchr() probably gives faster code anyway. Version 3.1 09-Feb-00 --------------------- The only change in this release is the fixing of some bugs in Makefile.in for the "install" target: (1) It was failing to install pcreposix.h. (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page. Version 3.0 01-Feb-00 --------------------- 1. Add support for the /+ modifier to perltest (to output $` like it does in pcretest). 2. Add support for the /g modifier to perltest. 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern matches null strings. 4. Fix perltest so that it doesn't do unwanted things when fed an empty pattern. Perl treats empty patterns specially - it reuses the most recent pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this effect. 5. The POSIX interface was broken in that it was just handing over the POSIX captured string vector to pcre_exec(), but (since release 2.00) PCRE has required a bigger vector, with some working space on the end. This means that the POSIX wrapper now has to get and free some memory, and copy the results. 6. Added some simple autoconf support, placing the test data and the documentation in separate directories, re-organizing some of the information files, and making it build pcre-config (a GNU standard). Also added libtool support for building PCRE as a shared library, which is now the default. 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and 09 are not valid octal constants. Single digits will be used for minor values less than 10. 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that existing programs that set these in the POSIX interface can use PCRE without modification. 9. Added a new function, pcre_fullinfo() with an extensible interface. It can return all that pcre_info() returns, plus additional data. The pcre_info() function is retained for compatibility, but is considered to be obsolete. 10. Added experimental recursion feature (?R) to handle one common case that Perl 5.6 will be able to do with (?p{...}). 11. Added support for POSIX character classes like [:alpha:], which Perl is adopting. Version 2.08 31-Aug-99 ---------------------- 1. When startoffset was not zero and the pattern began with ".*", PCRE was not trying to match at the startoffset position, but instead was moving forward to the next newline as if a previous match had failed. 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G, and could get into a loop if a null string was matched other than at the start of the subject. 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can be distinguished at compile time, and for completeness also added PCRE_DATE. 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL in GnuWin32 environments. Version 2.07 29-Jul-99 ---------------------- 1. The documentation is now supplied in plain text form and HTML as well as in the form of man page sources. 2. C++ compilers don't like assigning (void *) values to other pointer types. In particular this affects malloc(). Although there is no problem in Standard C, I've put in casts to keep C++ compilers happy. 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call should be (const char *). 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may be useful for non-Unix systems who don't want to bother with the POSIX stuff. However, I haven't made this a standard facility. The documentation doesn't mention it, and the Makefile doesn't support it. 5. The Makefile now contains an "install" target, with editable destinations at the top of the file. The pcretest program is not installed. 6. pgrep -V now gives the PCRE version number and date. 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was causing the entire string to be ignored, instead of just the last character. 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a non-matching string, it can take a very, very long time, even for strings of quite modest length, because of the nested recursion. PCRE now does better in some of these cases. It does this by remembering the last required literal character in the pattern, and pre-searching the subject to ensure it is present before running the real match. In other words, it applies a heuristic to detect some types of certain failure quickly, and in the above example, if presented with a string that has no trailing " it gives "no match" very quickly. 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored; other alternatives are tried instead. Version 2.06 09-Jun-99 ---------------------- 1. Change pcretest's output for amount of store used to show just the code space, because the remainder (the data block) varies in size between 32-bit and 64-bit systems. 2. Added an extra argument to pcre_exec() to supply an offset in the subject to start matching at. This allows lookbehinds to work when searching for multiple occurrences in a string. 3. Added additional options to pcretest for testing multiple occurrences: /+ outputs the rest of the string that follows a match /g loops for multiple occurrences, using the new startoffset argument /G loops for multiple occurrences by passing an incremented pointer 4. PCRE wasn't doing the "first character" optimization for patterns starting with \b or \B, though it was doing it for other lookbehind assertions. That is, it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with the letter 'x'. On long subject strings, this gives a significant speed-up. Version 2.05 21-Apr-99 ---------------------- 1. Changed the type of magic_number from int to long int so that it works properly on 16-bit systems. 2. Fixed a bug which caused patterns starting with .* not to work correctly when the subject string contained newline characters. PCRE was assuming anchoring for such patterns in all cases, which is not correct because .* will not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if DOTALL is set at top level; otherwise it knows that patterns starting with .* must be retried after every newline in the subject. Version 2.04 18-Feb-99 ---------------------- 1. For parenthesized subpatterns with repeats whose minimum was zero, the computation of the store needed to hold the pattern was incorrect (too large). If such patterns were nested a few deep, this could multiply and become a real problem. 2. Added /M option to pcretest to show the memory requirement of a specific pattern. Made -m a synonym of -s (which does this globally) for compatibility. 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being compiled in such a way that the backtracking after subsequent failure was pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size. Version 2.03 02-Feb-99 ---------------------- 1. Fixed typo and small mistake in man page. 2. Added 4th condition (GPL supersedes if conflict) and created separate LICENCE file containing the conditions. 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in Perl, that is the internal \ allows the delimiter to be included in the pattern. Locked out the use of \ as a delimiter. If \ immediately follows the final delimiter, add \ to the end of the pattern (to test the error). 4. Added the convenience functions for extracting substrings after a successful match. Updated pcretest to make it able to test these functions. Version 2.02 14-Jan-99 ---------------------- 1. Initialized the working variables associated with each extraction so that their saving and restoring doesn't refer to uninitialized store. 2. Put dummy code into study.c in order to trick the optimizer of the IBM C compiler for OS/2 into generating correct code. Apparently IBM isn't going to fix the problem. 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution calls, and wasn't printing the correct value for compiling calls. Increased the default value of LOOPREPEAT, and the number of significant figures in the times. 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT. 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid a building problem on Windows NT with a FAT file system. Version 2.01 21-Oct-98 ---------------------- 1. Changed the API for pcre_compile() to allow for the provision of a pointer to character tables built by pcre_maketables() in the current locale. If NULL is passed, the default tables are used. Version 2.00 24-Sep-98 ---------------------- 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable it any more. 2. Allow quantification of (?>) groups, and make it work correctly. 3. The first character computation wasn't working for (?>) groups. 4. Correct the implementation of \Z (it is permitted to match on the \n at the end of the subject) and add 5.005's \z, which really does match only at the very end of the subject. 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater. 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005 localized options. All options to pcre_study() were also removed. 7. Add other new features from 5.005: $(?<= positive lookbehind $(?a*))*/ (a PCRE_EXTRA facility). Version 1.00 18-Nov-97 ---------------------- 1. Added compile-time macros to support systems such as SunOS4 which don't have memmove() or strerror() but have other things that can be used instead. 2. Arranged that "make clean" removes the executables. Version 0.99 27-Oct-97 ---------------------- 1. Fixed bug in code for optimizing classes with only one character. It was initializing a 32-byte map regardless, which could cause it to run off the end of the memory it had got. 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction. Version 0.98 22-Oct-97 ---------------------- 1. Fixed bug in code for handling temporary memory usage when there are more back references than supplied space in the ovector. This could cause segfaults. Version 0.97 21-Oct-97 ---------------------- 1. Added the \X "cut" facility, conditional on PCRE_EXTRA. 2. Optimized negated single characters not to use a bit map. 3. Brought error texts together as macro definitions; clarified some of them; fixed one that was wrong - it said "range out of order" when it meant "invalid escape sequence". 4. Changed some char * arguments to const char *. 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX). 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in pcretest. Version 0.96 16-Oct-97 ---------------------- 1. Added a simple "pgrep" utility to the distribution. 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}" where "ddd" means "one or more decimal digits". 3. Fixed serious bug. If a pattern had a back reference, but the call to pcre_exec() didn't supply a large enough ovector to record the related identifying subpattern, the match always failed. PCRE now remembers the number of the largest back reference, and gets some temporary memory in which to save the offsets during matching if necessary, in order to ensure that backreferences always work. 4. Increased the compatibility with Perl in a number of ways: (a) . no longer matches \n by default; an option PCRE_DOTALL is provided to request this handling. The option can be set at compile or exec time. (b) $ matches before a terminating newline by default; an option PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline mode). The option can be set at compile or exec time. (c) The handling of \ followed by a digit other than 0 is now supposed to be the same as Perl's. If the decimal number it represents is less than 10 or there aren't that many previous left capturing parentheses, an octal escape is read. Inside a character class, it's always an octal escape, even if it is a single digit. (d) An escaped but undefined alphabetic character is taken as a literal, unless PCRE_EXTRA is set. Currently this just reserves the remaining escapes. (e) {0} is now permitted. (The previous item is removed from the compiled pattern). 5. Changed all the names of code files so that the basic parts are no longer than 10 characters, and abolished the teeny "globals.c" file. 6. Changed the handling of character classes; they are now done with a 32-byte bit map always. 7. Added the -d and /D options to pcretest to make it possible to look at the internals of compilation without having to recompile pcre. Version 0.95 23-Sep-97 ---------------------- 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or \x20 at the start of a run of normal characters. These were being treated as real characters, instead of the source characters being re-checked. Version 0.94 18-Sep-97 ---------------------- 1. The functions are now thread-safe, with the caveat that the global variables containing pointers to malloc() and free() or alternative functions are the same for all threads. 2. Get pcre_study() to generate a bitmap of initial characters for non- anchored patterns when this is possible, and use it if passed to pcre_exec(). Version 0.93 15-Sep-97 ---------------------- 1. /(b)|(:+)/ was computing an incorrect first character. 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(), but not actually doing anything yet. 3. Treat "-" characters in classes that cannot be part of ranges as literals, as Perl does (e.g. [-az] or [az-]). 4. Set the anchored flag if a branch starts with .* or .*? because that tests all possible positions. 5. Split up into different modules to avoid including unneeded functions in a compiled binary. However, compile and exec are still in one module. The "study" function is split off. 6. The character tables are now in a separate module whose source is generated by an auxiliary program - but can then be edited by hand if required. There are now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or toupper() in the code. 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and make them global. Abolish the function for setting them, as the caller can now set them directly. Version 0.92 11-Sep-97 ---------------------- 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character (e.g. /a{1,3}/) was broken (I mis-optimized it). 2. Caseless matching was not working in character classes if the characters in the pattern were in upper case. 3. Make ranges like [W-c] work in the same way as Perl for caseless matching. 4. Make PCRE_ANCHORED public and accept as a compile option. 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to pass them. 6. Give an error if bad option bits passed at compile or run time. 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to pcretest to cause it to pass that flag. 8. Add pcre_info(), to get the number of identifying subpatterns, the stored options, and the first character, if set. 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character. Version 0.91 10-Sep-97 ---------------------- 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could match the empty string as in /(a*)*/. It was looping and ultimately crashing. 2. PCRE was looping on encountering an indefinitely repeated back reference to a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what Perl does - treats the match as successful. ****