ChangeLog for PCRE ------------------ Version 6.2 01-Aug-05 --------------------- 1. There was no test for integer overflow of quantifier values. A construction such as {1111111111111111} would give undefined results. What is worse, if a minimum quantifier for a parenthesized subpattern overflowed and became negative, the calculation of the memory size went wrong. This could have led to memory overwriting. 2. Building PCRE using VPATH was broken. Hopefully it is now fixed. 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like operating environments where this matters. 4. Applied Giuseppe Maxia's patch to add additional features for controlling PCRE options from within the C++ wrapper. 5. Named capturing subpatterns were not being correctly counted when a pattern was compiled. This caused two problems: (a) If there were more than 100 such subpatterns, the calculation of the memory needed for the whole compiled pattern went wrong, leading to an overflow error. (b) Numerical back references of the form \12, where the number was greater than 9, were not recognized as back references, even though there were sufficient previous subpatterns. 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older versions of gcc, e.g. 2.95.4. Version 6.1 21-Jun-05 --------------------- 1. There was one reference to the variable "posix" in pcretest.c that was not surrounded by "#if !defined NOPOSIX". 2. Make it possible to compile pcretest without DFA support, UTF8 support, or the cross-check on the old pcre_info() function, for the benefit of the cut-down version of PCRE that is currently imported into Exim. 3. A (silly) pattern starting with (?i)(?-i) caused an internal space allocation error. I've done the easy fix, which wastes 2 bytes for sensible patterns that start (?i) but I don't think that matters. The use of (?i) is just an example; this all applies to the other options as well. 4. Since libtool seems to echo the compile commands it is issuing, the output from "make" can be reduced a bit by putting "@" in front of each libtool compile command. 5. Patch from the folks at Google for configure.in to be a bit more thorough in checking for a suitable C++ installation before trying to compile the C++ stuff. This should fix a reported problem when a compiler was present, but no suitable headers. 6. The man pages all had just "PCRE" as their title. I have changed them to be the relevant file name. I have also arranged that these names are retained in the file doc/pcre.txt, which is a concatenation in text format of all the man pages except the little individual ones for each function. 7. The NON-UNIX-USE file had not been updated for the different set of source files that come with release 6. I also added a few comments about the C++ wrapper. Version 6.0 07-Jun-05 --------------------- 1. Some minor internal re-organization to help with my DFA experiments. 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that didn't matter for the library itself when fully configured, but did matter when compiling without UCP support, or within Exim, where the ucp files are not imported. 3. Refactoring of the library code to split up the various functions into different source modules. The addition of the new DFA matching code (see below) to a single monolithic source would have made it really too unwieldy, quite apart from causing all the code to be include in a statically linked application, when only some functions are used. This is relevant even without the DFA addition now that patterns can be compiled in one application and matched in another. The downside of splitting up is that there have to be some external functions and data tables that are used internally in different modules of the library but which are not part of the API. These have all had their names changed to start with "_pcre_" so that they are unlikely to clash with other external names. 4. Added an alternate matching function, pcre_dfa_exec(), which matches using a different (DFA) algorithm. Although it is slower than the original function, it does have some advantages for certain types of matching problem. 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(), including restarting after a partial match. 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not defined when compiling for Windows was sent to me. I have put it into the code, though I have no means of testing or verifying it. 7. Added the pcre_refcount() auxiliary function. 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to match before or at the first newline in the subject string. In pcretest, the /f option on a pattern can be used to set this. 9. A repeated \w when used in UTF-8 mode with characters greater than 256 would behave wrongly. This has been present in PCRE since release 4.0. 10. A number of changes to the pcregrep command: (a) Refactored how -x works; insert ^(...)$ instead of setting PCRE_ANCHORED and checking the length, in preparation for adding something similar for -w. (b) Added the -w (match as a word) option. (c) Refactored the way lines are read and buffered so as to have more than one at a time available. (d) Implemented a pcregrep test script. (e) Added the -M (multiline match) option. This allows patterns to match over several lines of the subject. The buffering ensures that at least 8K, or the rest of the document (whichever is the shorter) is available for matching (and similarly the previous 8K for lookbehind assertions). (f) Changed the --help output so that it now says -w, --word-regex(p) instead of two lines, one with "regex" and the other with "regexp" because that confused at least one person since the short forms are the same. (This required a bit of code, as the output is generated automatically from a table. It wasn't just a text change.) (g) -- can be used to terminate pcregrep options if the next thing isn't an option but starts with a hyphen. Could be a pattern or a path name starting with a hyphen, for instance. (h) "-" can be given as a file name to represent stdin. (i) When file names are being printed, "(standard input)" is used for the standard input, for compatibility with GNU grep. Previously "" was used. (j) The option --label=xxx can be used to supply a name to be used for stdin when file names are being printed. There is no short form. (k) Re-factored the options decoding logic because we are going to add two more options that take data. Such options can now be given in four different ways, e.g. "-fname", "-f name", "--file=name", "--file name". (l) Added the -A, -B, and -C options for requesting that lines of context around matches be printed. (m) Added the -L option to print the names of files that do not contain any matching lines, that is, the complement of -l. (n) The return code is 2 if any file cannot be opened, but pcregrep does continue to scan other files. (o) The -s option was incorrectly implemented. For compatibility with other greps, it now suppresses the error message for a non-existent or non- accessible file (but not the return code). There is a new option called -q that suppresses the output of matching lines, which was what -s was previously doing. (p) Added --include and --exclude options to specify files for inclusion and exclusion when recursing. 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly. Hopefully, it now does. 12. Missing cast in pcre_study(). 13. Added an "uninstall" target to the makefile. 14. Replaced "extern" in the function prototypes in Makefile.in with "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix world, but is set differently for Windows. 15. Added a second compiling function called pcre_compile2(). The only difference is that it has an extra argument, which is a pointer to an integer error code. When there is a compile-time failure, this is set non-zero, in addition to the error test pointer being set to point to an error message. The new argument may be NULL if no error number is required (but then you may as well call pcre_compile(), which is now just a wrapper). This facility is provided because some applications need a numeric error indication, but it has also enabled me to tidy up the way compile-time errors are handled in the POSIX wrapper. 16. Added VPATH=.libs to the makefile; this should help when building with one prefix path and installing with another. (Or so I'm told by someone who knows more about this stuff than I do.) 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This passes PCRE_DOTALL to the pcre_compile() function, making the "." character match everything, including newlines. This is not POSIX-compatible, but somebody wanted the feature. From pcretest it can be activated by using both the P and the s flags. 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one. 19. libpcre.pc was being incorrectly installed as executable. 20. A couple of places in pcretest check for end-of-line by looking for '\n'; it now also looks for '\r' so that it will work unmodified on Windows. 21. Added Google's contributed C++ wrapper to the distribution. 22. Added some untidy missing memory free() calls in pcretest, to keep Electric Fence happy when testing. Version 5.0 13-Sep-04 --------------------- 1. Internal change: literal characters are no longer packed up into items containing multiple characters in a single byte-string. Each character is now matched using a separate opcode. However, there may be more than one byte in the character in UTF-8 mode. 2. The pcre_callout_block structure has two new fields: pattern_position and next_item_length. These contain the offset in the pattern to the next match item, and its length, respectively. 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic insertion of callouts before each pattern item. Added the /C option to pcretest to make use of this. 4. On the advice of a Windows user, the lines #if defined(_WIN32) || defined(WIN32) _setmode( _fileno( stdout ), 0x8000 ); #endif /* defined(_WIN32) || defined(WIN32) */ have been added to the source of pcretest. This apparently does useful magic in relation to line terminators. 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb" for the benefit of those environments where the "b" makes a difference. 6. The icc compiler has the same options as gcc, but "configure" doesn't seem to know about it. I have put a hack into configure.in that adds in code to set GCC=yes if CC=icc. This seems to end up at a point in the generated configure script that is early enough to affect the setting of compiler options, which is what is needed, but I have no means of testing whether it really works. (The user who reported this had patched the generated configure script, which of course I cannot do.) LATER: After change 22 below (new libtool files), the configure script seems to know about icc (and also ecc). Therefore, I have commented out this hack in configure.in. 7. Added support for pkg-config (2 patches were sent in). 8. Negated POSIX character classes that used a combination of internal tables were completely broken. These were [[:^alpha:]], [[:^alnum:]], and [[:^ascii]]. Typically, they would match almost any characters. The other POSIX classes were not broken in this way. 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed to find the match, as PCRE was deluded into thinking that the match had to start at the start point or following a newline. The same bug applied to patterns with negative forward assertions or any backward assertions preceding ".*" at the start, unless the pattern required a fixed first character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed. 10. In UTF-8 mode, when moving forwards in the subject after a failed match starting at the last subject character, bytes beyond the end of the subject string were read. 11. Renamed the variable "class" as "classbits" to make life easier for C++ users. (Previously there was a macro definition, but it apparently wasn't enough.) 12. Added the new field "tables" to the extra data so that tables can be passed in at exec time, or the internal tables can be re-selected. This allows a compiled regex to be saved and re-used at a later time by a different program that might have everything at different addresses. 13. Modified the pcre-config script so that, when run on Solaris, it shows a -R library as well as a -L library. 14. The debugging options of pcretest (-d on the command line or D on a pattern) showed incorrect output for anything following an extended class that contained multibyte characters and which was followed by a quantifier. 15. Added optional support for general category Unicode character properties via the \p, \P, and \X escapes. Unicode property support implies UTF-8 support. It adds about 90K to the size of the library. The meanings of the inbuilt class escapes such as \d and \s have NOT been changed. 16. Updated pcredemo.c to include calls to free() to release the memory for the compiled pattern. 17. The generated file chartables.c was being created in the source directory instead of in the building directory. This caused the build to fail if the source directory was different from the building directory, and was read-only. 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE file. No doubt somebody will tell me if they don't make sense... Also added Dan Mooney's comments about building on OpenVMS. 19. Added support for partial matching via the PCRE_PARTIAL option for pcre_exec() and the \P data escape in pcretest. 20. Extended pcretest with 3 new pattern features: (i) A pattern option of the form ">rest-of-line" causes pcretest to write the compiled pattern to the file whose name is "rest-of-line". This is a straight binary dump of the data, with the saved pointer to the character tables forced to be NULL. The study data, if any, is written too. After writing, pcretest reads a new pattern. (ii) If, instead of a pattern, ": new target : new target : use native compiler : use native linker : handle Windows platform correctly : ditto : ditto copy DLL to top builddir before testing As part of these changes, -no-undefined was removed again. This was reported to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea in any case. 3. Some tidies to get rid of compiler warnings: . In the match_data structure, match_limit was an unsigned long int, whereas match_call_count was an int. I've made them both unsigned long ints. . In pcretest the fact that a const uschar * doesn't automatically cast to a void * provoked a warning. . Turning on some more compiler warnings threw up some "shadow" variables and a few more missing casts. 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8 option, a class that contained a single character with a value between 128 and 255 (e.g. /[\xFF]/) caused PCRE to crash. 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8 option, a class that contained several characters, but with at least one whose value was between 128 and 255 caused PCRE to crash. Version 4.1 12-Mar-03 --------------------- 1. Compiling with gcc -pedantic found a couple of places where casts were needed, and a string in dftables.c that was longer than standard compilers are required to support. 2. Compiling with Sun's compiler found a few more places where the code could be tidied up in order to avoid warnings. 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the first of these names is deprecated in the latest Autoconf in favour of the name CC_FOR_BUILD, because "host" is typically used to mean the system on which the compiled code will be run. I can't find a reference for HOST_CFLAGS, but by analogy I have changed it to CFLAGS_FOR_BUILD. 4. Added -no-undefined to the linking command in the Makefile, because this is apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the linking step for the pcreposix library. 5. PCRE was failing to diagnose the case of two named groups with the same name. 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a literal character that is needed in the subject for a match, and scans along to ensure that it is present before embarking on the full matching process. This saves time in cases of nested unlimited repeats that are never going to match. Problem: the scan can take a lot of time if the subject is very long (e.g. megabytes), thus penalizing straightforward matches. It is now done only if the amount of subject to be scanned is less than 1000 bytes. 7. A lesser problem with the same optimization is that it was recording the first character of an anchored pattern as "needed", thus provoking a search right along the subject, even when the first match of the pattern was going to fail. The "needed" character is now not set for anchored patterns, unless it follows something in the pattern that is of non-fixed length. Thus, it still fulfils its original purpose of finding quick non-matches in cases of nested unlimited repeats, but isn't used for simple anchored patterns such as /^abc/. Version 4.0 17-Feb-03 --------------------- 1. If a comment in an extended regex that started immediately after a meta-item extended to the end of string, PCRE compiled incorrect data. This could lead to all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not. 2. Moved to autoconf 2.53 and libtool 1.4.2. 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently, the special perltest8 script is no longer needed - all the tests can be run from a single perltest script. 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined by \s. It has now been removed in PCRE. This means it isn't recognized as whitespace in /x regexes too, which is the same as Perl. Note that the POSIX class [:space:] *does* include VT, thereby creating a mess. 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only space and tab. 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use its new features into the main test script, reducing the number of scripts. 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions were backward compatible, and made the (?i) apply to the whole pattern, as if /i were given. Now it behaves more logically, and applies the option setting only to what follows. PCRE has been changed to follow suit. However, if it finds options settings right at the start of the pattern, it extracts them into the global options, as before. Thus, they show up in the info data. 8. Added support for the \Q...\E escape sequence. Characters in between are treated as literals. This is slightly different from Perl in that $ and @ are also handled as literals inside the quotes. In Perl, they will cause variable interpolation. Note the following examples: Pattern PCRE matches Perl matches \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz \Qabc\$xyz\E abc\$xyz abc\$xyz \Qabc\E\$\Qxyz\E abc$xyz abc$xyz For compatibility with Perl, \Q...\E sequences are recognized inside character classes as well as outside them. 9. Re-organized 3 code statements in pcretest to avoid "overflow in floating-point constant arithmetic" warnings from a Microsoft compiler. Added a (size_t) cast to one statement in pcretest and one in pcreposix to avoid signed/unsigned warnings. 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o option for pcretest, so I've replaced it by a simple function that does just that job. 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or "pcregrep -". 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java package. This provides some syntactic sugar for simple cases of what my documentation calls "once-only subpatterns". A pattern such as x*+ is the same as (?>x*). In other words, if what is inside (?>...) is just a single repeated item, you can use this simplified notation. Note that only makes sense with greedy quantifiers. Consequently, the use of the possessive quantifier forces greediness, whatever the setting of the PCRE_UNGREEDY option. 13. A change of greediness default within a pattern was not taking effect at the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option was abstracted outside. 14. PCRE now supports the \G assertion. It is true when the current matching position is at the start point of the match. This differs from \A when the starting offset is non-zero. Used with the /g option of pcretest (or similar code), it works in the same way as it does for Perl's /g option. If all alternatives of a regex begin with \G, the expression is anchored to the start match position, and the "anchored" flag is set in the compiled expression. 15. Some bugs concerning the handling of certain option changes within patterns have been fixed. These applied to options other than (?ims). For example, "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have been the other way round. Some of this was related to change 7 above. 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/ and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports POSIX classes only within a class (e.g. /[[:alpha:]]/). 17. Added support for Perl's \C escape. This matches one byte, even in UTF8 mode. Unlike ".", it always matches newline, whatever the setting of PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind assertions. Perl allows it, but it doesn't (in general) work because it can't calculate the length of the lookbehind. At least, that's the case for Perl 5.8.0 - I've been told they are going to document that it doesn't work in future. 18. Added an error diagnosis for escapes that PCRE does not support: these are \L, \l, \N, \P, \p, \U, \u, and \X. 19. Although correctly diagnosing a missing ']' in a character class, PCRE was reading past the end of the pattern in cases such as /[abcd/. 20. PCRE was getting more memory than necessary for patterns with classes that contained both POSIX named classes and other characters, e.g. /[[:space:]abc/. 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for compiling PCRE for use with Virtual Pascal. 22. Small fix to the Makefile to make it work properly if the build is done outside the source tree. 23. Added a new extension: a condition to go with recursion. If a conditional subpattern starts with (?(R) the "true" branch is used if recursion has happened, whereas the "false" branch is used only at the top level. 24. When there was a very long string of literal characters (over 255 bytes without UTF support, over 250 bytes with UTF support), the computation of how much memory was required could be incorrect, leading to segfaults or other strange effects. 25. PCRE was incorrectly assuming anchoring (either to start of subject or to start of line for a non-DOTALL pattern) when a pattern started with (.*) and there was a subsequent back reference to those brackets. This meant that, for example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't possible to check for precisely this case. All we can do is abandon the optimization if .* occurs inside capturing brackets when there are any back references whatsoever. (See below for a better fix that came later.) 26. The handling of the optimization for finding the first character of a non-anchored pattern, and for finding a character that is required later in the match were failing in some cases. This didn't break the matching; it just failed to optimize when it could. The way this is done has been re-implemented. 27. Fixed typo in error message for invalid (?R item (it said "(?p"). 28. Added a new feature that provides some of the functionality that Perl provides with (?{...}). The facility is termed a "callout". The way it is done in PCRE is for the caller to provide an optional function, by setting pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a global variable. By default it is unset, which disables all calling out. To get the function called, the regex must include (?C) at appropriate points. This is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C). This provides a means of identifying different callout points. When PCRE reaches such a point in the regex, if pcre_callout has been set, the external function is called. It is provided with data in a structure called pcre_callout_block, which is defined in pcre.h. If the function returns 0, matching continues; if it returns a non-zero value, the match at the current point fails. However, backtracking will occur if possible. [This was changed later and other features added - see item 49 below.] 29. pcretest is upgraded to test the callout functionality. It provides a callout function that displays information. By default, it shows the start of the match and the current position in the text. There are some new data escapes to vary what happens: \C+ in addition, show current contents of captured substrings \C- do not supply a callout function \C!n return 1 when callout number n is reached \C!n!m return 1 when callout number n is reached for the mth time 30. If pcregrep was called with the -l option and just a single file name, it output "" if a match was found, instead of the file name. 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to pcre_exec(). This saves a malloc/free per call. The default value of POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold when configuring. 32. The default maximum size of a compiled pattern is 64K. There have been a few cases of people hitting this limit. The code now uses macros to handle the storing of links as offsets within the compiled pattern. It defaults to 2-byte links, but this can be changed to 3 or 4 bytes by --with-link-size when configuring. Tests 2 and 5 work only with 2-byte links because they output debugging information about compiled patterns. 33. Internal code re-arrangements: (a) Moved the debugging function for printing out a compiled regex into its own source file (printint.c) and used #include to pull it into pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two separate copies. (b) Defined the list of op-code names for debugging as a macro in internal.h so that it is next to the definition of the opcodes. (c) Defined a table of op-code lengths for simpler skipping along compiled code. This is again a macro in internal.h so that it is next to the definition of the opcodes. 34. Added support for recursive calls to individual subpatterns, along the lines of Robin Houston's patch (but implemented somewhat differently). 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to allow it to read and process whole directories in Win32. This code was contributed by Lionel Fourquaux; it has not been tested by me. 36. Added support for named subpatterns. The Python syntax (?P...) is used to name a group. Names consist of alphanumerics and underscores, and must be unique. Back references use the syntax (?P=name) and recursive calls use (?P>name) which is a PCRE extension to the Python extension. Groups still have numbers. The function pcre_fullinfo() can be used after compilation to extract a name/number map. There are three relevant calls: PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map PCRE_INFO_NAMECOUNT yields the number of entries PCRE_INFO_NAMETABLE yields a pointer to the map. The map is a vector of fixed-size entries. The size of each entry depends on the length of the longest name used. The first two bytes of each entry are the group number, most significant byte first. There follows the corresponding name, zero terminated. The names are in alphabetical order. 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8 case instead of 255. Making it the same both with and without UTF-8 support means that the same test output works with both. 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid calling malloc() with a zero argument. 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring optimization. I've improved things by keeping a bitmap of backreferences with numbers 1-31 so that if .* occurs inside capturing brackets that are not in fact referenced, the optimization can be applied. It is unlikely that a relevant occurrence of .* (i.e. one which might indicate anchoring or forcing the match to follow \n) will appear inside brackets with a number greater than 31, but if it does, any back reference > 31 suppresses the optimization. 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect of disabling numbered capturing parentheses. Any opening parenthesis that is not followed by ? behaves as if it were followed by ?: but named parentheses can still be used for capturing (and they will acquire numbers in the usual way). 41. Redesigned the return codes from the match() function into yes/no/error so that errors can be passed back from deep inside the nested calls. A malloc failure while inside a recursive subpattern call now causes the PCRE_ERROR_NOMEMORY return instead of quietly going wrong. 42. It is now possible to set a limit on the number of times the match() function is called in a call to pcre_exec(). This facility makes it possible to limit the amount of recursion and backtracking, though not in a directly obvious way, because the match() function is used in a number of different circumstances. The count starts from zero for each position in the subject string (for non-anchored patterns). The default limit is, for compatibility, a large number, namely 10 000 000. You can change this in two ways: (a) When configuring PCRE before making, you can use --with-match-limit=n to set a default value for the compiled library. (b) For each call to pcre_exec(), you can pass a pcre_extra block in which a different value is set. See 45 below. If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT. 43. Added a new function pcre_config(int, void *) to enable run-time extraction of things that can be changed at compile time. The first argument specifies what is wanted and the second points to where the information is to be placed. The current list of available information is: PCRE_CONFIG_UTF8 The output is an integer that is set to one if UTF-8 support is available; otherwise it is set to zero. PCRE_CONFIG_NEWLINE The output is an integer that it set to the value of the code that is used for newline. It is either LF (10) or CR (13). PCRE_CONFIG_LINK_SIZE The output is an integer that contains the number of bytes used for internal linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above. PCRE_CONFIG_POSIX_MALLOC_THRESHOLD The output is an integer that contains the threshold above which the POSIX interface uses malloc() for output vectors. See item 31 above. PCRE_CONFIG_MATCH_LIMIT The output is an unsigned integer that contains the default limit of the number of match() calls in a pcre_exec() execution. See 42 above. 44. pcretest has been upgraded by the addition of the -C option. This causes it to extract all the available output from the new pcre_config() function, and to output it. The program then exits immediately. 45. A need has arisen to pass over additional data with calls to pcre_exec() in order to support additional features. One way would have been to define pcre_exec2() (for example) with extra arguments, but this would not have been extensible, and would also have required all calls to the original function to be mapped to the new one. Instead, I have chosen to extend the mechanism that is used for passing in "extra" data from pcre_study(). The pcre_extra structure is now exposed and defined in pcre.h. It currently contains the following fields: flags a bitmap indicating which of the following fields are set study_data opaque data from pcre_study() match_limit a way of specifying a limit on match() calls for a specific call to pcre_exec() callout_data data for callouts (see 49 below) The flag bits are also defined in pcre.h, and are PCRE_EXTRA_STUDY_DATA PCRE_EXTRA_MATCH_LIMIT PCRE_EXTRA_CALLOUT_DATA The pcre_study() function now returns one of these new pcre_extra blocks, with the actual study data pointed to by the study_data field, and the PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as before. That is, this change is entirely upwards-compatible and requires no change to existing code. If you want to pass in additional data to pcre_exec(), you can either place it in a pcre_extra block provided by pcre_study(), or create your own pcre_extra block. 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a data string contains the escape sequence \M, pcretest calls pcre_exec() several times with different match limits, until it finds the minimum value needed for pcre_exec() to complete. The value is then output. This can be instructive; for most simple matches the number is quite small, but for pathological cases it gets very large very quickly. 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It returns the size of the data block pointed to by the study_data field in a pcre_extra block, that is, the value that was passed as the argument to pcre_malloc() when PCRE was getting memory in which to place the information created by pcre_study(). The fourth argument should point to a size_t variable. pcretest has been extended so that this information is shown after a successful pcre_study() call when information about the compiled regex is being displayed. 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR) because what follows is always an absolute path. (Later: it turns out that this is more than cosmetic for MinGW, because it doesn't like empty path components.) 49. Some changes have been made to the callout feature (see 28 above): (i) A callout function now has three choices for what it returns: 0 => success, carry on matching > 0 => failure at this point, but backtrack if possible < 0 => serious error, return this value from pcre_exec() Negative values should normally be chosen from the set of PCRE_ERROR_xxx values. In particular, returning PCRE_ERROR_NOMATCH forces a standard "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for use by callout functions. It will never be used by PCRE itself. (ii) The pcre_extra structure (see 45 above) has a void * field called callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The pcre_callout_block structure has a field of the same name. The contents of the field passed in the pcre_extra structure are passed to the callout function in the corresponding field in the callout block. This makes it easier to use the same callout-containing regex from multiple threads. For testing, the pcretest program has a new data escape \C*n pass the number n (may be negative) as callout_data If the callout function in pcretest receives a non-zero value as callout_data, it returns that value. 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also, there were some redundant $(CFLAGS) in commands that are now specified as $(LINK), which already includes $(CFLAGS). 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE has been compiled with UTF-8 support *and* pcre_compile() has been compiled with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume one-byte characters throughout. Note that case-insensitive matching applies only to characters whose values are less than 256. PCRE doesn't support the notion of cases for higher-valued characters. (i) A character class whose characters are all within 0-255 is handled as a bit map, and the map is inverted for negative classes. Previously, a character > 255 always failed to match such a class; however it should match if the class was a negative one (e.g. [^ab]). This has been fixed. (ii) A negated character class with a single character < 255 is coded as "not this character" (OP_NOT). This wasn't working properly when the test character was multibyte, either singly or repeated. (iii) Repeats of multibyte characters are now handled correctly in UTF-8 mode, for example: \x{100}{2,3}. (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either singly or repeated) now correctly test multibyte characters. However, PCRE doesn't recognize any characters with values greater than 255 as digits, spaces, or word characters. Such characters always match \D, \S, and \W, and never match \d, \s, or \w. (v) Classes may now contain characters and character ranges with values greater than 255. For example: [ab\x{100}-\x{400}]. (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call PCRE in UTF-8 mode. 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is retained for backwards compatibility. (Note that LASTLITERAL is also a byte value.) 53. The single man page has become too large. I have therefore split it up into a number of separate man pages. These also give rise to individual HTML pages; these are now put in a separate directory, and there is an index.html page that lists them all. Some hyperlinking between the pages has been installed. 54. Added convenience functions for handling named capturing parentheses. 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also true in PCRE, except when the PCRE_EXTENDED option is set, in which case they are faulted. 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when calling configure. These values are used when compiling the dftables.c program which is run to generate the source of the default character tables. They default to the values of CC and CFLAGS. If you are cross-compiling PCRE, you will need to set these values. 57. Updated the building process for Windows DLL, as provided by Fred Cox. Version 3.9 02-Jan-02 --------------------- 1. A bit of extraneous text had somehow crept into the pcregrep documentation. 2. If --disable-static was given, the building process failed when trying to build pcretest and pcregrep. (For some reason it was using libtool to compile them, which is not right, as they aren't part of the library.) Version 3.8 18-Dec-01 --------------------- 1. The experimental UTF-8 code was completely screwed up. It was packing the bytes in the wrong order. How dumb can you get? Version 3.7 29-Oct-01 --------------------- 1. In updating pcretest to check change 1 of version 3.6, I screwed up. This caused pcretest, when used on the test data, to segfault. Unfortunately, this didn't happen under Solaris 8, where I normally test things. 2. The Makefile had to be changed to make it work on BSD systems, where 'make' doesn't seem to recognize that ./xxx and xxx are the same file. (This entry isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made this fix an hour or so after the initial 3.7 release.) Version 3.6 23-Oct-01 --------------------- 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if offsets passed as NULL with zero offset count. 2. The config.guess and config.sub files had not been updated when I moved to the latest autoconf. Version 3.5 15-Aug-01 --------------------- 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that had been forgotten. 2. By using declared but undefined structures, we can avoid using "void" definitions in pcre.h while keeping the internal definitions of the structures private. 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a user point of view, this means that both static and shared libraries are built by default, but this can be individually controlled. More of the work of handling this static/shared cases is now inside libtool instead of PCRE's make file. 4. The pcretest utility is now installed along with pcregrep because it is useful for users (to test regexs) and by doing this, it automatically gets relinked by libtool. The documentation has been turned into a man page, so there are now .1, .txt, and .html versions in /doc. 5. Upgrades to pcregrep: (i) Added long-form option names like gnu grep. (ii) Added --help to list all options with an explanatory phrase. (iii) Added -r, --recursive to recurse into sub-directories. (iv) Added -f, --file to read patterns from a file. 6. pcre_exec() was referring to its "code" argument before testing that argument for NULL (and giving an error if it was NULL). 7. Upgraded Makefile.in to allow for compiling in a different directory from the source directory. 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the options bits, the pointer it was passed was to an int instead of to an unsigned long int. This mattered only on 64-bit systems. 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is generated) instead of pcre.in, which it its source. Also made the same change in several of the .c files. 10. A new release of gcc defines printf() as a macro, which broke pcretest because it had an ifdef in the middle of a string argument for printf(). Fixed by using separate calls to printf(). 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure script, to force use of CR or LF instead of \n in the source. On non-Unix systems, the value can be set in config.h. 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an absolute limit. Changed the text of the error message to make this clear, and likewise updated the man page. 13. The limit of 99 on the number of capturing subpatterns has been removed. The new limit is 65535, which I hope will not be a "real" limit. 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. ****