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 News about PCRE releases
 ------------------------

 Release 5.0 13-Sep-04
 ---------------------

 The licence under which PCRE is released has been changed to the more
 conventional "BSD" licence.

 In the code, some bugs have been fixed, and there are also some major changes
 in this release (which is why I've increased the number to 5.0). Some changes
 are internal rearrangements, and some provide a number of new facilities. The
 new features are:

 1. There's an "automatic callout" feature that inserts callouts before every
    item in the regex, and there's a new callout field that gives the position
    in the pattern - useful for debugging and tracing.

 2. The extra_data structure can now be used to pass in a set of character
    tables at exec time. This is useful if compiled regex are saved and re-used
    at a later time when the tables may not be at the same address. If the
    default internal tables are used, the pointer saved with the compiled
    pattern is now set to NULL, which means that you don't need to do anything
    special unless you are using custom tables.

 3. It is possible, with some restrictions on the content of the regex, to
    request "partial" matching. A special return code is given if all of the
    subject string matched part of the regex. This could be useful for testing
    an input field as it is being typed.

 4. There is now some optional support for Unicode character properties, which
    means that the patterns items such as \p{Lu} and \X can now be used. Only
    the general category properties are supported. If PCRE is compiled with this
    support, an additional 90K data structure is include, which increases the
    size of the library dramatically.

 5. There is support for saving compiled patterns and re-using them later.

 6. There is support for running regular expressions that were compiled on a
    different host with the opposite endianness.

 7. The pcretest program has been extended to accommodate the new features.

 The main internal rearrangement is that sequences of literal characters are no
 longer handled as strings. Instead, each character is handled on its own. This
 makes some UTF-8 handling easier, and makes the support of partial matching
 possible. Compiled patterns containing long literal strings will be larger as a
 result of this change; I hope that performance will not be much affected.


 Release 4.5 01-Dec-03
 ---------------------

 Again mainly a bug-fix and tidying release, with only a couple of new features:

 1. It's possible now to compile PCRE so that it does not use recursive
 function calls when matching. Instead it gets memory from the heap. This slows
 things down, but may be necessary on systems with limited stacks.

 2. UTF-8 string checking has been tightened to reject overlong sequences and to
 check that a starting offset points to the start of a character. Failure of the
 latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.

 3. PCRE can now be compiled for systems that use EBCDIC code.


 Release 4.4 21-Aug-03
 ---------------------

 This is mainly a bug-fix and tidying release. The only new feature is that PCRE
 checks UTF-8 strings for validity by default. There is an option to suppress
 this, just in case anybody wants that teeny extra bit of performance.


 Releases 4.1 - 4.3
 ------------------

 Sorry, I forgot about updating the NEWS file for these releases. Please take a
 look at ChangeLog.


 Release 4.0 17-Feb-03
 ---------------------

 There have been a lot of changes for the 4.0 release, adding additional
 functionality and mending bugs. Below is a list of the highlights of the new
 functionality. For full details of these features, please consult the
 documentation. For a complete list of changes, see the ChangeLog file.

 1. Support for Perl's \Q...\E escapes.

 2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
 package. They provide some syntactic sugar for simple cases of "atomic
 grouping".

 3. Support for the \G assertion. It is true when the current matching position
 is at the start point of the match.

 4. 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. To get the function called, the regex must include (?C) at
 appropriate points.

 5. Support for recursive calls to individual subpatterns. This makes it really
 easy to get totally confused.

 6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
 name a group.

 7. Several extensions to UTF-8 support; it is now fairly complete. There is an
 option for pcregrep to make it operate in UTF-8 mode.

 8. The single man page has been split into a number of separate man pages.
 These also give rise to individual HTML pages which are put in a separate
 directory. There is an index.html page that lists them all. Some hyperlinking
 between the pages has been installed.


 Release 3.5 15-Aug-01
 ---------------------

 1. The configuring system has been upgraded to use later versions of autoconf
 and libtool. By default it builds both a shared and a static library if the OS
 supports it. You can use --disable-shared or --disable-static on the configure
 command if you want only one of them.

 2. 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.

 3. 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.

 4. 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.

 5. 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.

 6. 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.


 Release 3.3 01-Aug-00
 ---------------------

 There is some support for UTF-8 character strings. This is incomplete and
 experimental. The documentation describes what is and what is not implemented.
 Otherwise, this is just a bug-fixing release.


 Release 3.0 01-Feb-00
 ---------------------

 1. A "configure" script is now used to configure PCRE for Unix systems. It
 builds a Makefile, a config.h file, and the pcre-config script.

 2. PCRE is built as a shared library by default.

 3. There is support for POSIX classes such as [:alpha:].

 5. There is an experimental recursion feature.

 ----------------------------------------------------------------------------
           IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00

 Please note that there has been a change in the API such that a larger
 ovector is required at matching time, to provide some additional workspace.
 The new man page has details. This change was necessary in order to support
 some of the new functionality in Perl 5.005.

           IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.00

 Another (I hope this is the last!) change has been made to the API for the
 pcre_compile() function. An additional argument has been added to make it
 possible to pass over a pointer to character tables built in the current
 locale by pcre_maketables(). To use the default tables, this new arguement
 should be passed as NULL.

           IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.05

 Yet another (and again I hope this really is the last) change has been made
 to the API for the pcre_exec() function. An additional argument has been
 added to make it possible to start the match other than at the start of the
 subject string. This is important if there are lookbehinds. The new man
 page has the details, but you just want to convert existing programs, all
 you need to do is to stick in a new fifth argument to pcre_exec(), with a
 value of zero. For example, change

   pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
 to
   pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)

 ****
	News about PCRE releases
	------------------------

	Release 5.0 13-Sep-04
	---------------------

	The licence under which PCRE is released has been changed to the more
	conventional "BSD" licence.

	In the code, some bugs have been fixed, and there are also some major changes
	in this release (which is why I've increased the number to 5.0). Some changes
	are internal rearrangements, and some provide a number of new facilities. The
	new features are:

	1. There's an "automatic callout" feature that inserts callouts before every
	item in the regex, and there's a new callout field that gives the position
	in the pattern - useful for debugging and tracing.

	2. The extra_data structure can now be used to pass in a set of character
	tables at exec time. This is useful if compiled regex are saved and re-used
	at a later time when the tables may not be at the same address. If the
	default internal tables are used, the pointer saved with the compiled
	pattern is now set to NULL, which means that you don't need to do anything
	special unless you are using custom tables.

	3. It is possible, with some restrictions on the content of the regex, to
	request "partial" matching. A special return code is given if all of the
	subject string matched part of the regex. This could be useful for testing
	an input field as it is being typed.

	4. There is now some optional support for Unicode character properties, which
	means that the patterns items such as \p{Lu} and \X can now be used. Only
	the general category properties are supported. If PCRE is compiled with this
	support, an additional 90K data structure is include, which increases the
	size of the library dramatically.

	5. There is support for saving compiled patterns and re-using them later.

	6. There is support for running regular expressions that were compiled on a
	different host with the opposite endianness.

	7. The pcretest program has been extended to accommodate the new features.

	The main internal rearrangement is that sequences of literal characters are no
	longer handled as strings. Instead, each character is handled on its own. This
	makes some UTF-8 handling easier, and makes the support of partial matching
	possible. Compiled patterns containing long literal strings will be larger as a
	result of this change; I hope that performance will not be much affected.


	Release 4.5 01-Dec-03
	---------------------

	Again mainly a bug-fix and tidying release, with only a couple of new features:

	1. It's possible now to compile PCRE so that it does not use recursive
	function calls when matching. Instead it gets memory from the heap. This slows
	things down, but may be necessary on systems with limited stacks.

	2. UTF-8 string checking has been tightened to reject overlong sequences and to
	check that a starting offset points to the start of a character. Failure of the
	latter returns a new error code: PCRE_ERROR_BADUTF8_OFFSET.

	3. PCRE can now be compiled for systems that use EBCDIC code.


	Release 4.4 21-Aug-03
	---------------------

	This is mainly a bug-fix and tidying release. The only new feature is that PCRE
	checks UTF-8 strings for validity by default. There is an option to suppress
	this, just in case anybody wants that teeny extra bit of performance.


	Releases 4.1 - 4.3
	------------------

	Sorry, I forgot about updating the NEWS file for these releases. Please take a
	look at ChangeLog.


	Release 4.0 17-Feb-03
	---------------------

	There have been a lot of changes for the 4.0 release, adding additional
	functionality and mending bugs. Below is a list of the highlights of the new
	functionality. For full details of these features, please consult the
	documentation. For a complete list of changes, see the ChangeLog file.

	1. Support for Perl's \Q...\E escapes.

	2. "Possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's Java
	package. They provide some syntactic sugar for simple cases of "atomic
	grouping".

	3. Support for the \G assertion. It is true when the current matching position
	is at the start point of the match.

	4. 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. To get the function called, the regex must include (?C) at
	appropriate points.

	5. Support for recursive calls to individual subpatterns. This makes it really
	easy to get totally confused.

	6. Support for named subpatterns. The Python syntax (?P<name>...) is used to
	name a group.

	7. Several extensions to UTF-8 support; it is now fairly complete. There is an
	option for pcregrep to make it operate in UTF-8 mode.

	8. The single man page has been split into a number of separate man pages.
	These also give rise to individual HTML pages which are put in a separate
	directory. There is an index.html page that lists them all. Some hyperlinking
	between the pages has been installed.


	Release 3.5 15-Aug-01
	---------------------

	1. The configuring system has been upgraded to use later versions of autoconf
	and libtool. By default it builds both a shared and a static library if the OS
	supports it. You can use --disable-shared or --disable-static on the configure
	command if you want only one of them.

	2. 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.

	3. 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.

	4. 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.

	5. 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.

	6. 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.


	Release 3.3 01-Aug-00
	---------------------

	There is some support for UTF-8 character strings. This is incomplete and
	experimental. The documentation describes what is and what is not implemented.
	Otherwise, this is just a bug-fixing release.


	Release 3.0 01-Feb-00
	---------------------

	1. A "configure" script is now used to configure PCRE for Unix systems. It
	builds a Makefile, a config.h file, and the pcre-config script.

	2. PCRE is built as a shared library by default.

	3. There is support for POSIX classes such as [:alpha:].

	5. There is an experimental recursion feature.

	----------------------------------------------------------------------------
	IMPORTANT FOR THOSE UPGRADING FROM VERSIONS BEFORE 2.00

	Please note that there has been a change in the API such that a larger
	ovector is required at matching time, to provide some additional workspace.
	The new man page has details. This change was necessary in order to support
	some of the new functionality in Perl 5.005.

	IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.00

	Another (I hope this is the last!) change has been made to the API for the
	pcre_compile() function. An additional argument has been added to make it
	possible to pass over a pointer to character tables built in the current
	locale by pcre_maketables(). To use the default tables, this new arguement
	should be passed as NULL.

	IMPORTANT FOR THOSE UPGRADING FROM VERSION 2.05

	Yet another (and again I hope this really is the last) change has been made
	to the API for the pcre_exec() function. An additional argument has been
	added to make it possible to start the match other than at the start of the
	subject string. This is important if there are lookbehinds. The new man
	page has the details, but you just want to convert existing programs, all
	you need to do is to stick in a new fifth argument to pcre_exec(), with a
	value of zero. For example, change

	pcre_exec(pattern, extra, subject, length, options, ovec, ovecsize)
	to
	pcre_exec(pattern, extra, subject, length, 0, options, ovec, ovecsize)

	****