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PCRE(3)			   Library Functions Manual		       PCRE(3)

NAME
       PCRE - Perl-compatible regular expressions

       #include	<pcre.h>

PCRE 16-BIT API	BASIC FUNCTIONS
       pcre16 *pcre16_compile(PCRE_SPTR16 pattern, int options,
	    const char **errptr, int *erroffset,
	    const unsigned char	*tableptr);

       pcre16 *pcre16_compile2(PCRE_SPTR16 pattern, int	options,
	    int	*errorcodeptr,
	    const char **errptr, int *erroffset,
	    const unsigned char	*tableptr);

       pcre16_extra *pcre16_study(const	pcre16 *code, int options,
	    const char **errptr);

       void pcre16_free_study(pcre16_extra *extra);

       int pcre16_exec(const pcre16 *code, const pcre16_extra *extra,
	    PCRE_SPTR16	subject, int length, int startoffset,
	    int	options, int *ovector, int ovecsize);

       int pcre16_dfa_exec(const pcre16	*code, const pcre16_extra *extra,
	    PCRE_SPTR16	subject, int length, int startoffset,
	    int	options, int *ovector, int ovecsize,
	    int	*workspace, int	wscount);

PCRE 16-BIT API	STRING EXTRACTION FUNCTIONS
       int pcre16_copy_named_substring(const pcre16 *code,
	    PCRE_SPTR16	subject, int *ovector,
	    int	stringcount, PCRE_SPTR16 stringname,
	    PCRE_UCHAR16 *buffer, int buffersize);

       int pcre16_copy_substring(PCRE_SPTR16 subject, int *ovector,
	    int	stringcount, int stringnumber, PCRE_UCHAR16 *buffer,
	    int	buffersize);

       int pcre16_get_named_substring(const pcre16 *code,
	    PCRE_SPTR16	subject, int *ovector,
	    int	stringcount, PCRE_SPTR16 stringname,
	    PCRE_SPTR16	*stringptr);

       int pcre16_get_stringnumber(const pcre16	*code,
	    PCRE_SPTR16	name);

       int pcre16_get_stringtable_entries(const	pcre16 *code,
	    PCRE_SPTR16	name, PCRE_UCHAR16 **first, PCRE_UCHAR16 **last);

       int pcre16_get_substring(PCRE_SPTR16 subject, int *ovector,
	    int	stringcount, int stringnumber,
	    PCRE_SPTR16	*stringptr);

       int pcre16_get_substring_list(PCRE_SPTR16 subject,
	    int	*ovector, int stringcount, PCRE_SPTR16 **listptr);

       void pcre16_free_substring(PCRE_SPTR16 stringptr);

       void pcre16_free_substring_list(PCRE_SPTR16 *stringptr);

PCRE 16-BIT API	AUXILIARY FUNCTIONS
       pcre16_jit_stack	*pcre16_jit_stack_alloc(int startsize, int maxsize);

       void pcre16_jit_stack_free(pcre16_jit_stack *stack);

       void pcre16_assign_jit_stack(pcre16_extra *extra,
	    pcre16_jit_callback	callback, void *data);

       const unsigned char *pcre16_maketables(void);

       int pcre16_fullinfo(const pcre16	*code, const pcre16_extra *extra,
	    int	what, void *where);

       int pcre16_refcount(pcre16 *code, int adjust);

       int pcre16_config(int what, void	*where);

       const char *pcre16_version(void);

       int pcre16_pattern_to_host_byte_order(pcre16 *code,
	    pcre16_extra *extra, const unsigned	char *tables);

PCRE 16-BIT API	INDIRECTED FUNCTIONS
       void *(*pcre16_malloc)(size_t);

       void (*pcre16_free)(void	*);

       void *(*pcre16_stack_malloc)(size_t);

       void (*pcre16_stack_free)(void *);

       int (*pcre16_callout)(pcre16_callout_block *);

PCRE 16-BIT API	16-BIT-ONLY FUNCTION
       int pcre16_utf16_to_host_byte_order(PCRE_UCHAR16	*output,
	    PCRE_SPTR16	input, int length, int *byte_order,
	    int	keep_boms);

THE PCRE 16-BIT	LIBRARY
       Starting	 with  release	8.30, it is possible to	compile	a PCRE library
       that supports 16-bit character strings, including  UTF-16  strings,  as
       well  as	 or instead of the original 8-bit library. The majority	of the
       work to make this possible was done by  Zoltan  Herczeg.	 The  two  li-
       braries	contain	 identical sets	of functions, used in exactly the same
       way. Only the names of the functions and	the data types of their	 argu-
       ments  and results are different. To avoid over-complication and	reduce
       the documentation maintenance load, most	of the PCRE documentation  de-
       scribes	the  8-bit  library,  with  only  occasional references	to the
       16-bit library. This page describes what	is different when you use  the
       16-bit library.

       WARNING:	 A  single  application	can be linked with both	libraries, but
       you must	take care when processing any particular pattern to use	 func-
       tions  from  just one library. For example, if you want to study	a pat-
       tern that was compiled with  pcre16_compile(),  you  must  do  so  with
       pcre16_study(), not pcre_study(), and you must free the study data with
       pcre16_free_study().

THE HEADER FILE
       There is	only one header	file, pcre.h. It contains prototypes  for  all
       the functions in	all libraries, as well as definitions of flags,	struc-
       tures, error codes, etc.

THE LIBRARY NAME
       In Unix-like systems, the 16-bit	library	is called libpcre16,  and  can
       normally	 be  accesss  by adding	-lpcre16 to the	command	for linking an
       application that	uses PCRE.

STRING TYPES
       In the 8-bit library, strings are passed	to PCRE	library	 functions  as
       vectors	of  bytes  with	 the  C	 type "char *".	In the 16-bit library,
       strings are passed as vectors of	unsigned 16-bit	quantities. The	 macro
       PCRE_UCHAR16 specifies an appropriate data type,	and PCRE_SPTR16	is de-
       fined as	"const PCRE_UCHAR16 *".	In very	many environments, "short int"
       is  a  16-bit data type.	When PCRE is built, it defines PCRE_UCHAR16 as
       "unsigned short int", but checks	that it	really is a 16-bit data	 type.
       If  it  is not, the build fails with an error message telling the main-
       tainer to modify	the definition appropriately.

STRUCTURE TYPES
       The types of the	opaque structures that are used	 for  compiled	16-bit
       patterns	 and  JIT stacks are pcre16 and	pcre16_jit_stack respectively.
       The  type  of  the  user-accessible  structure  that  is	 returned   by
       pcre16_study()  is  pcre16_extra, and the type of the structure that is
       used for	passing	data to	a callout  function  is	 pcre16_callout_block.
       These structures	contain	the same fields, with the same names, as their
       8-bit counterparts. The only difference is that pointers	 to  character
       strings are 16-bit instead of 8-bit types.

16-BIT FUNCTIONS
       For  every function in the 8-bit	library	there is a corresponding func-
       tion in the 16-bit library with a name that starts with pcre16_ instead
       of  pcre_.  The	prototypes are listed above. In	addition, there	is one
       extra function, pcre16_utf16_to_host_byte_order(). This	is  a  utility
       function	 that converts a UTF-16	character string to host byte order if
       necessary. The other 16-bit  functions  expect  the  strings  they  are
       passed to be in host byte order.

       The input and output arguments of pcre16_utf16_to_host_byte_order() may
       point to	the same address, that is, conversion in place	is  supported.
       The output buffer must be at least as long as the input.

       The  length  argument  specifies	the number of 16-bit data units	in the
       input string; a negative	value specifies	a zero-terminated string.

       If byte_order is	NULL, it is assumed that the string starts off in host
       byte  order. This may be	changed	by byte-order marks (BOMs) anywhere in
       the string (commonly as the first character).

       If byte_order is	not NULL, a non-zero value of the integer to which  it
       points  means  that  the	input starts off in host byte order, otherwise
       the opposite order is assumed. Again, BOMs in  the  string  can	change
       this. The final byte order is passed back at the	end of processing.

       If  keep_boms  is  not  zero,  byte-order  mark characters (0xfeff) are
       copied into the output string. Otherwise	they are discarded.

       The result of the function is the number	of 16-bit  units  placed  into
       the  output  buffer,  including	the  zero terminator if	the string was
       zero-terminated.

SUBJECT	STRING OFFSETS
       The lengths and starting	offsets	of subject strings must	 be  specified
       in  16-bit  data	units, and the offsets within subject strings that are
       returned	by the matching	functions are in also 16-bit units rather than
       bytes.

NAMED SUBPATTERNS
       The  name-to-number translation table that is maintained	for named sub-
       patterns	uses 16-bit characters.	 The  pcre16_get_stringtable_entries()
       function	returns	the length of each entry in the	table as the number of
       16-bit data units.

OPTION NAMES
       There   are   two   new	 general   option   names,   PCRE_UTF16	   and
       PCRE_NO_UTF16_CHECK,	which	  correspond	to    PCRE_UTF8	   and
       PCRE_NO_UTF8_CHECK in the 8-bit library.	In fact, these new options de-
       fine the	same bits in the options word. There is	a discussion about the
       validity	of UTF-16 strings in the pcreunicode page.

       For the pcre16_config() function	there is an  option  PCRE_CONFIG_UTF16
       that  returns  1	 if UTF-16 support is configured, otherwise 0. If this
       option  is  given  to  pcre_config()  or	 pcre32_config(),  or  if  the
       PCRE_CONFIG_UTF8	 or  PCRE_CONFIG_UTF32	option is given	to pcre16_con-
       fig(), the result is the	PCRE_ERROR_BADOPTION error.

CHARACTER CODES
       In 16-bit mode, when  PCRE_UTF16	 is  not  set,	character  values  are
       treated in the same way as in 8-bit, non	UTF-8 mode, except, of course,
       that they can range from	0 to 0xffff instead of 0  to  0xff.  Character
       types  for characters less than 0xff can	therefore be influenced	by the
       locale in the same way as before.  Characters greater  than  0xff  have
       only one	case, and no "type" (such as letter or digit).

       In  UTF-16  mode,  the  character  code	is  Unicode, in	the range 0 to
       0x10ffff, with the exception of values in the range  0xd800  to	0xdfff
       because	those  are "surrogate" values that are used in pairs to	encode
       values greater than 0xffff.

       A UTF-16	string can indicate its	endianness by special code knows as  a
       byte-order mark (BOM). The PCRE functions do not	handle this, expecting
       strings	to  be	in  host  byte	order.	A  utility   function	called
       pcre16_utf16_to_host_byte_order()  is  provided	to help	with this (see
       above).

ERROR NAMES
       The errors PCRE_ERROR_BADUTF16_OFFSET and PCRE_ERROR_SHORTUTF16	corre-
       spond  to  their	 8-bit	counterparts.  The error PCRE_ERROR_BADMODE is
       given when a compiled pattern is	passed to a  function  that  processes
       patterns	 in  the  other	 mode, for example, if a pattern compiled with
       pcre_compile() is passed	to pcre16_exec().

       There are new error codes whose names begin with	PCRE_UTF16_ERR for in-
       valid  UTF-16  strings,	corresponding  to  the PCRE_UTF8_ERR codes for
       UTF-8 strings that are described	in the section entitled	"Reason	 codes
       for  invalid UTF-8 strings" in the main pcreapi page. The UTF-16	errors
       are:

	 PCRE_UTF16_ERR1  Missing low surrogate	at end of string
	 PCRE_UTF16_ERR2  Invalid low surrogate	follows	high surrogate
	 PCRE_UTF16_ERR3  Isolated low surrogate
	 PCRE_UTF16_ERR4  Non-character

ERROR TEXTS
       If there	is an error while compiling a pattern, the error text that  is
       passed  back by pcre16_compile()	or pcre16_compile2() is	still an 8-bit
       character string, zero-terminated.

CALLOUTS
       The subject and mark fields in the callout block	that is	 passed	 to  a
       callout function	point to 16-bit	vectors.

TESTING
       The  pcretest  program continues	to operate with	8-bit input and	output
       files, but it can be used for testing the 16-bit	library. If it is  run
       with the	command	line option -16, patterns and subject strings are con-
       verted from 8-bit to 16-bit before being	passed to PCRE,	and the	16-bit
       library	functions  are used instead of the 8-bit ones. Returned	16-bit
       strings are converted to	8-bit for output. If both the  8-bit  and  the
       32-bit libraries	were not compiled, pcretest defaults to	16-bit and the
       -16 option is ignored.

       When PCRE is being built, the RunTest script that is  called  by	 "make
       check"  uses  the  pcretest  -C	option to discover which of the	8-bit,
       16-bit and 32-bit libraries has been built, and runs the	 tests	appro-
       priately.

NOT SUPPORTED IN 16-BIT	MODE
       Not all the features of the 8-bit library are available with the	16-bit
       library.	The C++	and POSIX wrapper functions support only the 8-bit li-
       brary, and the pcregrep program is at present 8-bit only.

AUTHOR
       Philip Hazel
       University Computing Service
       Cambridge CB2 3QH, England.

REVISION
       Last updated: 12	May 2013
       Copyright (c) 1997-2013 University of Cambridge.

PCRE 8.33			  12 May 2013			       PCRE(3)

NAME | PCRE 16-BIT API BASIC FUNCTIONS | PCRE 16-BIT API STRING EXTRACTION FUNCTIONS | PCRE 16-BIT API AUXILIARY FUNCTIONS | PCRE 16-BIT API INDIRECTED FUNCTIONS | PCRE 16-BIT API 16-BIT-ONLY FUNCTION | THE PCRE 16-BIT LIBRARY | THE HEADER FILE | THE LIBRARY NAME | STRING TYPES | STRUCTURE TYPES | 16-BIT FUNCTIONS | SUBJECT STRING OFFSETS | NAMED SUBPATTERNS | OPTION NAMES | CHARACTER CODES | ERROR NAMES | ERROR TEXTS | CALLOUTS | TESTING | NOT SUPPORTED IN 16-BIT MODE | AUTHOR | REVISION

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