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Utf(3)			    Tcl	Library	Procedures			Utf(3)

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NAME
       Tcl_UniChar,   Tcl_UniCharToUtf,	 Tcl_UtfToUniChar,  Tcl_UniCharToUtfD-
       String,	 Tcl_UtfToUniCharDString,   Tcl_UniCharLen,   Tcl_UniCharNcmp,
       Tcl_UniCharNcasecmp,   Tcl_UniCharCaseMatch,   Tcl_UtfNcmp,   Tcl_UtfN-
       casecmp,	  Tcl_UtfCharComplete,	 Tcl_NumUtfChars,    Tcl_UtfFindFirst,
       Tcl_UtfFindLast,	 Tcl_UtfNext, Tcl_UtfPrev, Tcl_UniCharAtIndex, Tcl_Ut-
       fAtIndex, Tcl_UtfBackslash - routines for manipulating UTF-8 strings

SYNOPSIS
       #include	<tcl.h>

       typedef ... Tcl_UniChar;

       int
       Tcl_UniCharToUtf(ch, buf)

       int
       Tcl_UtfToUniChar(src, chPtr)

       char *
       Tcl_UniCharToUtfDString(uniStr, uniLength, dsPtr)

       Tcl_UniChar *
       Tcl_UtfToUniCharDString(src, length, dsPtr)

       int
       Tcl_UniCharLen(uniStr)

       int
       Tcl_UniCharNcmp(ucs, uct, numChars)

       int
       Tcl_UniCharNcasecmp(ucs,	uct, numChars)

       int
       Tcl_UniCharCaseMatch(uniStr, uniPattern,	nocase)

       int
       Tcl_UtfNcmp(cs, ct, numChars)

       int
       Tcl_UtfNcasecmp(cs, ct, numChars)

       int
       Tcl_UtfCharComplete(src,	length)

       int
       Tcl_NumUtfChars(src, length)

       const char *
       Tcl_UtfFindFirst(src, ch)

       const char *
       Tcl_UtfFindLast(src, ch)

       const char *
       Tcl_UtfNext(src)

       const char *
       Tcl_UtfPrev(src,	start)

       Tcl_UniChar
       Tcl_UniCharAtIndex(src, index)

       const char *
       Tcl_UtfAtIndex(src, index)

       int
       Tcl_UtfBackslash(src, readPtr, dst)

ARGUMENTS
       char *buf (out)				   Buffer in which  the	 UTF-8
						   representation    of	   the
						   Tcl_UniChar is stored.   At
						   most	 TCL_UTF_MAX bytes are
						   stored in the buffer.

       int ch (in)				   The Unicode character to be
						   converted or	examined.

       Tcl_UniChar *chPtr (out)			   Filled with the Tcl_UniChar
						   represented by the head  of
						   the UTF-8 string.

       const char *src (in)			   Pointer to a	UTF-8 string.

       const char *cs (in)			   Pointer to a	UTF-8 string.

       const char *ct (in)			   Pointer to a	UTF-8 string.

       const Tcl_UniChar *uniStr (in)		   A  null-terminated  Unicode
						   string.

       const Tcl_UniChar *ucs (in)		   A  null-terminated  Unicode
						   string.

       const Tcl_UniChar *uct (in)		   A  null-terminated  Unicode
						   string.

       const Tcl_UniChar *uniPattern (in)	   A  null-terminated  Unicode
						   string.

       int length (in)				   The	length	of  the	 UTF-8
						   string in bytes (not	 UTF-8
						   characters).	  If negative,
						   all bytes up	to  the	 first
						   null	byte are used.

       int uniLength (in)			   The	length	of the Unicode
						   string in characters.  Must
						   be greater than or equal to
						   0.

       Tcl_DString *dsPtr (in/out)		   A pointer to	 a  previously
						   initialized Tcl_DString.

       unsigned	long numChars (in)		   The number of characters to
						   compare.

       const char *start (in)			   Pointer to the beginning of
						   a UTF-8 string.

       int index (in)				   The	index  of  a character
						   (not	 byte)	in  the	 UTF-8
						   string.

       int *readPtr (out)			   If  non-NULL,  filled  with
						   the number of bytes in  the
						   backslash sequence, includ-
						   ing the  backslash  charac-
						   ter.

       char *dst (out)				   Buffer  in  which the bytes
						   represented	by  the	 back-
						   slash  sequence are stored.
						   At most  TCL_UTF_MAX	 bytes
						   are stored in the buffer.

       int nocase (in)				   Specifies whether the match
						   should be done  case-sensi-
						   tive	 (0)  or case-insensi-
						   tive	(1).
______________________________________________________________________________

DESCRIPTION
       These routines convert  between	UTF-8  strings	and  Tcl_UniChars.   A
       Tcl_UniChar  is	a Unicode character represented	as an unsigned,	fixed-
       size quantity.  A UTF-8 character is a Unicode character	represented as
       a  varying-length  sequence  of	up  to TCL_UTF_MAX bytes.  A multibyte
       UTF-8 sequence consists of a lead byte followed by some number of trail
       bytes.

       TCL_UTF_MAX  is	the maximum number of bytes that it takes to represent
       one Unicode character in	the UTF-8 representation.

       Tcl_UniCharToUtf	stores the Tcl_UniChar ch as a UTF-8 string in	start-
       ing at buf.  The	return value is	the number of bytes stored in buf.

       Tcl_UtfToUniChar	 reads	one UTF-8 character starting at	src and	stores
       it as a Tcl_UniChar in *chPtr.  The return value	is the number of bytes
       read  from  src.	 The caller must ensure	that the source	buffer is long
       enough such that	this routine does not run off the end and  dereference
       non-existent  or	 random	 memory;  if  the source buffer	is known to be
       null-terminated,	this will not happen.  If the input is not  in	proper
       UTF-8 format, Tcl_UtfToUniChar will store the first byte	of src in *ch-
       Ptr as a	Tcl_UniChar between 0x0000 and 0x00ff and return 1.

       Tcl_UniCharToUtfDString converts	the given  Unicode  string  to	UTF-8,
       storing	the  result in a previously initialized	Tcl_DString.  You must
       specify uniLength, the length of	the given Unicode string.  The	return
       value  is  a pointer to the UTF-8 representation	of the Unicode string.
       Storage for the return value is appended	to the end of the Tcl_DString.

       Tcl_UtfToUniCharDString converts	the given  UTF-8  string  to  Unicode,
       storing	the  result in the previously initialized Tcl_DString.	In the
       argument	length,	you may	either specify the length of the  given	 UTF-8
       string  in  bytes  or  "-1", in which case Tcl_UtfToUniCharDString uses
       strlen to calculate the length.	The return value is a pointer  to  the
       Unicode	representation	of  the	 UTF-8 string.	Storage	for the	return
       value is	appended to the	end of the Tcl_DString.	 The Unicode string is
       terminated with a Unicode null character.

       Tcl_UniCharLen  corresponds  to	strlen for Unicode characters.	It ac-
       cepts a null-terminated Unicode string and returns the number  of  Uni-
       code characters (not bytes) in that string.

       Tcl_UniCharNcmp and Tcl_UniCharNcasecmp correspond to strncmp and strn-
       casecmp,	respectively, for Unicode characters.  They accept  two	 null-
       terminated  Unicode  strings  and  the number of	characters to compare.
       Both strings are	assumed	to  be	at  least  numChars  characters	 long.
       Tcl_UniCharNcmp	 compares  the	two strings character-by-character ac-
       cording to the Unicode  character  ordering.   It  returns  an  integer
       greater	than,  equal to, or less than 0	if the first string is greater
       than,  equal  to,  or  less  than  the  second	string	 respectively.
       Tcl_UniCharNcasecmp is the Unicode case insensitive version.

       Tcl_UniCharCaseMatch  is	the Unicode equivalent to Tcl_StringCaseMatch.
       It accepts a null-terminated Unicode string, a Unicode pattern,	and  a
       boolean value specifying	whether	the match should be case sensitive and
       returns whether the string matches the pattern.

       Tcl_UtfNcmp corresponds to strncmp for UTF-8 strings.  It  accepts  two
       null-terminated	UTF-8 strings and the number of	characters to compare.
       (Both strings are assumed to be at  least  numChars  characters	long.)
       Tcl_UtfNcmp  compares  the two strings character-by-character according
       to the Unicode character	ordering.  It returns an integer greater than,
       equal to, or less than 0	if the first string is greater than, equal to,
       or less than the	second string respectively.

       Tcl_UtfNcasecmp corresponds to strncasecmp for UTF-8  strings.	It  is
       similar	to  Tcl_UtfNcmp	 except	comparisons ignore differences in case
       when comparing upper, lower or title case characters.

       Tcl_UtfCharComplete returns 1 if	the source UTF-8 string	src of	length
       bytes is	long enough to be decoded by Tcl_UtfToUniChar, or 0 otherwise.
       This function does not guarantee	that  the  UTF-8  string  is  properly
       formed.	 This  routine	is  used by procedures that are	operating on a
       byte at a time and need to know if a full Tcl_UniChar has been seen.

       Tcl_NumUtfChars corresponds to strlen for UTF-8	strings.   It  returns
       the  number  of	Tcl_UniChars  that are represented by the UTF-8	string
       src.  The length	of the source string is	length bytes.  If  the	length
       is negative, all	bytes up to the	first null byte	are used.

       Tcl_UtfFindFirst	corresponds to strchr for UTF-8	strings.  It returns a
       pointer to the first occurrence of the Tcl_UniChar ch in	the  null-ter-
       minated	UTF-8  string  src.  The null terminator is considered part of
       the UTF-8 string.

       Tcl_UtfFindLast corresponds to strrchr for UTF-8	strings.  It returns a
       pointer to the last occurrence of the Tcl_UniChar ch in the null-termi-
       nated UTF-8 string src.	The null terminator is considered part of  the
       UTF-8 string.

       Given  src,  a  pointer to some location	in a UTF-8 string, Tcl_UtfNext
       returns a pointer to the	next  UTF-8  character	in  the	 string.   The
       caller  must not	ask for	the next character after the last character in
       the string if the string	is not terminated by a null character.

       Given src, a pointer to some location in	a UTF-8	string (or to  a  null
       byte  immediately  following  such  a  string),	Tcl_UtfPrev  returns a
       pointer to the closest preceding	byte that starts  a  UTF-8  character.
       This function will not back up to a position before start, the start of
       the UTF-8 string.  If src was already at	start, the return  value  will
       be start.

       Tcl_UniCharAtIndex  corresponds	to a C string array dereference	or the
       Pascal Ord() function.  It returns the Tcl_UniChar represented  at  the
       specified  character  (not  byte)  index	 in the	UTF-8 string src.  The
       source string must contain at least index characters.  Behavior is  un-
       defined if a negative index is given.

       Tcl_UtfAtIndex  returns a pointer to the	specified character (not byte)
       index in	the UTF-8 string src.  The source string must contain at least
       index  characters.   This  is  equivalent  to calling Tcl_UtfNext index
       times.  If a negative index is given, the return	pointer	points to  the
       first character in the source string.

       Tcl_UtfBackslash	is a utility procedure used by several of the Tcl com-
       mands.  It parses a backslash sequence and stores the  properly	formed
       UTF-8  character	 represented  by  the backslash	sequence in the	output
       buffer dst.  At most  TCL_UTF_MAX  bytes	 are  stored  in  the  buffer.
       Tcl_UtfBackslash	 modifies  *readPtr  to	contain	the number of bytes in
       the backslash sequence, including the backslash character.  The	return
       value is	the number of bytes stored in the output buffer.

       See  the	 Tcl  manual  entry for	information on the valid backslash se-
       quences.	 All of	the sequences described	in the Tcl  manual  entry  are
       supported by Tcl_UtfBackslash.

KEYWORDS
       utf, unicode, backslash

Tcl				      8.1				Utf(3)

NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | KEYWORDS

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