Provided by: tcl8.4-doc_8.4.19-4ubuntu3_all bug

NAME

       Tcl_UniChar,       Tcl_UniCharCaseMatch,       Tcl_UniCharNcasecmp,      Tcl_UniCharToUtf,
       Tcl_UtfToUniChar,   Tcl_UniCharToUtfDString,   Tcl_UtfToUniCharDString,    Tcl_UniCharLen,
       Tcl_UniCharNcmp,  Tcl_UtfCharComplete, Tcl_NumUtfChars, Tcl_UtfFindFirst, Tcl_UtfFindLast,
       Tcl_UtfNext, Tcl_UtfPrev, Tcl_UniCharAtIndex, Tcl_UtfAtIndex, 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, numChars, dstPtr)                                          │

       Tcl_UniChar *                                                                              │
       Tcl_UtfToUniCharDString(src, len, dstPtr)                                                  │

       int
       Tcl_UniCharLen(uniStr)

       int
       Tcl_UniCharNcmp(uniStr, uniStr, num)

       int                                                                                        │
       Tcl_UniCharNcasecmp(uniStr, uniStr, num)                                                   │

       int                                                                                        │
       Tcl_UniCharCaseMatch(uniStr, uniPattern, nocase)                                           │

       int
       Tcl_UtfNcmp(src, src, num)

       int
       Tcl_UtfNcasecmp(src, src, num)

       int
       Tcl_UtfCharComplete(src, len)

       int
       Tcl_NumUtfChars(src, len)

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

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

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

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

       unsigned long       num        (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, including  the  backslash
                                                character.

       char                *dst       (out)     Buffer  in  which  the  bytes  represented by the
                                                backslash   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- │
                                                sensitive (0) or case-insensitive (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  starting  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  *chPtr  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 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.   you may either specify the length of the given
       UTF-8 string 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 accepts a null-terminated
       Unicode string and returns the number of Unicode characters (not bytes) in that string.

       Tcl_UniCharNcmp  and  Tcl_UniCharNcasecmp   correspond   to   strncmp   and   strncasecmp,
       respectively,  for  Unicode  characters.  They accepts two null-terminated Unicode strings
       and the number of characters to compare.  Both strings are assumed  to  be  at  least  len
       characters   long.   Tcl_UniCharNcmp   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_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
       len  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 len 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  len 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-terminated 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-terminated 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 undefined 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 commands.  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 sequences.  All of the
       sequences described in the Tcl manual entry are supported by Tcl_UtfBackslash.

KEYWORDS

       utf, unicode, backslash