Provided by: tcl8.5-doc_8.5.15-2ubuntu1_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, 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 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 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,  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 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 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 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
       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
       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-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