mbchar(3C)           COMPATIBILITY FUNCTIONS           mbchar(3C)



NAME
     mbchar: mbtowc, mblen, wctomb - multibyte character handling

SYNOPSIS
     #include <stdlib.h>

     int mbtowc (wchart *pwc, const char *s, sizet n);

     int mblen (const char *s, sizet n);

     int wctomb (char *s, wchart wchar);

DESCRIPTION
     Multibyte characters are used to represent characters in  an
     extended  character set.  This is needed for locales where 8
     bits are not enough to represent all the characters  in  the
     character set.

     The multibyte character handling functions provide the means
     of translating multibyte characters into wide characters and
     back again.  Wide characters have type wchart  (defined  in
     stdlib.h),  which  is an integral type whose range of values
     can represent distinct codes for all members of the  largest
     extended   character   set  specified  among  the  supported
     locales.

     A maximum of 3 extended character  sets  are  supported  for
     each  locale.   The number of bytes in an extended character
     set is defined by the LCCTYPE category of the  locale  [see
     setlocale(3C)].  However, the maximum number of bytes in any
     multibyte character will never be greater  than  MBLENMAX.
     which  is  defined in stdlib.h.  The maximum number of bytes
     in a character in an extended character set in  the  current
     locale  is  given  by the macro, MBCURMAX, also defined in
     stdlib.h.

     mbtowc determines the number of bytes that comprise the mul-
     tibyte character pointed to by s. Also, if pwc is not a null
     pointer, mbtowc converts the multibyte character to  a  wide
     character  and places the result in the object pointed to by
     pwc. (The value of the wide character corresponding  to  the
     null character is zero.)  At most n characters will be exam-
     ined, starting at the character pointed to by s.

     If s is a null pointer, mbtowc simply returns 0.   If  s  is
     not a null pointer, then, if s points to the null character,
     mbtowc returns 0; if the next n or fewer bytes form a  valid
     multibyte character, mbtowc returns the number of bytes that
     comprise the converted  multibyte  character;  otherwise,  s
     does  not  point  to  a valid multibyte character and mbtowc
     returns -1.




          Last change: C Programming Language Utilities         1

mbchar(3C)           COMPATIBILITY FUNCTIONS           mbchar(3C)



     mblen determines the number of bytes comprising  the  multi-
     byte character pointed to by s.  It is equivalent to

          mbtowc ((wchar_t *)0, s, n);

     wctomb determines the number of bytes  needed  to  represent
     the  multibyte  character  corresponding  to  the code whose
     value is wchar, and, if s is not a null pointer, stores  the
     multibyte  character  representation in the array pointed to
     by s.  At most MBCURMAX characters are stored.

     If s is a null pointer, wctomb simply returns 0.   If  s  is
     not  a null pointer, wctomb returns -1 if the value of wchar
     does not correspond to a valid multibyte  character;  other-
     wise it returns the number of bytes that comprise the multi-
     byte character corresponding to the value of wchar.

SEE ALSO
     mbstring(3C), setlocale(3C), environ(5).
     chrtbl(1M) in the System Administrator's Reference Manual.



































          Last change: C Programming Language Utilities         2