mbtowc

MBTOWC(3)		  Linux Programmer’s Manual		    MBTOWC(3)



NAME
       mbtowc - convert a multibyte sequence to a wide character

SYNOPSIS
       #include <stdlib.h>

       int mbtowc(wchar_t *pwc, const char *s, size_t n);

DESCRIPTION
       The  main  case for this function is when s is not NULL and pwc is not
       NULL. In this case, the mbtowc function inspects at most	 n  bytes  of
       the  multibyte string starting at s, extracts the next complete multi-
       byte character, converts it to a wide character and stores it at *pwc.
       It  updates an internal shift state only known to the mbtowc function.
       If s does not point to a ’\0’ byte, it returns  the  number  of	bytes
       that were consumed from s, otherwise it returns 0.

       If the n bytes starting at s do not contain a complete multibyte char-
       acter, or if  they  contain  an	invalid	 multibyte  sequence,  mbtowc
       returns	-1. This can happen even if n >= MB_CUR_MAX, if the multibyte
       string contains redundant shift sequences.

       A different case is when s is not NULL but pwc is NULL. In  this	 case
       the  mbtowc  function behaves as above, excepts that it does not store
       the converted wide character in memory.

       A third case is when s is NULL. In this case, pwc and n	are  ignored.
       The  mbtowc  function resets the shift state, only known to this func-
       tion, to the initial state, and returns non-zero if the	encoding  has
       non-trivial shift state, or zero if the encoding is stateless.

RETURN VALUE
       If  s  is not NULL, the mbtowc function returns the number of consumed
       bytes starting at s, or 0 if s points to a null byte, or -1 upon fail-
       ure.

       If s is NULL, the mbtowc function returns non-zero if the encoding has
       non-trivial shift state, or zero if the encoding is stateless.

CONFORMING TO
       ISO/ANSI C, UNIX98

SEE ALSO
       mbrtowc(3), mbstowcs(3), MB_CUR_MAX(3)

NOTES
       The behaviour of mbtowc depends on the LC_CTYPE category of  the	 cur-
       rent locale.

       This  function is not multi-thread safe. The function mbrtowc provides
       a better interface to the same functionality.



GNU				  2001-07-04			    MBTOWC(3)