redhat man page for 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 multibyte 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 '' 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 character, 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 current 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)