MBTOWC(3)

NAME
2.29 `mbtowc'--minimal multibyte to wide char converter

SYNOPSIS
     #include <stdlib.h>
     int mbtowc(wchar_t *PWC, const char *S, size_t N);

DESCRIPTION
When _MB_CAPABLE is not defined, this is a minimal ANSI-conforming implementation of `mbtowc'. In this case, only "multi-byte character sequences" recognized are single bytes, and they are "converted" to themselves. Each call to `mbtowc' copies one character from `*S' to `*PWC', unless S is a null pointer. The argument n is ignored.
   When _MB_CAPABLE is defined, this routine calls `_mbtowc_r' to perform the conversion, passing a state variable to allow state dependent decoding. The result is based on the locale setting which may be restricted to a defined set of locales.

RETURNS
This implementation of `mbtowc' returns `0' if S is `NULL' or is the empty string; it returns `1' if not _MB_CAPABLE or the character is a single-byte character; it returns `-1' if n is `0' or the multi-byte character is invalid; otherwise it returns the number of bytes in the multibyte character. If the return value is -1, no changes are made to the `pwc' output string. If the input is the empty string, a wchar_t nul is placed in the output string and 0 is returned. If the input has a length of 0, no changes are made to the `pwc' output string.

PORTABILITY
`mbtowc' is required in the ANSI C standard. However, the precise effects vary with the locale.
   `mbtowc' requires no supporting OS subroutines.

SEE ALSO
mbtowc is part of the library. The full documentation for is maintained as a Texinfo manual. If info and are properly installed at your site, the command

    info

will give you access to the complete manual.