wcstombs—minimal wide char string to multibyte string converter #include <stdlib.h>
size_t wcstombs(char *restrict s, const wchar_t *restrict pwc, size_t n);
Description
When _MB_CAPABLE is not defined, this is a minimal ANSI-conforming
implementation of wcstombs. In this case,
all wide-characters are expected to represent single bytes and so
are converted simply by casting to char.
When _MB_CAPABLE is defined, this routine calls _wcstombs_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
wcstombs returns 0 if
s is NULL or is the empty string;
it returns -1 if _MB_CAPABLE and one of the
wide-char characters does not represent a valid multi-byte character;
otherwise it returns the minimum of: n or the
number of bytes that are transferred to s, not including the
nul terminator.
If the return value is -1, the state of the pwc string is
indeterminate. If the input has a length of 0, the output
string will be modified to contain a wchar_t nul terminator if
n > 0.
Portability
wcstombs is required in the ANSI C standard. However, the precise
effects vary with the locale.
wcstombs requires no supporting OS subroutines.