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/*
FUNCTION
<<wcstombs>>---minimal wide char string to multibyte string converter
 
INDEX
	wcstombs
 
ANSI_SYNOPSIS
	#include <stdlib.h>
	int wcstombs(const char *<[s]>, wchar_t *<[pwc]>, size_t <[n]>);
 
TRAD_SYNOPSIS
	#include <stdlib.h>
	int wcstombs(<[s]>, <[pwc]>, <[n]>)
	const char *<[s]>;
	wchar_t *<[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
This implementation of <<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.
*/
 
#include <stdlib.h>
 
size_t
_DEFUN (wcstombs, (s, pwcs, n),
        char          *s    _AND
        const wchar_t *pwcs _AND
        size_t         n)
{
#ifdef MB_CAPABLE
        int state = 0;
 
        return _wcstombs_r (_REENT, s, pwcs, n, &state);
#else /* not MB_CAPABLE */
        int count = 0;
 
        if (n != 0) {
                do {
                        if ((*s++ = (char) *pwcs++) == 0)
                                break;
                        count++;
                } while (--n != 0);
        }
 
        return count;
#endif /* not MB_CAPABLE */
}