Subversion Repositories or1k

/*

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 */

}