WCSRTOMBS(3)

NAME
wcsrtombs, wcsrtombs_l, wcsnrtombs, wcsnrtombs_l - convert a wide-character string to a character string (restartable)

LIBRARY
libc

SYNOPSIS
#include <wchar.h>
size_t
wcsrtombs(char * restrict dst, const wchar_t ** restrict src, size_t len, mbstate_t * restrict ps);
size_t
wcsnrtombs(char * restrict dst, const wchar_t ** restrict src, size_t nwc, size_t len, mbstate_t * restrict ps);
#include <xlocale.h>
size_t
wcsrtombs_l(char * restrict dst, const wchar_t ** restrict src, size_t len, mbstate_t * restrict ps, locale_t locale);
size_t
wcsnrtombs_l(char * restrict dst, const wchar_t ** restrict src, size_t nwc, size_t len, mbstate_t * restrict ps, locale_t locale);

DESCRIPTION
The wcsrtombs() and wcsrtombs_l() functions convert a string of wide characters indirectly pointed to by src to a corresponding multibyte character string stored in the array pointed to by dst. No more than len bytes are written to dst.

If dst is NULL, no characters are stored.

If dst is not NULL, the pointer pointed to by src is updated to point to the character after the one that conversion stopped at. If conversion stops because a null character is encountered, *src is set to NULL.

The mbstate_t argument, ps, is used to keep track of the shift state. If it is NULL, wcsrtombs() and wcsrtombs_l() use an internal, static mbstate_t object, which is initialized to the initial conversion state at program startup.

The wcsnrtombs() and wcsnrtombs_l() functions behave identically to wcsrtombs() and wcsrtombs_l(), except that conversion stops after reading at most nwc characters from the buffer pointed to by src.

The wcsrtombs_l() and wcsnrtombs_l() functions take an explicit locale argument, whereas the wcsrtombs() and wcsnrtombs() functions use the current global or per-thread locale.

RETURN VALUES
The wcsrtombs(), wcsrtombs_l(), wcsnrtombs(), and wcsnrtombs_l() functions return the number of bytes stored in the array pointed to by dst (not including any terminating null), if successful, otherwise they return (size_t)-1.

ERRORS
The wcsrtombs(), wcsrtombs_l(), wcsnrtombs(), and wcsnrtombs_l() functions will fail if:

[EILSEQ]
    An invalid wide character was encountered.

[EINVAL]
    The conversion state is invalid.

SEE ALSO
mbsrtowcs(3), wcrtomb(3), wcstombs(3), xlocale(3)

STANDARDS
The wcsrtombs() function conforms to isoC-99.

The wcsrtombs_l(), wcsnrtombs(), and wcsnrtombs_l() functions are an extension to the standard.