wcsrtombs - convert a wide-character string to a multibyte string
size_t wcsrtombs(char *dest, const wchar_t **src,
size_t len, mbstate_t *ps);
is not NULL, the wcsrtombs
() function converts the
wide-character string *src
to a multibyte string starting at
. At most len
bytes are written to dest
. The shift
is updated. The conversion is effectively performed by
repeatedly calling wcrtomb(dest, *src, ps)
, as long as this call
succeeds, and then incrementing dest
by the number of bytes written and
by one. The conversion can stop for three reasons:
- A wide character has been encountered that can not be represented as a
multibyte sequence (according to the current locale). In this case,
*src is left pointing to the invalid wide character,
(size_t) -1 is returned, and errno is set to
- The length limit forces a stop. In this case, *src is left pointing
to the next wide character to be converted, and the number of bytes
written to dest is returned.
- The wide-character string has been completely converted, including the
terminating null wide character (L'\0'), which has the side effect of
bringing back *ps to the initial state. In this case, *src
is set to NULL, and the number of bytes written to dest, excluding
the terminating null byte ('\0'), is returned.
is NULL, len
is ignored, and the conversion proceeds as
above, except that the converted bytes are not written out to memory, and that
no length limit exists.
In both of the above cases, if ps
is NULL, a static anonymous state known
only to the wcsrtombs
() function is used instead.
The programmer must ensure that there is room for at least len
() function returns the number of bytes that make up the
converted part of multibyte sequence, not including the terminating null byte.
If a wide character was encountered which could not be converted,
is returned, and errno
set to EILSEQ
For an explanation of the terms used in this section, see attributes
POSIX.1-2001, POSIX.1-2008, C99.
The behavior of wcsrtombs
() depends on the LC_CTYPE
the current locale.
Passing NULL as ps
is not multithread safe.