wcsnrtombs - convert a wide-character string to a multibyte string
Standard C library (
libc,
-lc)
#include <wchar.h>
size_t wcsnrtombs(char dest[restrict .len], const wchar_t **restrict src,
size_t nwc, size_t len, mbstate_t *restrict ps);
wcsnrtombs():
Since glibc 2.10:
_POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
_GNU_SOURCE
The
wcsnrtombs() function is like the
wcsrtombs(3) function,
except that the number of wide characters to be converted, starting at
*src, is limited to
nwc.
If
dest is not NULL, the
wcsnrtombs() function converts at most
nwc wide characters from the wide-character string
*src to a
multibyte string starting at
dest. At most
len bytes are written
to
dest. The shift state
*ps 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
*src 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
EILSEQ.
- •
-
nwc wide characters have been converted without
encountering a null wide character (L'\0'), or 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 (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.
If
dest 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 destination length limit exists.
In both of the above cases, if
ps is NULL, a static anonymous state known
only to the
wcsnrtombs() function is used instead.
The programmer must ensure that there is room for at least
len bytes at
dest.
The
wcsnrtombs() 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,
(size_t) -1 is returned, and
errno set to
EILSEQ.
For an explanation of the terms used in this section, see
attributes(7).
Interface |
Attribute |
Value |
wcsnrtombs () |
Thread safety |
MT-Unsafe race:wcsnrtombs/!ps |
POSIX.1-2008.
The behavior of
wcsnrtombs() depends on the
LC_CTYPE category of
the current locale.
Passing NULL as
ps is not multithread safe.
iconv(3),
mbsinit(3),
wcsrtombs(3)