WCSNRTOMBS(3) Linux Programmer's Manual WCSNRTOMBS(3)NAMEwcsnrtombs - convert a wide-character string to a multibyte string
SYNOPSIS
#include <wchar.h>
size_t wcsnrtombs(char *dest, const wchar_t **src, size_t nwc,
size_t len, mbstate_t *ps);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
wcsnrtombs():
Since glibc 2.10:
_POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
_GNU_SOURCE
DESCRIPTION
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 suc‐
ceeds, and then incrementing dest by the number of bytes written and
*src by one. The conversion can stop for three reasons:
1. 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.
2. 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 con‐
verted, and the number of bytes written to dest is returned.
3. 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 ter‐
minating 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.
RETURN VALUE
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 con‐
verted, (size_t) -1 is returned, and errno set to EILSEQ.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
┌─────────────┬───────────────┬───────────────────────────────┐
│Interface │ Attribute │ Value │
├─────────────┼───────────────┼───────────────────────────────┤
│wcsnrtombs() │ Thread safety │ MT-Unsafe race:wcsnrtombs/!ps │
└─────────────┴───────────────┴───────────────────────────────┘
CONFORMING TO
POSIX.1-2008.
NOTES
The behavior of wcsnrtombs() depends on the LC_CTYPE category of the
current locale.
Passing NULL as ps is not multithread safe.
SEE ALSOiconv(3), mbsinit(3), wcsrtombs(3)COLOPHON
This page is part of release 4.14 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
GNU 2017-09-15 WCSNRTOMBS(3)
