wcsnrtombs(3) — Linux manual page


WCSNRTOMBS(3)             Linux Programmer's Manual            WCSNRTOMBS(3)

NAME         top

       wcsnrtombs - convert a wide-character string to a multibyte string

SYNOPSIS         top

       #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)):

           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:

DESCRIPTION         top

       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:

       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 converted, 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 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.

RETURN VALUE         top

       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

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface    Attribute     Value                         │
       │wcsnrtombs() │ Thread safety │ MT-Unsafe race:wcsnrtombs/!ps │

CONFORMING TO         top


NOTES         top

       The behavior of wcsnrtombs() depends on the LC_CTYPE category of the
       current locale.

       Passing NULL as ps is not multithread safe.

SEE ALSO         top

       iconv(3), mbsinit(3), wcsrtombs(3)

COLOPHON         top

       This page is part of release 5.08 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

GNU                              2019-03-06                    WCSNRTOMBS(3)

Pages that refer to this page: wcsrtombs(3)