wcstombs(3) — Linux manual page


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

NAME         top

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

SYNOPSIS         top

       #include <stdlib.h>

       size_t wcstombs(char *dest, const wchar_t *src, size_t n);

DESCRIPTION         top

       If dest is not NULL, the wcstombs() function converts the wide-
       character string src to a multibyte string starting at dest.  At most
       n bytes are written to dest.  The sequence of characters placed in
       dest begins in the initial shift state.  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, (size_t) -1 is returned.

       2. The length limit forces a stop.  In this case, the number of bytes
          written to dest is returned, but the shift state at this point is

       3. The wide-character string has been completely converted, including
          the terminating null wide character (L'\0').  In this case, the
          conversion ends in the initial shift state.  The number of bytes
          written to dest, excluding the terminating null byte ('\0'), is

       The programmer must ensure that there is room for at least n bytes at

       If dest is NULL, n is ignored, and the conversion proceeds as above,
       except that the converted bytes are not written out to memory, and no
       length limit exists.

       In order to avoid the case 2 above, the programmer should make sure n
       is greater than or equal to wcstombs(NULL,src,0)+1.

RETURN VALUE         top

       The wcstombs() function returns the number of bytes that make up the
       converted part of a multibyte sequence, not including the terminating
       null byte.  If a wide character was encountered which could not be
       converted, (size_t) -1 is returned.

ATTRIBUTES         top

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

       │Interface  Attribute     Value   │
       │wcstombs() │ Thread safety │ MT-Safe │

CONFORMING TO         top

       POSIX.1-2001, POSIX.1-2008, C99.

NOTES         top

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

       The function wcsrtombs(3) provides a better interface to the same

SEE ALSO         top

       mblen(3), mbstowcs(3), mbtowc(3), wcsrtombs(3), wctomb(3)

COLOPHON         top

       This page is part of release 5.07 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                              2020-06-09                      WCSTOMBS(3)

Pages that refer to this page: mb_cur_max(3)MB_CUR_MAX(3)mbstowcs(3)mbtowc(3)wcsrtombs(3)wctomb(3)locale(7)