wcstombs(3)                Library Functions Manual                wcstombs(3)

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

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <stdlib.h>

       size_t wcstombs(char dest[restrict .n], const wchar_t *restrict src,
                       size_t n);

DESCRIPTION
       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:

       o  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.

       o  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
          lost.

       o  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
          returned.

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

       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
       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
       For an explanation of the terms used in this section, see
       attributes(7).

       +--------------------------------------------+---------------+---------+
       |Interface                                   | Attribute     | Value   |
       +--------------------------------------------+---------------+---------+
       |wcstombs ()                                 | Thread safety | MT-Safe |
       +--------------------------------------------+---------------+---------+
VERSIONS
       The function wcsrtombs(3) provides a better interface to the same
       functionality.

STANDARDS
       C11, POSIX.1-2008.

HISTORY
       POSIX.1-2001, C99.

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

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

Linux man-pages 6.7               2023-10-31                       wcstombs(3)