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:

       •  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.

       •  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.

       •  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)