NAME

       mbstowcs - convert a multibyte string to a wide character string

SYNOPSIS

       #include <stdlib.h>

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

DESCRIPTION

       If  dest  is  not  a  NULL  pointer,  the  mbstowcs function converts the multibyte string src to a wide-
       character string starting at dest.  At most n wide characters are written to dest. The conversion  starts
       in the initial state. The conversion can stop for three reasons:

       1. An invalid multibyte sequence has been encountered. In this case (size_t)(-1) is returned.

       2.  n  non-L'\0'  wide  characters  have  been stored at dest. In this case the number of wide characters
       written to dest is returned, but the shift state at this point is lost.

       3. The multibyte string has been completely converted, including the terminating '\0'. In this  case  the
       number of wide characters written to dest, excluding the terminating L'\0' character, is returned.

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

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

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

RETURN VALUE

       The  mbstowcs  function returns the number of wide characters that make up the converted part of the wide
       character string, not including the terminating null wide character. If an invalid multibyte sequence was
       encountered, (size_t)(-1) is returned.

CONFORMING TO

       ISO/ANSI C, UNIX98

SEE ALSO

       mbsrtowcs(3)

NOTES

       The behaviour of mbstowcs depends on the LC_CTYPE category of the current locale.

       The function mbsrtowcs provides a better interface to the same functionality.

GNU                                               July 25, 1999                                      MBSTOWCS(3)