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 null wide character
          ('\0').  In this case the number of wide characters written to dest, excluding  the  terminating  null
          wide 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

       C99.

NOTES

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

       The function mbsrtowcs(3) provides a better interface to the same functionality.

SEE ALSO

       mbsrtowcs(3), wcstombs(3)

COLOPHON

       This  page  is  part  of  release 3.54 of the Linux man-pages project.  A description of the project, and
       information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.

GNU                                                2011-09-28                                        MBSTOWCS(3)