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



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 rea-
       sons:

       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, exclud-
          ing 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  con-
       verted 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 3.53 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)