mbstowcs

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 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 mem-
       ory, 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 cur-
       rent locale.

       The  function  mbsrtowcs provides a better interface to the same func-
       tionality.



GNU				  1999-07-25			  MBSTOWCS(3)