mbsrtowcs

MBSRTOWCS(3)		  Linux Programmer’s Manual		 MBSRTOWCS(3)



NAME
       mbsrtowcs - convert a multibyte string to a wide character string

SYNOPSIS
       #include <wchar.h>

       size_t mbsrtowcs(wchar_t *dest, const char **src,
			 size_t len, mbstate_t *ps);

DESCRIPTION
       If  dest	 is  not  a NULL pointer, the mbsrtowcs function converts the
       multibyte string *src to a wide-character string starting at dest.  At
       most  len  wide characters are written to dest. The shift state *ps is
       updated. The conversion is effectively performed by repeatedly calling
       mbrtowc(dest,*src,n,ps)	where  n  is some positive number, as long as
       this call succeeds, and then incrementing dest by one and *src by  the
       number of bytes consumed. The conversion can stop for three reasons:

       1.  An  invalid	multibyte sequence has been encountered. In this case
       *src is left pointing to the invalid multibyte sequence,	 (size_t)(-1)
       is returned, and errno is set to EILSEQ.

       2.  len	non-L’\0’  wide	 characters have been stored at dest. In this
       case *src is left pointing to the next multibyte sequence to  be	 con-
       verted, and the number of wide characters written to dest is returned.

       3. The multibyte string has been completely converted,  including  the
       terminating  ’\0’  (which  has the side effect of bringing back *ps to
       the initial state). In this case *src is set to NULL, and  the  number
       of  wide	 characters  written to dest, excluding the terminating L’\0’
       character, is returned.

       If dest is NULL, len 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 both of the above cases, if ps is a NULL pointer, a  static  anony-
       mous state only known to the mbsrtowcs function is used instead.

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

RETURN VALUE
       The mbsrtowcs 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, and errno set to EILSEQ.

CONFORMING TO
       ISO/ANSI C, UNIX98

SEE ALSO
       mbstowcs(3), mbsnrtowcs(3), iconv(3)

NOTES
       The  behaviour  of  mbsrtowcs  depends on the LC_CTYPE category of the
       current locale.

       Passing NULL as ps is not multi-thread safe.



GNU				  1999-07-25			 MBSRTOWCS(3)