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 converted, 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 memory, and that no length limit exists.

       In both of the above cases, if ps is a NULL pointer, a static anonymous 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                                               July 25, 1999                                     MBSRTOWCS(3)