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 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
       C99.

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

       Passing NULL as ps is not multithread safe.

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

COLOPHON
       This  page  is  part of release 3.25 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                                                        1999-07-25                                               MBSRTOWCS(3)