Man Linux: Main Page and Category List


       mbsnrtowcs - convert a multibyte string to a wide-character string


       #define _GNU_SOURCE
       #include <wchar.h>

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


       The  mbsnrtowcs()  function  is  like the mbsrtowcs(3) function, except
       that the number of bytes to be converted, starting at *src, is  limited
       to nms.

       If  dest  is  not a NULL pointer, the mbsnrtowcs() function converts at
       most nms bytes from 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. The nms limit forces a stop, or 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 destination length limit exists.

       In both of the above cases, if ps is a NULL pointer, a static anonymous
       state only known to the mbsnrtowcs function is used instead.

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


       The  mbsnrtowcs()  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.


       This function is a GNU extension.


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

       Passing NULL as ps is not multithread safe.


       iconv(3), mbsrtowcs(3)


       This  page  is  part of release 3.24 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at