WCSNRTOMBS(3)                                       Linux Programmer's Manual                                      WCSNRTOMBS(3)



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

SYNOPSIS
       #define _GNU_SOURCE
       #include <wchar.h>

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

DESCRIPTION
       The  wcsnrtombs()  function is like the wcsrtombs(3) function, except that the number of wide characters to be converted,
       starting at *src, is limited to nwc.

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

       1. A wide character has been encountered that can not be represented as a multibyte sequence (according  to  the  current
       locale).   In this case *src is left pointing to the invalid wide character, (size_t) -1 is returned, and errno is set to
       EILSEQ.

       2. nwc wide characters have been converted without encountering a L'\0', or the length limit forces a stop.  In this case
       *src is left pointing to the next wide character to be converted, and the number of bytes written to dest is returned.

       3. The wide-character string has been completely converted, including the terminating L'\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  bytes  written  to  dest,
       excluding the terminating '\0' byte, is returned.

       If  dest  is  NULL, len is ignored, and the conversion proceeds as above, except that the converted bytes 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  wcsnrtombs  function  is
       used instead.

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

RETURN VALUE
       The  wcsnrtombs() function returns the number of bytes that make up the converted part of multibyte sequence, not includ-
       ing the terminating null byte.  If a wide character  was  encountered  which  could  not  be  converted,  (size_t) -1  is
       returned, and errno set to EILSEQ.

CONFORMING TO
       This function is a GNU extension.

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

       Passing NULL as ps is not multithread safe.

SEE ALSO
       iconv(3), wcsrtombs(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                                                        2007-07-26                                              WCSNRTOMBS(3)