MBSTOWCS(3P)                                        POSIX Programmer's Manual                                       MBSTOWCS(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       mbstowcs - convert a character string to a wide-character string

SYNOPSIS
       #include <stdlib.h>

       size_t mbstowcs(wchar_t *restrict pwcs, const char *restrict s,
              size_t n);


DESCRIPTION
       The  mbstowcs()  function  shall  convert  a sequence of characters that begins in the initial shift state from the array
       pointed to by s into a sequence of corresponding wide-character codes and shall store  not  more  than  n  wide-character
       codes  into the array pointed to by pwcs. No characters that follow a null byte (which is converted into a wide-character
       code with value 0) shall be examined or converted. Each character shall be converted as if by a call to mbtowc(),  except
       that the shift state of mbtowc() is not affected.

       No  more  than  n elements shall be modified in the array pointed to by pwcs. If copying takes place between objects that
       overlap, the behavior is undefined.

       The behavior of this function shall be affected by the LC_CTYPE category of the  current  locale.   If  pwcs  is  a  null
       pointer,  mbstowcs()  shall  return  the length required to convert the entire array regardless of the value of n, but no
       values are stored.

RETURN VALUE
       If an invalid character is encountered, mbstowcs() shall return (size_t)-1  and may set errno to indicate the error.

       Otherwise, mbstowcs() shall return the number of the array elements modified  (or required if pwcs is null),  not includ-
       ing a terminating 0 code, if any. The array shall not be zero-terminated if the value returned is n.

ERRORS
       The mbstowcs() function may fail if:

       EILSEQ Invalid byte sequence is detected.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       mblen(), mbtowc(), wctomb(), wcstombs(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open  Group
       Standard   is   the   referee   document.   The   original   Standard   can   be   obtained  online  at  http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                  MBSTOWCS(3P)