MBRLEN(3P)                                          POSIX Programmer's Manual                                         MBRLEN(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
       mbrlen - get number of bytes in a character (restartable)

SYNOPSIS
       #include <wchar.h>

       size_t mbrlen(const char *restrict s, size_t n,
              mbstate_t *restrict ps);


DESCRIPTION
       If  s  is not a null pointer, mbrlen() shall determine the number of bytes constituting the character pointed to by s. It
       shall be equivalent to:


              mbstate_t internal;
              mbrtowc(NULL, s, n, ps != NULL ? ps : &internal);

       If ps is a null pointer, the mbrlen() function shall use its own internal mbstate_t object, which is initialized at  pro-
       gram  start-up  to  the  initial conversion state. Otherwise, the mbstate_t object pointed to by ps shall be used to com-
       pletely describe the current conversion state of the associated character sequence. The implementation shall behave as if
       no function defined in this volume of IEEE Std 1003.1-2001 calls mbrlen().

       The behavior of this function is affected by the LC_CTYPE category of the current locale.

RETURN VALUE
       The mbrlen() function shall return the first of the following that applies:

       0      If the next n or fewer bytes complete the character that corresponds to the null wide character.

       positive
              If the next n or fewer bytes complete a valid character; the value returned shall be the number of bytes that com-
              plete the character.

       (size_t)-2
              If the next n bytes contribute to an incomplete but potentially valid character, and all n bytes  have  been  pro-
              cessed.  When  n  has  at  least  the  value  of the {MB_CUR_MAX} macro, this case can only occur if s points at a
              sequence of redundant shift sequences (for implementations with state-dependent encodings).

       (size_t)-1
              If an encoding error occurs, in which case the next n or fewer bytes do not contribute to  a  complete  and  valid
              character. In this case, [EILSEQ] shall be stored in errno and the conversion state is undefined.


ERRORS
       The mbrlen() function may fail if:

       EINVAL ps points to an object that contains an invalid conversion state.

       EILSEQ Invalid character sequence is detected.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       mbsinit(), mbrtowc(), the Base Definitions volume of IEEE Std 1003.1-2001, <wchar.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                                                    MBRLEN(3P)