The functionality described on this reference page is aligned with
the ISO C standard. Any conflict between the
requirements described here and the ISO C standard is unintentional.
This volume of IEEE Std 1003.1-2001 defers to
the ISO C standard.
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:
If ps is a null pointer, the mbrlen() function shall use
its own internal mbstate_t object, which is
initialized at program start-up to the initial conversion state. Otherwise,
the mbstate_t object pointed to by ps
shall be used to completely 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 complete
the character.
(size_t)-2
If the next n bytes contribute to an incomplete but potentially
valid character, and all n bytes have been
processed. 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, Copyright (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.opengroup.org/unix/online.html .
