MBRLEN(P) POSIX Programmer's Manual MBRLEN(P)NAMEmbrlen - 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 equiva‐
lent 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 inter‐
nal 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 corre‐
sponds 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 ALSOmbsinit() , 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 .
IEEE/The Open Group 2003 MBRLEN(P)
