Originální popis anglicky:
mbrlen - get number of bytes in a character (restartable)
Návod, kniha: POSIX Programmer's Manual
#include <wchar.h>
size_t mbrlen(const char *restrict
s, size_t
n,
mbstate_t *restrict
ps );
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 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.
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.
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.
None.
None.
None.
None.
mbsinit() ,
mbrtowc() , the Base Definitions volume of
IEEE Std 1003.1-2001,
<wchar.h>
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
.
