Originální popis anglicky:
mblen - get number of bytes in a character
Návod, kniha: POSIX Programmer's Manual
#include <stdlib.h>
int mblen(const char *
s, size_t
n );
If
s is not a null pointer,
mblen() shall determine the number of
bytes constituting the character pointed to by
s. Except that the shift
state of
mbtowc() is not affected, it shall be equivalent to:
mbtowc((wchar_t *)0, s, n);
The implementation shall behave as if no function defined in this volume of
IEEE Std 1003.1-2001 calls
mblen().
The behavior of this function is affected by the
LC_CTYPE category of the
current locale. For a state-dependent encoding, this function shall be placed
into its initial state by a call for which its character pointer argument,
s, is a null pointer. Subsequent calls with
s as other than a
null pointer shall cause the internal state of the function to be altered as
necessary. A call with
s as a null pointer shall cause this function to
return a non-zero value if encodings have state dependency, and 0 otherwise.
If the implementation employs special bytes to change the shift state, these
bytes shall not produce separate wide-character codes, but shall be grouped
with an adjacent character. Changing the
LC_CTYPE category causes the
shift state of this function to be unspecified.
If
s is a null pointer,
mblen() shall return a non-zero or 0
value, if character encodings, respectively, do or do not have state-dependent
encodings. If
s is not a null pointer,
mblen() shall either
return 0 (if
s points to the null byte), or return the number of bytes
that constitute the character (if the next
n or fewer bytes form a
valid character), or return -1 (if they do not form a valid character)
and may set
errno to indicate the error. In no case shall the
value returned be greater than
n or the value of the {MB_CUR_MAX}
macro.
The
mblen() function may fail if:
- EILSEQ
- Invalid character sequence is detected.
The following sections are informative.
None.
None.
None.
None.
mbtowc() ,
mbstowcs() ,
wctomb() ,
wcstombs() , the
Base Definitions volume of IEEE Std 1003.1-2001,
<stdlib.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
.
