MBLEN(3) | Library Functions Manual | MBLEN(3) |
mblen
—
#include <stdlib.h>
int
mblen
(const
char *s, size_t
n);
mblen
() function usually determines the number of
bytes in a multibyte character pointed to by s and
returns it. This function shall only examine max n bytes of the array
beginning from s.
In state-dependent encodings, s may point
the special sequence bytes to change the shift-state. Although such sequence
bytes corresponds to no individual wide-character code, the
mblen
() changes the own state by them and treats
them as if they are a part of the subsequent multibyte character.
Unlike mbrlen(3), the first n bytes pointed to by s need to form an entire multibyte character. Otherwise, this function causes an error.
mblen
() is equivalent to the following
call, except the internal state of the
mbtowc(3) function is not
affected:
mbtowc(NULL, s, n);
Calling any other functions in Standard
C Library (libc, -lc) never changes the internal state of
mblen
(), except for calling
setlocale(3) with the
LC_CTYPE
category changed to that of the current
locale. Such setlocale(3)
calls cause the internal state of this function to be indeterminate.
The behaviour of mblen
() is affected by
the LC_CTYPE
category of the current locale.
These are the special cases:
mblen
() initializes its own internal state to an
initial state, and determines whether the current encoding is
state-dependent. This function returns 0 if the encoding is
state-independent, otherwise non-zero.mblen
() always fails.mblen
() returns:
MB_CUR_MAX
macro.mblen
() also sets
errno to indicate the error.When s is equal to
NULL
, the mblen
()
returns:
mblen
() may cause an error in the following case:
EILSEQ
]mblen
() function conforms to ANSI
X3.159-1989 (“ANSI C89”).
February 3, 2002 | NetBSD 9.2 |