NAME
mbrlen() — get number of bytes in a character (restartable)
SYNOPSIS
#include <wchar.h>
size_t mbrlen(const char *s, size_t n, mbstate_t *ps);
DESCRIPTION
If
s
is not a null pointer,
mbrlen()
determines the number of bytes constituting the character pointed to by
s.
It is equivalent to:
mbstate_t internal;
mbrtowc(NULL, s, n, ps != NULL ? ps : &internal);
If
ps
is a null pointer, the
mbrlen()
function uses its own internal
mbstate_t
object, which is initialized
at program startup to the initial conversion state.
Otherwise, the
mbstate_t
object pointed to by
ps
is used to completely describe the current conversion state of
the associated character sequence.
EXTERNAL INFLUENCES
locale
The behavior of this function is affected by the
LC_CTYPE
category of the current locale.
RETURN VALUE
The
mbrlen()
function returns 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 is 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
is 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.
AUTHOR
mbrlen()
was developed by HP and Mitsubishi Electric Corporation.
