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NAME
mbrlen - 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 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.
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 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.
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 ALSO
mbsinit() , 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 .