Originální popis anglicky:
mblen - determine number of bytes in next multibyte character
Návod, kniha: Linux Programmer's Manual
#include <stdlib.h>
int mblen(const char *s, size_t n);
If
s is not a NULL pointer, the
mblen function inspects at most
n bytes of the multibyte string starting at
s and extracts the
next complete multibyte character. It uses a static anonymous shift state only
known to the mblen function. If the multibyte character is not the null wide
character, it returns the number of bytes that were consumed from
s. If
the multibyte character is the null wide character, it returns 0.
If the
n bytes starting at
s do not contain a complete multibyte
character,
mblen returns
-1. This can happen even if
n
>=
MB_CUR_MAX, if the multibyte string contains redundant shift
sequences.
If the multibyte string starting at
s contains an invalid multibyte
sequence before the next complete character,
mblen also returns
-1.
If
s is a NULL pointer, the
mblen function resets the shift state,
only known to this function, to the initial state, and returns non-zero if the
encoding has non-trivial shift state, or zero if the encoding is stateless.
The
mblen function returns the number of bytes parsed from the multibyte
sequence starting at
s, if a non-null wide character was recognized. It
returns 0, if a null wide character was recognized. It returns -1, if an
invalid multibyte sequence was encountered or if it couldn't parse a complete
multibyte character.
ISO/ANSI C, UNIX98
mbrlen(3)
The behaviour of
mblen depends on the LC_CTYPE category of the current
locale.
The function
mbrlen provides a better interface to the same
functionality.