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 is greater than or equal to 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 nontrivial shift state, or zero if the
encoding is stateless.
RETURN VALUE
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.
CONFORMING TO
C99.
NOTES
The behavior of
mblen()
depends on the
LC_CTYPE
category of the
current locale.
The function
mbrlen(3)
provides a better interface to the same
functionality.
This page is part of release 3.14 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
