mblen(3) - phpMan
MBLEN(3) Linux Programmer's Manual MBLEN(3)
mblen - determine number of bytes in next multibyte character
int mblen(const char *s, size_t n);
If s is not NULL, 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 anony‐
mous shift state known only 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 NULL, the mblen() function resets the shift state, known to only this function, to
the initial state, and returns nonzero if the encoding has nontrivial shift state, or zero
if the encoding is stateless.
The mblen() function returns the number of bytes parsed from the multibyte sequence start‐
ing at s, if a non-null wide character was recognized. It returns 0, if a null wide char‐
acter was recognized. It returns -1, if an invalid multibyte sequence was encountered or
if it couldn't parse a complete multibyte character.
Multithreading (see pthreads(7))
The mblen() function is not thread-safe.
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 3.74 of the Linux man-pages project. A description of the
project, information about reporting bugs, and the latest version of this page, can be
found at http://www.kernel.org/doc/man-pages/.
GNU 2013-06-21 MBLEN(3)