Tribblix: manual page: mblen.3c

MBLEN(3C) Standard C Library Functions MBLEN(3C)

NAME

mblen, mblen_l - get number of bytes in a character

SYNOPSIS

#include <stdlib.h>

int mblen(const char *s, size_t n);

#include <stdlib.h>
#include <xlocale.h>

int mblen_l(const char *s, size_t n, locale_t loc);

DESCRIPTION

If s is not a null pointer, mblen() and mblen_l() determine the
number of bytes constituting the character pointed to by s. The call

mblen(s, n);

is equivalent to:

mbtowc((wchar_t *)0, s, n);

A call with s as a null pointer causes this function to return 0.

Whereas the behavior of the mblen() function is affected by the
LC_CTYPE category of the current locale, the behavior of mblen_l() is
affected by the LC_CTYPE category of the locale specified by loc.

RETURN VALUES

If s is a null pointer, mblen() and mblen_l() returns 0. It s is not
a null pointer, mblen() and mblen_l() returns 0 (if s points to the
null byte), the number of bytes that constitute the character (if the
next n or fewer bytes form a valid character), or -1 (if they do not
form a valid character) and may set errno to indicate the error. In
no case will the value returned be greater than n or the value of the
MB_CUR_MAX macro.

ERRORS

The mblen() and mblen_l() functions may fail if:

EILSEQ
Invalid character sequence is detected.