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.TH MBLEN 3C "Jun 24, 2014"
.SH NAME
mblen, mblen_l \- get number of bytes in a character
.SH SYNOPSIS
.LP
.nf
#include <stdlib.h>

\fBint\fR \fBmblen\fR(\fBconst char *\fR\fIs\fR, \fBsize_t\fR \fIn\fR);
.fi
.LP
.nf
#include <stdlib.h>
#include <xlocale.h>

\fBint\fR \fBmblen_l\fR(\fBconst char *\fR\fIs\fR, \fBsize_t\fR \fIn\fR, \fBlocale_t\fR \fIloc\fR);
.fi

.SH DESCRIPTION
.sp
.LP
If \fIs\fR is not a null pointer, \fBmblen()\fR and \fBmblen_l()\fR
determine the number of bytes constituting the character pointed to by
\fIs\fR. The call
.IP
\fBmblen\fR(\fIs\fR, \fIn\fR);
.LP
is equivalent to:
.IP
\fBmbtowc\fR((\fBwchar_t\fR *)0, \fIs\fR, \fIn\fR);
.LP
A call with \fIs\fR as a null pointer causes this function to return \fB0\fR.
.LP
Whereas the behavior of the \fBmblen()\fR function is affected by the
\fBLC_CTYPE\fR category of the current locale, the behavior of
\fBmblen_l()\fR is affected by the \fBLC_CTYPE\fR category of the
locale specified by \fIloc\fR.
.SH RETURN VALUES
.LP
If \fIs\fR is a null pointer, \fBmblen()\fR and \fBmblen_l()\fR returns \fB0\fR. It \fIs\fR is not
a null pointer, \fBmblen()\fR and \fBmblen_l()\fR returns \fB0\fR (if \fIs\fR points to the null
byte), the number of bytes that constitute the character (if the next \fIn\fR
or fewer bytes form a valid character), or  \fB\(mi1\fR (if they do not form a
valid character) and may set \fBerrno\fR to indicate the error. In no case will
the value returned be greater than \fIn\fR or the value of the \fBMB_CUR_MAX\fR
macro.
.SH ERRORS
.sp
.LP
The \fBmblen()\fR and \fBmblen_l()\fR functions may fail if:
.sp
.ne 2
.na
\fB\fBEILSEQ\fR\fR
.ad
.RS 10n
Invalid character sequence is detected.
.RE
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
CSI	Enabled
_
Interface Stability	See below.
_
MT-Level	MT-Safe
.TE

.LP
The
.B mblen()
function is Standard. The
.B mblen_l()
function is Uncommitted.
.SH SEE ALSO
.LP
\fBmbstowcs\fR(3C), \fBmbtowc\fR(3C), \fBnewlocale\fR(3C), \fBsetlocale\fR(3C),
\fBwcstombs\fR(3C), \fBwctomb\fR(3C), \fBuselocale\fR(3C) \fBattributes\fR(7),
.BR standards (7)