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.TH PCAP_CAN_SET_RFMON 3PCAP "31 July 2016"
.SH NAME
pcap_can_set_rfmon \- check whether monitor mode can be set for a
not-yet-activated capture handle
.SH SYNOPSIS
.nf
.ft B
#include <pcap/pcap.h>
.LP
.ft B
int pcap_can_set_rfmon(pcap_t *p);
.ft
.fi
.SH DESCRIPTION
.BR pcap_can_set_rfmon ()
checks whether monitor mode could be set on a capture handle when
the handle is activated.
.SH RETURN VALUE
.BR pcap_can_set_rfmon ()
returns
.B 0
if monitor mode could not be set,
.B 1
if monitor mode could be set, and a negative value on error.
A negative return value indicates what error condition occurred.
The possible error values are:
.TP
.B PCAP_ERROR_NO_SUCH_DEVICE
The capture source specified when the handle was created doesn't
exist.
.TP
.B PCAP_ERROR_PERM_DENIED
The process doesn't have permission to check whether monitor mode
could be supported.
.TP
.B PCAP_ERROR_ACTIVATED
The capture handle has already been activated.
.TP
.B PCAP_ERROR
Another error occurred.
.BR pcap_geterr (3PCAP)
or
.BR \%pcap_perror (3PCAP)
may be called with
.I p
as an argument to fetch or display a message describing the error.
.LP
Additional error codes may be added in the future; a program should
check for
.BR 0 ,
.BR 1 ,
and negative, return codes, and treat all negative
return codes as errors.
.BR pcap_statustostr (3PCAP)
can be called, with a warning or error code as an argument, to fetch a
message describing the warning or error code.
.SH SEE ALSO
.BR pcap (3PCAP),
.BR pcap_create (3PCAP),
.BR pcap_activate (3PCAP),
.BR pcap_set_rfmon (3PCAP)