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.TH PCAP_ACTIVATE 3PCAP "31 July 2016"

.SH NAME

pcap_activate \- activate a capture handle

.SH SYNOPSIS

.nf

.ft B

#include <pcap/pcap.h>

.ft

.LP

.ft B

int pcap_activate(pcap_t *p);

.ft

.fi

.SH DESCRIPTION

.B pcap_activate()

is used to activate a packet capture handle to look

at packets on the network, with the options that were set on the handle

being in effect.

.SH RETURN VALUE

.B pcap_activate()

returns 0 on success without warnings, a non-zero positive value on

success with warnings, and a negative value on error.

A non-zero return value indicates what warning or error condition

occurred.

.LP

The possible warning values are:

.TP

.B PCAP_WARNING_PROMISC_NOTSUP

Promiscuous mode was requested, but the capture source doesn't support

promiscuous mode.

.TP

.B PCAP_WARNING_TSTAMP_TYPE_NOTSUP

The time stamp type specified in a previous

.B pcap_set_tstamp_type(3PCAP)

call isn't supported by the capture source (the time stamp type is

left as the default),

.TP

.B PCAP_WARNING

Another warning condition occurred;

.B pcap_geterr(3PCAP)

or

.B pcap_perror(3PCAP)

may be called with

.I p

as an argument to fetch or display a message describing the warning

condition.

.LP

The possible error values are:

.TP

.B PCAP_ERROR_ACTIVATED

The handle has already been activated.

.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 open the capture source.

.TP

.B PCAP_ERROR_PROMISC_PERM_DENIED

The process has permission to open the capture source but doesn't

have permission to put it into promiscuous mode.

.TP

.B PCAP_ERROR_RFMON_NOTSUP

Monitor mode was specified but the capture source doesn't support

monitor mode.

.TP

.B PCAP_ERROR_IFACE_NOT_UP

The capture source device is not up.

.TP

.B PCAP_ERROR

Another error occurred.

.B pcap_geterr()

or

.B pcap_perror()

may be called with

.I p

as an argument to fetch or display a message describing the error.

.LP

If

.BR PCAP_WARNING_PROMISC_NOTSUP ,

.BR PCAP_ERROR_NO_SUCH_DEVICE ,

or

.B PCAP_ERROR_PERM_DENIED

is returned,

.B pcap_geterr()

or

.B pcap_perror()

may be called with

.I p

as an argument to fetch or display an message giving additional details

about the problem that might be useful for debugging the problem if it's

unexpected.

.LP

Additional warning and error codes may be added in the future; a program

should check for positive, negative, and zero return codes, and treat

all positive return codes as warnings and all negative return

codes as errors.

.B 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

pcap(3PCAP)