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.TH PCAP_OPEN_LIVE 3PCAP "6 December 2017"

.SH NAME

pcap_open_live \- open a device for capturing

.SH SYNOPSIS

.nf

.ft B

#include <pcap/pcap.h>

.ft

.LP

.nf

.ft B

char errbuf[PCAP_ERRBUF_SIZE];

.ft

.LP

.ft B

pcap_t *pcap_open_live(const char *device, int snaplen,

.ti +8

int promisc, int to_ms, char *errbuf);

.ft

.fi

.SH DESCRIPTION

.B pcap_open_live()

is used to obtain a packet capture handle to look

at packets on the network.

.I device

is a string that specifies the network device to open; on Linux systems

with 2.2 or later kernels, a

.I device

argument of "any" or

.B NULL

can be used to capture packets from all interfaces.

.PP

.I snaplen

specifies the snapshot length to be set on the handle.

.PP

.I promisc

specifies if the interface is to be put into promiscuous mode.

.PP

.I to_ms

specifies the packet buffer timeout, as a non-negative value, in

milliseconds.  (See

.BR pcap (3PCAP)

for an explanation of the packet buffer timeout.)

.SH RETURN VALUE

.B pcap_open_live()

returns a

.I pcap_t *

on success and

.B NULL

on failure.

If

.B NULL

is returned,

.I errbuf

is filled in with an appropriate error message.

.I errbuf

may also be set to warning text when

.B pcap_open_live()

succeeds; to detect this case the caller should store a zero-length string in

.I errbuf

before calling

.B pcap_open_live()

and display the warning to the user if

.I errbuf

is no longer a zero-length string.

.I errbuf

is assumed to be able to hold at least

.B PCAP_ERRBUF_SIZE

chars.

.SH SEE ALSO

pcap_create(3PCAP), pcap_activate(3PCAP)