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.TH PCAP_LOOKUPNET 3PCAP "25 July 2018"
.SH NAME
pcap_lookupnet \- find the IPv4 network number and netmask for a device
.SH SYNOPSIS
.nf
.ft B
#include <pcap/pcap.h>
.ft
.LP
.nf
.ft B
char errbuf[PCAP_ERRBUF_SIZE];
.ft
.LP
.ft B
int pcap_lookupnet(const char *device, bpf_u_int32 *netp,
.ti +8
bpf_u_int32 *maskp, char *errbuf);
.ft
.fi
.SH DESCRIPTION
.B pcap_lookupnet()
is used to determine the IPv4 network number and mask
associated with the network device
.IR device .
Both
.I netp
and
.I maskp
are
.I bpf_u_int32
pointers.
.SH RETURN VALUE
.B pcap_lookupnet()
returns 0 on success and
.B PCAP_ERROR
on failure. If
.B PCAP_ERROR
is returned,
.I errbuf
is filled in with an appropriate error message.
.I errbuf
is assumed to be able to hold at least
.B PCAP_ERRBUF_SIZE
chars.
.SH SEE ALSO
pcap(3PCAP)