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.TH PCAP_SETFILTER 3PCAP "5 March 2022"
.SH NAME
pcap_setfilter \- set the filter
.SH SYNOPSIS
.nf
.ft B
#include <pcap/pcap.h>
.ft
.LP
.ft B
int pcap_setfilter(pcap_t *p, struct bpf_program *fp);
.ft
.fi
.SH DESCRIPTION
.BR pcap_setfilter ()
is used to specify a filter program.
.I fp
is a pointer to a
.I bpf_program
struct, usually the result of a call to
.BR \%pcap_compile (3PCAP).
.SH RETURN VALUE
.BR pcap_setfilter ()
returns
.B 0
on success,
.B PCAP_ERROR_NOT_ACTIVATED
if called on a capture handle that has been created but not activated, or
.B PCAP_ERROR
on other errors.  If
.B PCAP_ERROR
is returned,
.BR pcap_geterr (3PCAP)
or
.BR pcap_perror (3PCAP)
may be called with
.I p
as an argument to fetch or display the error text.
.SH SEE ALSO
.BR pcap (3PCAP)