csu3_am335x/EVSE/GPL/libpcap-1.9.0/pcap_open_dead.3pcap

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.TH PCAP_OPEN_DEAD 3PCAP "3 January 2014"
.SH NAME
pcap_open_dead, pcap_open_dead_with_tstamp_precision \- open a fake
pcap_t for compiling filters or opening a capture for output
.SH SYNOPSIS
.nf
.ft B
#include <pcap/pcap.h>
.ft
.LP
.ft B
pcap_t *pcap_open_dead(int linktype, int snaplen);
pcap_t *pcap_open_dead_with_tstamp_precision(int linktype, int snaplen,
    u_int precision);
.ft
.fi
.SH DESCRIPTION
.PP
.B pcap_open_dead()
and
.B pcap_open_dead_with_tstamp_precision()
are used for creating a
.B pcap_t
structure to use when calling the other functions in libpcap.  It is
typically used when just using libpcap for compiling BPF code; it can
also be used if using
.BR pcap_dump_open() ,
.BR pcap_dump() ,
and
.B pcap_dump_close()
to write a savefile if there is no
.B pcap_t
that supplies the packets to be written.
.PP
.I linktype
specifies the link-layer type for the
.BR pcap_t .
.PP
.I snaplen
specifies the snapshot length for the
.BR pcap_t .
.PP
When
.BR pcap_open_dead_with_tstamp_precision() ,
is used to create a
.B pcap_t
for use with
.BR pcap_dump_open() ,
.I precision
specifies the time stamp precision for packets;
.B PCAP_TSTAMP_PRECISION_MICRO
should be specified if the packets to be written have time stamps in
seconds and microseconds, and
.B PCAP_TSTAMP_PRECISION_NANO
should be specified if the packets to be written have time stamps in
seconds and nanoseconds.  Its value does not affect
.BR pcap_compile() .
.SH SEE ALSO
pcap(3PCAP), pcap_compile(3PCAP), pcap_dump_open(3PCAP),
\%pcap-linktype(7)