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.TH PCAP_STATS 3PCAP "25 July 2018"

.SH NAME

pcap_stats \- get capture statistics

.SH SYNOPSIS

.nf

.ft B

#include <pcap/pcap.h>

.ft

.LP

.ft B

int pcap_stats(pcap_t *p, struct pcap_stat *ps);

.ft

.fi

.SH DESCRIPTION

.B pcap_stats()

fills in the

.B struct pcap_stat

pointed to by its second argument.  The values represent

packet statistics from the start of the run to the time of the call.

.PP

.B pcap_stats()

is supported only on live captures, not on ``savefiles''; no statistics

are stored in ``savefiles'', so no statistics are available when reading

from a ``savefile''.

.PP

A

.B struct pcap_stat

has the following members:

.RS

.TP

.B ps_recv

number of packets received;

.TP

.B ps_drop

number of packets dropped because there was no room in the operating

system's buffer when they arrived, because packets weren't being read

fast enough;

.TP

.B ps_ifdrop

number of packets dropped by the network interface or its driver.

.RE

.PP

The statistics do not behave the same way on all platforms.

.B ps_recv

might count packets whether they passed any filter set with

.BR pcap_setfilter (3PCAP)

or not, or it might count only packets that pass the filter.

It also might, or might not, count packets dropped because there was no

room in the operating system's buffer when they arrived.

.B ps_drop

is not available on all platforms; it is zero on platforms where it's

not available.  If packet filtering is done in libpcap, rather than in

the operating system, it would count packets that don't pass the filter.

Both

.B ps_recv

and

.B ps_drop

might, or might not, count packets not yet read from the operating

system and thus not yet seen by the application.

.B ps_ifdrop

might, or might not, be implemented; if it's zero, that might mean that

no packets were dropped by the interface, or it might mean that the

statistic is unavailable, so it should not be treated as an indication

that the interface did not drop any packets.

.SH RETURN VALUE

.B pcap_stats()

returns 0 on success and returns

.B PCAP_ERROR

if there is an error or if

.I p

doesn't support packet statistics. If

.B PCAP_ERROR

is returned,

.B pcap_geterr(3PCAP)

or

.B pcap_perror(3PCAP)

may be called with

.I p

as an argument to fetch or display the error text.

.SH SEE ALSO

pcap(3PCAP)