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.TH PCAP_LIST_DATALINKS 3PCAP "25 July 2018"

.SH NAME

pcap_list_datalinks, pcap_free_datalinks \- get a list of link-layer header

types supported by a capture device, and free that list

.SH SYNOPSIS

.nf

.ft B

#include <pcap/pcap.h>

.ft

.LP

.ft B

int pcap_list_datalinks(pcap_t *p, int **dlt_buf);

void pcap_free_datalinks(int *dlt_list);

.ft

.fi

.SH DESCRIPTION

.B pcap_list_datalinks()

is used to get a list of the supported link-layer header types of the

interface associated with the pcap descriptor.

.B pcap_list_datalinks()

allocates an array to hold the list and sets

.IR *dlt_buf

to point to that array.

.LP

The caller is responsible for freeing the array with

.BR pcap_free_datalinks() ,

which frees the list of link-layer header types pointed to by

.IR dlt_list .

.LP

It must not be called on a pcap descriptor created by

.B \%pcap_create(3PCAP)

that has not yet been activated by

.BR \%pcap_activate(3PCAP) .

.SH RETURN VALUE

.B pcap_list_datalinks()

returns the number of link-layer header types in the array on success,

.B PCAP_ERROR_NOT_ACTIVATED

if called on a capture handle that has been created but not activated,

and

.B PCAP_ERROR

on other errors.

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),

pcap_datalink_val_to_name(3PCAP),

pcap-linktype(@MAN_MISC_INFO@)