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.TH PCAP_LIST_DATALINKS 3 "22 August 2010"
.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 .
.SH RETURN VALUE
.B pcap_list_datalinks()
returns the number of link-layer header types in the array on success
and \-1 on failure.
If \-1 is returned,
.B pcap_geterr()
or
.B pcap_perror()
may be called with
.I p
as an argument to fetch or display the error text.
.SH SEE ALSO
pcap(3), pcap_geterr(3),
pcap_datalink_val_to_name(3),
pcap-linktype(7)
