pcap_list_datalinks (3)

Leading comments

 Copyright (c) 1994, 1996, 1997
	The Regents of the University of California.  All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that: (1) source code distributions
 retain the above copyright notice and this paragraph in its entirety, (2)
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(The comments found at the beginning of the groff file "man3/pcap_list_datalinks.3pcap".)

NAME

pcap_list_datalinks, pcap_free_datalinks - get a list of link-layer header types supported by a capture device, and free that list

SYNOPSIS

#include <pcap/pcap.h>

int pcap_list_datalinks(pcap_t *p, int **dlt_buf);
void pcap_free_datalinks(int *dlt_list);

DESCRIPTION

pcap_list_datalinks() is used to get a list of the supported link-layer header types of the interface associated with the pcap descriptor. pcap_list_datalinks() allocates an array to hold the list and sets *dlt_buf to point to that array.

The caller is responsible for freeing the array with pcap_free_datalinks(), which frees the list of link-layer header types pointed to by dlt_list.

It must not be called on a pcap descriptor created by pcap_create() that has not yet been activated by pcap_activate().

RETURN VALUE

pcap_list_datalinks() returns the number of link-layer header types in the array on success, PCAP_ERROR_NOT_ACTIVATED if called on a capture handle that has been created but not activated, and PCAP_ERROR (-1) on other errors. If PCAP_ERROR is returned, pcap_geterr() or pcap_perror() may be called with p as an argument to fetch or display the error text.

SEE ALSO

pcap(3PCAP), pcap_geterr(3PCAP), pcap_datalink_val_to_name(3PCAP), pcap-linktype(7)