PCAP_DATALINK(3)					     Library Functions Manual						  PCAP_DATALINK(3)

NAME

       pcap_datalink - get the link-layer header type

SYNOPSIS

       #include <pcap/pcap.h>

       int pcap_datalink(pcap_t *p);

DESCRIPTION

       pcap_datalink() returns the link-layer header type for the live capture or ``savefile'' specified by p.

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

       http://www.tcpdump.org/linktypes.html lists the values pcap_datalink() can return and describes the packet formats that correspond to those
       values.

       Do NOT assume that the packets for a given capture or ``savefile`` will have any given link-layer header type, such as DLT_EN10MB for  Eth-
       ernet.  For example, the "any" device on Linux will have a link-layer header type of DLT_LINUX_SLL even if all devices on the system at the
       time the "any" device is opened have some other data link type, such as DLT_EN10MB for Ethernet.

RETURN VALUE

       pcap_datalink() returns the link-layer header type on success and PCAP_ERROR_NOT_ACTIVATED if called on a capture handle that has been cre-
       ated but not activated.

SEE ALSO

       pcap(3), pcap-linktype(7)

								  13 October 2013						  PCAP_DATALINK(3)