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 Ethernet.  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 created but not activated.

SEE ALSO

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

                                          22 August 2010                     PCAP_DATALINK(3PCAP)