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(3PCAP) that has not yet been activated by
https://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 or
DLT_LINUX_SLL2 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.
This page is part of the libpcap (packet capture library)
project. Information about the project can be found at
⟨http://www.tcpdump.org/⟩. If you have a bug report for this
manual page, see ⟨http://www.tcpdump.org/#patches⟩. This page
was obtained from the project's upstream Git repository
⟨https://github.com/the-tcpdump-group/libpcap.git⟩ on 2021-04-01.
(At that time, the date of the most recent commit that was found
in the repository was 2021-03-31.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
7 April 2014 PCAP_DATALINK(3PCAP)