This interface is obsoleted by pcap_findalldevs(3PCAP). To find
a default device on which to capture, call pcap_findalldevs()
and, if the list it returns is not empty, use the first device in
the list. (If the list is empty, there are no devices on which
capture is possible.)
If pcap_init(3PCAP) has been called, this interface alwaysreturns NULL.
pcap_lookupdev() returns a pointer to a string giving the name of
a network device suitable for use with pcap_create(3PCAP) and
pcap_activate(3PCAP), or with pcap_open_live(3PCAP), and with
pcap_lookupnet(3PCAP). If there is an error, or if
pcap_init(3PCAP) has been called, NULL is returned and errbuf is
filled in with an appropriate error message. errbuf is assumed
to be able to hold at least PCAP_ERRBUF_SIZE chars.
The pointer returned by pcap_lookupdev() points to a static
buffer; subsequent calls to pcap_lookupdev() in the same thread,
or calls to pcap_lookupdev() in another thread, may overwrite
In WinPcap and Npcap, this function may return a UTF-16 string
rather than an ASCII or UTF-8 string.
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 2021-08-27.
(At that time, the date of the most recent commit that was found
in the repository was 2021-08-17.) 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
8 September 2017 PCAP_LOOKUPDEV(3PCAP)