pcap_lookupdev(3pcap) — Linux manual page


PCAP_LOOKUPDEV(3PCAP)                              PCAP_LOOKUPDEV(3PCAP)

NAME         top

       pcap_lookupdev - find the default device on which to capture

SYNOPSIS         top

       #include <pcap/pcap.h>

       char errbuf[PCAP_ERRBUF_SIZE];

       [DEPRECATED] char *pcap_lookupdev(char *errbuf);

DESCRIPTION         top

       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 always
       returns 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.

SEE ALSO         top


BUGS         top

       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
       that buffer.

       In WinPcap and Npcap, this function may return a UTF-16 string
       rather than an ASCII or UTF-8 string.

COLOPHON         top

       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 2023-06-23.
       (At that time, the date of the most recent commit that was found
       in the repository was 2023-06-21.)  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)