PCAP_LOOKUPDEV(3)      FreeBSD Library Functions Manual      PCAP_LOOKUPDEV(3)

NAME
       pcap_lookupdev - find the default device on which to capture

SYNOPSIS
       #include <pcap/pcap.h>

       char errbuf[PCAP_ERRBUF_SIZE];

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

DESCRIPTION
       This interface is obsoleted by pcap_findalldevs(3).  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.)

       pcap_lookupdev() returns a pointer to a string giving the name of a
       network device suitable for use with pcap_create(3) and
       pcap_activate(3), or with pcap_open_live(3), and with
       pcap_lookupnet(3).  If there is an error, 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
       pcap(3)

BUGS
       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, this function may return a UTF-16 string rather than an
       ASCII or UTF-8 string.

                               8 September 2017              PCAP_LOOKUPDEV(3)