Manual Pages  — PCAP_LOOKUPDEV

#include <pcap/pcap.h>

char errbuf[PCAP_ERRBUF_SIZE];

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

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.

pcap(3)