NAME

       pcap_open_live - open a device for capturing

SYNOPSIS

       #include <pcap/pcap.h>

       char errbuf[PCAP_ERRBUF_SIZE];

       pcap_t *pcap_open_live(const char *device, int snaplen,
           int promisc, int to_ms, char *errbuf);

DESCRIPTION

       pcap_open_live()  is used to obtain a packet capture handle to look at packets on the network.  device is
       a string that specifies the network device to open; on all supported Linux systems, as well as on  recent
       versions of macOS and Solaris, a device argument of "any" or NULL can be used to capture packets from all
       network  interfaces.   The  latter  should  not be confused with all available capture devices as seen by
       pcap_findalldevs(3PCAP), which may also include D-Bus, USB etc.

       snaplen specifies the snapshot length to be set on  the  handle.   If  the  packet  data  should  not  be
       truncated  at the end, a value of 262144 should be sufficient for most devices, but D-Bus devices require
       a value of 128MB (128*1024*1024).

       promisc specifies whether the interface is to be put into promiscuous  mode.   If  promisc  is  non-zero,
       promiscuous mode will be set, otherwise it will not be set.

       to_ms  specifies  the  packet buffer timeout, as a non-negative value, in milliseconds.  (See pcap(3PCAP)
       for an explanation of the packet buffer timeout.)

       errbuf is a buffer large enough to hold at least PCAP_ERRBUF_SIZE chars.

RETURN VALUE

       pcap_open_live() returns a pcap_t * on success and NULL on failure.   If  NULL  is  returned,  errbuf  is
       filled   in  with  an  appropriate  error  message.   errbuf  may  also  be  set  to  warning  text  when
       pcap_open_live() succeeds; to detect this case the caller should store a  zero-length  string  in  errbuf
       before  calling pcap_open_live() and display the warning to the user if errbuf is no longer a zero-length
       string.

SEE ALSO

       pcap_create(3PCAP), pcap_activate(3PCAP)

                                                  4 March 2024                             PCAP_OPEN_LIVE(3PCAP)