pcap_lookupnet(3pcap) [v7 man page]

PCAP_LOOKUPNET(3PCAP)													     PCAP_LOOKUPNET(3PCAP)

NAME

       pcap_lookupnet - find the IPv4 network number and netmask for a device

SYNOPSIS

       #include <pcap/pcap.h>

       char errbuf[PCAP_ERRBUF_SIZE];

       int pcap_lookupnet(const char *device, bpf_u_int32 *netp,
	       bpf_u_int32 *maskp, char *errbuf);

DESCRIPTION

       pcap_lookupnet()  is used to determine the IPv4 network number and mask associated with the network device device.  Both netp and maskp are
       bpf_u_int32 pointers.

RETURN VALUE

       pcap_lookupnet() returns 0 on success and -1 on failure.  If -1 is returned, 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(3PCAP)

								   5 April 2008 					     PCAP_LOOKUPNET(3PCAP)

PCAP_OPEN_LIVE(3PCAP)													     PCAP_OPEN_LIVE(3PCAP)

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 net-
       work device to open; on Linux systems with 2.2 or later kernels, a device argument of "any" or NULL can be used to capture packets from all
       interfaces.

       snaplen specifies the snapshot length to be set on the handle.

       promisc specifies if the interface is to be put into promiscuous mode.

       to_ms specifies the read timeout in milliseconds.

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.  errbuf
       is assumed to be able to hold at least PCAP_ERRBUF_SIZE chars.

SEE ALSO

       pcap(3PCAP), pcap_create(3PCAP), pcap_activate(3PCAP)

								   5 April 2008 					     PCAP_OPEN_LIVE(3PCAP)