netbsd man page for pcap_next_ex

PCAP_NEXT_EX(3) 					     Library Functions Manual						   PCAP_NEXT_EX(3)

NAME
       pcap_next_ex, pcap_next - read the next packet from a pcap_t

SYNOPSIS
       #include <pcap/pcap.h>

       int pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header,
	       const u_char **pkt_data);
       const u_char *pcap_next(pcap_t *p, struct pcap_pkthdr *h);

DESCRIPTION
       pcap_next_ex()  reads  the  next  packet  and  returns  a success/failure indication.  If the packet was read without problems, the pointer
       pointed to by the pkt_header argument is set to point to the pcap_pkthdr struct for the packet, and the pointer pointed to by the  pkt_data
       argument is set to point to the data in the packet.

       pcap_next()  reads  the	next  packet (by calling pcap_dispatch() with a cnt of 1) and returns a u_char pointer to the data in that packet.
       The pcap_pkthdr structure pointed to by h is filled in with the appropriate values for the packet.

RETURN VALUE
       pcap_next_ex() returns 1 if the packet was read without problems, 0 if packets are being read from a live capture, and the timeout expired,
       -1  if  an  error occurred while reading the packet, and -2 if packets are being read from a ``savefile'', and there are no more packets to
       read from the savefile.	If -1 is returned, pcap_geterr() or pcap_perror() may be called with p as an argument  to  fetch  or  display  the
       error text.

       pcap_next()  returns  a pointer to the packet data on success, and returns NULL if an error occured, or if no packets were read from a live
       capture (if, for example, they were discarded because they didn't pass the packet filter, or if, on platforms that support a  read  timeout
       that  starts  before any packets arrive, the timeout expires before any packets arrive, or if the file descriptor for the capture device is
       in non-blocking mode and no packets were available to be read), or if no more packets are  available  in  a  ``savefile.''   Unfortunately,
       there is no way to determine whether an error occured or not.

SEE ALSO
       pcap(3), pcap_geterr(3), pcap_dispatch(3)

								   5 April 2008 						   PCAP_NEXT_EX(3)