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PCAP_NEXT_EX(3PCAP)                                        PCAP_NEXT_EX(3PCAP)




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(3PCAP)

libpcap 1.0.0 - Generated Thu Oct 30 07:36:56 CDT 2008
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