bionic (3) pcap_compile.3pcap.gz

NAME

       pcap_compile - compile a filter expression

SYNOPSIS

       #include <pcap/pcap.h>

       int pcap_compile(pcap_t *p, struct bpf_program *fp,
               const char *str, int optimize, bpf_u_int32 netmask);

DESCRIPTION

       pcap_compile()  is  used  to  compile  the  string str into a filter program.  See pcap-filter(7) for the
       syntax of that string.  program is a pointer to a bpf_program struct and is filled in by  pcap_compile().
       optimize  controls  whether  optimization on the resulting code is performed.  netmask specifies the IPv4
       netmask of the network on which packets are being captured; it  is  used  only  when  checking  for  IPv4
       broadcast  addresses  in  the  filter  program.  If the netmask of the network on which packets are being
       captured isn't known to the program, or if packets are being captured on the Linux "any" pseudo-interface
       that  can  capture  on  more than one network, a value of PCAP_NETMASK_UNKNOWN can be supplied; tests for
       IPv4 broadcast addresses will fail to compile, but all other tests in the filter program will be OK.

RETURN VALUE

       pcap_compile() returns 0 on success and -1 on failure.  If -1 is returned, pcap_geterr() or pcap_perror()
       may be called with p as an argument to fetch or display the error text.

SEE ALSO

       pcap(3PCAP), pcap_setfilter(3PCAP), pcap_freecode(3PCAP), pcap_geterr(3PCAP), pcap-filter(7)

                                                  7 April 2014                               PCAP_COMPILE(3PCAP)