PCAP_COMPILE(3PCAP)													       PCAP_COMPILE(3PCAP)

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  per-
       formed.	 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_NET-
       MASK_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 argu-
       ment to fetch or display the error text.

SEE ALSO

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

								   5 April 2008 					       PCAP_COMPILE(3PCAP)