Manual Pages — PCAP_SETFILTER

#include <pcap/pcap.h>

int pcap_setfilter(pcap_t *p, struct bpf_program *fp);

pcap_setfilter() is used to specify a filter program. fp is a pointer to a bpf_program struct, usually the result of a call to pcap_compile(3) .

pcap_setfilter() returns 0 on success and PCAP_ERROR on failure. If PCAP_ERROR is returned, pcap_geterr(3) or pcap_perror(3) may be called with p as an argument to fetch or display the error text.

“	Like a classics radio station whose play list spans decades, Unix simultaneously exhibits its mixed and dated heritage. There's Clash-era graphics interfaces; Beatles-era two-letter command names; and systems programs (for example, ps) whose terse and obscure output was designed for slow teletypes; Bing Crosby-era command editing (# and @ are still the default line editing commands), and Scott Joplin-era core dumps.	”
— The Unix Haters' handbook