pcap_offline_filter(3PCAP) man page

Updated: 24 January 2025 • View in plain text • Return to Main Contents

This man page documents libpcap version 1.11.0-PRE-GIT (see also: 1.10.5, 1.10.4, 1.10.2, 1.10.1, 1.10.0, 1.9.1, 1.8.1, 1.7.4, 1.6.2, 1.5.3).

Your system may have a different version installed, possibly with some local modifications. To achieve the best results, please make sure this version of this man page suits your needs. If necessary, try to look for a different version on this web site or in the man pages available in your installation.

NAME

pcap_offline_filter - check whether a filter matches a packet

SYNOPSIS

#include <pcap/pcap.h>

int pcap_offline_filter(const struct bpf_program *fp,
    const struct pcap_pkthdr *h, const u_char *pkt);

DESCRIPTION

pcap_offline_filter() checks whether a filter matches a packet. fp is a pointer to a bpf_program struct, usually the result of a call to pcap_compile(3PCAP). h points to the pcap_pkthdr structure for the packet, and pkt points to the data in the packet.

The filter program must have been compiled for a link-layer header type that matches the packet data; also on Linux the filter must not use BPF extensions, see pcap_compile() for more information.

RETURN VALUE

pcap_offline_filter() returns the return value of the filter program. This will be zero if the packet doesn't match the filter and non-zero if the packet matches the filter.

COLOPHON

This HTML man page was generated at 00:20:13 GMT, January 28, 2025 from a source man page in "The Tcpdump Group" git repositories using man2html and other tools.