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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | SEE ALSO | COLOPHON |
PCAP_COMPILE(3PCAP) PCAP_COMPILE(3PCAP)
pcap_compile - compile a filter expression
#include <pcap/pcap.h>
int pcap_compile(pcap_t *p, struct bpf_program *fp,
const char *str, int optimize, bpf_u_int32 netmask);
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.
NOTE: in libpcap 1.8.0 and later, pcap_compile() can be used in
multiple threads within a single process. However, in earlier
versions of libpcap, it is not safe to use pcap_compile() in multiple
threads in a single process without some form of mutual exclusion
allowing only one thread to call it at any given time.
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.
pcap(3PCAP), pcap_setfilter(3PCAP), pcap_freecode(3PCAP),
pcap_geterr(3PCAP), pcap-filter(7)
This page is part of the libpcap (packet capture library) project.
Information about the project can be found at
⟨http://www.tcpdump.org/⟩. If you have a bug report for this manual
page, see ⟨http://www.tcpdump.org/#patches⟩. This page was obtained
from the project's upstream Git repository
⟨https://github.com/the-tcpdump-group/libpcap.git⟩ on 2017-07-05. If
you discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for the
page, or you have corrections or improvements to the information in
this COLOPHON (which is not part of the original manual page), send a
mail to man-pages@man7.org
7 April 2014 PCAP_COMPILE(3PCAP)