Movatterモバイル変換

pcap_setdirection(3pcap) — Linux manual page

PCAP_SETDIRECTION(3PCAP)PCAP_SETDIRECTION(3PCAP)

NAME        top

       pcap_setdirection - set the direction for which packets will be       captured

SYNOPSIS        top

#include <pcap/pcap.h>int pcap_setdirection(pcap_t *p, pcap_direction_t d);

DESCRIPTION        top

pcap_setdirection() is used to specify a direction that packets       will be captured.d is one of the constantsPCAP_D_IN,PCAP_D_OUT       orPCAP_D_INOUT.PCAP_D_INwill only capture packets received by       the device,PCAP_D_OUTwill only capture packets sent by the       device andPCAP_D_INOUTwill capture packets received by or sent       by the device.PCAP_D_INOUTis the default setting if this       function is not called.pcap_setdirection() isn't necessarily fully supported on all       platforms; some platforms might return an error for all values,       and some other platforms might not supportPCAP_D_OUT.       This operation is not supported if a ``savefile'' is being read.

RETURN VALUE        top

pcap_setdirection() returns0on success,PCAP_ERROR_NOT_ACTIVATED       if called on a capture handle that has been created but not       activated, orPCAP_ERRORon other errors. IfPCAP_ERRORis       returned,pcap_geterr(3PCAP) orpcap_perror(3PCAP) may be called       withp as an argument to fetch or display the error text.

SEE ALSO        top

pcap(3PCAP)

COLOPHON        top

       This page is part of thelibpcap (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 2025-08-11.       (At that time, the date of the most recent commit that was found       in the repository was 2025-08-10.)  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 isnot part of the original manual page), send a mail to       man-pages@man7.org                               5 March 2022PCAP_SETDIRECTION(3PCAP)

HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH.