+----------------------------------------------------------------------------+ | | | This man page documents libpcap version 1.11.0-PRE-GIT. | | | | 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. | | | +----------------------------------------------------------------------------+ PCAP_SET_IMMEDIATE_MODE(3PCAP) PCAP_SET_IMMEDIATE_MODE(3PCAP) NAME pcap_set_immediate_mode - set immediate mode for a not-yet-activated capture handle SYNOPSIS #include int pcap_set_immediate_mode(pcap_t *p, int immediate_mode); DESCRIPTION pcap_set_immediate_mode() sets whether immediate mode should be set on a capture handle when the handle is activated. In immediate mode, packets are always delivered as soon as they arrive, with no buffering. If immediate_mode is non-zero, immediate mode will be set, otherwise it will not be set. RETURN VALUE pcap_set_immediate_mode() returns 0 on success or PCAP_ERROR_ACTIVATED if called on a capture handle that has been activated. BACKWARD COMPATIBILITY This function became available in libpcap release 1.5.0. In previous releases, if immediate delivery of packets is required: on FreeBSD, NetBSD, OpenBSD, DragonFly BSD, macOS, and Solaris 11, immediate mode must be turned on with a BIOCIMMEDIATE ioctl(2), as documented in bpf(4), on the descriptor returned by pcap_fileno(3PCAP), after pcap_activate(3PCAP) is called; on Solaris 10 and earlier versions of Solaris, immediate mode must be turned on by using a read timeout of 0 when opening the device (this will not provide immediate delivery of packets on other platforms, so don't assume it's sufficient); on Windows, immediate mode must be turned on by calling pcap_setmintocopy() with a size of 0. On Linux, with previous releases of libpcap, capture devices are always in immediate mode; however, in 1.5.0 and later, they are, by default, not in immediate mode, so if pcap_set_immediate_mode() is available, it should be used. On other platforms, capture devices are always in immediate mode. SEE ALSO pcap(3PCAP), pcap_create(3PCAP), pcap_activate(3PCAP) 27 January 2024 PCAP_SET_IMMEDIATE_MODE(3PCAP)