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PCAP_OPEN_DEAD(3) FreeBSD Library Functions Manual PCAP_OPEN_DEAD(3) NAME pcap_open_dead, pcap_open_dead_with_tstamp_precision - open a fake pcap_t for compiling filters or opening a capture for output SYNOPSIS #include <pcap/pcap.h> pcap_t *pcap_open_dead(int linktype, int snaplen); pcap_t *pcap_open_dead_with_tstamp_precision(int linktype, int snaplen, u_int precision); DESCRIPTION pcap_open_dead() and pcap_open_dead_with_tstamp_precision() are used for creating a pcap_t structure to use when calling the other functions in libpcap. It is typically used when just using libpcap for compiling BPF code; it can also be used if using pcap_dump_open(3), pcap_dump(3), and pcap_dump_close(3) to write a savefile if there is no pcap_t that supplies the packets to be written. linktype specifies the link-layer type for the pcap_t. snaplen specifies the snapshot length for the pcap_t. When pcap_open_dead_with_tstamp_precision(), is used to create a pcap_t for use with pcap_dump_open(), precision specifies the time stamp precision for packets; PCAP_TSTAMP_PRECISION_MICRO should be specified if the packets to be written have time stamps in seconds and microseconds, and PCAP_TSTAMP_PRECISION_NANO should be specified if the packets to be written have time stamps in seconds and nanoseconds. Its value does not affect pcap_compile(3). BACKWARD COMPATIBILITY The pcap_open_dead_with_tstamp_precision() function became available in libpcap release 1.5.1. In previous releases, there was no mechanism to open a savefile for writing with time stamps given in seconds and nanoseconds. SEE ALSO pcap(3), pcap-linktype(7) 3 January 2014 PCAP_OPEN_DEAD(3)