#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);
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(), pcap_dump(), and pcap_dump_close() 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().