pcap_t *pcap_open_offline(const char *fname, char *errbuf);
pcap_t *pcap_fopen_offline(FILE *fp, char *errbuf);
DESCRIPTIONpcap_open_offline() is called to open a ``savefile'' for reading.
fname specifies the name of the file to open. The file can have the pcap file format as described in pcap-savefile(5), which is the file format used by, among other programs, tcpdump(1) and tcpslice(1), or can have the pcap-ng file format, although not all pcap-ng files can be read. The name "-" in a synonym for stdin.
Alternatively, you may call pcap_fopen_offline() to read dumped data from an existing open stream fp. Note that on Windows, that stream should be opened in binary mode.