#include <pcap/pcap.h> pcap_dumper_t *pcap_dump_open(pcap_t *p, const char *fname); pcap_dumper_t *pcap_dump_open_append(pcap_t *p, const char *fname); pcap_dumper_t *pcap_dump_fopen(pcap_t *p, FILE *fp);
pcap_dump_fopen() is called to write data to an existing open stream fp; this stream will be closed by a subsequent call to pcap_dump_close(). Note that on Windows, that stream should be opened in binary mode.
p is a capture or ``savefile'' handle returned by an earlier call to pcap_create() and activated by an earlier call to pcap_activate(), or returned by an earlier call to pcap_open_offline(), pcap_open_live(), or pcap_open_dead(). The time stamp precision, link-layer type, and snapshot length from p are used as the link-layer type and snapshot length of the output file.
pcap_dump_open_append() is like pcap_dump_open but does not create the file if it does not exist and, if it does already exist, and is a pcap file with the same byte order as the host opening the file, and has the same time stamp precision, link-layer header type, and snapshot length as p, it will write new packets at the end of the file.