freebsd man page for pcap_dump_open

PCAP_DUMP_OPEN(3)					     Library Functions Manual						 PCAP_DUMP_OPEN(3)

NAME
       pcap_dump_open, pcap_dump_fopen - open a file to which to write packets

SYNOPSIS
       #include <pcap/pcap.h>

       pcap_dumper_t *pcap_dump_open(pcap_t *p, const char *fname);
       pcap_dumper_t *pcap_dump_fopen(pcap_t *p, FILE *fp);

DESCRIPTION
       pcap_dump_open()  is  called to open a ``savefile'' for writing.  fname specifies the name of the file to open. The file will have the same
       format as those used by tcpdump(1) and tcpslice(1).  The name "-" is a synonym for stdout.

       pcap_dump_fopen() is called to write data to an existing open stream fp.  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 link-layer type and snapshot length from  p
       are used as the link-layer type and snapshot length of the output file.

RETURN VALUES
       A  pointer  to  a  pcap_dumper_t  structure  to	use in subsequent pcap_dump() and pcap_dump_close() calls is returned on success.  NULL is
       returned on failure.  If NULL is returned, pcap_geterr(p) can be used to get the error text.

SEE ALSO
       pcap(3), pcap_create(3), pcap_activate(3), pcap_open_offline(3), pcap_open_live(3),  pcap_open_dead(3),	pcap_dump(3),  pcap_dump_close(3),
       pcap_geterr(3), pcap-savefile(5)

								   5 April 2008 						 PCAP_DUMP_OPEN(3)