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

#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);

 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). If the file does not exist, it will be created; if the file exists, it
will be truncated and overwritten.
The name "-" is a synonym
for
 stdout . 

 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 (3PCAP). The stream is assumed to be at the beginning of a file that has been
newly created or truncated, so that writes will start at the beginning
of the file.
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 (3PCAP) and activated by an earlier call to
 \%pcap_activate (3PCAP), or returned by an earlier call to
 \%pcap_open_offline (3PCAP),  pcap_open_live (3PCAP), or
 pcap_open_dead (3PCAP). 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, if the file already exists, 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.
 RETURN VALUES
A pointer to a
 pcap_dumper_t structure to use in subsequent
 pcap_dump (3PCAP) and
 pcap_dump_close (3PCAP) calls is returned on success.
 NULL is returned on failure.
If
 NULL is returned,
 pcap_geterr (3PCAP) can be used to get the error text.
 BACKWARD COMPATIBILITY

The
 pcap_dump_open_append () function became available in libpcap release 1.7.2. In previous
releases, there is no support for appending packets to an existing
savefile.
 SEE ALSO
 pcap (3PCAP),  \%pcap-savefile (@MAN_FILE_FORMATS@)