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20 .TH PCAP_DUMP_OPEN 3PCAP "3 July 2020"
22 pcap_dump_open, pcap_dump_open_append, pcap_dump_fopen \- open a file to
23 which to write packets
27 #include <pcap/pcap.h>
32 pcap_dumper_t *pcap_dump_open(pcap_t *p, const char *fname);
33 pcap_dumper_t *pcap_dump_open_append(pcap_t *p, const char *fname);
34 pcap_dumper_t *pcap_dump_fopen(pcap_t *p, FILE *fp);
39 is called to open a ``savefile'' for writing.
41 specifies the name of the file to open. The file will have
42 the same format as those used by
46 If the file does not exist, it will be created; if the file exists, it
47 will be truncated and overwritten.
48 The name "-" is a synonym
52 .BR pcap_dump_fopen ()
53 is called to write data to an existing open stream
55 this stream will be closed by a subsequent call to
56 .BR pcap_dump_close (3PCAP).
57 The stream is assumed to be at the beginning of a file that has been
58 newly created or truncated, so that writes will start at the beginning
60 Note that on Windows, that stream should be opened in binary mode.
63 is a capture or ``savefile'' handle returned by an earlier call to
64 .BR pcap_create (3PCAP)
65 and activated by an earlier call to
66 .BR \%pcap_activate (3PCAP),
67 or returned by an earlier call to
68 .BR \%pcap_open_offline (3PCAP),
69 .BR pcap_open_live (3PCAP),
71 .BR pcap_open_dead (3PCAP).
72 The time stamp precision, link-layer type, and snapshot length from
74 are used as the link-layer type and snapshot length of the output file.
76 .BR pcap_dump_open_append ()
79 but, if the file already exists, and is a pcap file with the same byte
80 order as the host opening the file, and has the same time stamp
81 precision, link-layer header type, and snapshot length as
83 it will write new packets at the end of the file.
87 structure to use in subsequent
90 .BR pcap_dump_close (3PCAP)
91 calls is returned on success.
93 is returned on failure.
97 .BR pcap_geterr (3PCAP)
98 can be used to get the error text.
99 .SH BACKWARD COMPATIBILITY
102 .BR pcap_dump_open_append ()
103 function became available in libpcap release 1.7.2. In previous
104 releases, there is no support for appending packets to an existing
108 .BR \%pcap-savefile (@MAN_FILE_FORMATS@)