mergecap
(1)
名前
mergecap - Merges two or more capture files into one
形式
mergecap [ -a ] [ -F <file format> ] [ -h ] [ -s <snaplen> ]
[ -T <encapsulation type> ] [ -v ] -w <outfile>|- <infile>
[<infile> ...]
説明
The Wireshark Network Analyzer MERGECAP(1)
NAME
mergecap - Merges two or more capture files into one
SYNOPSIS
mergecap [ -a ] [ -F <file format> ] [ -h ] [ -s <snaplen> ]
[ -T <encapsulation type> ] [ -v ] -w <outfile>|- <infile>
[<infile> ...]
DESCRIPTION
Mergecap is a program that combines multiple saved capture
files into a single output file specified by the -w
argument. Mergecap knows how to read pcap capture files,
including those of tcpdump, Wireshark, and other tools that
write captures in that format.
By default, Mergecap writes the capture file in pcap format,
and writes all of the packets from the input capture files
to the output file.
Mergecap is able to detect, read and write the same capture
files that are supported by Wireshark. The input files
don't need a specific filename extension; the file format
and an optional gzip compression will be automatically
detected. Near the beginning of the DESCRIPTION section of
wireshark(1) or
http://www.wireshark.org/docs/man-pages/wireshark.html
<http://www.wireshark.org/docs/man-pages/wireshark.html> is
a detailed description of the way Wireshark handles this,
which is the same way Mergecap handles this.
Mergecap can write the file in several output formats. The
-F flag can be used to specify the format in which to write
the capture file, mergecap -F provides a list of the
available output formats.
Packets from the input files are merged in chronological
order based on each frame's timestamp, unless the -a flag is
specified. Mergecap assumes that frames within a single
capture file are already stored in chronological order.
When the -a flag is specified, packets are copied directly
from each input file to the output file, independent of each
frame's timestamp.
The output file frame encapsulation type is set to the type
of the input files if all input files have the same type.
If not all of the input files have the same frame
encapsulation type, the output file type is set to
WTAP_ENCAP_PER_PACKET. Note that some capture file formats,
most notably pcap, do not currently support
WTAP_ENCAP_PER_PACKET. This combination will cause the
output file creation to fail.
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The Wireshark Network Analyzer MERGECAP(1)
OPTIONS
-a Causes the frame timestamps to be ignored, writing all
packets from the first input file followed by all
packets from the second input file. By default, when -a
is not specified, the contents of the input files are
merged in chronological order based on each frame's
timestamp.
Note: when merging, mergecap assumes that packets within
a capture file are already in chronological order.
-F <file format>
Sets the file format of the output capture file.
Mergecap can write the file in several formats; mergecap
-F provides a list of the available output formats. The
default is to use the file format of the first input
file.
-h Prints the version and options and exits.
-s <snaplen>
Sets the snapshot length to use when writing the data.
If the -s flag is used to specify a snapshot length,
frames in the input file with more captured data than
the specified snapshot length will have only the amount
of data specified by the snapshot length written to the
output file. This may be useful if the program that is
to read the output file cannot handle packets larger
than a certain size (for example, the versions of snoop
in Solaris 2.5.1 and Solaris 2.6 appear to reject
Ethernet frames larger than the standard Ethernet MTU,
making them incapable of handling gigabit Ethernet
captures if jumbo frames were used).
-T <encapsulation type>
Sets the packet encapsulation type of the output capture
file. If the -T flag is used to specify a frame
encapsulation type, the encapsulation type of the output
capture file will be forced to the specified type,
rather than being the type appropriate to the
encapsulation type of the input capture files.
Note that this merely forces the encapsulation type of
the output file to be the specified type; the packet
headers of the packets will not be translated from the
encapsulation type of the input capture file to the
specified encapsulation type (for example, it will not
translate an Ethernet capture to an FDDI capture if an
Ethernet capture is read and '-T fddi' is specified).
-v Causes mergecap to print a number of messages while it's
working.
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The Wireshark Network Analyzer MERGECAP(1)
-w <outfile>|-
Sets the output filename. If the name is '-', stdout
will be used. This setting is mandatory.
EXAMPLES
To merge two capture files together, 100 seconds apart use:
capinfos -aeS a.pcap b.pcap
(Let's suppose a.pcap starts at 1009932757 and b.pcap ends
at 873660281. 1009932757 - 873660281 - 100 = 136272376
seconds.)
editcap -t 136272376 b.pcap b-shifted.pcap
mergecap -w compare.pcap a.pcap b-shifted.pcap
ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:
+---------------+---------------------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+---------------------------------------+
|Availability | diagnostic/wireshark/wireshark-common |
+---------------+---------------------------------------+
|Stability | Uncommitted |
+---------------+---------------------------------------+
SEE ALSO
pcap(3), wireshark(1), tshark(1), dumpcap(1), editcap(1),
text2pcap(1), pcap-filter(5) or tcpdump(1)
NOTES
Mergecap is based heavily upon editcap by Richard Sharpe
<sharpe[AT]ns.aus.com> and Guy Harris <guy[AT]alum.mit.edu>.
Mergecap is part of the Wireshark distribution. The latest
version of Wireshark can be found at
<http://www.wireshark.org>.
HTML versions of the Wireshark project man pages are
available at: http://www.wireshark.org/docs/man-pages
<http://www.wireshark.org/docs/man-pages>.
AUTHORS
Original Author
-------- ------
Scott Renfro <scott[AT]renfro.org>
Contributors
------------
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The Wireshark Network Analyzer MERGECAP(1)
Bill Guyton <guyton[AT]bguyton.com>
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from
http://www.wireshark.org/download/src/all-
versions/wireshark-1.10.7.tar.bz2
Further information about this software can be found on the
open source community website at http://www.wireshark.org/.
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