Editcap - Edit and/or translate the format of capture
       files


SYNOPSYS

       editcap [ -F file format ] [ -T encapsulation type ]
       [ -r ] [ -v ] [ -s snaplen ] [ -h ] infile outfile
       [ record# ... ]


DESCRIPTION

       Editcap is a program that reads a saved capture file and
       writes some or all of the packets in that capture file to
       another capture file.  Editcap knows how to read libpcap
       capture files, including those of tcpdump.  In addition,
       Editcap can read capture files from snoop (including
       Shomiti) and atmsnoop, LanAlyzer, Sniffer (compressed or
       uncompressed), Microsoft Network Monitor, AIX's iptrace,
       NetXray, Sniffer Pro, RADCOM's WAN/LAN analyzer,
       Lucent/Ascend router debug output, HP-UX's nettl, and the
       dump output from Toshiba's ISDN routers.  There is no need
       to tell Editcap what type of file you are reading; it will
       determine the file type by itself.  Editcap is also capa­
       ble of reading any of these file formats if they are com­
       pressed using gzip.  Editcap recognizes this directly from
       the file; the '.gz' extension is not required for this
       purpose.

       By default, it writes the capture file in libpcap format,
       and writes all of the packets in the capture file to the
       output file.  The -F flag can be used to specify the for­
       mat in which to write the capture file; it can write the
       file in libpcap format (standard libpcap format, a modi­
       fied format used by some patched versions of libpcap, the
       format used by Red Hat Linux 6.1, or the format used by
       SuSE Linux 6.3), snoop format, uncompressed Sniffer for­
       mat, Microsoft Network Monitor 1.x format, and the format
       used by Windows-based versions of the Sniffer software.

       A list of packet numbers can be specified on the command
       line; the packets with those numbers will not be written
       to the capture file, unless the -r flag is specified, in
       which case only those packets will be written to the cap­
       ture file.  Ranges of packet numbers can be specified as
       start-end, referring to all packets from start to end
       (removing them all if -r isn't specified, including them
       all if -r is specified).

       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 out­
       put 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

       frames larger than the standard Ethernet MTU, making them
       incapable of handling gigabit Ethernet captures if jumbo
       frames were used).

       If the -T flag is used to specify an 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
       file.  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 speci­
       fied encapsulation type (for example, it will not trans­
       late an Ethernet capture to an FDDI capture if an Ethernet
       capture is read and '-T fddi' is specified).


OPTIONS

       -F  Sets the file format of the output capture file.

       -T  Sets the packet encapsulation type of the output cap­
           ture file.

       -r  Causes the packets whose packet numbers are specified
           on the command line to be written to the output cap­
           ture file, and no other packets to be written to the
           output capture file.

       -v  Causes editcap to print a number of messages while
           it's working.

       -s  Sets the snapshot length to use when writing the data.

       -h  Prints the version and options and exits.


SEE ALSO

       tcpdump(8), pcap(3), ethereal(1)


NOTES

       Editcap is part of the Ethereal distribution.  The latest
       version of Ethereal can be found at http://www.ethe­
       real.com.


AUTHORS

         Original Author
         -------- ------
         Richard Sharpe           <sharpe@ns.aus.com>

         Contributors
         ------------
         Guy Harris               <guy@alum.mit.edu>


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