editcap - Edit and/or translate the format of capture files
-=head1 SYNOPSYS
+=head1 SYNOPSIS
B<editcap>
S<[ B<-c> E<lt>packets per fileE<gt> ]>
S<[ B<-A> E<lt>start timeE<gt> ]>
S<[ B<-B> E<lt>stop timeE<gt> ]>
S<[ B<-h> ]>
+S<[ B<-i> E<lt>seconds per fileE<gt> ]>
S<[ B<-r> ]>
S<[ B<-s> E<lt>snaplenE<gt> ]>
S<[ B<-t> E<lt>time adjustmentE<gt> ]>
+S<[ B<-S> E<lt>strict time adjustmentE<gt> ]>
S<[ B<-T> E<lt>encapsulation typeE<gt> ]>
S<[ B<-v> ]>
I<infile>
I<outfile> in libpcap file format.
An optional list of packet numbers can be specified on the command tail;
-individual packet numbers seperated by whitespace and/or ranges of packet
+individual packet numbers separated by whitespace and/or ranges of packet
numbers can be specified as I<start>-I<end>, referring to all packets from
I<start> to I<end>. By default the selected packets with those numbers will
I<not> be written to the capture file. If the B<-r> flag is specified, the
B<Editcap> can write the file in several output formats. The B<-F>
flag can be used to specify the format in which to write the capture
-file, B<editcap -F> provides a list of the available output formats.
+file; B<editcap -F> provides a list of the available output formats.
=head1 OPTIONS
=item -c E<lt>packets per fileE<gt>
-Sets the maximum number of packets per output file. Each output file will
+Splits the packet output to different files based on uniform packet counts
+with a maximum of <packets per file> each. Each output file will
be created with a suffix -nnnnn, starting with 00000. If the specified
-number of packets are written to the output file, the next output file is
+number of packets is written to the output file, the next output file is
opened. The default is to use a single output file.
=item -C E<lt>choplenE<gt>
Attempts to remove duplicate packets. The length and MD5 hash of the
current packet are compared to the previous four (4) packets. If a
-match is found, the current packet is skipped. This option is equilivent
+match is found, the current packet is skipped. This option is equivalent
to using the option B<-D 5>.
=item -D E<lt>dup windowE<gt>
can be useful in scripts to identify duplicate packets across trace
files.
-The <dup window> is specifed as an integer value between 0 and 1000000 (inclusive).
+The <dup window> is specified as an integer value between 0 and 1000000 (inclusive).
NOTE: Specifying large <dup window> values with large tracefiles can
result in very long processing times for B<editcap>.
Attempts to remove duplicate packets. The current packet's arrival time
is compared with up to 1000000 previous packets. If the packet's relative
-arrival time is I<less than> the <dup time window> of a previous packet
+arrival time is I<less than or equal to> the <dup time window> of a previous packet
and the packet length and MD5 hash of the current packet are the same then
the packet to skipped. The duplicate comparison test stops when
the current packet's relative arrival time is greater than <dup time window>.
-The <dup time window> is specifed as I<seconds>[I<.fractional seconds>].
+The <dup time window> is specified as I<seconds>[I<.fractional seconds>].
The [.fractional seconds] component can be specified to nine (9) decimal
places (billionths of a second) but most typical trace files have resolution
=item -E E<lt>error probabilityE<gt>
-Sets the probabilty that bytes in the output file are randomly changed.
+Sets the probability that bytes in the output file are randomly changed.
B<Editcap> uses that probability (between 0.0 and 1.0 inclusive)
to apply errors to each data byte in the file. For instance, a
probability of 0.02 means that each byte has a 2% chance of having an error.
=item -B E<lt>stop timeE<gt>
-Saves only the packets whose timestamp is on or before stop time.
+Saves only the packets whose timestamp is before stop time.
The time is given in the following format YYYY-MM-DD HH:MM:SS
=item -h
Prints the version and options and exits.
+=item -i E<lt>seconds per fileE<gt>
+
+Splits the packet output to different files based on uniform time intervals
+using a maximum interval of <seconds per file> each. Each output file will
+be created with a suffix -nnnnn, starting with 00000. If packets for the specified
+time interval are written to the output file, the next output file is
+opened. The default is to use a single output file.
+
=item -r
Reverse the packet selection.
collected on different machines where the time difference between the
two machines is known or can be estimated.
+=item -S E<lt>strict time adjustmentE<gt>
+
+Time adjust selected packets to insure strict chronological order.
+
+The <strict time adjustment> value represents relative seconds
+specified as [-]I<seconds>[I<.fractional seconds>].
+
+As the capture file is processed each packet's absolute time is
+I<possibly> adjusted to be equal to or greater than the previous
+packet's absolute timestamp depending on the <strict time
+adjustment> value.
+
+If <strict time adjustment> value is 0 or greater (e.g. 0.000001)
+then B<only> packets with a timestamp less than the previous packet
+will adjusted. The adjusted timestamp value will be set to be
+equal to the timestamp value of the previous packet plus the value
+of the <strict time adjustment> value. A <strict time adjustment>
+value of 0 will adjust the minimum number of timestamp values
+necessary to insure that the resulting capture file is in
+strict chronological order.
+
+If <strict time adjustment> value is specified as a
+negative value, then the timestamp values of B<all>
+packets will be adjusted to be equal to the timestamp value
+of the previous packet plus the absolute value of the
+<lt>strict time adjustment<gt> value. A <strict time
+adjustment> value of -0 will result in all packets
+having the timestamp value of the first packet.
+
+This feature is useful when the trace file has an occasional
+packet with a negative delta time relative to the previous
+packet.
+
=item -T E<lt>encapsulation typeE<gt>
Sets the packet encapsulation type of the output capture file.
editcap -D 101 capture.pcap dedup.pcap
-To remove duplicate packets seen I<less than> 1/10th of a second:
-
- editcap -w 0.1 capture.pcap dedup.pcap
-
To remove duplicate packets seen I<equal to or less than> 1/10th of a second:
editcap -w 0.1 capture.pcap dedup.pcap
editcap -v -D 0 capture.pcap NUL
+To advance the timestamps of each packet forward by 3.0827 seconds:
+
+ editcap -t 3.0827 capture.pcap adjusted.pcap
+
+To insure all timestamps are in strict chronological order:
+
+ editcap -S 0 capture.pcap adjusted.pcap
+
To introduce 5% random errors in a capture file use:
=over 4
git.samba.org / obnox / wireshark / wip.git / blobdiff