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Old 03-02-2004, 06:13 PM   #1
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tcpdump -w command doesn't write to file

Anyone know why when I run < tcpdump -w file > I get know output in the file specified. I get network traffic on standard output but nothing when I try to redirect to a file.
Old 03-02-2004, 06:54 PM   #2
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I don't know why, but, from man tcpdump:

"In all cases, only packets that match expression will be processed by tcpdump."

With expression being the last thing on the command line, or so it seems.
Old 03-03-2004, 08:10 AM   #3
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If you check the man pages, this writes the *raw* package to file, hence if you view the file, you'll get a load of binary. The quickest / easiest way to write to a file is:
# tcpdump > filename


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