Commands by mattjbarlow (1)

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See entire packet payload using tcpdump.

shows history of logins on the server
outputs a history of logins on the server (top 10, when piped to 'head'); optional flags: '-a' put the hostname at the end of the line (good for long hostnames), '-i' post the IP instead of the hostname, '-F' put the full login and logout times, rather than short times.

sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)
POSIX requires this "string truncating" functionality. might as well use it, at least for very small tasks where invoking sed and using RE is overkill.

The BOFH Excuse Server

send a circular
don't need echo :P

Count the frequency of every word for a given file
Counts the frequency of words in a file

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Use mplayer to save video streams to a file
I use this command to save RTSP video streams over night from one of our national TV stations, so I won't have to squeeze the data through my slow internet connection when I want to watch it the next day. For ease of use, you might want to put this in a file: #!/bin/bash FILE="`basename \"$1\"`" mplayer -dumpstream -dumpfile "$FILE" -playlist "$1"

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

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