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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"

Print ASCII Character Chart
Prints out an ascii chart using builtin bash! Then formats using cat -t and column. The best part is: $ echo -e "${p: -3} \\0$(( $i/64*100 + $i%64/8*10 + $i%8 ))"; From: http://www.askapache.com/linux/ascii-codes-and-reference.html

Scale,Rotate, brightness, contrast,...with Image Magick
$rotate: the rotate angle $width, $height: width and height to scale to $birghtness: change brighness

Efficiently extract lines between markers
GNU Sed can 'address' between two regex, but it continues parsing through to the end of the file. This slight alteration causes it to terminate reading the input file once the STOP match is made. In my example I have included an extra '/START/d' as my 'start' marker line contains the 'stop' string (I'm extracting data between 'resets' and using the time stamp as the 'start'). My previous coding using grep is slightly faster near the end of the file, but overall (extracting all the reset cycles in turn) the new SED method is quicker and a lot neater.

total text files in current dir

Remove all leading and trailing spaces or tabs from all lines of a text file
Bash only, no sed, no awk. Multiple spaces/tabs if exists INSIDE the line will be preserved. Empty lines stay intact, except they will be cleaned from spaces and tabs if any available.

Edit the Last Changed File

concat multiple videos into one (and add an audio track)
This is an extract from a larger script which formats the video for DVD. The videos I use have no audio track so I need to add one. Tweak as you like...

count processes with status "D" uninterruptible sleep

geoip information
That makes a function you can put in your ~/.bashrc to run it when you need in any term with an IP as argument


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