Commands by noisy (5)

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remove audio trac from a video file
create a copy of a video file without the audio tracs

Remove all unused kernels with apt-get
Remove old kernels (*-generic and *-generic-pae) via apt-get on debian/ubuntu based systems. Tested on ubuntu 10.04 - 12.04.

Get information on your graphics card on linux (such as graphics memory size)
Loop is needed if you have more then one card.

Encrypted chat with netcat and openssl (one-liner)
client$ while true; do read -n30 ui; echo $ui |openssl enc -aes-256-ctr -a -k PaSSw ; done | nc localhost 8877 | while read so; do decoded_so=`echo "$so"| openssl enc -d -a -aes-256-ctr -k PaSSw`; echo -e "Incoming: $decoded_so"; done This will establish a simple encrypted chat with AES-256-CTR using netcat and openssl only. More info here https://nixaid.com/encrypted-chat-with-netcat/

Ping a URL sending output to file and STDOUT
The tee (as in "T" junction) command is very useful for redirecting output to two places.

Write comments to your history.
A null operation with the name 'comment', allowing comments to be written to HISTFILE. Prepending '#' to a command will *not* write the command to the history file, although it will be available for the current session, thus '#' is not useful for keeping track of comments past the current session.

find out how many days since given date
You can also do this for seconds, minutes, hours, etc... Can't use dates before the epoch, though.

Insert a line at the top of a text file without sed or awk or bash loops
Yet another way to add a line at the top a of text file with the help of the tac command (reverse cat).

Push your present working directory to a stack that you can pop later
If are a Bash user and you are in a directory and need to go else where for a while but don't want to lose where you were, use pushd instead of cd. cd /home/complicated/path/.I/dont/want/to/forget pushd /tmp cd thing/in/tmp popd (returns you to /home/complicated/path/.I/dont/want/to/forget)

list files recursively by size


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