Commands by tremby (1)

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Selecting a random file/folder of a folder
I used only shuf command.

convert video format to youtube flv format

Produce a pseudo random password with given length in base 64
Don't copy trailing '=' or use head -c to limit to desired length.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

See OpenVZ Container id's of top 10 running processes by %cpu
This command will list the PID, VEID, and Name of the 10 highest cpu using processes on a openvz host. You must have vzpid installed.

Extract a bash function
I often need to extract a function from a bash script and this command will do it.

bypass any aliases and functions for the command
A simple directive which disables all aliases and functions for the command immediately following it. Shortcut for the bash built-in 'command' - "command linefoo". Think, {sic}...

RTFM function
Some commands have more information on 'info' than in the man pages

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"

Steve Reich - Piano Phase; interpreter: Bourne-Again Shell.
The Piano Phase piece, by Steve Reich is a minimalist composition which is played on two pianos played at slightly different tempos, a task that's very difficult to accomplish by human players. The auditive effects produced by the cell displacement produce beautiful patterns. See https://en.wikipedia.org/wiki/Piano_Phase . My rendered version: https://ydor.org/SteveReich/piano_phase.mp3 Requires sox to be installed on the system. There are multiple videos on youtube showing different approaches and experiences to this interpretation. There is also a synthesized version. Even if Bash can behave as a powerful pianist, a simple threaded version leaves full room to several time glitches and even negative displacements, the same issues that human pianists experience when playing the piece. The older the computer, the better the chaos added to the result due to the CPU load. Apparently that's the reason Steve Reich composes pieces such as this. Without further ado, please give a warm welcome to the Bash minimalist player on synthesized two-threaded pianos. Please turn off your cellphones.


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