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Force logout after 24 hours idle
Shell timeout variables (TMOUT) can be very liberal about what is classified as 'activity', like having an editor open. This command string will terminate the login shell for an user with more than a day's idle time.

The proper way to read kernel messages in realtime.

print all except first collumn

all out
How to force a userid to log out of a Linux host, by killing all processes owned by the user, including login shells:

Color man pages
Add the followin to ~/.bashrc #colour export LESS_TERMCAP_mb=$'\E[01;31m' export LESS_TERMCAP_md=$'\E[01;37m' export LESS_TERMCAP_me=$'\E[0m' export LESS_TERMCAP_se=$'\E[0m' export LESS_TERMCAP_so=$'\E[01;44;33m' export LESS_TERMCAP_ue=$'\E[0m' export LESS_TERMCAP_us=$'\E[01;32m'

Configure a serial line device so you can evaluate it with a shell script
I had a hard time in finding the correct settings to get reasonable output from a coin selector which sends its data over a serial line. In the end, minicom came to the rescue and pointed me on the right track. So, if you need to do something similar, these settings may help you. Replace ttyUSB0 with your device file, 9600 with your baud rate, 5 with your read timeout (10ths of a second), and 1 with the minimum numbers of characters you want to read. You can then open the device file like you are used to do, example: $ DATA="`xxd -ps -l 5 \"$DEV\"`"

Rename files in batch

Give {Open,True}Type files reasonable names
Just a quick hack to give reasonable filenames to TrueType and OpenType fonts. I'd accumulated a big bunch of bizarrely and inconsistently named font files in my ~/.fonts directory. I wanted to copy some, but not all, of them over to my new machine, but I had no idea what many of them were. This script renames .ttf files based on the name embedded inside the font. It will also work for .otf files, but make sure you change the mv part so it gives them the proper extension. REQUIREMENTS: Bash (for extended pattern globbing), showttf (Debian has it in the fontforge-extras package), GNU grep (for context), and rev (because it's hilarious). BUGS: Well, like I said, this is a quick hack. It grew piece by piece on the command line. I only needed to do this once and spent hardly any time on it, so it's a bit goofy. For example, I find 'rev | cut -f1 | rev' pleasantly amusing --- it seems so clearly wrong, and yet it works to print the last argument. I think flexibility in expressiveness like this is part of the beauty of Unix shell scripting. One-off tasks can be be written quickly, built-up as a person is "thinking aloud" at the command line. That's why Unix is such a huge boost to productivity: it allows each person to think their own way instead of enforcing some "right way". On a tangent: One of the things I wish commandlinefu would show is the command line HISTORY of the person as they developed the script. I think it's that conversation between programmer and computer, as the pipeline is built piece-by-piece, that is the more valuable lesson than any canned script.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Extract IPv4 addressess from file


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