Commands by 5z474n (3)

  • Add temporary entry to authorized_keys

    If you frequently need to connect to your ubersecure mainframe from various uberunsafe machines, you have to face difficult decision: (a) type the password everytime during the session (lame), (b) add local public key to mainframes authorized_keys file (unsafe), (c) as above, but remove this key at the end of the session (pain in the a55). So let's say you save The Command to tempauth file in bin directory of your mainframe's account and make it executable. Then, while you're on one of these unsafe ones, do: cat $HOME/.ssh/id_rsa.pub|ssh 5z474n@mainframe.nl bin/tempauth 30 and password prompts stop the harassment for 30 minutes and you don't have to care to remove the unsafe key after that.


    1
    Keys=$HOME/.ssh/authorized_keys;Back=$Keys.tmp.bak;Time=${1:-15};cp $Keys $Back;cat /dev/stdin >>$Keys;echo mv $Back $Keys|at now+${Time}minutes;
    5z474n · 2009-07-15 23:45:02 8
  • Hear the mice moving

    Beeps on mouse's every move. Bear in mind that, at least on Ubuntu, /dev/input/mice can be read only by root.


    4
    while true; do beep -l66 -f`head -c2 /dev/input/mice|hexdump -d|awk 'NR==1{print $2%10000}'`; done
    5z474n · 2009-07-11 12:01:27 28
  • Beep siren

    Infinitely plays beeps with sinusoidally changing sound frequency. Ideal for alarm on an event.


    1
    tempo=33; slope=10; maxfreq=888; function sinus { echo "s($1/$slope)*$maxfreq"|bc -l|tr -d '-'; }; for((i=1;;i++)); do beep -l$tempo -f`sinus $i`; done
    5z474n · 2009-07-10 21:24:11 3

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Set laptop display brightness
Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video). $ cat /proc/acpi/video/VGA/LCD/brightness to discover the possible values for your display.

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Moves the mouse 1 pixel down and to the right, then immediately back again, every 4 minutes. This keeps screensavers from turning on. I have used this extensively and I've never even noticed the mouse movement because it is so subtle.

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"

Reset hosed terminal,
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Function that outputs dots every second until command completes
Very useful in shell scripts because you can run a task nicely in the background using job-control and output progress until it completes. Here's an example of how I use it in backup scripts to run gpg in the background to encrypt an archive file (which I create in this same way). $! is the process ID of the last run command, which is saved here as the variable PI, then sleeper is called with the process id of the gpg task (PI), and sleeper is also specified to output : instead of the default . every 3 seconds instead of the default 1. So a shorter version would be sleeper $!; The wait is also used here, though it may not be needed on your system. $ echo ">>> ENCRYPTING SQL BACKUP" $ gpg --output archive.tgz.asc --encrypt archive.tgz 1>/dev/null & $ PI=$!; sleeper $PI ":" 3; wait $PI && rm archive.tgz &>/dev/null Previously to get around the $! not always being available, I would instead check for the existance of the process ID by checking if the directory /proc/$PID existed, but not everyone uses proc anymore. That version is currently the one at http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html but I plan on upgrading to this new version soon.

Remove all mail in Postfix mail queue.

Install pip with Proxy
Installs pip packages defining a proxy

Replace spaces in a filename with hyphens
As long as you have perl based rename. You can check: =$ rename --help Unknown option: help Usage: rename [-v] [-n] [-f] perlexpr [filenames] That's the good one.

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