This command will output 1 if the given argument is a valid ip address and 0 if it is not.

Files containing ascii art (e.g. with .nfo extension) are typically not correctly reproduced at the command line when using cat. With iconv one can easily write a wrapper to solve this:

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

I rarely use the system menu to start applications. I use keyboard shortcuts instead. Keyboard shortcuts are convenient time savers. To configure the shortcuts I use gconf-editor or CompizConfig Settings Manager (if I have Compiz turned on). Lately I've been using Chromium as my browser. Since Chromium is under heavy development it occasionally becomes unusable and I have to switch back to Firefox. I was hard-coding the browser command in my keyboard shortcuts. This became problematic with frequent browser hopping. I now use the xdg-open command when defining my keyboard shortcuts. xdg-open opens a file or URL in the user's preferred application. In the metacity keybinging_commands I have xdg-open http://gmail.com where I used to have firefox http://gmail.com. Now when switching browsers I don't have to update each keyboard binding command I just change my default browser in Ubuntu by clicking through the menu: System / Preferences / Preferred Applications / Web Browser. xdg-open is more convenient for this browser hopper.

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

I spent a bunch of time yesterday looking for the xsel package in Cygwin- turns out you can use the /dev/clipboard device to do the same thing.

If you just want to write or append some text to a file without having to run a text editor, run this command. After running the command, start typing away. To exit, type . on a line by itself.

Replacing the >> with a single > will let you overwrite your file.

print multiple increasing years using cal - calendar -. You can also try

src: http://tinyapps.org/weblog/nix/200907090700_linux_cal_print_multiple_years.html

It's the same command as submitted, but first with a command to make all characters green. It's the only way it looked "matrix-like" on my gnome-terminal.

Another wall matrix :)

gemInst.sh:

#!/bin/bash

for i in $@; do

if [ "$1" != "$i" ]

then

echo /newInstall/gem install $1 -v=\"$i\"

/newInstall/gem install $1 -v="$i"

if [ "$?" != "0" ]

then

echo -e "\n\nGEM INSTALL ERROR: $1\n\n"

echo "$1" > gemInst.err

fi

fi

done

When you use a "for" construct, it cycles on every word. If you want to cycle on a line-by-line basis (and, well, you can't use xargs -n1 :D), you can set the IFS variable to .

In my job I often have to deal with moving 100,000 files or more. A mv won't do it because there are too many. This will move everything in the current directory to the target path.

add it in ~/.bashrc

install bash-completion

html2text: http://www.mbayer.de/html2text/