Needs more cow...say!

I stumbled across a wonderful program today: cowsay! It is just as cool as you would imagine:

cowsay "Text"

gives you an ASCII-art cow saying your Text.

I think I will use it as the welcome banner on all my servers:

Handy Network Utilities: nast, fping

I discovered a wonderful utility last night: nast. I wanted to scan my local network, just to see what devices were on it, what their addresses were, etc. I could ping my entire subnet, but what if I had a machine that rejected ICMP packets? (Not that I do very often, but it can happen in larger environments). I thought using a protocol like ARP would be much more robust, since it is pretty much guaranteed to be available. Then I discovered nast.

nast can do a lot of neat things. The first I found was mapping a subnet of course, which you can do by running

sudo nast -i eth1 -m

adjusting the interface to fit. It will return something like:

Nast V. 0.2.0

Mapping the Lan for 255.255.255.0 subnet ... please wait

MAC address             Ip address (hostname)
===========================================================
00:19:D2:92:20:CE       192.168.1.1 (MyGateway)
00:1B:C0:B7:86:CB       192.168.1.2 (MyBox) (*)
00:14:38:E5:76:10       192.168.1.5 (SomeOtherBox)

nast can also try to find out if there are any nodes on your subnet acting in promiscuous mode, which I think is pretty hot. Check out the main nast page for the full feature set.

In my searching, I also came across fping. Its main improvements over regular old ping are:

• More than one host can be passed (as well as a file containing hosts)
• Its output is very simple and easy to parse, making it ideal for scripting
• It tries each host and moves on if there is no response, making the whole process faster

Instead of

ping -c 1 myhost1 ; ping -c 1 myhost2

you can just run

fping myhost1 myhost2

which just returns

myhost1 is alive
myhost2 is alive

Both nast and fping are available in the Ubuntu repos.

Crashing Application Greeter

I was playing around with themes and the like in Hardy Heron recently, and I ended up selecting a new login screen. Apparently, something was wrong with the one I installed, however, since the next time I went to login, I was presented with a black screen and the message "The greeter application appears to be crashing. Attempting to use a different one." Hitting Ok on this merely cycled through X starting up and led to the same message.

To fix this, I went into another tty with Alt + F2, logged in, and ran "sudo vim /etc/gdm/gdm.conf". I commented out the line "Greeter=/usr/lib/gdm/gdmgreeter" and added "Greeter=/usr/lib/gdm/gdmlogin". After restarting, a simple Gnome login screen appeared fine, which allowed me to get in and change the login screen to a know safe default.

Additional Tips for GNOME-Do

After having played with GNOME-Do for a few days, experiencing some pain and finding more fun things, I have some suggestions that may make your adoption of it smoother.

• Get to 0.5. 0.4 will likely be in your repo, so beware! It is a paltry substitute. If you have installed that, remove it and delete the plugins dir. Then add the repos to your "/etc/apt/sources.list" as described here, then run "sudo apt-get install gnome-do". Also, make sure you kill GNOME-Do if it is running, BEFORE you remove the old version and try to install.
  
• 0.5 has a lot of great features, mainly the built-in Preferences window, which lets you just check plugins you want. There is also a new Open With action, which comes in very handy. Get to 0.5.
• Very neat plugins: Skype (lets you chat or call with Skype contacts, like the Pidgin plugin), Upload to Flickr, Locate Files, Rhythmbox.
  
• Install "xclip" (is in repos). This will let you select any text, invoke GNOME-Do, and act on that text.

Once I got to 0.5 and got those plugins running, GNOME-Do started becoming even handier!

Killer App: GNOME-Do!

I started to doubt my beloved Ubuntu after a co-worker showed me the various virtues of Quicksilver on the Mac. But, I have... Beagle? Yuck. Lunchbox was cute, but never seemed to work right. But today, I take that doubt back, great Linux gods. Behold: GNOME Do!

If you know what Quicksilver is, then you are basically there. If you don't, just imagine a pretty app launched by a simple key combo that lets you do anything from open files, to play songs, to email people with just a few easy keystrokes.

David Siegel's beautiful site has lots of documentation, plugins, and more. Just be on Gutsy or Heron, add a repo to your sources, install. In case you don't know what "super-space" is, as I didn't, super is the meta key, so the one with a Windows Logo on it on most keyboards.

Some additional plugins I installed and found handy:

• Del.icio.us - Search your bookmarks and public ones
  
• Rhythmbox - Play songs in your library, control volume, and more
  
• Pidgin - IM people in your Pidgin lists
  

Handy script: LAMP stack version printer

Often when troubleshooting or setting up servers, I need to know the installed versions of applications commonly grouped into the "LAMP" stack. I dislike having to remember the slight differences between them when trying to coerce each to divulge their version. So I created a script that does that, and even prints it all in easy-to-read colors!

The code:

#!/bin/bash
###################################
#
# Written by Samuel Huckins
#
# July 2007
#
# Prints out version info for
# things in the LAMP stack.
#
###################################
#
echo -e "\e[1;34mThis machine's LAMP stack:\e[0m"
echo ""
# Linux:
LINUX=`cat /etc/issue`
echo -e -n " * \e[31mL\e[1;33minux: \e[0m"
echo "$LINUX"
# Apache:
echo -e -n " * \e[31mA\e[1;33mpache: \e[0m"
if [ -e /usr/sbin/httpd ]
then
echo "`/usr/sbin/httpd -v| head -n 1 | awk '{print $3}'`"
elif [ -e /usr/sbin/apache2 ]
then
echo "`/usr/sbin/apache2 -v| head -n 1 | awk '{print $3}'`"
else
echo -e "\e[37mNot present\e[0m"
fi
# MySQL:
echo -e -n " * \e[31mM\e[1;33mySQL: \e[0m"
if [ -e /usr/bin/mysql ]
then
echo "`/usr/bin/mysql --version | awk '/Ver/ {print $2, $3, $4, $5}' | sed 's/,//'`"
else
echo -e "\e[37mNot present\e[0m"
fi
# PHP:
echo -e -n " * \e[31mP\e[1;33mHP: \e[0m"
if [ -e /usr/bin/php ]
then
echo "`php -v`"
else
echo -e "\e[37mNot present\e[0m"
fi
# Perl:
echo -e -n " * \e[31mP\e[1;33merl: \e[0m"
if [ -e /usr/bin/perl ]
then
echo "`perl -v | awk '/This is perl/ {print $4}' | sed 's/v//'`"
else
echo -e "\e[37mNot present\e[0m"
fi
# Python:
echo -e -n " * \e[31mP\e[1;33mython: \e[0m"
if [ -e /usr/bin/python ]
then
echo "`/usr/bin/env python -V 2>&1 | awk '/Python/ {print $2}'`"
else
echo -e "\e[37mNot present\e[0m"
fi
# done
echo ""

The result:

Call it "lamp-version-printer.sh", and add something like "alias lamp="~/my/code/lamp-version-printer.sh". Couldn't be easier.

Minor caveat: While the script does check each program for existence, I only check the most common place. It could be better expanded to cover less used locations for applications, conventions on more OSes, etc.