Compact Ubuntu

I’ve always hated the fact that on Ubuntu with the default themes, there’s far too much space wasted. The buttons are too tall, the treeview wastes too much space so that if you’re on eclipse or some other ide, you see a precious few items on the screen.

I’ve been trying to tweak it to no end - even looking to see if there are any ~/.gtkrc-2.0 tweaks. Found a few links such as this Making Eclipse look good on Linux - Max’s blog - however, didn’t really satisfy my need.

And so it stayed until today when I came across Clearlooks Compact Gnome Theme.

I love it - one more for my list of must-haves!

Enjoy symlinks and hardlinks on NTFS

Can’t believe I didnt come across this before - if you’ve gotten used taming your hdd by creating links to folders and have been annoyed with the lack of symlinks and hardlinks on NTFS, then despair no more. I’ve been using Mark Russinovich’s (of sysinternals fame) tool - junction.exe all this while and though it works great, have always wanted something that would integrate with Explorer too. For an in-depth discussion - read http://shell-shocked.org/article.php?id=284 Anyways, I’m extremely happy with NTFS Link - this will surely go into my list of “Must have tools - install immediately on a new machine” list

VPN into Windows VPN Server from Ubuntu Hardy

Ok - this was easy - and while there’s some resources on google, I had to figure out a few itty bitty things for my work VPN setup.

install

• network-manager-pptp
• pptp-linux

Restart network manager with

killall nm-applet
sudo /etc/init.d/dbus restart
nm-applet –sm-disable &

Configure VPN settings

Click on the network manager applet and click on VPN connections

1. Create a new VPN connection
2. Ensure that you select Refuse CHAP  in the authentication tab.
3. In the routing tab, you can give netmasks that need to go through VPN - for my work network, I have: 10.10.5.0/24 172.16.106.0/24

That’s it. Now click on the Network applet, and connect to your VPN. In the authentication dialog, use <domain>\username and your windows domain password.

Free subversion hosting - What’s the best?

All - I’ve just signed up for an Assembla account - these folks provide free subversion hosting with a 500 meg space and unlimited spaces.

Will see how it goes.

Hardy heron - first impressions

He he - finally got Ubuntu Hardy heron beta on my home and work laptop. first impressions below:

1. Wubi install from within windows is easy and works great. If after setting up so many boxes, I can go on and on about it, I’m sure that its great help for anyone who’s on Windoze. I mean, the barrier to entry has never gone down so much.

2. I guess once you’ve installed via Wubi and configured your system to your liking, you can uninstall and take an image that you finall install to a dedicated partition - isn’t that just awesome.

3. Comes installed with Firefox 3b4 -which is awesome. Given that FF crashes badly on yahoo, this might be a bummer for many people. Should probably have some first time customization that will let you install Opera.

4. Installation is super fast - took about 10 mins for wubi to install, reboot once, finish installation and reboot again. Grub default to Last selected would probably be a better idea.

The not so good

1. Wifi doesnt work out of the box - didn’t on my Dell Inspiron 1501 or the Dell Latitude D620. Its the ye olde broadcom problem. This is really the BIGGEST turn off. Hope it will get fixed by the time the final release is out. Meanwhile, had to jump through hoops getting ndiswrapper in. I didn’t go the broadcom fwcutter way since that only allows a 802.11b connection from what I read. I’m still not sure what fixed the issue - irrespective, I had to update the system and then things started working like a charm.

2. Compiz configuration isnt installed by default. If this is your first time on Ubuntu and you’ve come this way to see the awesome 3D desktop, then this is a bummer. Finding out what you need to do is a pain too.

I think that’s all there is to it. Its great once wifi starts working normally.

Gnuplot, dstat - easy graphing on Linux

Recently, started fiddling around with how to monitor and graph performance data on linux boxes. Other than the usual tools like top and vmstat, which are either interactive (top) or too textual to do anything much.

First off, vmstat, doesnt lend itself well to graphing without additional scripts to lay out the data so tools like gnuplot can be used. Secondly, and more seriously, it doesn’t include a timestamp in the output.

Looking around a bit found that dstat seems to be a good replacement to vmstat (and iostat) - and the generated data is consumable with gnuplot.

Here’s a quick example of generating graphs for CPU user, system and idle times

dstat -tc 5 500 > dstat.raw

now fire up gnuplot and go ahead and plot it

gnuplot> set xdata time gnuplot> set timefmt "%s" gnuplot> set format x "%M:%S" gnuplot> plot "dstat.raw" using 1:2 title "User" with lines, "dstat.raw" using 1:3 title "Sys" with lines, "dstat.raw" using 1:4 title "Idle" using lines

To make gnuplot generat an output file, you need

gnuplot> set term png

gnuplot> set output “dstat.png”

gnuplot> replot

And you’re done. here’s the graph generated on my machine. There’s loads more that you can do - and admittedly, you can do everything by dumping your file to excel. However, that doesn’t lend itself well to a completely automated process. When you’re doing performance testing and such like, you will likely repeat this enough number of times. Not having to do it manually helps big time!

Working with huge XML files - tools of the trade.

XMLStarlet is great for slicing and dicing huge XML files. Had a run in recently - had a 80 Mb XML file in a single line :D. Guess what, most editors that I tried balked and fell over. This was on a 2Gig Core2 Duo machine.

XMLSpy, vi, emacs, notepad++ all died - and trying to do something with a 80 Gig XML where the 80 gigs are on a single line isnt much fun. So the first order of business was to pretty print the XML. XMLstarlet worked great -

xmlstarlet fo file.xml > output.xml

and you’re done.

The next order of business was that we needed to validate the XML document against a schema. Our first attempt was with Sun’s multi schema validator (MSV). MSV does not validate the whole document but instead stops after a certain number of failures. So, MSV - out, XMLStarlet in. XMLStarlet can validate documents again W3C schema, DTD  or a RELAXNG schema.

xmlstarlet val --err --xsd schema.xsd input.xml >  errors.txt

And presto! - you get an error report that you can slice and dice with sed/awk or anything else at all.

XMLStarlet also allows you to write Xpaths to query the xml - however, I found the syntax too weird and round about. A better alternative is a perl based solutions - XSH2 - a command line xml editing shell. You can install it under cygwin and it supports basic command pipelining and redirection.

So go ahead and launch XSH. At your cygwin prompt

[~]xsh
—————————————
 xsh - XML Editing Shell version 2.1.1
—————————————

Copyright (c) 2002 Petr Pajas.
This is free software, you may use it and distribute it under
either the GNU GPL Version 2, or under the Perl Artistic License.
Using terminal type: Term::ReadLine::Gnu
Hint: Type `help’ or `help | less’ to get more help.
$scratch/>

Now, lets load up our document, type

$scratch/>$x:=open formatted.xml

Your prompt changes to

$x/>

So go ahead and try a few xpaths

$x/> ls /path/to/node

and XSH prints out the matching nodes. Now what if you need to create a document fragment of nodes matching a certain xpath? Piece of cake - do ahead

$x/> ls /path/to/node | tee fragment.xml

XSH2 has many, many more features - but this should be good enough to get you off the ground.

HOWTO: Access your machine from the internet without a static IP

For machines to be accessible on the internet, usually you need a static IP that’s leased from your ISP so that when someone types in your IP address, so that packets can be routed over to your machine. However, getting a static ip is costly and for the most part, internet users have dynamic IP address that the ISP allocates each time an end user connects to the internet. Since the ip address keeps changing on each connection, there’s no straightforward way to connect to the machine without knowing the IP address that’s been allocated - or so it was at least till Dynamic DNS came along (it isnt new - has been around for ages, but for some reason isn’t that well known)

Typically, when you type in www.google.com in your browser, your machine performs a DNS (Domain name service) lookup with the DNS servers from your ISP to find out the IP address corresponding to www.google.com. With DDNS (dynamic DNS) this is made to work with your dynamically allocated IP address also. Here’s how it works

1. Register with a DDNS service provider. Service provider provide free accounts for personal use - go to www.dyndns.org
2. Once you’ve created your account, go ahead and set up your hostname. DDNS service providers will have some domains that you can choose from and you get to choose the host part. For a fee, you can also use a domain name of your choice.
3. If your set up has a router at your end, check your router administration page if it supports dynamic DNS. If it does, you need to enter the hostname, account and password. Everytime your router connects to the internet, it sends an update notification to the DDNS service notifying the new IP obtained from your ISP. The DDNS service takes care of sending update notifications to routers on the internet.
4. If you dont have a router, then download the DDNS client software from the service provider. Most DDNS providers have windows, mac and linux clients. These run on your machine and do the same thing - notify the DDNS service provider of your new IP whenever you establish a connection with your ISP.
5. If you’ve got all this set up, then you can reach your machine from the net - try ping <your host name>

If you’re running Linux/Ubuntu, make sure your’re running SSH service and try ssh <your host name>. If you have a router setup, then you will need an additional step - basically the DDNS name refers to your router IP - and not the machine behind the router that you wish to reach. You will also need to make sure that your machine has a static IP from your router. To set up your router, go to your router administration page.

1. Go to the LAN section and give a range of IPs outside of the static IP. Most routers have lan addresses like 192.168.x.y - 192.168.x.z. If you want your host to have an IP address of 192.168.1.100, then give a LAN range that does not include this IP - say 192.168.1.110 - 192.168.1.200.
2. Save and reboot your router.
3. Now go to your network settings and enter your static IP (192.168.1.100), netmask 255.255.255.255, gateway (usually 192.168.1.1).
4. Go to your router administration page and look for a section like virtual server - your router will allow you to forward packets received on a particular port to a host and port within your LAN. You will have to enter the external port (we’ll use 22), the internal machine to forward (192.168.1.100) and the port to forward to (22). With this in place, any packets received on port 22 (ssh) on your router will be forwarded to the 192.168.1.100 machine on the ssh port.
5. Save and reboot your router.
6. Give it a spin.

From a different machine (or from the same one -doesnt matter), try out ssh <your host> and you should be able to login to your machine - via the internet.

Sluggish Firefox - and what a hog!

Okay - for the past few days I’ve been irritated with the browsing experience at home. Pages (google reader, Yahoo mail etc seemed inexplicably slower than before - but they’d load alright - just seemed that teeny weeny bit slower that’s enough to leave you suspicious).

I first suspected my ISP (verizon) for frequent dropped connections (saw the DSL modem lights reset a couple of times a day), then my wifi modem (not a high end one), then spyware/malware. So after the usual barrage of tests - wifi interference sources/anti virus/anti spyware/cable tests etc, I still hadn’t nailed it.

Finally, used procexp ( you can use plain ‘ole Task manager too - this is just flashier) and saw that FF had 330 MB of RAM with 3 or 4 tabs. Also, just plain clicking on a text box was slow, typing into a text field would echo characters after a noticeable delay - so this was definitely a browser problem.

When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.

– Sherlock Holmes

Ain’t that an apt quote??? I love the addons I have and probably I have one too many. This page on problematic addons  was a life-saver - after disabling a bunch of infrequently used addons (stumble upon toolbar, google toolbar, browser sync, adblock filterset g, foxy tunes and some more), I’m back in browsing heaven. The only addons I have now enabled are

• diigo toolbar
• all in one gestures
• Adblock
• Flashgot
• Piclens

What a relief!

BTW, addons are also the latest attack vector. So be wary of who you let into your browser!

Piclens - full screen slideshows with flickr (and others)

discovered Piclens

Its a great addin for firefox - and integrates with Flickr to give you full screen slideshows a’la Picasa slideshows on your machine!! Its a bit tricky to figure out how to get it to work - Just hover any picture on any page  and click on the blue bubbly overlay button that appears