Pesky little bash quoting problem

Have to admit it - this happens every time I sit down to write a some shell script that manipulates paths on windows (where path names often end up with spaces). Soon I find my nifty little script running into problems when it doesn't handle spaces properly and I find myself reading up on bash quoting rules once again...

Anyway, so this post is mostly for self reference :) and to put down some simple rules in the hope that writing it down will help committing it to memory.

The latest (mis)adventure was to make irfanview run under wine and a little script to allow irfanview to open a file provided on the command line. Irfanview being a windoze executable, its necessary to cd to the folder and then pass the file as argument to irfanview. Trivial isn't it....until I found that the script fell over when it got a path liek /path/to/a folder with spaces/image.jpeg.

#! /bin/bash
DIRNAME=$(dirname "$1")           # double quotes necessary - since $1 could have embedded spaces

FILENAME=$(basename "$1")
echo $DIRNAME
echo $FILENAME
cd "$DIRNAME"                               # once more, double quotes necessart
irfanview $FILENAME

Golden Rule

When passing a path as argument, always enclose in double quotes.

Firefox 3 Beta 2 on Ubuntu Gutsy

I'm having weird problems with firefox 3b2 on ubuntu gutsy - and as far as I can tell, I seem to be the only one. Did not find anything similar on ubuntu forums too.

Installed firefox 3 beta 2 from Mozilla to /usr/lib/firefox3b2 folder and created

lrwxrwxrwx 1 root root 27 2007-12-30 23:44 /usr/bin/firefox-3b2 -> /usr/lib/firefox3b2/firefox

When I launch firefox3b2, I get firefox alright, however, in the location bar if I type in a url and press Enter, nothing happens - absolutely nothing at all. I have to go and click the green arrow for the browser to open the URL. The search box is even weirder - neither the Enter key works nor does the mouse!

I'm at a loss - and nor can I find any similar experiences on forums etc - ideas welcome :D

SOLVED 01/20:Backed up my .mozilla folder and started firefox 3 b2 - no problems now :D

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.

Back in circulation

I'm on vacation in Bangalore, and guess what - fixing my home computer. Mostly things like lost drivers, screen resolution, cruft in the drives - its an old machine - a P4/512 Meg, but good enough for surfing the net.

Did a few fun things in the midst, and its been ages since I've added anything to this blog. Will summarize for now and put in longer posts with more details in cases someone's interested.

1. Fixed my windows C drive which was running out of space - used trusty old windirstat for that.


2. Set up wifi at home with ADSL modem from BSNL - MT800. Again, wasn't as straightforward as I'd thought.


3. Replaced old pcq linux 2006 with ubuntu gutsy - without losing stuff :D. Need to have /home in a separate partition, but otherwise this is a breeze.


4. Having fun with compiz-fusion. Its great - however, the documentation isnt easily locatable/consumable enough for first timers (me).


5. Set up DNS caching proxy on my linux box - has improved my net/web experience a 100 fold. Was a piece of cake too.


6. Set up Dynamic DNS and remote SSH access to my box - this has been the single most important utility/maintainance action.

More later.

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

Python, cygwin, TurboGears, mysql hell

Ok - here goes - I've always liked python, though definitely a noob. I was interested in python on the web and after a bit of googling, seems like TurboGears is the way to go.

First things first - decided to use mysql as the database (already have it on my machine and didn't want to install one more database (postgresql/sqlite). Now it turns out that MySQL doesnt have a cygwin package. More googling - mysql server can't run on cygwin due to something to do with pthreads. You can compile the mysql client on cygwin though.

That's what I decided to do - grabbed the Linux tar.gz source from mysql.com, got it into a directory and ran ./configure --without-server, followed by make && make install. All went through fine -other than the fact that it was time consuming and pretty boring (more so since I had to download and install gcc, bintools first in cygwin)

I thought I'd got through the hard part and what remained was to install python-MySQLdb package. Off I went to

easy_install MySQLdb

No luck there - package build failed with missing library -lmysqlclient_r. Turns out that the 'thread-safe' version of mysql client (mysqlclient_r) is preferred but the mysql build doesnt build this by default. What a shame!!!

Anyway, so I wasnt going to redo the whole mysql client library build again - more README files and googling later, grabbed mysql-python-1.2.2 tarball, got it into a folder, edited site.cfg and changed 'threadsafe=false'. The next run on python setup.py build worked properly, with the python mysql linking against the non threadsafe mysqlclient library.

Think troubles are over yet? No way.

Off I went to test - started the python interpreter and did a import MySQLdb, and got a Permission Denied in some 'egg' file!!! What the heck are these egg files anyway. Well, I did'nt have much of a clue and more google later got educated that these are install packages used by the easy install system. The more I looked, the more it seems that the easy install is anything but easy :(. Anyway, this one had me floored - since I couldnt get to the line of source where the error was and had no clue how to view the contents of an 'egg' (they're zips - but I didnt know that and very helpfully there's hardly anyplace where they say that they're zips with the extension of egg!!! Baaah!! - why couldn't they just use .zip?)

More and more hard googling - and this time the info's really sketchy till eventually found a post from a guy who asked the exact same question. Guess what, the easy_install system unzips the eggs to some folder (pointed by PYTHON_EGG_CACHE env var) and there I needed to do a chmod a+x on the _mysql.dll. Well so I did echo $PYTHON_EGG_CACHE and the var isnt set!!! Admittedly at this point, I'm not looking sharp either - what started out as a quick spin has become a quagmire of installation issues - but I'll be damned if I let it sink me!!! Eventually, had the Eureka moment and checked ~/.python-eggs and sure enough found the truant _mysql.dll. Quick chmod a+x and presto - import MySQLdb worked!!! YAHOOOOOOOOOOOOOOOOOOOO!!!!

And now back to where I started - went back to turbogears, did a tg-admin quickstart, setup a mysql database and started with python start-testproject.py. Guess what - no luck yet - turns out that mysql cant client to my windows server with a socket.

More googling - and this time its really desperate - and more enlightenment - the windows mysqld doesnt do unix sockets - how do I force tcp/ip? Simple - use 127.0.0.1 as hostname in the connection settings instead of localhost!! Finally something that was easy to fix. Finally after 8 hours of on and off hacking away at installation issues I'm glad to see a turbogears web page.

Bottomline: Python's great, from the looks of it, turbo gears seems well designed. Mysql is a great database - a cygwin native server would be great - or atleast a client package. But if one has to run through all these hoops just go get a 'quick spin' then adoption's going to be difficult.

I havent tried RoR - but has someone tried a similar thing on cygwin (cygwin, ruby, RoR, mysql)? How does the experience compare - is it any easier to get off the ground?

Maven Emma plugin - filters dont work

Using v0.5 of the Maven emma plugin. Found that if you specify an include/exclude filter, no classes are instrumented....On digging a little deeper under the covers, it seems that there's a bug with the Maven emma plugin - I've edited the plugin's jelly script and using it here.

Posted the bug and the fix to Maven's sourceforge developer forum. You can find it here

The fixed plugin.jelly's here - Maven emma plugin 0.5 fixed

Building a FC6 server for Java development

It has come upon me to build a FC6 server with a Java build environment that is going to serve as the build machine. This is the first time I'm coming to Fedora - always having used Debian in the past.

1. OS installation was smooth. I installed with KDE since some folks prefer the GUI.


2. During the installation, I chose Java Development - and all the gcj components got installed. Then post installation, I downloaded JDK from Sun and installed it too. The (gcj) tomcat of course didnt work very well in this mess. Fixing it was easy - just fired up yum via Add or Remove Programs and removed gcj - which removed all the other gcj tools and libraries too.


3. Setting the host name - unexpectedly, had trouble doing this - finally used system-config-network.


4. Environment variables - again a little digging around to figure out how to set environment variables so that they are effective for all users on the system - essentially JAVA_HOME, JRE_HOME, CATALINA_HOME, MAVEN_HOME etc. Finally found that this is best set in /etc/environment where it works for all users.


5. Downloaded java tools and libraries - housed tomcat and maven under /usr/lib/java/maven-xxx and /usr/lib/java/apache-tomcat-x.xx and created symlinks. Placed symlinks to tomcat's startup.sh and shutdown.sh in /usr/bin. Placing a symlink to maven doesnt work - but an alias works as well. To make it work for all users, simply put it in /etc/profile
   

   alias maven=/usr/lib/java/maven/bin/maven

   
   


6. Created a group java and added users to the group. Set permissions on the maven installation folder so that java group has write access (this is so that maven plugin:download for additional plugins works properly and can write to the maven plugins folder)

That's all there is to it. Just make sure that you do everything as the 'application' user - dont do it with your account or the root account.

Ant - Debugging classpath

Here's a nice tip on debugging classpaths in Ant: http://www.javalobby.org/java/forums/t71033.html

Essentially,

<?xml version="1.0"?>
<project name="project" default="default">
	<property name="lib" value="web/WEB-INF/lib"/>
	<property name="src" value="src"/>
	<property name="dist" value="dist"/>

	<path id="classpath">
	  <fileset dir="${lib}">
		  <include name="**/*.jar"/>
	  </fileset>
	</path>

    <target name="default" description="--> description">
    	<javac srcdir="${src}" destdir="${dist}">
    		<classpath refid="classpath"/>
	</javac>
    </target>

</project>

Cobertura vs EMMA

This is a rant against the Cobertura maven integration - and to a certain extent on Cobertura also - and hopefully an objective one ;). Hopefully this'll help someone select between the two big (open source) coverage tools out there.

We've been using Cobertura at work till now and its done its job nicely - the reports look great and the maven 1.x integration, while not neat, is functional. While we knew that someday we were going to have to merge coverage data and have a single report across multiple test methods (junit, selenium tests and manual), cobertura documentation stated that this was possible and so we weren't really bothered.

Thought I'd give it a whirl and set it up - and that's when the trouble started. Atleast, with the maven integration.

First of all - there's no way to just instrument code. You can generate the report (which will instrument classes and run the tests) but if you just want to instrument classes so that the final deployable contains instrumented classes, its a no go with the maven plugin tools.

Obviously, no point giving it up there - so thought I'd just include the ant tasks and go the ant way in my maven goal. Turns out that there's no 'plugin init' kind of goal that can be called post build:start that will set up dependencies and import the cobertura ant tasks. You have to do it all yourself.  Fine - went that way too - so now my maven.xml uses the cobertura ant tasks and finally I'm able to generate an instrumented build. YIPPPPPPPEEEEEE.... or wait...lets' just make sure that this thing works...

Does it?

Turns out - no - it doesnt - so I dropped the WAR into tomcat and accessed the login page of the application and then shut down tomcat nicely. There's even a cobertura.ser created in the tomcat bin folder and I'm thinking that probably this will all work together finally...

So I go ahead, tweak my Maven.xml further with a coverage task that will merge the data from the junit runs and servlet container runs. Turn the switch on... and lo and behold...Exception reading the merged data file. Back to google and after hunting around for sometime found this Bug while merging reports

So finally I'm ready to give up cobertura and give Emma a try...and it couldnt have been better...

1. Goals are nicely setup

2. You can init the emma system with the emma:init goal and then use ant tasks if you want flexibility for doing things like merging reports.

3. The merging works :))

One sticky issue that I did come up  with was that the for the same source and test cases the coverage reported by cobertura and emma differ widely. With Cobertura, we were at 40% coverage while with EMMA, the number's up to 60% coverage - and while EMMA has some literature on how it does things - I'd be glad if someone did explain why or how the reported numbers could be so different for the same base code and unit test suite?

Tulip festival at Skagit county

We visited the Tulip festival at Skagit valley. Its hard to describe in words - and a picture's worth a thousand words - so here's a bunch of pics - let them do the talking :).

Anyway, had a lovely weekend driving up to Mount Vernon with friends and had a memorable weekend.

TulipFestival

Ninotech Path Copy 4

Ninotech Path Copy 4
Novell Cool Solutions: Cool Tool

Was looking for a shell extension to copy filenames from explorer. Thought there'd be a dime a dozen - and it turns out that
a) they have 20 other things that I dont want.
b) Its trial ware.

Finally after searching high and low, came across this and it's GREAT!

powered by performancing firefox

Production Eclipse Configuration

Part of the game of getting code out that conforms to coding standards without having to go through the "One Big spring cleaning" exercise is configuring and centralizing the tools.

At a minimum, it helps to have a central Eclipse installation that has all the tools configured and setup - so each person doesn't have to do it. Alternatively, there should be a reference set of plugins and their configuration files available in the source control repository.  Here's my eclipse configuration

Tips for using Eclipse

http://www.aspectprogrammer.org/blogs/adrian/2006/02/tips_for_using.html

Great Article - full of very very useful tips!

Firefox - not so obvious search

I discovered this - totally by accident.

In Firefox, you can use / (forward slash) to search for text OR links - and if its a link, then you can follow the link just by clicking Enter!  That is way cool - especially when you're on a laptop and cant/dont have your mouse around. I've always find it a pain to do a "link find"  - ' (single quote) and a text find - ctrl-f separately...Never knew that there was a shortcut that did both and what more - its way natural if you're used to 'less'!!

To complete the keys for Firefox mouseless browsing,

• space -  page down


• shift - space - page up

Performancing and Wordpress - initial imression - very nice!

Performancing | Firefox Add-ons | Mozilla Corporation

Performancing for Firefox is a full featured blog editor that sits right in your Firefox browser and lets you post to your blog easily. You can drag and drop formatted text from the page you happen to be browsing, and take notes as well as post to your blog.

powered by performancing firefox

Diigo - a hidden gem

If you use del.icio.us for online bookmarking and like google's notepad for online research, then suggest that you take a look at Diigo's offering. It's all those rolled in one and then some.

I've been using it for quite some time now (after trying out del.icio.us and google notepad) and I'm not budging! Recently I was doing a bunch of research online and diigo excelled!

1. Online bookmarking - will also simultaneously post to your del.icio.account


2. Firefox toolbar


3. tagging


4. Web clipping


5. Web annotation

Now to "hidden" - I've been on Diigo more than 8 months or so now - and yet I'm still to meet someone who knew about Diigo!!
Diigo rocks!

Imaging the tenth dimension

Amazing flash movie!

Great flash movie explaining dimensions 4 (time), 5, 6 all the way uptil 10. And why they stop after 10!

I've never come across a clearer explanation ever and the great visualization does the trick.

Instant messenger client utopia

GAIM...

I hate running 3 different chat clients (yahoo, msn, gtalk) on my machine - and that's just 3x memory, startup programs and useless adversting too many.

And I hate msn and yahoo's advertising that's built into their clients...esp on MSN which insists on opening a mini page on login...

Use GAIM - and do yourself a favour. Of course that's if you don't need the very specialized features :)).

Installation is a breeze and use plugins you like and avoid the bloat....The best plugins I like are guifications and text replace. Lastly, if you keep moving between machines as much as I do, then its a breeze to retain your settings between all your machines.