My Linux Journey

My Linux Journey

My linux journey started in my engineering days when i got 3 cds of redhat 9.0. I did not have internet connection and only source was friends and computer magazines. I was very much impressed with it first i installed it but then i did not have anything to do with it i had Photoshop, Flash, Dreamweaver and Frontpage in windows and Age Of Empires too!!. I installed software called System Commander which was sort of protector for my system. At that time i did not have any guts to play with GRUB. And no live CDs for recovery. It is boot loader and system software. One time i had 6-7 different OS on my system - Windows 98/NT (don't exactly remember but i am proud of the fact i had worked on all version of windows - 3.1,95,98,ME,NT4,XP,2000,2003 and now VISTA, funny thing is that all of them have crashed on my system - blue screen of death. Most delicate was ME and NT,2003 were rock solid XP being most practical), Windows XP, Red hat 9, Damn small linux, Minix, some linux distro that used to fit on floppy i had installed it on my harddisk thanks to System Commander. I used test new versions and flavor of linux Just for fun.

By the way Just For Fun is autobiography of Linux Torvalds - very funny book if you are geek/programmer you will definitely like it. i did.

But then after lot of crashes, partition formatting/reformatting,i settled on Windows XP which worked without any hassles. Occasionally i used to boot into linux again just for fun.

After i got my first salary i started upgrading my pc. I bought new 80GB harddisk so that i could have more space to store data for windows. I reserved 20 GB for linux and tried a new (for me till that time i was familiar with only redhat linux) and hot distro of that time - UBUNTU. I liked it so much that i replaced my fedora with ubuntu moving all my data to it. But i still thought XP is better than ubuntu.

For last 6 months my brother's laptop has been sort of laboratory for me. My old (infact very old) PIII 800Mhz box can not take it any more. I was very much excited to idea of virtualization. Till 6 months before i was not confident enough on linux desktop so i was using Windows XP and with virtualization i could run ubuntu right within windows - best of two worlds. I tried ubuntu 7.04, 7.10 8.04, Kububtu 7.10, gOs2 beta, Oracle Linux, and Fedora.

I have been successful in attempts to convert my borther in to a linux follower - thanks to the buggy and resource hungry Windows Vista. Who want that eye candy when you get similar( though not that good though) graphics effects on linux without any performance loss.

After lauch of Ubuntu 8.0 beta i thought i will give it a try for desktop linux. I used ubuntu for over a week without booting linux on my old box PIII 800Mhz 256MB RAM. Whenver i required any application i went to Add/Remove did a simple search and i could find and use ( without any crash - earlier also i had used linux but most of the time something used to crash) equivalent linux application. Only reason i had to boot into windows being to check my office applications - Site works only on Internet Explorer. I never tried Wine yet now i
need it.

Most suprising thing is that Ubuntu 8.0 worked out of the box on Sony VIAO CR12GH/B laptop. Ubuntu 7.10 has some difficulty recognising intel x3100 graphics accelerator hence screen resolution was limited to 800x600 ( i tweaked Xorg conf and it worked with resolution 1200x800 on ubuntu 7.10 as well).

Earlier whenever i worked on linux i knew something would go wrong and i accepted it now i dont have that feeling - Ubuntu ROCKS.

Till that moment i used to think linux is just not ready for desktop for normal user( i am half normal and half geek - i am passionate about linux but have grown in comforts of windows) ( there are plenty reasons for it - h/w is one major reason i feel). But last 2 years i have seen great growth in linux distros mainly Fedora, Suse and Ubuntu.

If you have good standard hardware on your box linux is READY for you and certainly is for Me and it will beat windows vista in user experience. Major reason for this fact is buggy and bulky VISTA. i get rating of only 3.0 out of 5.0 with very strong hardware for laptop. What the heck what do you want exactly VISTA? 5 GHz processor. 2 GB graphics card????

Here is my list:

Rythmbox
Window Media Player/Winamp - Windows media player takes around 50% CPU when playing high beat rate (more than 150 Kbps) mp3 Winamp and rythmbox take less cpu.

Totem/VLC
Movie player I love VLC. Its best player avaialable. Windows Media player really sucks here. I just cannot run any movie in my p3 box with version 10 onwards. VLC is much better both on windows and linux. Whats better than having your favoiurite application avaialable on both systems. Again windows application sucks here.

Bit-torrent
Microtorrent is very good but so is azureus and Transmission. No problems here too.

Browser
Firefox 3.0 rocks and blazingly fast on sony vaio laptop. I can not get same performance on Vista/IE or Vista/Firefox combination. Most developers say Firefox 3.0 is the FASTEST browser to date. I did not get any improvment on my p3 box (windows xp). But i could feel firefox more responsive on linux on both systems - XP(PIII) as well as Vista(Core 2 Duo T7100). Why is so?. I really dont know neither i don't believe in benchmark numbers ( i have done performance testing/benchmarking i know how misleading sometime they could be). As performance engineer i used to give importance on fact how end-users are experincing it. Did they find any improvement or felt good. With firefox 3.0 on linux i felt. On other note IE7 is not that bad too. But i am firefox convert. long time ago.

Programming
Editplus beats any lightweight editor in linux. I have not tried anything other that GEdit. Gedit is little bit heavy ( on P3). But i could find editor called Geany i liked it very much. I used Ecliplse for most of my Java programming and was disappointed a bit on linux. On thing about IDE i care is how it uses screen effectively to pack useful stuff. On linux SWT occupies much more space than on windows.

Office
Nothing to say. OpenOffice is really behind MS Office. but i have different opinion here. Dominance of MS Office is just because of numbers. What would you do if you have to write some document and mail it to somebody. I could find one alternative in OpenOffice, Convert that document to PDF and mail it. I just hate rebooting again to windows and edit that doc.

For other applications you can refer to this interesting links :

• Awesome Ubuntu/Linux Apps you might not know about
• Top Best 50 Ubuntu App for Designing

And last thing i want to say about VISTA is that its fooling people around. It takes seconds to load dekstop and pretend ready for action but reality is
different. It take much more time to get all networking started and then i can start my browser. With linux it takes time to login but i know when its
now ready - ready for anything file explorer, browser and mp3. In and all if you don't have any reason to stick to windows like you IDE works only in
windows then go and install ubuntu (or any linux) give it a try. Vista is just not ready for countries like india where latest hardware comes to
mainstream atleast 6-8 months after. Concepts like open source, linux, ubuntu, free document formats (openoffice), OLAP (one laptop per child) are very much suitable in developing countries. This will make sure that user gets what it need and hes not forced to buy first windows then Microsoft office and
then anti-virus then internet protection software to protect windows. its chain that's not needed and can certainly be avoided.

More or less computing is for fun as said by Linus Torvalds in his thoughts on life... so enjoy it. I certainly enjoyed it with linux.

Oracle on Ubuntu Hardy Haron

I had hard time installing oracle on my brother's sony vaio laptop. Not because of linux but because of windows i was out of space on ubuntu and wanted to shrink windows partition. i had strage expeprice with it. Windows does not let me to shring below 1 GB. Why? may be some technical difficuly. huh! then i started with ubuntu 8.0 live cd, opened Gparted i could resize my NTFS partition. Wow! why windows wouldnt allow then? Does it know that i had ubuntu installed on this laptop and user of this laptop dosent prefer windows. Only reson that i went to windows to resize is because vista is very particular of stratup files and my exprience with NTFS on linux is bad. lost lot of data once.
Within 2 hour gparted moved my 50 gb partition. freed 16 gb for linux and 2gb for swap.

Very first thing i noticed is that oracle doesnt support ubuntu as officially supported linux distribution but i could manange to find installation guide for debian. Its recommended to go with RHEL/SUSE Enterprise if you are using for commercial purpose.

Here are some of links for pre-setup tasks :

• http://linux.togaware.com/survivor/Oracle_10g.html
• http://www.akshaymehta.com/2006/12/10/installing-oracle-10g-r2-on-ubuntu-edgy/
• http://rossov.com/2006/02/08/oracle-10g-ubuntu-linux-vmware-part-ii/
• http://www.oracle.com/technology/pub/articles/smiley_10gdb_install.html

Even oracle's Installation Guide is also helpful.

Follow all the steps correctly. This actually helps you in case you come across some problem, Since you know what is installed where?
So here we go start terminal with oracle users

su oracle
./runInstaller -ignoreSysPrereqs

-ignoreSysPrereqs is flag that allows oracle to proceed without check. Alternative is to create file /etc/release and pretend that i am rhel.

Installlation went more or less smooth but i faced some problem which are faced by many people. I has faced similar problems on RHEL too!. Little bit of googling will solve most of them.

• Linking phase fails for 10gR2 on Ubuntu 6.06: undefined ref to 'nnfyboot'

Solution : Create following sysmlinks and relink
ln -s $ORACLE_HOME/lib/libclient10.a $ORACLE_HOME/lib/libagtsh.a
$ORACLE_HOME/bin/genagtsh $ORACLE_HOME/lib/libagtsh.so 1.0

This problme is discussed here and worked on ubuntu 8 too:

• Right version libstc++ library on my ubuntu 8.04 version was 6.x. So i created following symlink

libstdc++.so.6 -> libstdc++.so.1 ( Present)
libstdc++.so.5 -> libstdc++.so.1 ( Oracle tries to find it, so i added)

• "ORA-12547: TNS:lost contact" when creating database in Oracle 10g. Lib AIO Error This is very annoying.After installation oracle starts configuration assistant DBCA. After googling a bit around i found out libaio was required. In ubunntu it is called libaio1.
  

So do apt-get install libaio1


This problm is discussed in this thread for Fedora.

Most of the problems were in linking phase hence i did $ORACLE_HOME/bin/relink all again to make sure that all changes have been affected.

Now oracle is working fine on ubuntu 8.04 beta.

How to integrate DWR and Struts

DWR is AJAX framework for JAVA. Using DWR you can call directly any method of java class asynchronously ie. without entire page reload. With following you can even integrate DWR with struts so as to have access to important formbeans and also any other java classes. Only restriction being : methods to be called has to be form methods. This is easily done by refactoring code in Action class to form class. By this way you can call this code from Action class as well as via ajax.

Add dwr.jar to web project

Modify Web.xml Add following code to web.xml. Make sure DWR servlet gets loaded after ActionServlet.

<servlet>
    <servlet-name>dwr-invoker</servlet-name>
    <servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
    <init-param>
      <param-name>debug</param-name>
      <param-value>true</param-value>
    </init-param>
    <init-param>
      <param-name>activeReverseAjaxEnabled</param-name>
      <param-value>true</param-value>
    </init-param>
    <init-param>
      <param-name>initApplicationScopeCreatorsAtStartup</param-name>
      <param-value>true</param-value>
    </init-param>
    <init-param>
      <param-name>maxWaitAfterWrite</param-name>
      <param-value>100</param-value>
    </init-param>
    <!--
    <init-param>
      <param-name>org.directwebremoting.extend.ServerLoadMonitor</param-name>
      <param-value>org.directwebremoting.impl.PollingServerLoadMonitor</param-value>
    </init-param>
    -->
    <load-on-startup>2</load-on-startup>
  </servlet>

  <servlet-mapping>
    <servlet-name>dwr-invoker</servlet-name>
    <url-pattern>/dwr/*</url-pattern>
  </servlet-mapping>

Create dwr.xml file. This file will tell DWR which classes are to be exposed for asynchronous calls. Following example file exposes PersonFrom class using interface name Forms using Struts Creator. It also exposes Date class as remote class JDate.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://getahead.org/dwr//dwr20.dtd">
<dwr>
 <allow>
  <create creator="new" javascript="JDate">
   <param name="class" value="java.util.Date" />
  </create>
  <create creator="struts" javascript="forms">
   <param name="formBean" value="personForm" />
  </create>
  <convert converter="bean" match="$Proxy*" />
 </allow>
</dwr>

Include following lines in JSP for adding DWR javascripts. “forms.js” refers to our “forms” class exposed in dwr.xml. These files do not exist physically but are dynamically generated and served by DWR servlet.

<script type='text/javascript' src='dwr/engine.js'> </script>
<script type='text/javascript' src='dwr/util.js'> </script>
<script type='text/javascript' src='dwr/interface/forms.js'> </script>

Now you can call any method of form PersonForm class. PersonForm class has method called generateAntiSpamMailto. You can directly call this method using javascript. See following example. Following example basically dynamically calls “generateAntiSpamMailto” method on server to get anti-spam text and puts in to the div and makes the div visible. This is done by defining function as the third argument. First two arguments are regular arguments which are same as java arguments.

function process() {
  var address = dwr.util.getValue("address");
  var name = dwr.util.getValue("name");
  alert('Addres is ' + address);
  alert('Name is ' + name);
  
  forms.generateAntiSpamMailto(name, address, function(contents) {
    alert('content is ' + contents);
    dwr.util.setValue("outputFull", contents, { escapeHtml:false });
    dwr.util.byId("output").style.display = "block";
  });
}

and HTML part as

<input id="submit" type="button" value="Submit Query" onclick="process()"/>
<html:submit>Submit Query</html:submit>
</html:form>

<div id="output" style="display:none;">
  <h2>Generated Links</h2>
  <textarea id="outputFull" rows="9" cols="70">
  </textarea>
</div>

You can even use DWR to validate certain field on the spot when user finishes typing the data. Validation will be done on the server but called asynchronously via AJAX. Following is an example which makes use of Apache Commons Validator framework to validate an email address. This require certain jars to added to lib(BSF, BSH,Commons jars included in the zip file attached).

DWR xml

<create creator="script" javascript="EmailValidator" scope="application">
<param name="language" value="beanshell"/>
<param name="script">
import org.apache.commons.validator.EmailValidator;
return EmailValidator.getInstance();
</param>
</create>

and HTML /JavaScript part

<script> 
function verifyAddress() {
  var address = dwr.util.getValue("address");
  EmailValidator.isValid(address, function(valid) {
    dwr.util.setValue("addressError", valid ? "" : "Please enter a valid email address");
  });
}
</script>

<html:text property="name" size="16" onkeypress="dwr.util.onReturn(event, process)" onblur="verifyAddress()"/>