blah.... blah.... blah...

Blog @ Blogger ends here....

2006-05-10T15:44:00.000+05:30

No more blogging on Blogger, coz my blog contains invalid stuff. Will post new link, if I found a successfully validatable blog.

Credits: JavaShit emitted by Blogger.

Good Bye World

ReactOS

2006-05-10T15:24:00.000+05:30

ReactOS, a Free and Open Source OS, compatible with Windows NT.

ReactOS Boot Loader Screen
ReactOS Splash Screen	ReactOS Command Prompt
ReactOS About box	ReactOS Registry Editor

Screen shots of ReactOS, taken by me, on QEmu. There are more screenshots available at: http://www.reactos.org/xhtml/en/screenshots.html .

Even I worked on PA-RISC too

2006-04-27T04:28:00.000+05:30

Well, today I worked on PA-RISC processor based system, like one of my friend Gautam who worked on it @ his university.

Well, I was looking for some information on PA-RISC processors. I was surprised to know that most of its processors (forgot to mention, it is actually a family of processors) don't have L2 caches, recent ones (so big, 64 MiB L2 cache of PA-RISC vs. my 2 MiB L2 Cache of Pentium 4 ;-) ), and 2 processors in mid generation have L2 caches. Anyways, you can read more about PA-RISC processors, @.....

Now, comes to the GNU/Linux play with the box. The PA-RISC box runs Debian GNU/Linux (Linux pa64 2.6.15-1-parisc64 #2 Mon Mar 6 17:39:49 GMT 2006 parisc64 GNU/Linux). A session with box is displayed below:

21287@pa64:~$ cat /proc/cpuinfo
processor       : 0
cpu family      : PA-RISC 2.0
cpu             : PA8600 (PCX-W+)
cpu MHz         : 400.000000
model           : 9000/785/B2000
model name      : Kazoo W+
hversion        : 0x00005d00
sversion        : 0x00000481
I-cache         : 512 KB
D-cache         : 1024 KB (WB, 0-way associative)
ITLB entries    : 160
DTLB entries    : 160 - shared with ITLB
bogomips        : 796.67
software id     : 2003331839

21287@pa64:~$ cat /proc/meminfo
MemTotal:      1793744 kB
MemFree:         33096 kB
Buffers:         67936 kB
Cached:         917148 kB
SwapCached:          0 kB
Active:         784156 kB
Inactive:       715640 kB
HighTotal:           0 kB
HighFree:            0 kB
LowTotal:      1793744 kB
LowFree:         33096 kB
SwapTotal:      524280 kB
SwapFree:       524192 kB
Dirty:             352 kB
Writeback:           0 kB
Mapped:         586212 kB
Slab:           226992 kB
CommitLimit:   1421152 kB
Committed_AS:   839260 kB
PageTables:      10520 kB
VmallocTotal:   245728 kB
VmallocUsed:      3764 kB
VmallocChunk:   241600 kB
21287@pa64:~$ mount
/dev/sda5 on / type ext3 (rw,errors=remount-ro)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
tmpfs on /dev/shm type tmpfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev type tmpfs (rw,size=10M,mode=0755)
/dev/sda1 on /mnt/sda1 type ext3 (rw)
21287@pa64:~$ /sbin/ifconfig
eth0      Link encap:Ethernet  HWaddr 00:10:83:FF:6D:23
          inet addr:192.168.1.7  Bcast:255.255.255.255  Mask:255.255.255.0
          inet6 addr: fe80::210:83ff:feff:6d23/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:54875344 errors:1 dropped:0 overruns:0 frame:0
          TX packets:93060665 errors:415 dropped:0 overruns:0 carrier:243
          collisions:5825773 txqueuelen:1000
          RX bytes:15922891349 (14.8 GiB)  TX bytes:41259342948 (38.4 GiB)
          Interrupt:65 Base address:0xf00

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:1281187 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1281187 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:118301798 (112.8 MiB)  TX bytes:118301798 (112.8 MiB)

21287@pa64:~$ ping -b 192.168.1.255
WARNING: pinging broadcast address
PING 192.168.1.255 (192.168.1.255) 56(84) bytes of data.
64 bytes from 192.168.1.5: icmp_seq=1 ttl=255 time=0.624 ms
64 bytes from 192.168.1.4: icmp_seq=1 ttl=64 time=1.11 ms (DUP!)
64 bytes from 192.168.1.3: icmp_seq=1 ttl=255 time=2.04 ms (DUP!)
64 bytes from 192.168.1.6: icmp_seq=1 ttl=64 time=3.27 ms (DUP!)
64 bytes from 192.168.1.5: icmp_seq=2 ttl=255 time=0.482 ms
64 bytes from 192.168.1.4: icmp_seq=2 ttl=64 time=0.645 ms (DUP!)
64 bytes from 192.168.1.3: icmp_seq=2 ttl=255 time=0.880 ms (DUP!)
64 bytes from 192.168.1.6: icmp_seq=2 ttl=64 time=1.06 ms (DUP!)

--- 192.168.1.255 ping statistics ---
2 packets transmitted, 2 received, +6 duplicates, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 0.482/1.266/3.271/0.884 ms
21287@pa64:~$ lspci
0000:00:0c.0 Ethernet controller: Digital Equipment Corporation DECchip 21142/43 (rev 41)
0000:00:0d.0 Multimedia audio controller: Analog Devices AD1889 sound chip
0000:00:0e.0 IDE interface: National Semiconductor Corporation 87415/87560 IDE (rev 03)
0000:00:0e.1 Bridge: National Semiconductor Corporation 87560 Legacy I/O (rev 01)
0000:00:0e.2 USB Controller: National Semiconductor Corporation USB Controller (rev 02)
0000:00:0f.0 SCSI storage controller: LSI Logic / Symbios Logic 53c895a (rev 01)
0000:01:00.0 3D controller: Hewlett-Packard Company Visualize FXe (rev 03)
21287@pa64:~$ who
the1     pts/0        Apr 19 13:12 (192.168.1.5)
the1     pts/11       Apr 17 19:12 (192.168.1.11)
21233    pts/53       Apr 26 13:51 (dslb-082-083-234-190.pools.arcor-ip.net)
the1     pts/36       Apr 17 19:13 (192.168.1.11:0.0)
1444     pts/72       Apr 26 11:02 (80-219-149-147.dclient.hispeed.ch)
the1     pts/80       Apr 26 14:30 (adsl-68-23-47-109.dsl.chcgil.ameritech.net)
21287    pts/2        Apr 26 15:01 (61.246.76.12)
21225    pts/77       Apr 20 02:07 (s010600045a2d8536:S.0)
21225    pts/69       Apr 20 02:19 (s010600045a2d8536:S.1)
21287@pa64:~$ lsusb
Bus 001 Device 002: ID 05a4:9760 Ortek Technology, Inc.
Bus 001 Device 001: ID 0000:0000

And hey, I even ran a X application (xedit) also, not on my DISPLAY but some other user's ;-) . I even tried to sudo, but I'm not in /etc/sudoers ;-) . I even have a webpage of mine hosted there @ http://unixclan.no-ip.org/~21287/. And I even worked on Compaq Alpha (when ?? guess...).

Although, I dream to have one day my own PA-RISC box, my own Alpha box, my own IA-64 box, my own MIPS box, my own PowerPC box, my own PowerPC (64bit) box, my own Sparc box, any other processor box you can think of, and my own processor box. BTW, I'm not interested in processors, but in their boxes ;-) .

This post is dedicated to Gautam (the person who always inspire me).

Good Morning

What is your good name ?

2006-04-23T21:05:00.000+05:30

Today, while talking to Gautam, I came to know common mistakes I used to made while speaking in English. It's not just bad pronounciation, but some other mistakes also. e.g.

I'm giving (taking) examination.
Today, I'm going to give (take) an interview ?
What's your good name ? (What is your name ?)
and tons of more...

This usage of English is wrong. But, I still don't know which body governs English language ? There is more than this explained in the Wiki article titled Indian English.

Thanks to Gautam, for pointing out

There might be some other grammatical mistakes in this blog entry or some of my other writings, so please forgive me for my English ;-)

Internet Radio, Podcast on GNU/Linux

2006-04-22T19:33:00.000+05:30

Yesterday, I've experienced my first Internet Radio show on GNU/Linux. This show's invitation I've received from GPLv3 site. Though, I've not listened to the full show, but it was really cool show (covering some good topics from Java to Free software), available @ http://gplv3.fsf.org/av.

Well, there are other sites also which offer Internet Radio shows. One such site is ShoutCast.com, which maintains a registry of internet radio stations. The applications in GNU/Linux which support listening to Internet Radio shows are Rhythmbox, based on GStreamer, and amaroK based on GStreamer, Xine etc. The amaroK RPMs available from Fedora Extras, comes with only GStreamer backend, where support for Internet Radio is broken. So you can go for Xine backend, which can be downloaded as amarok-extras-nonfree RPM package from Livna RPM repository.

Podcasting support is also there. But in Rhythmbox, support for podcasting is broken, so I've opted for amaroK. A good podcast source is The Podcast Network, and a good podcast available is GNU/Linux User Show, but unfortunately it is available only in MP3 codec (advertised through RSS feed), not Ogg as I expected it to be. :-(

In case streaming audio (or video) is MPEG III (or any other patented codec), you also need appropriate codec plugins for the audio backend engines you're using.

Wah Fedora Core 5 "Bordeaux" !!

2006-04-13T03:10:00.000+05:30

Fedora Core 5 Desktop: Running X-CHAT on GNOME

Fedora Core 5 "Bordeaux", I recently installed this distribution. It consists of 5 discs, which I downloaded in 11 days on 128 Kbps (though not continuous running). Installation of it consisted of several hacks for me. But, I love hacks. ;-)

Initially, after download is over, I was unable to burn any ISOs as my CD-R/W is bad currently, so have to install (clean install I mean because upgrade creates some glitches :-(, so it is recommended that you keep a separate partition for /home) from hard disk. So, in order to bootstrap installation, I've loop mounted first disc, and extracted kernel (vmlinuz) and initrd (initrd.img) from /isolinux directory and copied it on hard disk. I copied on /boot partition. But make sure, wherever you copy this you won't overwrite any files with the same name. Now, restarted my machine. I'm on GRUB. So, at GRUB I switched to command line mode and did:

> kernel (hd0,1)/fc5/vmlinuz
> initrd (hd0,1)/fc5/initrd.img
> boot

This'll boot system from the hard disk using linux kernel copied from the CD. After booting, it starts Anaconda, and asks where to install from. I select Hard Disk and then it asks for the partition where CD ISOs are , and the directory where CD ISOs under that partition. Here I located my /home, and directory where I kept my ISOs. After some Next, Next. Next, it prompted for partitions where I want to install. I selected the /, /home, /boot, which I was previously using with Fedora Core 4 "Stentz". But there it gave me error that my /home can't be used. Why ?? because it's already mounted and is in use. So, I've to restart my old Linux kernel, and copied it to my FAT32 partition. And then re-started installation in the same way. Now, after this I selected a basic packages (including GNOME UI). And then finally, I installed my Fedora Core 5.

But story doesn't end here. Now, my X server display was not well, as I was expecting 1024x768 but I'm getting it also but only 800x600 at a time (rest is out of screen and I've to scroll). Checked my xorg.conf, it uses i810 driver. Being on 800x600 I'm happy to see that DRI support is working fine. So, anyhow, I changed "i810" driver to "vesa" in my xorg.conf. And restarted X, now it started in 1024x768, but oops no DRI, because it is VBE calls :-((

So, now here is another hack, I looked on several sites about this kind of problem, I found that I need to manually set my display mode timings that should work on my monitor. I found a tool xtimings, that generates appropriate modeline based on certain parameters. But that didn't work either as modeline it generated my monitor can't handle, and hence same problem. Finally, I entered IRC channel #fedora on irc.freenode.net, there I found a hacker RizeNine who suggested too many things but nothing worked. Finally, I asked him if there is any tool which can print current modeline, he suggested xvidtune. I started my X server with "vesa" driver into 1024x768 mode. From the shell, I executed this command:

[wahjava@homepc ~]$ xvidtune -show
"1024x768"     0   1024 0 0 0    768  0  0  0 -hsync -vsync

I copy pasted this modeline into my xorg.conf and reset display driver to "i810" and restarted X. Yippee!!, it worked and DRI is working too.

Now, the final hack. I'm unable to install rest of the packages from ISO images I downloaded, becuase the Fedora Core team, removed system-config-packages utility, and replaced it with pirut, and GUI for yum. Anyways, I've not hacked in this yet. So, might hack very soon

But, Fedora Core 5 is really very-very improved esp. with application like Beagle, searching is very fast. The improvements are great. And forgot to mention an important thing. Well, in other Fedora Core has undergone a great change except the installation problem.

And, BTW X11 progressed to X11R7.

Outlook Express to mbox conversion

2006-03-26T02:42:00.000+05:30

Yesterday, I was at my dad's office. He recently migrated some of his office PCs to Linux. One of the big problems encountered after transition to Linux is migration of e-mails from his previous e-mail client Microsoft Outlook Express 6 (on Microsoft Windows). I'm already using Evolution since November' 2005 (since I got an internet connection at my place :-D). I've heard of Outport for export of mails from Microsoft Outlook Express. So, I downloaded and installed it on his Windows OS. And then started it but it terminated with an error saying Microsoft Outlook is not installed. Oops, but we're not using Microsoft Outlook. So, all the hope of exporting mail from Outlook Express was lost till I got an idea

The idea to export a folder was to select all mails in any folder, and then using DnD feature provided by Windows (drag-and-drop), drag them to a Explorer window and drop them (a CommonDialog will work too but I've not tried that). This will copy all mails in as .EML files in the current directory in Explorer window. The good thing about these .EML files are they're plain text files representing a mail in MIME format which mbox file uses.

An mbox file looks like below. When mbox is passed to file utility for recognition it recognizes as ASCII mail text, with very long lines. Whenever a new mail arrives it is appended to mbox with a starting line similar to From tycoon@someorganization.tld Tue Jul 31 13:21:11 2008. This line is not part of MIME specification.

From evolution@novell.com Tue Sep 25 07:45:12 2001
Return-Path: <evolution@novell.com>
Received: from pop.novell.com (IDENT:mail@localhost [127.0.0.1]) by
        pop.novell.com (8.9.3/8.9.3) with ESMTP id HAA20680; Tue, 25 Sep 2001
        07:45:12 -0400
Received: from smtp.novell.com (smtp.novell.com [141.154.95.10]) by
        pop.novell.com (8.9.3/8.9.3) with ESMTP id HAA20659 for
        <evolution@novell.com>; Tue, 25 Sep 2001 07:45:10 -0400
Received: (qmail 5610 invoked from network); 25 Sep 2001 11:45:02 -0000
Received: from smtp.novell.com (HELO localhost) (141.154.95.10) by
        pop.novell.com with SMTP; 25 Sep 2001 11:45:02 -0000
From: "The Evolution Team" <evolution@novell.com<
To: Evolution Users <evolution@novell.com>
Content-Type: multipart/related; type="multipart/alternative"; boundary="=-t4dRE6cqcdSBHOrMdTQ1"
X-Mailer: Evolution/1.1.99 (Preview Release)
Date: 7 September 2005 14:45:00 +0300
Message-Id: <1001418302.27070.20.camel@spectrolite>
Mime-Version: 1.0
Subject: Welcome to Evolution!
Sender: evolution@novell.com
Errors-To: evolution@novell.com
....
....

So, now you know where to hack. ;-). Just wrote a simple shell script (or an operating system driver ;-) ) that concatenates each file and delimits them with the line similar to From tycoon@someorganization.tld Tue Jul 31 12:40:33 2008. Most of the mail programs doesn't consider this line to be meaningful (I think so) and consider it as a mail delimiter. So a fake line need resembling above needs to added before each mail entry. The from address and date are instead extracted from From: and Date: MIME headers. So basic pseudocode is

Create a empty [mbox file]
Initialize default delimiter [line]
For each [file] in [list of files] do {
Echo [line] to the [mbox file] in append mode¹.
Type [file] to the [mbox file] in append mode¹.
}

I'm not providing any shell script to do this job for you. Since one of the major pillars in GNU/Linux is Software Toolbox philosphy. And if you're learning these utilities, this might be a good project for you. If you're lucky enough somebody might have posted the script as comment in my blog. ;-)

¹HINT: cat abcd.txt >>file_opened_in_append_mode.

A useful thought

2006-03-26T00:38:00.000+05:30

The only key to success (or precisely optimised life) is precision. It doesn't matter with how much hardwork you achieved that precision. If you never achieved that precision you're not living optimally. In field of algorithms analysis, it is known as tightly bounding, running time of algorithm. In troubleshooting field, it means accurately identifying problems. Optimization of code depends on precise definition of what is the objective of code. Different words in different fields but the same meaning.

precision

an AWKward day

2006-03-11T17:54:00.000+05:30

A day towards learning AWK. Although I've not planned my day to learn AWK, but it happened accidentally (or by chance ;-)). Today, I was in my practical class, and there I saw an old machine is running Fedora Core 1. I thought what I can do with that system, since the system doesn't has any development tools. It has tools without documentation. Then I thought AWK might be there so, why not learn AWK. Because, I've tried learning AWK previously too many times, but wasn't successful (it was not tough, but because I don't know what to do with that language). So today, I thought why not XMLify, the /etc/passwd (one of the primary target of awk tutorials) and /etc/group. And then, I opened its infopages by executing info awk. but oops info is displaying its manpages. Then I recalled that on GNU/Linux machines AWK comes GAWK, so I did info gawk. And started reading Getting started.

So, within half-an hour I've produced my AWK script to XMLify /etc/passwd and /etc/group. Here I'm giving my AWK script to /etc/passwd.

# passwd2xml.awk: An AWK script to transform /etc/passwd file into passwd.xml
BEGIN { 
 FS=":";
 print "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<passwd>";
}
/:/  {
 printf "\t<user id=\"%s\" uid=\"%s\" gid=\"%s\" home=\"%s\" comment=\"%s\" password=\"%s\" shell=\"%s\"/>\n", $1, $3, $4, $6, $5, $2, $7;
}
END {
 print "</passwd>";
}

You can execute this script and then pipe that output to xmllint to check for well-formedness of the document as shown below:

[wahjava@pc awk]$ awk -f passwd2xml.awk /etc/passwd |xmllint -

GAWK also comes for Windows and available here.

BTW, this script is not the correct way to XMLify the /etc/passwd since XMLifying needs entitifying some characters e.g. <, > etc.

Your own Google Logo !!

2006-03-06T14:40:00.000+05:30

Create your own customized search page including customized Google logo from here. BTW, this service is not provided by Google

IPC using TCP/IP under Windows XP Firewall

2006-02-25T14:36:00.000+05:30

After the release of Microsoft Windows XP Service Pack 2, there is a builtin firewall. Any software, that attempts to listen on any TCP/IP port is caught by this firewall. And, for small applications which uses TCP/IP on the same computer for IPC (Interprocess Communication) also get caught by the firewall. To ensure that they won't get stopped by firewall, change server to always listen on only local loopback address. Whereas usually, any server written will listen on all interfaces. Since, it is not required in this kind of application, for the purpose of security you should avoid this. There is a java sample code, I've written to illustrate this, although you can write any equivalent code in C/C++ or any language which has an interface with BSD Sockets, or Winsock.

import java.net.Socket;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.SocketAddress;
import java.net.InetSocketAddress;

import java.io.IOException;

public class FirewalledServer {
 private static int PORT = 19450;

 private static void Main() throws IOException {
  // instead of starting using traditional way:
  // ServerSocket server = new ServerSocket(PORT);
  ServerSocket server = new ServerSocket();

  // Get localhost:PORT address
  SocketAddress sockaddr = new InetSocketAddress(
       InetAddress.getLocalHost(), PORT);

  // Bind and listen to it with backlog 3 (you can have any backlog)
  server.bind(sockaddr, 3);
  Socket client = server.accept();
  System.out.printf("Connection arrived from %s\n", client.getRemoteSocketAddress());
  client.close();
  server.close();
 }

 public static void main(String[] args0) {
  try {
   Main();
   System.exit(0);
  } catch(IOException e) {
   System.err.printf("I/O Error: %s\n", e.getMessage());
   System.exit(-1);
  }
 }
}

// vim:ts=4

I've tested above code in JDK 5.0 update 4 and it may work on earlier releases too. For accurate information check for the availability of routines. I was using Jext and whenever I started Jext, firewall blocks. So with the help of my friend's Unix Networking Programming by W. Richards Stevens, I got this idea.

Anyways, its a good practise to perform only what is required accurately or precisely

Standards and Freedom

2006-02-23T18:00:00.000+05:30

We create standards to make our life easier, but then gradually we start breaking those standards, and inventing our own standards. And then our remaining life spends in maintaining those non-standard stuff. There are many reasons why we did so, in order to ease our pain, or to look different from others. The problem starts when interaction with external world happens.

For example, Our text files on Linux, looks horrible in Windows Notepad. Why ? Because Windows and Linux have their own standards for text files, i.e. Windows apps expects that each line in ending with \r\n (CR LF) whereas Linux assumes each line ending with \n (LF). The problem will be more when trying to sharing same set of batch scripts between both the systems.

Using proprietary closed source standards (are they really standards ;-)) are hell, because they affect freedom. You can't use other application because all your previous work is in other properietary format and which your other application won't understands and hence you're screwed. You can't expect everybody to be using same thing. If you expect whole world to be using that software, then imagine if whole world is using your rival's products. This is where this GNU thing comes into picture. It is not there to give you another proprietary software, but it is there to assure that the software is open and free like air. So, instead of binding users with any software forcibly, you a creator of software is offering user a choice that user should use your software if he/she thinks your software is worth it. This helps in increasing growth of your software due to competition.

Also use of publicly available standards lessens burden on you, a developer. You don't have to research on a new file format. You don't have to write any import plugin to import public standards files into your file formats. Other software developer's don't have to write any import filters for your application's file formats. Your software users won't get screwed at least their data is in publicly available format. Imagine you're having some critical data in a proprietary format, and then when some flaws are discovered in that software, you won't migrate because you're attached to that properietary thing. Binding users to their softwares in this way is common practise among proprietary application developers but what that means is that user is using your software not because it solves his problems but because, he's trapped.

How to earn money ? This is a big question for those who're developing free software but won't considering it because of earning. Remember those who really going to purchase your softwares are either impressed by its features or are either expecting support for it. Remember you won't tackle piracy ever^[1]. But even if you still try to go for anti-piracy techniques, things like dongles, product keys, hardware IDs, activations are available. But anybody (who thinks your software is worth cracking) can bypass these things by patching your code, generating fake keys etc. So, if people think your software is worth cracking, due to its features, why not release it under GPL (General Public License), so that more and more users can use it (anyways they're going to use it illegally, if you won't release under GPL) legally and increase its proliferation, and contribute in its development. Those users who're really happy with its features will pay for it or fund its development.

What free software has to do with standards ? Since no one wants to reinvent wheel (reinvent a new standard) unless current wheel (standard) works for them. And even if somebody invents his standard XYZ, it'll be publicly available. Others can use XYZ standard, if they think it works for them.

The standards are invented in order to make our life easy, not hell. The single way to design best software is to just implement specifications (or standards). This practise will make your applications secure, bug-free. As philosphy of software toolbox goes it is better to write, debug, maintain small programs than to a large. I recommend reading the doc pointed by previous link as I was unable to describe that philosphy better. If you're writing new applications and want to know if what you're going to do and can be persisted in a standard format, few places worth looking at are WWW Consortium, IETF, Unicode, ISO, IEEE, IUPAC and other standards organizations you can think of.

^[1]The only way to tackle piracy to change user's mindset. If you know any other way, please definitely contact me... ;-)

My PGP keys

2006-02-11T13:48:00.000+05:30

My PGP Key ID is: 0xA03F4261
My PGP finger print is: BBA9 AD7D BA71 61EB BE46 8CF5 E44A C663 A03F 4261
My PGP Public key is here.

If you don't understand a word of above, read more about PGP (Pretty Good Privacy) at http://www.pgpi.org/doc/. To give you a brief idea, it is something like digital signatures, encryption/decryption. This is free. If you're in US, please go to http://www.pgp.com/.

When GUI fails...

2006-02-07T19:22:00.000+05:30

I was burning a CD on Ubuntu Linux @ my dad's office. I started GnomeBaker (I've never used it earlier since I'm using K3B at my place). After dragging all files into the directory tree, a clicked on "Create Data CD" button, and then a dialog popped-up with options like label, boot image etc. I decided to go with default options. And pressing OK, the application crashed. I then tried X-CD Roast, but it hasn't detected my CD recorder, and asking for enabling SCSI emulation. ooops. Finally, the last option to me was go with cdrecord. But cdrecord, needs an ISO image not files. So, I've to built an ISO image for it. To build ISO image, I've used mkisofs. I've never tried these tools. So it was a pain for me because their manpages comes with tons of options. I know that giving tons of options means providing flexibility but sometimes these works as catalyst in increasing doubts. But to ease the pain, these manpages shipped with the examples. So for building iso image and burning to my CD recorder I executed following commands.

wahjava@server ~$ mkisofs -o cd.iso cdroot
wahjava@server ~$ cdrecord -dao dev=/dev/hdb speed=32 cd.iso

That's all I was done. I can customize the disc recording more but I was in hurry (or scared ;-)). So moral of the story is always try to know what is happening in the behind the scenes because all (I mean most or some) of these GUI tools used these command-line tools. It is also better to learn these command line tools, because they provide a flexibility which these GUI tools can't provide you.

I haven't installed K3B, because I don't have time to do so and more over I want to restrict this server installation to GNOME only.

Tricky TFTP

2006-02-07T12:12:00.000+05:30

Yesterday, I was setting up firewall for my dad's office's server, I came to know about TFTP details (see RFC 1350). In short TFTP (read request) works as follows:

Client connects (oops. it is UDP so no connects but sends datagram) to port 69 (i.e. TFTP port) of server requesting the file.
Server replies to the client from other port (randomly chosen, so that the probability that the same number is chosen twice in immediate succession is very low), let's call it φ.
After then all communications with server from that client happen over port φ.

So, it's very hard to decide what ports should remain open in firewall. One solution to start server with a fixed port range to be used for TFTP. Anyways, if u know what I want, please post it here... ;-).

Don't trust IndiaTimes.com Poll results

2006-02-04T19:31:00.000+05:30

The indiatimes.com poll (see in the bottom of the site, which used to publish daily in The Times of India newspaper) is not a genuine poll. Never trust this poll. I've tried biasing it and I'm successful. I've tried it in Linux. You can try it any OS, you just have to create a bot ;-). Following is my linux bot script using lynx web browser (one of my favorite web browsers):

cmd
lynx --post_data http://timesofindia.indiatimes.com/vote.cms <post

post
txtPolliD=1400703&PRadio=1&submit=submit
---
Don't ignore above hyphens '---'

Command for posting 301 times. Tested on bash
wahjava@pc ~$  for (( i = 0; i <= 300 ; i++ )); do ./cmd >/dev/null; echo $i; done;

I hope they'll repair their poll soon. They've not added any human verification schemes. So I think poll is targeted for machines. i.e. What they think of the situation ? But humans are also given chance to participate. ;-)

Finally I installed LTSP

2006-01-30T19:14:00.000+05:30

Finally, I installed LTSP. LTSP is a great distribution of network booting Linux. It has all the preconfigured files, you need to boot Linux over network. And overall performance is cool. I've currently tested it with GNOME. It runs fine with no network delays as if I'm working on my own desktop. I'm planning for installing IceWM. IceWM is a simple and sleek Window Manager for X.

Recovering from lost MBR

2006-01-30T13:08:00.000+05:30

Last night, I lost my hard disk's MBR, (i.e. 0th sector of my HDD). I was so confused and tensed, that I actually forgot the sizes of my deleted partitions. Thanx to my memory I remembered the filesystems of my partitions.

My primary partitions were:

NTFS
FAT32
EXT3
EXTENDED

My extended partitions are:

EXT3
EXT3
SWAP (LINUX)

I've my Ubuntu Live CD so I booted from it.

And then I created a fake MBR (with the help of fdisk, shipped with Linux) where my first partition is spanning whole hard disk and system id is NTFS. I then flushed changes to the disk.

My first partition is NTFS, so I checked the hexdump (hexdump -C /dev/sda1) and then with the help of NTFS Volume Information format (as described in Upgrading and Reparing PCs by Scott Mueller), got the count of sectors reserved by NTFS partition. So I've replaced the count of sectors of NTFS partition with the size of first partition in MBR. So, my first partition is recovered.

Similarly, I created 2nd partition (FAT32) in MBR spanning rest of the disk. And with the help of FAT32 Volume Information format (as described in Upgrading and Reparing PCs by Scott Mueller), I corrected its sector count. And its entry gets restored tooo...

For 3rd EXT3 partition, there is no information in the book, so I've to use a tool named dumpe2fs (or e2fsdump), to get the count of sectors occupied by the third partition. I corrected its sector count. And its entry gets restored tooo...

For EXTENDED partition, I've to tweak a bit. First, I created an EXT3 partition (because I doubted that creating an extended partition might zero my existing extended partitions), spanning rest of the disk and flushed it. Then read the MBR in a file named "mbr" with dd (dd if=/dev/sda of=mbr bs=512 count=1). With the help of hex editor (GNU eMacs in hexl-mode), I manually changed last partition's system id (498th byte) to 0F (Extended partition's system ID). Then re-wrote the "mbr" file to disk via dd (dd of=/dev/sda if=mbr bs=512 count=1), asked the kernel to reload partitions via fdisk (echo w |fdisk /dev/sda). Now, all my partitions are restored, since only my primary partitions are erased.

And finally re-installed GRUB on my hard disk locating images on my 2nd primary partition (EXT3).

In this way, I restored my hard disk's partiton table.

Tip: Never boot FreeBSD from its BootEasy MBR (because it copies itself back to the hard disk from where it is booted) instead use GRUB (0.94, 0.95). These versions can read UFS partitions very well.

How Dual Channel memory works ?

2006-01-29T18:05:00.000+05:30

The dual channel memory architecture's working has interested me so much. I was confused by the fact that what benefit would you get if you're desired memory addresses are mapped in only channel. But, today after reading the Intel 915G chipset memory configuration guide, I got to know that in symmetrical dual channel environment, memory is interleaved. It is interleaved at the interval of every cache line (usually 128 bytes in Pentium 4). So my solution lies in population of memory

Thanx to Gautam, who pointed out that I should refer to GMCH specs.

Checkout Intel 915G/915GV/910GL Express Chipset memory configuration guide

Configured DNS...

2006-01-24T18:54:00.000+05:30

And today I'd configured DNS. Configuring DNS is very easy if you know theory of DNS very well. I think configuring this server will give me a kick to learn Linux from the bottom (since I'm running on console mode, I've not installed X on Linux, so I've to do ifup, ifdown, start-stop-daemon etc..). And, my web browser is Lynx. But I'm really enjoying it. :-)

Installed server...

2006-01-23T20:30:00.000+05:30

Since Saturday January. 21, 2006, I was busy installing Linux on a new server for my dad's company. They've opted for a assembling a server from Intel instead of getting a readymade (or branded server). I really appreciate this. Their requirement was to reuse their old Pentium II systems. So I suggested why not go for Linux and netbooting it. I've tried to create a prototype of PXE booting on Linux but, it was unsuccessful and now. One of Linux Guru, suggested me LTSP. So I decided to try it.

So on saturday, I began installation of server. Installed Ubuntu Linux which I ordered from shipit.ubuntu.com. It was a complex installing Linux on a server. The first task was to figure out how to configure RAID, I've referred to some docs on the Internet which says my server board comes with software RAID (or fakeraid) not a hardware RAID, that was a surprise to me. Now finally I've installed my system...

Tomorrow I'll configure DNS and DHCP , and then finally LTSP I don't want LTSP to manage DHCP or DNS for me

CustomDomains beta from Windows Live

2006-01-23T13:51:00.000+05:30

Signup for custom domains on Windows Live. https://domains.live.com/Signup.

This will give you a free yourname@yourdomain.com email address if you own a domain name. It is from Microsoft Windows Live.

Check it out...

New mail signature

2006-01-23T11:03:00.000+05:30

I was fed up with a same signature (actually quote) all the time. So I've created a shell script which will give up new quote everytime it is executed. It uses fortune and sed. I'm using this script as my email signature in Evolution. You can use it and customize it accordingly.

#!/bin/bash

#Make it executable: chmod +x ./mailsign

#This script requires some hacking because Evolution exepcts signatures
#in HTML whether mail is text or not. So, if mail is in text format, the
#formatted text of signature is taken without HTML tags.
#So to have any kind of formatting in your signature use appropriate HTML.
#e.g. If multiple continuous whitespace is encountered, according to SGML
#specs, it should be merged into single whitespace until unless u give an
#entity &nbsp; [non-breakable white space]. Another hack is to replace new lines
#with <br/> tags. I've also added underline to the hyperlinks by enclosing
#them in the <a> tag.

#This script requires 'fortune' for quotes and 'sed' for formatting.
#Any other program's output instead of fortune...

echo "--<br/>"
echo "Ashish Shukla \"Wah Java !!\"<br/>"
echo "--<br/>"
fortune |sed s[\$[\<br/\>[g |sed s/\ /\\\&nbsp\;/g

Generifying JavaCUP

2006-01-19T17:49:00.000+05:30

I've generified source code of JavaCUP 0.10k (converted to use generics) but too my surprise, they already generified that stuff. :D I've checked their site 2 weeks ago but that time no migration link was there.

JavaCUP is a LR parser generator for Java language. It is included in the recent JDK also (oops, it is not exposed publically but all it's classes are already there in the JDK), see Mustang. It's very cool and very easy to use. You can find it here.

My Localized Name

2006-01-11T13:56:00.000+05:30

This time I've tried to localize my name into different Indian scripts (those based on Brahmi script, those which are listed in ISCII-91 standard and are available in Unicode). So, please post your comments if any of the localized spellings are incorrect. You need to have unicode fonts installed, in order to view of any this stuff.

Oriya      - ଆଶୀଷ

Devanagari - आशीष

Malayalam  - ആശീഷ

Bengali    - আশীষ

Gujarati   - આશીષ

Telugu     - ఆశీష

Kannada    - ಆಶೀಷ

Hello Postscript World...

2006-01-06T16:51:00.000+05:30

It all started off with HPGL, when in 1997, or 1998 my daddy used to export outputs of his designed PCBs (in DOS), as PRN files. These PRN files are in HPGL. I'd once seen (typed) the HPGL file and it consisted of purely text (some part of text resembles LOGO), I understood that it was some kind of language that HP plotters will understand. I decided to learn that language but no docs, so I dropped the idea.

But then, after few years I got to work on DTP softwares, and there I heard this Postscript, Encapsulated Postscript. I even had a book on Adobe Pagemaker 4, there I also seen this Postscript. And recently in one of the iLUG-d meet (actually on 23rd May, 2004), Raj Mathur told that how powerful Postscript was, that you can write a compiler in it. The next encounter with Postscript is when I got the NASM source code, the author supplied the documentation as a single text file, and with a perl script. The perl script generates the Postscript, RTF, HTML, etc. output from that file. I'm amazed I thought Postscript was as simple as HTML, or RTF. And now recently (actually 4th January, 2006), I downloaded the Postscript Language Reference Manual, and PostScript Language Tutorial & Cookbook. And then found that Postscript was as simple as writing programs for a stack machine.

Postscript machine is a stack machine with separate dictionary like memory (where it holds fonts, variables), etc. Anyways, here is one of my first postscript program.

/box {
 % stack contents
 % stroke width
 % right
 % top
 % left
 % bottom

 /outline exch def
 /right exch def
 /top exch def
 /left exch def
 /bottom exch def

 newpath
 left bottom moveto
 left top lineto
 right top lineto
 right bottom lineto
 left bottom lineto
 closepath
 outline setlinewidth
 stroke
} def

% Draw 4 boxes of stroke width 4/72"
100 100 200 200 4 box
100 100 175 275 4 box
100 100 150 250 4 box
100 100 225 225 4 box

% load a Times-Roman font
/Times-Roman findfont
36 scalefont
setfont

100 400 moveto
(Hello Postscript World) show
showpage

You can execute the above program on a Postscript interpreter (an opensource interpreter, GNU Ghostscript). Just after an hour of reading the tutorial, I've written this program. If you've ever programmed on a stack machine, you'll find programming in Postscript very easy. If not programmed on stack machine, then also it is easy ;-).

Well, Postscript is really cool language. Give it a try.

P.S. The links I've provided for Postscript docs, I've found when I've searched for docs via Google and are not from the Adobe.com.

VMS (Virtual Memory System)

2006-01-05T16:47:00.000+05:30

Few weeks ago, I discovered a free public VMS cluster available for telnet, it's available on http://deathrow.vistech.net/deathrow.shtml.

If you're intersted in VMS more, then there is free GPL VMS project going on, FreeVMS. Install it on a Bochs and play with it. It's a multiboot kernel. I'm going to install it soon.

Mysterious Ratio

2006-01-04T17:56:00.000+05:30

Golden ratio (φ). Also known as divine proportion. I came across it first time, when I was reading Introduction to Algorithms, and there I encountered it in a question based on Fibonacci Series. I thought it was just a normal ratio, but then I've encountered it in several topics, e.g. In Algorithms, the authors told that Knuth has recommended this ratio for generating primes, and in Numerical methods of computation too. And more recently, I've seen it on Wiki, and a website dedicated to it. How is it related to so many real world things...

My BCA Project...

2006-01-02T17:47:00.000+05:30

I'm thinking of what to do for my BCA project. It would be great if my BCA project would be one which I desire to do since a long time:

An Operating System is the thing I'm waiting to do since a long time. The problem I'm having is primary page level allocator. I've seen Tim Robinson's article on memory management which suggests whether to go for bitmap as page allocator or stack as a page allocator. I've opted for stack based memory allocator, and is written as a multiboot kernel, the problem is with implementation, dealing with E820 memory map.