File fetchrequest.sh

#!/bin/bash
while [ 10 -eq 10 ]

#Runs in a infinite loop checking request file at server B every second
do
if [ `env | grep -c lastCounter` = 1 ];then
newCounter=`curl -s http://serverB/requestFile.txt | tail -1 | cut -d: -f1`

#Reading request file at server B
param=`curl -s serverB/requestFile.txt | tail -1 | cut -d: -f2` #Extracting the request parameters
echo newCounter : $newCounter lastCounter : $lastCounter

#If there is a new request, sending a response back to the server B
if [ "$newCounter" != "$lastCounter" ]; then
echo "Need to send a response"
echo "Response URL : http://serverA/something.pl?action=something&param1&param2"

#Trimming of the response that needs to be send to serverB and storing it in a variable
output=`curl -s "http://serverA/something.pl?action=something&param1&param2" | grep 'cap\\|img' |
sed \ 's/<src>.*<\/src>//g;s/<cap>/\:/g;s/<\/cap>//g;s/<img>/\:/g;s/<\/img>//g'`
echo "Response received : $output"

#writing the response to a flat file to be FTPed to server B
`echo $output>"rp_$newCounter.txt"`
`export filename==rp_$newCounter.txt`
`echo ls -l "rp_$newCounter.txt"`
typeset -i responseSize=`wc -c rp_$newCounter.txt | cut -d" " -f1`
echo "Response size $responseSize"

#If the process response is garbled, small or null, sending a dummy error in FTP file
if [ $responseSize = 1 ];then
`echo "We are working , try later" > "rp_$newCounter.txt"`
fi

#making an FTP connection to serverB and launching the response file
`curl -s -T "rp_$newCounter.txt" -u username:password"ftp://serverB/rp_$newCounter.txt"`
echo "Uploaded the FTP file for $newCounter request"
`rm -f rp_$newCounter.txt`
echo "Deleting rp_$newCounter.txt after upload"

#Updating the request environment variable
lastCounter=$newCounter
export lastCounter
fi
else
lastCounter=`curl -s http://serverB/mobRequests.txt | tail -1 | cut -d: -f1`
export lastCounter
fi
done

The whole system works very well, and the requests are processed and response send to user. There are however limitations to this model.

Download the new version’s (say FC 10)  iso(DVD) image and save it to a disk drive partition. I used a pen drive for the same. It works very well for filesystems viz. FAT32,ext2 and not NTFS. Copy the image file to any directory say for example /mnt/FedoraCoreDVD.iso( Assuming, that pen drive is mounted at /mnt) . Mount the iso image in a directory(any) to extract the isolinux folder.

#mount -o loop /mnt/FedoraCoreDVD.iso /home/user/Fedora/

Copy the isolinux folder and paste it inside the boot folder.

#cp -r /home/user/Fedora/isolinux /boot

Now we need to make an entry in the grub file to boot the copied isolinux folder’s install.img

# cat /etc/grub.conf

______________________________

title Fedora Upgrade
root (hd0,8) ———–> should be your  partition containing the current linux installation (0->First Hard Drive,8-> Partition number on this drive )
kernel /isolinux/vmlinuz
initrd /isolinux/initrd.img
______________________________

Copy the isolinux folder also to the pen drive(/dev/sdb, mounted at /mnt in this case) and reboot the system. Select the ” Fedora Upgrade” option in grub and the normal installation/upgrade demon anaconda will start. It will ask for the option of disk partition and folder containing the iso image and iso linux folder, which is /dev/sdb1 in this case. Select the same and the upgradation works like a charm.

- Make sure libvirtd demon is running
- Allocate the space as per your needs viz hard disk, RAM etc
- This one is the key step, do not forget to add a cdrom (/dev/hdc) pointning to iso image of Windows XP Disc, as after the first boot, XP installation searches for the Windows XP disk and it cannot read the host’s CDROM.

Everything goes on smooth with all these parameters.

import java.awt.image.*;
import javax.swing.*;
import javax.swing.JComponent.*;

public class circles extends JFrame {
public static void main(String args[]) {
double d=Double.parseDouble(args[0]);
int diameter= (int)d;
circles ca= new circles();
ca.drawCircle(diameter);
}
public void drawCircle(int diameter) {
int x=0,y=0,radius;
JFrame frame=new JFrame();
JLabel lab;
BufferedImage bi=new BufferedImage (diameter,diameter,BufferedImage.TYPE_BYTE_GRAY );
WritableRaster raster=bi.getRaster();
double [] iPix=new double [diameter*diameter];
if(diameter%2 == 1) {
diameter-=1;
}
radius=diameter/2;
for(int i=0;i(radius)){
y=y%(radius);
}
else
{
y-=radius;
y=-y;
}
if((x*x+y*y)<=((radius)*(radius))) { iPix[i]=255; } else { iPix[i]=0; } }
raster.setPixels(0,0,diameter,diameter,iPix); lab=new JLabel(new ImageIcon(bi)); frame.add(lab);
frame.setVisible(true); frame.setSize(600,600);
}
}

compile the program as javac circles.java

run as java circles diameter_value

e.g. java circles 500

I had a tough time configuring wired internet connection on UBUNTU (7.10 Gusty Gibbon) and FEDORA Core 8 boxes. However after few amendments, I was able to fix and start internet in both. The Network Adapter (eth0) was not able to take IP address from the DHCP servers of my ISP ( Reliance, the case here) because the Linux distros support the future i.e. IPv6. Hence, the task at hand was to disable IPv6 and enable IPv4.

Let us discuss both of them in detail.

Ubuntu

There is process avahi-demon running which is responsible for IPv6 assignment. It can be disabled by removing from the following location
/etc/init.d/avahi-demon. Please not that all these should be done as sudo.
This should be able to fix the problem. You can restart the network and network interfaces by

/etc/init.d/networking restart
ifdown eth0
ifup eth0

Also, the interfaces file specifies starting of Network adapter and assigning address.
cd /etc/Network/interface

It should have following entry to take IP from dhcp server for eth0.

# The loopback network interfaceauto loiface lo inet loopback

# The primary network interfaceauto eth0iface eth0 inet dhcp

Forcibly , IP address can be assigned by dhclient eth0.

Fedora Core

Disabling IPv6 in Fedora core 8 can also be done in similar fashion.

Now here is how you can do this with FC8 to disable IPv6:

1. Append the following line to /etc/modprobe.conf:
   install ipv6 /bin/true
alias net-pf-10 off
   alias ipv6 off

2. Append the following line to /etc/sysconfig/network:
   NETWORKING_IPV6=no

3. Ensure your network adapter is configured not to use IPv6. This is an easy edit in the system-config-network gui, or do it manually in /etc/sysconfig/network-scripts/ifcfg-eth0 (ammend for name of your adapter) by appending IPV6INIT=no

To restart the Network Adapter and assign address using DHCP.
ifconfig eth0 down
ifconfig eth0 up
dhclient eth0

After all these changes are made the network adapter takes an IPv4 IP address and works fine.

__________________________________________________________________________________

*type shutdown on windows server 2003 command prompt and read carefully