Hacker's Blog

End of Blog

2011-03-10T13:13:00.001+05:30

Blog and site Migration

2011-03-10T13:07:00.003+05:30

Hi,

I am migrating all my contents to guptav.com
Hopefully, the migration will be completed by 1st April 2011.
The guptav.com has more content, rich content, and structured content.

Regards,
Vaibhav.

How to : QEMU Networking

2008-11-04T19:25:00.002+05:30

Well,
I have posted the original article here.

Copying it here for readers.
------------------------------------------------------
Hi All,
It has been ages since I have written anything over here. One of the main reason is that I have started posting mathematical post at my wordpress blog.

Anyways, Sameer and I were trying to get our hands dirty on Qemu networking. Although there is a fairly good description is given over here, I am trying to fill in here a few missing bits.

Okay, so here is the scenario we want to create.

On one machine ( say host-A ) we want to create many guest machines ( guestA1, guestA2 ) etc. Similarly, there is another machine ( host-B ) having many guest machines ( guestB1, guestB2 ). We want to make guestA* communicate with guestB*.

I am assuming that readers are aware of how to install a guest OS on a guest machine created by qemu.

First we need to configure a ipv4-over-ipv4 tunnel for the host machines.

--host-A configuration is as follows

ip : 172.27.16.1
netmask : 255.255.255.0
default gateway : 172.27.16.254

host-B configuration is
ip : 172.27.16.2

netmask and gateway is the same as above.

--In host-A ( as root ) do the following

root@hostA# ip tunnel add tunl1 mode ipip remote 172.27.16.2 dev eth0

-- this command essentially create one endpoint of the tunnel in host-A. It says that the other end of the tunnel lies at ip 172.27.16.2. Also, the tunnel device will use eth0 as its physical device.

root@hostA# ip link set tunl1 up

-- this command will bring up the tunnel interface

root@hostA#ifconfig tunl1 10.0.1.1 pointopoint 172.27.16.2

-- guestA network will be 10.0.1.0/24 network and tunnel device should be a part of it. This command gives the tunnel device an ip address and it says that other endpoint of the tunnel will be at 172.27.16.2

root@hostA# route

--this will show you the current configuration of routing table. There might be an entry in the routing table

172.27.16.2 * 255.255.255.255 U 0 0 tunl1

--you need to delete this entry using following command :

root@hostA# route del -net 172.27.16.2 netmask 255.255.255.255 dev tunl1

--Also you need to tell routing table that guestB network ( 10.0.2.0/24) should be routed through the tunnel

root@hostA# route add -net 10.0.2.0 netmask 255.255.255.0 dev tunl1

--You need to repeat the same procedure for hostB with suitable ips ( use 10.0.1.* instead of 10.0.2.* and vice versa , replace 172.27.16.1 with 172.27.16.2 and vice versa )

--By now, your tunnel should be working. To check, try

root@hostA# ping 10.0.2.1

root@hostB# ping 10.0.1.1

--If it does not ping, it might be the case that your firewall is coming into the way. If you are expert enough, modify your firewall rules with iptables. If not, lets first save your firewall rules

root@hostA# iptables-save | cat > iptablebackup.bak

--flush the firewall rules now

root@hostA# iptables -F
root@hostA# iptables -t nat -F

--Now, that firewall is completely disabled, the tunnel should work. (Of course, you need to disable your firewall at hostB as well! ) If it still does not work, then there might be some other problem or you might not have done things right.

-- you can restore your firewall ( later ) with

root@hostA# cat iptablebackup.bak | iptables-restore

--Okay, so the tunnel is working now!! Great news!! But what next??
Next we create a tapping device - a virtual network interface - which will be visible to the guest OSes.

root@hostA# tunctl -u username

-- provide a username here. This user will be able to use this tapping device while initializing qemu process. This command would have created a tapping device (tap0) in your system

--assign an ip address of guestA network to tapping device

root@hostA# ip addr add 10.0.1.2 dev tap0

-- bring the tapping device up

root@hostA# ip link set tap0 up

-- Also create a file /etc/qemu-ifup which can look like following :
#!/bin/bash
#echo "bringing up interface $1"

-- Now start the first guestOS

username@hostA$ qemu -net nic,macaddr=macaddr1 -net tap,ifname=tap0 -net socket,mcast=230.0.0.1:9999 ....

--second guestOS can be started with following
username@hostA$ qemu -net nic,macaddr=macaddr2 -net socket, mcast=230.0.0.1:9999 ...

-- multicast socket is needed for mchines in guestA network to talk to each other

--In the guestA1 do the following :

root@guestA1# ifconfig eth0 10.0.1.3 netmask 255.255.255.0
root@guestA1# route add default gw 10.0.1.2 dev eth0

-- Note that we have given the ip address of tapping device as the gateway fo guest OSes
-- second, third etc guest machines can be configured with different ip addresses for their eth0

-- Repeat this procedure on host-B as well with appropriate ip addresses.

-- Now, you should be able to ping machines from guestA network to guestB network and vice versa. However, this does not yet allow you to connect to host network. To do that, you need to enable ip forwardng

root@hostA# echo "1" > /proc/sys/net/ipv4/ip_forward

-- perform source NAT

root@hostA# iptables -t nat -I POSTROUTING 1 -o eth0 -j SNAT --to-source 172.27.16.1

--Now, from guestA network ( 10.0.1.0/24 ) you should be able to connect to ( 10.0.2.0/24 ) as well as host network ( 172.27.16.0/24 )

-- To delete the tunnel

root@hostA# ip link set tunl1 down
root@hostA# ip tunnel del tunl1

--To delte the tapping device

root@hostA# tunctl -d tap0

--Above mentioned setup is tested with host machines running fedora core 9 and guest machines running Arch Linux, Debian etc.

If you have any queries post it as comments, I will be willing to answer if I can.

goosh.org - the unofficial google shell.

2008-06-25T17:33:00.001+05:30

<snip>
Goosh goosh.org 0.5.0-beta #1 Mon, 23 Jun 08 12:32:53 UTC Google/Ajax

Welcome to goosh.org - the unofficial google shell.

This google-interface behaves similar to a unix-shell.
You type commands and the results are shown on this page.

goosh is powered by google.

goosh is written by Stefan Grothkopp <grothkopp@gmail.com>
it is NOT an official google product!

Enter help or h for a list of commands.

Loading local settings...
guest@goosh.org:/web>

</snip>
Go to http://goosh.org/

Vaibhav.

Duplex printing script

2008-04-09T21:59:00.004+05:30

Well,
I don't want to write the same thing again. So please refer to this link to see what this article is about :-).
It is basically about a script for duplex printing.

--Saurabh

Programming Challenges

2008-02-09T22:09:00.000+05:30

Today, I had a chat with ali on different online programming challenges as IOPC is going on write now and ali has taken part in it. I was remembering my glorious days when I won a jacket in bitwise.

I am just going to enlist a few programming challenges. Obviously, the list is not exhaustive.

1) ACM ICPC : I believe it is one of the most prestigious programming challenges. It is an IBM sponsored annual event.

2) Top Coder : This too is one of the most prestigious programming challenges. General belief is that the emphasis is more on programming rather than algorithms.

3) IOCCC : Well, here one can find the weirdest C programs. Most of the time it will seem that the winning entry programs won't even compile. However, they do but it is difficult ( rather next to impossible ) to find out what they would do by merely reading the code. My favorite program is here. And yeah, it DOES compile and run.

4) Bitwise : One of the most prestigious INDIAN programming challenges. I used the word "Indian" because it is held by Indian Institute of Technology, Kharagpur. The challenge however is open internationally. It is really a pity to see that since the inception of the event, only once an Indian team could grab the first prize. Ameya Karkare ( aka crack-kare ) and Navneet Lohiwal ( aka lollu ) from Indian Institute of technology Bombay (my alma-matter :-) ) played with handle "AK47", undoubtedly shooting down all competing teams.

5) OPC : Held annually by Chennai Mathematical Institute. One of the toughest programming challenge I have ever faced.

6) CodeCraft : Held annually by International Institute of Information Technology, Hyderabad as part of their technology festival Felicity.

7) IOPC : Hosted by IIT Kanpur as part of its technology festival techkriti.

Pune Innovation 2008 : Ideas in Practice

2008-01-11T14:43:00.001+05:30

Website: http://www.innovations-pune.com/
Government : www.dsir.gov.in [Click TePP]

1. Do the innovation. It should be unique. It can be simple and obvious too. Think Beyond Imagination.
2. Find out a pricing model / revenue model. Strategy/People.
3. Do the market analysis. Compare with other products. Pros/Cons of your and others products.
4. What are the pin points of your product?
5. Take care of customers and their expectations. Think as if you are one of them. User experience.
6. Think not only for early bird advantage but in long terms. Think Fast. Vision.
7. Do the Risks/Liabilities.
8. How do you do marketing? Promote. Om Shanti Om.
9. Always have the exit plan ready. (Just like in sysadgiri where you should always have the backup plan ready.)
10. Blank. (You have to fill this by yourself.)

Vaibhav.

ps: What your Dreams really mean!

My AJAX Notes.

2008-01-11T00:14:00.001+05:30

My AJAX Notes.

Vaibhav.

Kool Linux Sites

2007-09-25T12:44:00.001+05:30

http://www.slax.org/

: Get the Software

http://linuxhardware.org/ : Find about Hardware

http://www.linuxdevices.com/ : The Device part

http://tldp.org/LDP/sag/html/ : Do sysad

http://www.winehq.org/site/about : Want to plat games

http://newdata.box.sk/bx/hacker/ : Do something.

Vaibhav.

"When you guys actually learn something, come to me
and say, 'We learned something! We learned something!' and I'll
show you some cool stuff."

Tiddlywiki

2007-09-19T12:02:00.001+05:30

http://www.tiddlywiki.com/

To set up:

wget http://www.tiddlywiki.com/empty.html
firefox file:///`pwd`/empty.html

Done.
<snip>
The easiest way to learn about TiddlyWiki is to use it! Try clicking
on various links and see what happens - you cannot damage
tiddlywiki.com or your browser.
</snip>

VIM Tip

2007-07-26T18:39:00.001+05:30

Convert any file to html file using vim from command prompt :
vim -c ":runtime! syntax/2html.vim | :wq | :q " <FILENAME>
File Created: <FILENAME>.html

Example:
vim -c ":runtime! syntax/2html.vim | :wq | :q " a.c

will create a file "a.c.html"

[Perl] Script to check stock

2007-05-11T11:56:00.001+05:30

Script to check the stock and their graph :D
Uses finance.yahoo.com to get the graphs.

INPUT : stock.conf : contains stock symbol (one per line ) for each company.
You can find the symbols on http://finance.yahoo.com/lookup, if you don't know.

OUTPUT: Generates a html page that contains the information and graph for the given companies in stock.conf.

Requires: lynx
Usages: Put stocks.cgi and stock.conf in your cgi-bin directory. Open in firefox. Refresh to get latest info.
Note: you can also run the script from shell prompt and then redirect the output to a html file , then open this file in firefox :D But you need to run it every time you want the latest info.
# perl stock.cgi > mystocks.html
# firefox mystocks.html

Here are the files:

----- stocks.cgi ---
#!/usr/bin/perl -w
use strict;
use CGI qw(:standard);
#Written by Vaibhav Gupta
################ Variables ######################
my $stockfile = "stock.conf";
my $tab_width = 3;
################################################

sub generatestockhtml () {
my @allfile = `cat $stockfile `;
my $toprint = "<table frame=box><tr>\n";
my $count=0;

foreach my $line (@allfile) {
chomp $line;
my ($firstchar) = ($line =~ /(.)/ );
my $stock=`lynx -source " http://finance.yahoo.com/d/quotes.csv?s=$line&f=l1d1t1c6ohgn&e=.csv"` ;
my ($lasttrade,$lasttradedate,$lasttradetime,$change,$open,$dayhigh,$daylow,$name) = split(/,/,$stock);
#Not Printing lasttradetime
$toprint .="<td>
$name Trade Date = $lasttradedate 
Current: $lasttrade Change: $change 
Open: $open High: $dayhigh Low: $daylow
<a href=\" http://ichart.yahoo.com/v?s=$line\">
<img src=\"http://chart.yahoo.com/c/0b/$firstchar/$line.gif\">
</a> 
<a href=\"http://finance.yahoo.com/q?s=$line&d=b\"> More Info</a>
</td>
\n";
$count++;
if($count % $tab_width == 0) {
$toprint .= "</tr><tr>";
}
}
$toprint .= "</tr></table>";
print $toprint;
}

print header("text/html"),
start_html("Vaibhav Gupta's Stock Page");
my $cur = CGI->new() ;
&generatestockhtml();
print end_html;

--- stock.conf --
goog
yhoo
msft
amzn
emc

Trapping signals (^C and ^Z) in Bash

2007-04-19T16:41:00.001+05:30

#!/bin/bash
#Script written by Vaibhav Gupta
#Trapping HUP TERM INT and ^Z in shell.

echo "Process ID = $$";
stty susp "" #Trapping CTRL-Z
trap 'echo "Trapping CTRL-C, TERM and HUP";' HUP TERM INT
echo

echo "Sleeping for some time"
for i in `seq 1 20`; do
sleep 1
echo -n "."
done
echo
stty susp "^Z"

Koool bash Functions

2007-04-19T16:30:00.001+05:30

http://www.novell.com/coolsolutions/tools/18639.html

Script to exchange ssh keys

2007-04-17T20:48:00.001+05:30

 1 #!/usr/bin/perl
 2 use Expect;
 3 #USAGE:  ssh-key-exchange.pl <IP> <USERNAME> <PASSWORD>
 4 
 5 my $ip =  $ARGV[0];
 6 my $login = $ARGV[ 1];
 7 my $password = $ARGV[2 ];
 8 my $private_key='/root/.ssh/id_rsa ';
 9 my $public_key='/root/.ssh/id_rsa.pub ';
10 my $authorisedkeyfile='/root/.ssh/authorized_keys ';
11 my $timeout = 10;
12 my  $aft = new Expect;
13 
14 #Generate the public and private key on the local m/c A 
15 if(!(( -e $public_key ) &&( -e $private_key )))  {
16     print "Generating the Public and Private Key:\n ";
17     @result=`ssh-keygen -t rsa -f /root/.ssh/id_rsa -P "" `;
18     #print @result;
19 }
20 #Copy the file to m/c B 
21 print "Copying Public Key from A to B.\n ";
22 $aft->spawn("scp $public_key  $login\@$ip:/tmp/");
 23 $aft->expect($timeout,[ qr'\? $' ,     sub { my $fh=shift; $fh->send("yes\n"); exp_continue; } ],
 24                       [ 'Password: $',sub {  my $fh=shift;$fh->send("$password \n");exp_continue;}  ],
25 #                      '-re','\# $'     
 26                   );
27 $aft->do_soft_close();
28 
29  
30 #Add Keys to authorised keys in B
31 print " Adding Keys to authorised key in B with IP=$ip,[ $login $password  ] \n";
32 my $aft = new Expect; 
33 $aft->log_file("/tmp/expect_log" ,"w");
34 $aft->spawn( "ssh $login\@$ip") or  die "Cannot ssh to the machine \n";
35  $aft->expect($timeout,[ qr'\? $',      sub { my $fh=shift;$fh ->send("yes\n"); exp_continue; } ],
36                       [  'Password: $',sub { my  $fh=shift;$fh->send("$password\n ");exp_continue;}  ],
37                        '-re', '\# $'
38                   );
39 $aft ->send("touch $authorisedkeyfile\n");
 40 $aft->expect($timeout,'-re' ,'\# $');
41 $aft->send( "cat /tmp/id_rsa.pub >> $authorisedkeyfile\n");
42  $aft->expect($timeout,'-re', '\# $');
43 $aft->send(" exit\n");
44 $aft->do_soft_close();
 45

My New Homepage.

2006-11-27T13:14:00.000+05:30

Check my new homepage at http://vaibhav.gupta.googlepages.com/
You can download all the scripts from the given page.
My stumble page http://vaibhav.stumbleupon.com/

Vaibhav.

[perl] Create dir and links for a given dir.

2006-11-24T16:48:00.000+05:30

#!/usr/bin/perl
#written by vaibhav gupta
#Creates a new directory for a given directory and creates links for files.
$dir = $ARGV[0];
&usages unless $dir ;
©
sub usages {
 print "Usages: <Dirname> \n";
 exit;
}
sub copy {
 @result = `find $dir -type d`;
 $dirname = `echo "$dir" | rev | cut -d"/" -f 1 | rev`;
 chomp $dirname;
 $desination = "$dirname";
 foreach $d(@result) {
 chomp $d;
 ($a,$b) = split(/$dirname/,$d);
 print "Creating $desination$b\n";
# print "[$a -- $b]";
 @res = `mkdir -p $desination$b`;
 print @res;
 }
 @result = `find $dir -type f `;
 foreach $d(@result) {
 chomp $d;
 ($a,$b) = split(/$dirname/,$d);
 print "Copying $d\n";
 @res = `ln -s $d $desination$b`;
 print @res;
 }
}

[perl] Popup window

2006-11-24T16:42:00.000+05:30

#!/usr/bin/perl
# written by vaibhav gupta
use Gtk2 '-init';
$x=100;$y=100; #default Cordinates
$blue = 0xffff ;
$label = "Hello there";
$label = $ARGV[0] if $ARGV[0];
$delay = 5 ;
$delay = $ARGV[1] if $ARGV[1];
$x = $ARGV[2] if $ARGV[2];
$y = $ARGV[3] if $ARGV[3];
$blue = $ARGV[4] if $ARGV[4] ;

sub usages {
print "\n $ARGV[0] <label> <delay> <x> <y> <color>\n";
}

$window = Gtk2::Window->new("popup");
$window->set_title("Hello");
$window->signal_connect( destroy => sub {Gtk2->main_quit}) ;
$label = Gtk2::Label->new($label);
$label->modify_fg('normal',Gtk2::Gdk::Color->new(0,0,$blue) );
$window->add($label);
$window->move($x,$y);
#$window->resize(300,30);
$window->show_all();
Glib::Idle->add( sub { Gtk2->main_quit; 0 } );
#$window->begin_move_drag(0,100,100,1);
Gtk2->main;
print `sleep $delay`;

[python] Start Python

2006-11-24T16:26:00.000+05:30

#!/usr/bin/python
import sys
import os
import __builtin__

def helloworld():
   print "Dare to Challenge http://www.pythonchallenge.com/"
   print "Hello World\n";
   print "This is system Path : "
   print sys.path #this is search Path
   sys.path.append("this/is/test/path");
   print "This is system Path after appending test path "
   print sys.path
   filename = os.environ.get('PYTHONSTARTUP')
   print filename
   if filename and os.path.isfile(filename):
        execfile(filename)
   li = []
   print "Method of list ", dir(li) # list all the method of list
   info(__builtin__, 20) # gives the list of built in function

#Factorial Function Start
def fact(n):
   if n > 1:
       return n * fact(n-1)
       else:
       return 1
def info(object, spacing=10, collapse=1):
   """Print methods and doc strings.

   Takes module, class, list, dictionary, or string."""
   # note
   methodList = [e for e in dir(object) if callable(getattr(object, e))]
   processFunc = collapse and (lambda s: " ".join(s.split())) or (lambda s: s)
   print "\n".join(["%s %s" %
                   (method.ljust(spacing),
                      processFunc(str(getattr(object, method).__doc__)))
                   for method in methodList])


def datatypes():
   str = "This is a string."
   print str
   dict = {"server":"mpilgrim", "database":"this will be deleted"}
   print "Currnt Dictionary: ", dict # NOte that it printed in a sorted way.
   dict["server"] = "CHANGED"
   dict["uid"] = "added"
   dict["Uid"] = "case sensitive"
   dict[2] = "mixed data"
   dict["mixed"] = 123
   del dict["database"]
   print "Now Dictionary   : " , dict
   dict.clear() # To clear all the contents
   list = ["a", "b", "mpilgrim", "removethis", "example","pop"]
   print "Current List   :" , list
   print "Length of List : ", len(list)
   print "list[-1]   :", list[-1] #"li[-n] == li[len(li) - n]"
   print "Slicing    :", list[1:-1]
   print "Pop Element: ", list.pop()
   list.append("append")
   list.extend(["extend1","extend2"]) #note the arg is a list. Concatenates
   list.insert(2,"inserthere")
   list.remove("removethis");
   list += ["Operators"]
   print "Now List   : ",list
   print "Searching extend1 (first occurence): Found at location ", list.index("extend1")
   print "Found c in list:" , "c" in list
   list = ["1","2"]
   print "List Operator : ", list * 10
   tuple = ("son","mon","tue","wed","thu","fri","sat") # Ordered, fast, But can not be modified
   print tuple
   (a,b,c,d,e,f,g) = range(7)
   print "rnage d = ", d
   #3.6

#Calling main Functions.
helloworld()
#print fact(500)
#datatypes();
#info(list)

""" Notes
---------- and-or Trick ----------

>>> a = "first"
>>> b = "second"
>>> 1 and a or b
'first'
>>> 0 and a or b
'second'
---------- and-or Trick Safely ----------
>>> a = ""
>>> b = "second"
>>> (1 and [a] or [b])[0]
---------- split With No Arguments ----------
>>> s = "this    is\na\ttest"
>>> print s
this   is
a       test
>>> print s.split()
['this', 'is', 'a', 'test']
>>> print " ".join(s.split())
'this is a test'

"""

The Fastest Language

2006-11-24T15:22:00.000+05:30

Well,
Though this post is a little digression from what this forum is meant
for. It is really an interesting one because many a times we think

Which language is the fastest?

Considering the same hardware/environments are provided, it will all
depend on how well a compiler/interpreter make use of underlying
hardware/environment to generate native/interpreted code.

In a computer language shootout [Survey]
differrent compiler for different languages tested against their
ability to translate code for Ackermann Function
[Ackermann_function], Fibonacci numbers[Fibonacci_number] and
Tak functions [TAKFunction.html].

I was really happy to see that my favourite compiler gcc rules :-)

-by sbjoshi

[Perl] Script to take backups

2006-09-27T11:54:00.000+05:30

#!/usr/bin/perl
# Written By Vaibhav Gupta
# vaibhav.gupta@gmail.com
# Modify @FILES_TO_BACKUP @DIRS_TO_BACKUP @FILES_PATH as per your need.

$Directory=`date +%Y%m%d%k%M`;
chomp $Directory; # you know why ?
$HOMEDIRECTORY="~guptav/";
@FILES_TO_BACKUP=(".vimrc",".bashrc","public_html/cgi-bin/index.cgi");
@DIRS_TO_BACKUP=( "cvsroot","public_html/","bin");
@FILES_PATH=("/etc/httpd/conf/httpd.conf");

print "\nCreating directory $Directory\n";
@message = `mkdir $Directory`;

foreach $filename (@FILES_TO_BACKUP) {
@message = `cp $HOMEDIRECTORY$filename $Directory`;
}
foreach $filename (@FILES_PATH) { #Absolute Filename
@message = `cp $filename $Directory`;
}
foreach $dirname (@DIRS_TO_BACKUP) {
@message = `cp -r $HOMEDIRECTORY$dirname $Directory`;
}
@message = `tar -cvzf $Directory.tgz $Directory`;
print @message;

#Vaibhav.

[shell] To find the PPID of a PID and more.

2006-09-11T17:33:00.000+05:30

1 #!/bin/bash
2 pid=$1
3 if [ -f "/proc/$pid/stat" ]; then
4 name=`cat /proc/$pid/stat | cut -d" " -f 2`
5 else
6 echo "Not a Valid pid $pid"
7 exit
8 fi
9
10
11 while [ "$pid" -gt "0" ]; do
12 echo -n $pid
13 echo -n [$name]
14 echo -n " --> "
15 name=`cat /proc/$pid/stat | cut -d" " -f 2`
16 pid=`cat /proc/$pid/stat | cut -d" " -f 4`
17 done
18
19 echo "0"
20

-Vaibhav

Writing Kernel Modules for 2.6

2006-09-11T13:17:00.000+05:30

hello.c
1 #include <linux/module.h>
2 #include <linux/kernel.h>
3
4 int init_module(void)
5 {
6 printk(KERN_INFO "Hello world \n");
7 return 0;
8 }
9
10 void cleanup_module(void)
11 {
12 printk(KERN_INFO "Goodbye world \n");
13 }

Makefile
1 obj-m += hello.o
2
3 all:
4 make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
5
6
7 clean:
8 make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
9 fresh: clean all

Commands:

Install Module# insmod hello.ko
Remove Module # rmmod hello.ko
Module info # modinfr hello.ko
List Module # lsmod
Check Log # tail /var/log/messages

Files :
/proc/modules | List of modules |
/proc/kallsyms | List of Symbols |

Vaibhav.

[c++] Source code to find Prime numbers < n+1

2006-07-02T21:23:00.000+05:30

/*Code is written by Vaibhav Gupta*/

int prime(int n){

bool *prime = new bool[n+1];
int i;
for(i=0;i<n+1;i++){
prime[i] = true;
}
prime[0]=false;
prime[1]=false;
int m = (int)sqrt((float)n);

for (i=2; i<=m; i++)
if (prime[i])
for (int k=i*i; k<=n; k+=i)
prime[k]=false;

for (i=0; i<n+1; i++){
if (prime[i]) cout << i << " ";
}
cout << endl;
return 0;
}

[ebooks] Over 1 billion ebooks.......

2006-06-20T11:16:00.000+05:30

Hi friends,

Some sites may not be working.....

http://www.freebookzone.com/
http://en.wikipedia.org/wiki/E-book

ftp://194.105.193.56/pub/warez/books/os/
ftp://194.85.35.67/BOOKS/
ftp://193.231.20.1/pub/books/
ftp://218.104.214.138/4tF/2003/Xmas/
fxp://fxp.runnet.ru/BOOKS - flashget
ftp://se-lab-server.ddns.comp.nus.edu.sg/ebooks/
http://sleekfreak.ath.cx:81/books/
http://preterhuman.net/texts/
http://www.waneesoft.net/books/
http://www.itcertifer.com - www.itcertifer.com
http://cgdn.net/books/
http://www.nerd-star.com/books/
http://publib-b.boulder.ibm.com/Redbooks.nsf/redbooks/
http://classics.mit.edu/Browse/index-Homer.html
http://www.cybersecurity.com.br/Livros/
http://amitmathur.8m.com/ebooks.html
http://mail.stibanas.ac.id/ebooks/
http://www.wolfgarten.com
http://johnny.ihackstuff.com
http://www.law.fsu.edu
http://mail.stibanas.ac.id/ebooks
http://www.comms.scitech.susx.ac.uk/fft/
http://www.cadforum.cz/cadforum_en/default.asp http://en.fixdown.com/eall_1.htm
http://en.fixdown.com/download.asp?id=1658...589&soft=sxdown
http://en.fixdown.com/download.asp?id=1588...886&soft=kldown
http://en.fixdown.com/download.asp?id=1588...886&soft=fjdown
http://en.fixdown.com/download.asp?id=1588...886&soft=bjdown
http://preterhuman.net/texts/
http://www.eicage.org/eicage.asp
http://bjxebook.myetang.com/pc.html
http://www.about-flash.com/
http://docs.rinet.ru:8080/DEFAULT.HTML
http://www.bsmooth.de/BSolutions/
http://newdata.box.sk/raven/books.html
http://www.maththinking.com/boat/computerbooks.html
http://dhruvaraj.150m.com/
http://podgoretsky.pri.ee/ms.html
http://www.comms.scitech.susx.ac.uk/fft/
http://www.intelinfo.com/free_computer_books.html
http://www.e-book.com.au/freebooks.htm
http://www.mcsedirectory.com/books.shtml
http://www.gorkhali.com/kamal/download.htm
http://www.winnetmag.com/windowsnt20002003faq/
http://www.2000trainers.com/
http://www.w3schools.com/
http://members.rogers.com/thekickman/ebooks.htm
http://www.techtutorials.com/Applications/
http://sunsite.iisc.ernet.in/virlib/
http:// www.bdsoft.com/links.html
http://www.python.org/doc/
http://www.graphic-design.com/Photoshop/
http://bjxebook.myetang.com/pc_ebooks/db.htm
http://neworder.box.sk/box.php3?gfx=neword...0Unix%20systems
http://www.exameware.com
http://www.comms.scitech.susx.ac.uk/fft/
http://rahmat.zikri.com/books.html
http://freebooks.by.ru/
http://www.mindview.net/Books/DownloadSites
http://www.maththinking.com/boat/computerbooks.html
http://docs.rinet.ru:8080/
http://www.ebone.at/files.php?show=Books
http://www.empowermentzone.com/#unix
http://skaiste.elekta.lt/Books/
http://content.443.ch/pub/
http://www.ods.com.ua/index.phtml
http://kavosh.irost.net/books/library.htm
http://stommel.tamu.edu/~baum/programming.html
http://digital.library.upenn.edu/books/
http://zikri.indoglobal.com/books.html
http://www.greylib.align.ru/index.html
http://www.itcertifer.com/en/download/default.asp
http://www.lib.ru
http://lib.km.ru
http://aldebaran.ru
http://lib.bigmir.net
http://books.myweb.ru
http://book.pp.ru
http://www.biglib.com.ua/
http://www.lib.com.ua/
http://www.bestlibrary.ru/
http://www.citforum.ru/
http://i2r.rusfund.ru/
http://www.yaxoo.com/books/
http://docs.gets.ru/
http://bookz.ru/
http://www.bestbooks.ru/
http://leoslibrary.on.to/
http://www.bomanuar.ru/
http://molbiol.ru/review/index.html
http://lib.rin.ru/
http://www.bomanuar.ru/
http://www.voronezh.net/library/
http://www.xnt.info/category.php?all=44&start=5&id=9
http://www.emc.maricopa.edu/faculty/farabe...BioBookTOC.html
http://netfoo.net/unix_iso/unixbook.iso
http://maui.fornex.net/e-book/pdf-books/
http://books.dimka.ee/ - HUGE COLLECTION
http://cgdn.net/books/ - Game Programming
http://www.whitefreespeech.com/sub/TurnerDiaries.pdf
http://www.solargeneral.com/library
http://classics.mit.edu/Browse
http://www.nerd-star.com/books/
http://web.starman.ee/winxp/Windows%20XP%2...nside%20Out.rar
http://www.comms.engg.susx.ac.uk/fft/
http://www.vdr-era.cjb.net/documentos/
http://devsaa.narod.ru/books
http://www.ibiblio.org/obp/electricCircuits
http://www.highend3d.com/artists/artist.3d...=yinako&iid=197

http://narod.yandex.ru/cgi-bin/yandmarkup?...og=0x2757571A&H
ndlQuery=757312448&PageNum=0&g=0&d=0&ag=host&tg=1&q0=54598832&p=

http://onlinebooks.library.upenn.edu/webbi...le=&tmode=words

http://macbeht.narod.ru/bucher.htm
http://www.pcworld.com/resource/PDF/circ_2.asp
http://www.emc.maricopa.edu/faculty/farabe...BioBookTOC.html
http://netfoo.net/unix_iso/unixbook.iso
http://maui.fornex.net/e-book/pdf-books/
http://books.dimka.ee/
http://www.click-now.net/ebooks.htm
http://www.baen.com/
http://www.ebookmall.com/ebook/5613-ebook.htm
http://etext.library.adelaide.edu.au/
http://www.freebooks4doctors.com
http://gutenberg.net/cgi-bin/search/t9.cgi
http://gutenberg.net/gutenberg/find.shtml
http://freetechstuff.netfirms.com/dotnet/books.htm
http://www.soldierx.com/books/ACTIVEX_PROG...SHED/index.html

http://www.soldierx.com/books/CHARLIE_CALV...SHED/index.html

http://www.strath.ac.uk/IT/Docs/Ccourse/
http://www.brpreiss.com/books/opus4/html/book.html

http://onlinebooks.library.upenn.edu/webbi...le=&tmode=words

http://www.xatrix.org/index.php
http://www.fintech.ru/Library/prog/Getstrt...DB/getstart.htm
http://www.commandprompt.com/ppbook/
http://www.vijaymukhi.com/documents/books/...oap/xmlsoap.htm
http://www.vijaymukhi.com/documents/books/wap/wap.html
http://www.vijaymukhi.com/documents/books/...sp/javajsp.html
http://www.vijaymukhi.com/documents/books/...s/j2me/j2me.htm
http://www.vijaymukhi.com/documents/books/...s/j2me/j2me.htm
http://www.vijaymukhi.com/documents/books/...cs/csharp1.html
http://www.vijaymukhi.com/documents/books/...dv/csharp2.html
http://www.vijaymukhi.com/documents/books/...vbnet/vbnet.htm
http://www.vijaymukhi.com/documents/books/...ta/metadata.htm
http://www.vijaymukhi.com/documents/books/...net/content.htm
http://www.vijaymukhi.com/documents/books/...2net/vs2net.htm
http://www.vijaymukhi.com/documents/books/...et1/aspnet.html
http://docs.rinet.ru/Cold/
http://www.syncfusion.com/FAQ/WinForms/default.asp#86

http://www.ssuet.edu.pk/~amkhan/cisco/(ebo...ching/Table.htm

http://www.blindprogramming.com/
http://ssuet.edu.pk/taimoor/books/1-57521-...163-7/index.htm
http://www.manastungare.com
http://world.std.com/obi/
http://www.itebooks.net/onlineebooks/Networking.html
http://www.itebooks.net/onlineebooks/Certi...tification.html
http://www.itebooks.net/onlineebooks/Opera...ingSystems.html
http://www.itebooks.net/onlineebooks/Enterprise.html
http://www.itebooks.net/onlineebooks/Internet.html
http://www.itebooks.net/onlineebooks/Programming.html
http://www.itebooks.net/onlineebooks/Database.html
http://www.itebooks.net/onlineebooks/Graphics.html
http://www.itebooks.net/onlineebooks/DesktopApps.html
http://www.itebooks.net/onlineebooks/Hardware.html
http://freebooks.boom.ru
http://the-tech.mit.edu/Shakespeare/
http://www.vecpix.com/
http://kristi.erdves.lt/books/
http://www.zionwap.net/books/main.html
http://www.nopayweb.com/computerbook/
http://leon83.com/download/book/FreeBookList.htm
http://www.mslit.com
http://www.python.org/doc/current/tut/tut.html
http://esspc-ebooks.com
http://en.fixdown.com/eall_3.htm
http://www.xnt.info/category.php?id=9
http://www.bluesfear.com/v5.php
http://www.teamphotoshop.com/photoshop/tut...ials/ps_tut.php
http://www.80four.co.uk/tutorials/photoshop.html
http://www.eyesondesign.net/pshop/tuts.htm
http://www.good-tutorials.com/
http://www.grafx-design.com/tutorials.html
http://myjanee.home.insightbb.com/tutorials.htm
http://www.photoshoproadmap.com/photoshop- ...rials-tips.html
http://rainworld.com/psworkshop/

http://131.128.51.37/se-lab-server.ddns.....edu.sg/ebooks/
http://www.et.utt.ro/public/Docs/
http://www.docs.rinet.ru
http://www.tutorialized.com
http://books.malonus.com/ebooks/computer_science/
http://www.intersoftlb.com/blog4.aspx (mcsd books)
http://131.128.51.37/se-lab-server.ddns.....edu.sg/ebooks/
(nice)(electronic...computer)
http://www.et.utt.ro/public/Docs/
http://www.docs.rinet.ru
http://www.tutorialized.com
http://books.malonus.com/ebooks/computer_science/ (nice)
http://cip.uni-trier.de/jia/links/weball.htm
http://www.gorkhali.com/kamal/download.htm
ftp://ftp.runnet.ru/BOOKS/

Happy reading.......

Bye

How to set up thinclient in Linux

2006-05-30T19:47:00.000+05:30

Thin Client How to by Vaibhav Gupta

How to set up Thintux Server
You need to setup dhcp server and copy thintux folder on the server.
Setting up dhcp server
a. Make dhcpd configuration file :-> /etc/dhcpd.conf
b. Starting dhcpd :-> /etc/init.d/dhcpd start

Configuring dhcpd.conf Manually:-
1. Set subnet,netmask,router and range of IPs.
2. Set Thintux session server address, resolution and color depth.
3. Detailed Information man dhcpd, man dhcpd.conf
4. Get Sample Configuration dhcpd.conf (For Linux)<a
href="thintux/dhcpd.conf" >[dhcpd.conf] </a>

Format of dhcp.conf :-
[code]
#global parameters...
subnet 10.105.0.0 netmask 255.255.128.0 {
# subnet-specific parameters...
range 10.105.13.101 10.105.13.210;
option routers 10.105.1.250;
option THINTUX_SESSION_SERVER "10.105.11.23";
option THINTUX_SCREEN_RESOLUTION "800x600";
option THINTUX_SCREEN_COLOR_DEPTH "8";
}
group {
#group-specific parameters...
host abc.iitb.ac.in {
#host-specific parameters...
}
}
[/code]
Configuring using config-dhcpd :-
1. http://config-dhcpd.sourceforge.net/

Start X Display Manager
1. vim /usr/X11R6/lib/X11/xdm/xdm-config
2. Comment the last line as below :-
!DisplayManager.requestPort: 0
3. Save and Exit
4. vim /usr/X11R6/lib/X11/xdm/Xaccess
5. uncomment the following line (By removing #)
#* #any host can get a login window
6. Save and Exit
7. Start xdm :-> xdm

Help and Debug :-
1. man xdm
2. Error Logs :-> /var/log/xdm-errors
or :-> /usr/X11R6/lib/X11/xdm/xdm-errors
3. X -query 10.105.11.23

Check tftp is enable on server
1. vim /etc/xinetd.d/tftp
2. Change the disable option to "no" as Below.
disable = no
3. Save file and exit
4. Restart xinitd

Copy /thintux folder in /tftboot on server
<a href="thintux/thintux.tgz" >[thintux][tgz] </a>

http://thintux.sourceforge.net/

How to setup thinclient
Client already contaning Linux OS
1. Copy "localdsk" as /root/thinlinux on Client <a
href="thintux/localdsk" >[localdsk][x86 boot sector] </a>
2. Modify /etc/lilo.conf
3. Run lilo
4. Restart the PC

Add following Entries to lilo.conf:-

default=thin-linux # Add or Modify this line for default Booting from N/w
image=/root/thinlinux
label=thin-linux
read-only

Client that doesnot contain Linux OS
For all the following steps you have to use Dos Bootable Floopy
containg fdisk, format, syslinux.com and linux image(thintux) [as
downloaded above].

1. Delete all partitions on Hard Drive using fdisk.
2. Execute :-> fdisk /mbr
3. Create 20MB Dos Partion and Make active
4. Reboot
5. Execute:-> Format C:
6. Execute:-> syslinux c:
7. Execute:-> copy linux c: The above file "linux" is same as "localdsk". Only the name is
changed in this case.
8. Remove Floppy and Reboot

For Debugging
1. Use tcpdump as
tcpdump -n port 7100
tcpdump -n port tftp

Links
http://thintux.sourceforge.net
http://www.dhcp.org
http://www.dhcp-handbook.com/dhcp_faq.html
http://syslinux.zytor.com
http://www.vlug.org/vlug/meetings/X-terminal_presentation/overview.html

C++ Programs [Interview]

2006-05-30T14:46:00.000+05:30

Find the number which is odd number of times? [Interview]
Dated: Wed Dec 28 22:44:42 IST 2005

14 int findodd(int *n,int len)
15 {
16 int num=0;
17 for(int i=0;i<len;i++)
18 num^=n[i];
19 return num;
20 }

How would u sort of 0s and 1s in just single pass? [Interview]
Dated: Wed Dec 28 22:27:42 IST 2005

1 void sort_01 (int *n,int len)
2 {
3 int i=0,j=len-1;
4 while(1){
5 while((!n[i])&&(i<len)) i++;
6 while((n[j])&&(j>-1)) j--;
7 if(i>=j) break;
8 n[i]=~n[i]&1;
9 n[j]=~n[j]&1;
10 i++;j--;
11 }
12 }

Find all possible splits for any given number n. [Interview]
Dated: Wed Dec 28 21:33:48 IST 2005

Init : int array[5]={0,0,0,0,0};
Function Call : split(array,5,0);

1 void split(int *n,int count,int len)
2 {
3 if(count==1) {
4 int i;
5 for(i=0;i<len;i++)
6 printf("%d+",n[i]);
7 printf("%d\n",n[i]+1);
8 return;
9 }
10 else {
11 n[len]+=1;
12 split(n,count-1,len);
13 split(n,count-1,len+1);
14 n[len]-=1;
15 }
16 return ;
17 }

WAP to check a integer (as binary string) is pallindrome? [Interview]
Dated: Wed Dec 28 18:27:43 IST 2005

1 bool panlindrome(unsigned long i)
2 {
3 if(!(i&1)) return false;
4 unsigned long t=i,rev=1;
5 t>>=1;
6 while(t) {
7 rev<<=1;
8 if(t&1) rev |=1;
9 t >>=1;
10 }
11 if(rev==i) return true;
12 return false;
13 }

Find the number of ones in an integer? [Interview]
Dated: Wed Dec 28 18:17:14 IST 2005

1 unsigned noofone(unsigned long i)
2 {
3 int count=0;
4 while(i) i=i&(~(i&(~i+1))),count++;
5 return count;
6 }

WAP to convert a given integer to octal number? [Interview]
Dated: Wed Dec 28 17:45:04 IST 2005

1 #include<stdio.h>
2 void int2octal (unsigned long i)
3 {
4 if(i) {
5 unsigned long o = i&7;
6 i>>=3;
7 int2octal(i);
8 printf("%d",o);
9 }
10 else printf("0");
11 }

How to reverse a singly-linked list? [Interview]
Dated: Tue Dec 27 06:49:35 IST 2005

1 node* reverse_list(node *list)
2 {
3 node *rev=NULL;
4 while(list !=NULL) {
5 node *t = list->next;
6 list->next = rev;
7 rev = list;
8 list = t;
9 }
10 return rev;
11 }

How To Speed Up Firefox [Howto]

2006-05-30T14:42:00.000+05:30

Here's something for broadband people that will really speed Firefox up:

1.Type "about:config" into the address bar and hit return. Scroll down and
look for the following entries:

network.http.pipelining network.http.proxy.pipelining
network.http.pipelining.maxrequests

Normally the browser will make one request to a web page at a time. When you
enable pipelining it will make several at once, which really speeds up page
loading.

2. Alter the entries as follows:

Set "network.http.pipelining" to "true"

Set "network.http.proxy.pipelining" to "true"

Set "network.http.pipelining.maxrequests" to some number like 30. This means
it will make 30 requests at once.

3. Lastly right-click anywhere and select New-> Integer. Name it
"nglayout.initialpaint.delay" and set its value to "0". This value is the
amount of time the browser waits before it acts on information it recieves.

If you're using a broadband connection you'll load pages MUCH faster now!

Vaibhav.

How to Export sound in Linux [Howto]

2006-05-30T14:41:00.000+05:30

Exporting sound :-

Run 'artsd -n -u -p 5001' on system on which u want to hear sound.
Run 'export ARTS_SERVER=ip_of_system_on_which_sound_it_to_be_heard:5001'
on system where sound application will be run (like mplayer)
Run 'mplayer -ao arts soundfile.mp3'

Vim Movements

2006-05-29T19:54:00.000+05:30

Moving Around
k (up),
h(left) l (right).
j (down)
(Ex 5k,j,3l )

Word Movement
w (Forward Word Movement Ex. f,5f )
b (Backword Word Movement Ex. b,2b)
e (Forward Word Movement at the end of word Ex. e,3e )
ge (Backword Word Movement at the end of word Ex. ge,3ge )

Moving to the Start or End of a Line
$(End Of Line Ex. $,2$)
^(Start Of Line Ex. ^,3^)

Searching Along a Single Line
f<Charcter> (Searching Charcter Forward Ex. fa, 2fv)
F<Charcter> (Searching Charcter Backword Ex. Fg,2Ft)
t<Charcter> (Search till Forward )
T<Charcter> (Search till Backword)

Moving to a Specific Line
<Line No.>G (Go to Line No.)
CTRL-G (Where I am in the File)
g CTRL-G (Count col, line, words and bytes)
CTRL-O Jump to previous location.
<TAB> Jump to next location (line 10).

Where are you in File
:set number
:set nonumber

Scrolling Up and Down
CTRL-U (scrolls up half a screen of text.)
CTRL-Y (scrolls up a line of text.)
CTRL-B (scrolls up a entire screen at a time.)
CTRL-D (scrolls down half a screen of text.)
CTRL-E (scrolls down one line.)
CTRL-F (scrolls down one screen of text.)
z<Enter> (screen line on the top)
88z<Enter> positions line 88 at the top.
zt (Leaves the cursor where it is.)
z- (scrolls line to the end of the screen)
zb (Leaves the cursor where it is)
z. (Center of the screen)
zz (Leaves the cursor where it is .)

:set scroll=10
:set scrolljump=5
:set scrolloff=3

Deleting
x delete character under the cursor (short for "dl")
X delete character before the cursor (short for "dh")
dw (Delete Word Ex. dw,3dw,d3w,3d2w,d$,d^,df> )
dd (Delete Line Ex. dd,3dd)
D (Delete up to end of line. )(short for "d$")
diw delete word under the cursor (excluding white space)
daw delete word under the cursor (including white space)
dG delete until the end of the file
dgg delete until the start of the file

Arthemetic
CTRL-A Incrmenting Number (123, 0177, 0x1f,-98)
CTRL-X Decrementing Number

:set nrformats=""

Changing Text
cw (Change Word Ex cw,c2w)
C stands for c$ (change to end of the line)
s stands for cl (change one character)
S stands for cc (change a whole line)

The . Command
It repeats the last delete or change command.

Joining Lines
J (Join Lines to One. Ex J,3J)
gJ (Join Lines without Spaces)

Replacing Charcter
r<Charcter> (Replace Charater Under Cursour. Ex. ru,5ra,3r<Enter> )
R<Charcter>

Changing Case
~ (Change Case of Character Ex. ~,12~,~fq)
U (Make the text Uppercase)
u (Make the text Lowercase)
g~motion (It does not depend on tildeop)
g~~ or g~g~ (Changes case of whole line)
gUmotion (All uppercase)
gUU (Changes to uppercase for whole line)
gUw (Changes to uppercase for word)
guw (Changes to lowercase for word)

How to set up ssh keys for Linux

2006-05-29T19:42:00.000+05:30

How to set up ssh keys for Linux

1. Run "ssh-keygen -t dsa" on the machine which is the client.
Files Generated :
$(HOME)/.ssh/id_dsa : Your private Key
$(HOME)/.ssh/id_dsa.pub : Your public Key
You can enter empty passphrase.
Type can rsa and dsa for version 2 and rsa1 for version 1.
2. Now ssh into the server.You need to type password this time.
you have to transfer the publickey to server.
cd $(HOME)/.ssh
cat $(HOME)/.ssh/id_dsa.pub >> authorized_keys2

Note : Don't introduce any extra spaces, slashes or any other characters
If the file already exists, append the output of id_dsa.pub to EOF.

3. Repeat for Other machine if you want.
4. Now you can login without entering passwords.
On some machines, it might ask you to verify the host key,
but will happen only for the first time.

Changing MySQL root password

2006-05-29T19:41:00.000+05:30

Changing MySQL root password

Sometimes you forget the root password, or something went wrong
modifying it. Here's how to reset the root password for mysql on a
Redhat Linux box:

[root@host root]#killall mysqld
[root@host root]#/usr/libexec/mysqld -Sg --user=root &
[root@host root]# mysql
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 1 to server version: 3.xx.xx
Type 'help;' or 'h' for help. Type 'c' to clear the buffer.
mysql> USE mysql

Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> UPDATE user
-> SET password=password("newpassword")
-> WHERE user="root";
Query OK, 2 rows affected (0.03 sec)
Rows matched: 2 Changed: 2 Warnings: 0
mysql> flush privileges;
Query OK, 0 rows affected (0.02 sec)
mysql> exit;
[root@host root]#killall mysqld

Then start MySQL again:

/etc/init.d/mysqld start

Makefile for c++ project

2006-05-29T19:40:00.000+05:30

#---------------------------------------------------------------#
# Written By Vaibhav Gupta
#---------------------------------------------------------------#
# TARGETS:
# wire - default target
# dwire - debug target
# tag - For generating tag file
# clean/fresh - clean obj files.
#---------------------------------------------------------------#
#-- Customized variables
BINDIR=bin
OBJDIR=obj
SRCDIR=src
INCDIR=include

CC = g++
CWARN = -W -Wall -Wshadow -Wimplicit -Wreturn-type -Wcomment -Wtrigraphs -Wformat -Wparentheses -Wpointer-arith -Wuninitialized -O

CDBG = -g $(CWARN) -fno-inline
CFLAGS = -I$(INCDIR) $(CDBG)
DFLAGS = -I$(INCDIR) -g $(CWARN) -fno-inline -DDEBUG=1

CTAG = ctags
CTAGFILE = filelist
# src, object and bin files
TGT=wire
#Debug Target
DBGTGT=dwire

HEADERS = $(INCDIR)/global.h

COMMONOBJS = $(OBJDIR)/BaseStation.o $(OBJDIR)/SubscriberStation.o
$(OBJDIR)/Packet.o $(OBJDIR)/Queue.o $(OBJDIR)/Global.o $(OBJDIR)/Simulate.o

OBJS = $(COMMONOBJS) $(OBJDIR)/main.o
DBGOBJS = $(COMMONOBJS) $(OBJDIR)/main.dbg.o

#-- Rules
all: $(TGT)
dbg: $(DBGTGT)

$(TGT): $(BINDIR)/$(TGT)
@echo "$@ uptodate"

$(DBGTGT): $(BINDIR)/$(DBGTGT)
@echo "$@ uptodate"

$(BINDIR)/$(DBGTGT): $(DBGOBJS)
$(CC) $(CFLAGS) -o $@ $(DBGOBJS)

$(OBJDIR)/%.dbg.o: $(SRCDIR)/%.cpp
$(CC) $(CFLAGS) -DDEBUG=1 -c -o $@ $?

$(BINDIR)/$(TGT): $(OBJS)
$(CC) $(CFLAGS) -o $@ $(OBJS)

$(OBJDIR)/%.o: $(SRCDIR)/%.cpp
$(CC) $(CFLAGS) -c -o $@ $?

.PHONY : clean depend fresh
tag :
find src/*.cpp include/*.h > filelist
$(CTAG) -L $(CTAGFILE)

clean :
-rm -f $(OBJDIR)/*.o $(PARSE_C) $(PARSE_H)
-rm -f $(SRCDIR)/*.output $(LEX_C)
-rm -f */*~ *~ core
-rm -f $(BINDIR)/$(TGT) $(BINDIR)/$(DBGTGT)

fresh : clean all

Picking a random quote or signature from a file [perl]

2006-05-29T19:35:00.000+05:30

Generates a Random Signature from a signature file

script
--------

#!/usr/bin/perl
&pick_quote;
sub pick_quote {
my $path = "/usr/signature/";
my $sigfile = "$path/signature.txt"; # Signature FILE
open (SIGS, "< $sigfile" ) or die "can't open $sigfile";
local $/ = "%%\n";
local $_;
my $quip;
rand($.) < 1 && ($quip = $_) while <SIGS>;
close SIGS;
chomp $quip;
print $quip || "ENOSIG: This signature file is empty.\n";
}

Sample Signature File
---------------------------------

Signatures are a waste of bandwidth.
%%
Help stamp out signatures.
%%
'Calm down -- it's only ones and zeros.'
%%
According to my calculations the problem doesn't exist.
%%
A day for firm decisions!!!!! Or is it?
%%
A few hours grace before the madness begins again.
%%
A gift of a flower will soon be made to you.
%%
A long-forgotten loved one will appear soon.

Buy the negatives at any price.
%%

Linux Tips

2006-05-29T19:24:00.000+05:30

------------------------------------------------------------------------------------
Who is SUPER USER in linux

awk -F: '$3 == 0{print $1,"superuser!"}' /etc/passwd
------------------------------------------------------------------------------------
How to get Environment for a process
If the process id is 920.

(cat /proc/920/environ; echo) : tr "\000" "\n"
------------------------------------------------------------------------------------
How to list files with their complete path
If 'childdir' is the name of directory.

find childdir -type f -printf "%AY%Am%Ad%AH%AM %p\n" : sort -r : gawk
'{print $2}'
------------------------------------------------------------------------------------
How to find open files in linux

find /proc -regex "/proc/[0-9]*/fd/.*" -ls
------------------------------------------------------------------------------------
Formatting man pages

man ls : col -bx > myfile.txt
------------------------------------------------------------------------------------
Finding the biggest files

ls -l : sort +4n
------------------------------------------------------------------------------------
Searching files for content

find / -name "filename" : xargs grep -n content
------------------------------------------------------------------------------------
Largest Directories

du -kx : egrep -v "\./.+/" : sort -n
-----------------------------------------------------------------------------------
List today's files only

ls -al --time-style +%D : grep `date +%D`
------------------------------------------------------------------------------------
Encrypt some plain text

perl -e 'print crypt("ke", "password");'
-----------------------------------------------------------------------------------
Look for unusual SUID root files

find / -uid 0 -perm -4000 -print
-----------------------------------------------------------------------------------
Look for unusual large files (> 10 Mb)

find / -size +10000k -print
-----------------------------------------------------------------------------------

Linux Command Line Tips

2006-05-29T19:17:00.000+05:30

Linux Command Line Tips

http://www.pixelbeat.org/timeline.html

Vim Folding Tips

2006-05-29T18:48:00.000+05:30

# folding : hide sections to allow easier comparisons

zf{motion} or {Visual}zf :Operator to create a fold.
zf'a : fold to mark
zF :Create a fold for N lines.
zd :Delete one fold at the cursor.
zD :Delete folds recursively at the cursor.
zE :Eliminate all folds in the window.
zo :Open one fold.
zO :Open all folds recursively.
zc :Close one fold.
zC :Close all folds recursively.
za :When on a closed fold: open it.and vice-versa.
zA :When on a closed fold: open it recursively.and vice-versa.
zR :Open all folds.
zM :Close all folds:
zn :Fold none: reset 'foldenable'. All folds will be open.
zN :Fold normal: set 'foldenable'. All folds will be as they were before.
zi :Invert 'foldenable'.

[z :Move to the start of the current open fold.
]z :Move to the end of the current open fold.
zj :Move downwards. to the start of the next fold.
zk :Move upwards to the end of the previous fold.

My vimrc: Open a c/cpp/java/perl programm. Press <F6> and see the power of
vim :-)

nmap <F6> /}<CR>zf%<ESC>:nohlsearch<CR>

Vaibhav.

How to Search in Google

2006-05-29T18:47:00.000+05:30

How to Search in Google

1. allintitle: graph partition triangle
2. +("index of") +("/ebooks":"/book") +(chm:pdf:zip:rar) +apache
3. allinurl: +(rar:chm:zip:pdf:tgz) TheTitle
4. allinurl:config.txt site:.jp
5. allinurl:admin.txt site:.edu
6. "Index of /something"
7. filetype:doc site:edu

Links:-

http://www.googleguide.com/advanced_operators_reference.html
http://www.google.com/help/operators.html

Vim and HTML

2006-05-29T18:45:00.001+05:30

HTML and vim Tips:

:runtime! syntax/2html.vim :convert txt to html
:%s#<[^>]\+>##g : delete html tags, leave text

My vim.rc : Type a word and press ",," without quote

imap <silent> ,, <ESC>"_yiw:s/$\%#\w\+$/<\1> <\\\1>/<cr><c-o><c-l>f>a

Vaibhav.

Extract links from a file [perl]

2006-05-29T18:45:00.000+05:30

How to extractlinks from a file

#!/usr/bin/perl
use HTML::SimpleLinkExtor;
my $file = new HTML::SimpleLinkExtor();

# Extracts Links from a HTML File
# Written by Vaibhav Gupta guptav@cse.iitb.ac.in
$filename = $ARGV[0];
$url = $ARGV[1]; #base url else empty string

if($filename eq "" ) {
print "\nUsages: ./extractlink.pl filename.html\n";
exit ;
}

$file->parse_file($filename);
my @links= $file->a;
foreach $link (@links){
chomp;
print "$url$link\n";
}

Networking Hacks

2006-05-29T18:42:00.000+05:30

How to chat without using talk

At Server side:
nc -l -p 5600 -vv
At client Side:
nc 10.100.116.37 5600

Here 10.100.116.37 is the ip of server. 5600 is the port.

How to transfer file with out using ftp

At Server Side:
nc -v -w 30 -p 5600 -l > filename.back
At Client Side:
nc -v -w 2 10.100.116.37 5600 < filename

How to mail using telnet

2006-05-29T18:41:00.000+05:30

C: client
S: Server

C:telnet smtp.iitb.ac.in 25
S:220 smtp2.iitb.ac.in ESMTP
C:helo
S:250 smtp2.iitb.ac.in
C:mail from:<root@10.100.106.50>
S:250 ok
C:rcpt to:<guptav@cse.iitb.ac.in>
S:250 ok
C:data
S:354 go ahead
C:Subject: This is subject line.
C:hi vaibhav,
C:how r u? i m fine.
C:bye for now
C:vaibhav
C:.
S:250 ok 1095622024 qp 2471
S:502 unimplemented (#5.5.1)
C:quit
S:221 smtp2.iitb.ac.in
S:Connection closed by foreign host.

SMTP Commands

2006-05-29T18:39:00.000+05:30

SMTP commands are ASCII messages sent between SMTP hosts.

*Command: Description
*DATA: Begins message composition.
*EXPN <string> : Returns names on the specified mail list.
*HELO <domain> : Returns identity of mail server.
*HELP <command>: Returns information on the specified command.
*MAIL FROM <host> : Initiates a mail session from host.
*NOOP : Causes no action, except acknowledgement from server.
*QUIT : Terminates the mail session.
*RCPT TO <user>: Designates who receives mail.
*RSET : Resets mail connection.
*SAML FROM <host> : Sends mail to user terminal and mailbox.
*SEND FROM <host> : Sends mail to user terminal.
*SOML FROM <host> : Sends mail to user terminal or mailbox.
*TURN : Switches role of receiver and sender.
*VRFY <user> : Verifies the identity of a user.

Forgot password for Windows 2000?

2006-04-18T16:54:00.000+05:30

Hi,
well, this trick can work only if you have got a dual boot machine with linux as one of the os. Also, either you should be a root or the windows partition should be mounten with appropriate permission.

just delete the file
"winnt/system32/config/sam"
and you are done. you can boot your machine in windows and can get entry with
user : administrator
passwd :

leave the password field null.

Running commands using script

2006-04-15T23:57:00.000+05:30


#!/usr/bin/perl
#Written by Vaibhav.
#guptav[at]cse[dot]iitb[dot]ac[dot]in on Mon Mar 7

use Expect;
#List of IPs in file 'IPS'
open(IP,"<IPS");
@IPS=<IP>;
close IP;
my $newpassword = "yourpassword";

foreach $ip(@IPS) {
       chomp $ip;
       print "-------$ip-------\n";
       my $timeout = 50;
       my $aft = new Expect;
       $aft->spawn("ssh $ip")
               or die "Cannot ssh to the machine \n";
       $aft->log_file("/tmp/expect_log");
       $aft->expect($timeout,'-re','\? $');
       $aft->send("yes\n");
       $aft->expect($timeout,'-re','password: $');
       $aft->send("$newpassword\n");
       $aft->expect($timeout,'-re','# $');
       $aft->send("ls\n"); # OR LIST OF COMMANDS
       $aft->expect($timeout,'-re','# $');
       $aft->send("exit\n");
}

Welcome

2005-11-04T11:12:00.000+05:30

Hi all,

Welcome to my blog. Happy Hacking.
Check my current blog.
Vaibhav.