Vivek Kutal's Blog

Bash Tips

2006-10-24T13:34:00.000-07:00

Here are some tips for customizing bash

1. Directory shortcuts

You can assign shortcuts to the directories u frequently use.

just add the following in your .bashrc

function l
{
command cd /opt/development/linux-2.6.18
}
export l

now l is a new shortcut to the linux-2.6.18 directory , just type l and enter to go there.

add more functions like this to create shortcuts to dirs u frequently use.

2. New Command names

most of the time we use commands like
ps ax | grep xyz or cat abc | grep xyz
now instead for typing this every time u can give them new names

function pgrep
{
command ps ax | grep "$@"
}
export pgrep

and

function catg
{
command cat "$1" | grep "$2"
}
export catg

"$@" inserts the arguments passed .
"$1" , "$2" are ur 1st and 2nd arguments

now u can use "pgrep xyz" instead of typing "grep ax | grep xyz"

here are some of the commands that I use

sudo apt-get install --> ainstall
sudo apt-get remove --> aremove
.
.
all apt-get commands

make menucnfig --> mmc
make distclean --> mdc
.
.
all frequently used make commands

grep -rin "$@" * --> cgrep
find . -name "$@" --> nfind

and all frequently edited files and frequently used ssh and scp commands.

(here is a link on howto use ssh and scp without passwords)

3. Usefull shortcuts

ctrl + l --> Clear Screen
ctrl + w --> Delete last word
ctrl + c --> Cancel the command you are typing
alt + u --> Make the word uppercase
ctrl + r --> Search History
ctrl + d --> Exit the Shell

Likely / Unlikely Macros in the Linux kernel

2006-03-27T01:49:00.000-08:00

In 2.6 we many times see something like this

if (unlikely(pmd_bad(*pmd))) {
pmd_ERROR(*pmd);
pmd_clear(pmd);
return;
}

and these macros are defined in compiler.h as

#define likely(x) __builtin_expect(!!(x), 1)
#define unlikely(x) __builtin_expect(!!(x), 0)

I just found a nice article explaining this in detail , this is the link .

do {......} while(0)

2006-03-13T00:10:00.000-08:00

A few days ago a came across a macro in the linux kernel code

#define MACRONAME do {Some code} while (0)

now I was wondering what is the use of having while(0)
here's the explaination for it, by Ben Collins , on kernelnewbies

It allows you to use more complex macros in conditional code. Imagine a macro of several lines of code like:
```
#define FOO(x)  printf("arg is %s\n", x); do_something_useful(x);
```

Now imagine using it like:

        if (blah == 2)
          FOO(blah);

This interprets to:

        if (blah == 2)
          printf("arg is %s\n", blah);
          do_something_useful(blah);;

As you can see, the if then only encompasses the printf(), and the do_something_useful() call is unconditional (not within the scope of the if), like you wanted it. So, by using a block like do{...}while(0), you would get this:

        if (blah == 2)
          do {
                  printf("arg is %s\n", blah);
                  do_something_useful(blah);
          } while (0);

Which is exactly what you want.

(from Per Persson) As Collins point out, you want a block statement so you can have several lines of code and declare local variables. But then the natural thing would be to just use for example:
```
  #define exch(x,y) { int tmp; tmp=x; x=y; y=tmp; }
```
However that wouldn't work in some cases. The following code is meant to be an if-statement with two branches:
```
  if(x>y)
exch(x,y);          // Branch 1
else
do_something();     // Branch 2
```
But it would be interpreted as an if-statement with only one branch:
```
  if(x>y) {          // Single-branch if-statement!!!
int tmp;            // The one and only branch consists
tmp = x;            // of the block.
x = y;
y = tmp;
}
;                     // empty statement
else                  // ERROR!!! "parse error before else"
do_something();
```
The problem is the semi-colon (;) coming directly after the block.

The solution for this is to sandwich the block between do and while(0). Then we have a single statement with the capabilities of a block, but not considered as being a block statement by the compiler.

Our if-statement now becomes:
```
  if(x>y)
do {
int tmp;
tmp = x;
x = y;
y = tmp;
} while(0);
else
do_something();
```

List of commands to run from the run prompt in XP

2006-03-05T04:19:00.000-08:00

Accessibility Controls
access.cpl

Add Hardware Wizard
hdwwiz.cpl

Add/Remove Programs
appwiz.cpl

Administrative Tools
control admintools

Automatic Updates
wuaucpl.cpl

Bluetooth Transfer Wizard
fsquirt

Calculator
calc

Check Disk Utility
chkdsk

Command Prompt
cmd

Computer Management
compmgmt.msc

Date and Time Properties
timedate.cpl

Device Manager
devmgmt.msc

Direct X Control Panel (If Installed)*
directx.cpl

Direct X Troubleshooter
dxdiag

Disk Cleanup Utility
cleanmgr

Disk Defragment
dfrg.msc

Disk Management
diskmgmt.msc

Disk Partition Manager
diskpart

Display Properties
control desktop

Display Properties
desk.cpl

Display Properties (w/Appearance Tab Preselected)
control color

Fonts
control fonts

Fonts Folder
fonts

Hearts Card Game
mshearts

Iexpress Wizard
iexpress

Internet Properties
inetcpl.cpl

IP Configuration (Display Connection Configuration)
ipconfig /all

java Control Panel (If Installed)
jpicpl32.cpl

Java Control Panel (If Installed)
javaws

Keyboard Properties
control keyboard

Local Security Settings
secpol.msc

Local Users and Groups
lusrmgr.msc

Logs You Out Of Windows
logoff

Microsoft Chat
winchat

Minesweeper Game
winmine

Mouse Properties
control mouse

Mouse Properties
main.cpl

Network Connections
ncpa.cpl

Network Setup Wizard
netsetup.cpl

Notepad
notepad

On Screen Keyboard
osk

Password Properties
password.cpl

Performance Monitor
perfmon.msc

Phone and Modem Options
telephon.cpl

Power Configuration
powercfg.cpl

Printers and Faxes
control printers

Printers Folder
printers

Quicktime (If Installed)
QuickTime.cpl

Regional Settings
intl.cpl

Registry Editor
regedit

Registry Editor
regedit32

Remote Desktop
mstsc

Removable Storage
ntmsmgr.msc

Removable Storage Operator Requests
ntmsoprq.msc

Scanners and Cameras
sticpl.cpl

Scheduled Tasks
control schedtasks

Security Center
wscui.cpl

Services
services.msc

Shared Folders
fsmgmt.msc

Shuts Down Windows
shutdown

Sounds and Audio
mmsys.cpl

Spider Solitare Card Game
spider

System Configuration Editor
sysedit

System Configuration Utility
msconfig

System File Checker Utility (Scan Immediately)
sfc /scannow

Task Manager
taskmgr

Telnet Client
telnet

User Account Management
nusrmgr.cpl

Utility Manager
utilman

Windows Firewall
firewall.cpl

Windows Magnifier
magnify

Windows Update Launches
wupdmgr

Wordpad
write

Taken from here

Downloading Google Videos

2006-02-02T02:51:00.000-08:00

We cannot view google videos in India but now we can downlaod them and that too in a avi fromat.
You can download it from here , just need to paste the link of the video.

Actually we can view the videos in India but there a long procedure for it and if you can download it why would anyone want to see it online :-).

Pune On Google Earth

2005-12-30T11:26:00.000-08:00

A search engine that identifies songs for you

2005-12-25T11:07:00.000-08:00

Tutanic is a new search engine which identifies songs for you (Name and the Artist) .
You just need to play the song in your Microphone and it identifies it in seconds , offcourse if it is present in its database but worked for most of the songs that I tested.

Click here to Download It (530 KB)

Wordpress is now available to all

2005-11-21T08:17:00.000-08:00

Wordpress Is now available to all , you don't need a invitation now. http://vivek.wordpress.com/ is my new account ,I was lucky to get my name :-).

Pics From Google Earth

2005-11-16T07:37:00.000-08:00

Pune

The Parliament

The India Gate

The Gateway Of India

The Eiffile Tower

The Statue Of Liberty

Click here to know how Google Earth Works

How Google.com looked in 1998

2005-10-14T17:26:00.000-07:00

Take a Look at google's first website (1998)
http://web.archive.org/web/19981202230410/http://www.google.com/
and yahoo (1996)
http://web.archive.org/web/19961017235908/http://www2.yahoo.com/

You can Browse through 40 billion web pages archived from 1996 using this site
http://www.archive.org/web/web.php

George Bush Is a Failure

2005-10-11T00:02:00.000-07:00

Well I am not the one who is saying this just try the following

1. Go to www.google.com
2. Type "failure" (without double quotes) in the search text box.
3. Press "I'm Feeling Lucky" button just next to "Google Search" button.

and see what happens.

Click here to see why this happens.

Why Linux Need Not Replace Windows

2005-10-10T09:38:00.000-07:00

A well written article on why linux will never need to replace windows.

Click Here

Email Icon Generator

2005-10-10T01:57:00.000-07:00

From AOL to Yahoo! this handy little online program will create an email icon for you and your address. Use this in place of a mailto: link on your webpages. Cool!
Take a look http://services.nexodyne.com/email/

Al Qaeda puts job ads on Internet

2005-10-09T12:52:00.000-07:00

"Al Qaeda has put job advertisements on the Internet asking for supporters to help put together its Web statements and video montages, an Arabic newspaper reported".........***Applicants must have pure hatred of the West; Photoshop experience a PLUS!***

read more | digg story

Exporting Gmail Contacts

2005-10-02T22:15:00.000-07:00

Now you can export your gmail contacts, either to a new gmail account or a .csv file
I always had problems maintaining my Outlook address book and gmail contacts.
Its easy now.......

Quotes By Mahatma Gandhi

2005-10-02T03:08:00.000-07:00

Its Gandhi jayanti today, here are some of his Quotes

Live as if you were to die tomorrow. Learn as if you were to live forever.

Fear is not a disease of the body; fear kills the soul.

The principle of majority does not work when differences on fundamentals are involved.

Freedom is not worth having if it does not include the freedom to make mistakes.

It is better to be violent, if there is violence in our hearts, than to put on the cloak of nonviolence to cover impotence.

It is unwise to be too sure of one's own wisdom. It is healthy to be reminded that the strongest might weaken and the wisest might err.

You must not lose faith in humanity. Humanity is an ocean; if a few drops of the ocean are dirty, the ocean does not become dirty.

Honest differences are often a healthy sign of progress.

Whatever you do may be insignificant, but it is very important that you do it.

Get Administrator password of Windows XP

2005-09-27T01:43:00.000-07:00

This site helps you to get your forgotten Administrator password http://www.loginrecovery.com/
You need to download a file from this site , write it into a floppy and boot from it , after booting some programs from the floppy runs and collects the data needed in upload.txt file in the floppy.
Now you just need to upload this file on their site and you will get the password in minutes(paid service).
If you want it for free then u need to wait for 48 hrs and again visit the site.
It displays passwords of all the users with the administrator.
So u can now get your forgotten password or u can use it get your friends password........

INTERESTING COMPARISONS

2005-09-05T23:33:00.000-07:00

HERE ARE SOME INTERESTING COMPARISONS

Inches of rain in new orleans due to hurricane katrina... 18

Inches of rain in mumbai (July 27th).... 37.1

Population of new orleans... 484,674

Population of mumbai.... 12,622,500

Deaths in new orleans within 48 hours of katrina...100

Deaths in mumbai within 48hours of rain.. 37.

Number of people to be evacuated in new orleans... entire city..wohh

Number of people evacuated in mumbai...10,000

Cases of shooting and violence in new orleans...Countless

Cases of shooting and violence in mumbai.. NONE

Time taken for US army to reach new orleans... 48hours

Time taken for Indian army and navy to reach mumbai...12hours

Status 48hours later...new orleans is still waiting for relief, armyand electricty

Status 48hours later..mumbai is back on its feet and is business is as usual

USA...world's most developed nation

India...JUST A DEVELOPING NATION..

Fun With Google Logo Maker

2005-09-03T06:45:00.000-07:00

My first blog

2005-08-30T04:17:00.000-07:00

This is my first blog here.