Open HackDay

Yahoo! Bangalore will be conducting an open hack day on October 5th and6th at Bangalore. More information on this event is available from
http://www.hackday.org/

Extract the RAR file in Linux

If you are using ubutu/debian, install the unrar package using apt-get

# apt-get install unrar

List the files in RAR archive

$ unrar l file.rar

To test the integrity of the RAR archive

$ unrar t file.rar

To extract the files into the current directory

$ unrar e file.rar

To extract the files into the some other directory(use full path)

$ unrar x file.rar

Debian/Ubutnu run levels(Using inittab)

In ubuntu, you can't find any file name inittab under /etc.
ubuntu call it as UpStart(http://upstart.ubuntu.com/)

First, we look at the run levels in ubuntu


* 0 - Halt
* 1 - Single
* 2 - Full multi-user with display manager (GUI)
* 3 - Full multi-user with display manager (GUI)
* 4 - Full multi-user with display manager (GUI)
* 5 - Full multi-user with display manager (GUI)
* 6 - Reboot

refer the following link and look at the section 10.5

http://www.debian.org/doc/FAQ/ch-customizing.en.html

If you want to know the current runlevel, just give

zoobave@zoobave-desktop:~$ runlevel
N 5

There are two ways are available to change the current runlevel
I)use the telinit command

zoobave@zoobave-desktop:~$ sudo telinit 3

II) Create/Edit the /etc/initab file and change the the initdefault value in the
id:3:initdefault entry

# /etc/inittab: init( configuration.
# $Id: inittab,v 1.91 2002/01/25 13:35:21 miquels Exp $

# The default runlevel.
id:3:initdefault:

# Boot-time system configuration/initialization script.
# This is run first except when booting in emergency (-b) mode.
si::sysinit:/etc/init.d/rcS

# What to do in single-user mode.
~~:S:wait:/sbin/sulogin

# /etc/init.d executes the S and K scripts upon change
# of runlevel.
#
# Runlevel 0 is halt.
# Runlevel 1 is single-user.
# Runlevels 2-5 are multi-user.
# Runlevel 6 is reboot.

l0:0:wait:/etc/init.d/rc 0
l1:1:wait:/etc/init.d/rc 1
l2:2:wait:/etc/init.d/rc 2
l3:3:wait:/etc/init.d/rc 3
l4:4:wait:/etc/init.d/rc 4
l5:5:wait:/etc/init.d/rc 5
l6:6:wait:/etc/init.d/rc 6
# Normally not reached, but fallthrough in case of emergency.
z6:6:respawn:/sbin/sulogin

# What to do when CTRL-ALT-DEL is pressed.
ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now

# Action on special keypress (ALT-UpArrow).
#kb::kbrequest:/bin/echo "Keyboard Request--edit /etc/inittab to let this work."

# What to do when the power fails/returns.
pf:owerwait:/etc/init.d/powerfail start
pn:owerfailnow:/etc/init.d/powerfail now
po:owerokwait:/etc/init.d/powerfail stop

# /sbin/getty invocations for the runlevels.
#
# The "id" field MUST be the same as the last
# characters of the device (after "tty").
#
# Format:
# :::
#
# Note that on most Debian systems tty7 is used by the X Window System,
# so if you want to add more getty's go ahead but skip tty7 if you run X.
#
1:2345:respawn:/sbin/mingetty --noclear --autologin matt tty1
2:23:respawn:/sbin/mingetty tty2
3:23:respawn:/sbin/mingetty tty3
4:23:respawn:/sbin/mingetty tty4
5:23:respawn:/sbin/mingetty tty5
6:23:respawn:/sbin/mingetty tty6

But, there is no difference between runlevels 2,3,4 and 5. If you want to customize, add/remove the entries in /etc/rcN.d/ directory
For, example, if you don't want to start your X server during runlevel 3, just remove the S13gdm file under /etc/rc3.d/ directory

zoobave@zoobave-desktop:~$ sudo rm /etc/rc5.d/S13gdm

A cool article about web 3.0

http://www.web2journal.com/read/236036.htm

Manually change the default login session

1) Goto the user's home directory

  $ cd

2) edit the file .dmrc

  $ gedit .dmrc 

3) change the session to kde (or) gnome
[Desktop]
Session=kde
4) save the file and logout

Force file system check during next boot

Its very simple, just create a "forcefsck" in root (/) directory
$ sudo touch /forcefsck

Google Talk (gtalk) for Linux

I have been searching a long time for google talk for linux. Somebody suggest me to use gaim (or) pidgin jabber account. But, i couldn't make a call to gtalk users.
I found two packages to make the voip calls to gtalk users in linux

1) Gizmo (http://gizmoproject.com/)
2) Jabbin (http://www.jabbin.com/int/index.php/configure-jabbin-for-google-talk/)

Scons

http://www.scons.org/
SCons is an Open Source software construction tool—that is, a next-generation build tool. Think of SCons as an improved, cross-platform substitute for the classic Make utility with integrated functionality similar to autoconf/automake and compiler caches such as ccache. In short, SCons is an easier, more reliable and faster way to build software.

Some Popular Linux IDEs

jedit(PHP, Python)
vim, gvim
Emacs, XEmacs
Elipse
MonoDevelop(C#)
Kdevelop
gedit
bluefish(HTML, CSS, PHP)
netbeans (Java)
quanta (HTML, CSS)
Anjuta (C, C++)
nano (PERL, CGI)
nvu (HTML)
Glade
JBuilder
nvi
screem (HTML, XML)
freeRIDE (Ruby)
wing IDE (Python)
Zend Studio (PHP)
Dev-PHP (PHP)
IntelliJ IDEA (Java)
SciTE
Kate
Kylix
eric3 (Python, Ruby)
NEdit
JGRASP (Java, C++)
Geany
Code::Blocks (C++)

Run the shell scripts like batch file in M$ Windows

Add the current directory to the $PATH environment variable

$ PATH = .:$PATH
$ export $PATH

$ file.sh (instead of [./file.sh] or [sh file.sh] )