How to enable the root account in Ubuntu

Ubuntu is one of the few Linux distributions out there that will not enable the root account.In case you want to enable root login on your Ubuntu system this post will show you how you can do that.

As you have noticed during the Ubuntu installation there was no question about the root password,as you might have been used to see during other Linux distributioninstallation process. This is why the root account is inactive andcan’t be used (no password configured) until we will setup a properpassword for it. To do this, we simply need to run:

sudo passwd root

This will ask for a new root password and once you confirm it, you can start using the root account to login.

In case you will want tdisable back the root account, just lock the root account by running:

sudo passwd -l root

Are you aware of any other Linux distribution that doesn’t enablethe root account at installation time? I am just curious because Ibelieve that this is a great idea… but I haven’t seen it implemented inother distributions.

http://www.neowin.net/forum/topic/524651-how-to-enable-the-root-account-in-ubuntu/

Re-Add The Weather Indicator To Ubuntu 11.04

Installation

Want to install this indicator applet? Time to add a PPA! Run the following code in the Terminal:
sudo add-apt-repository ppa:weather-indicator-team/ppa
sudo apt-get update
sudo apt-get install indicator-weather

http://www.makeuseof.com/tag/readd-weather-ubuntu-1104s-panel-linux/

Howto mount partition onto ubuntu Linux

Q. How do I mount NTFS or FAT paritions under ubuntu Linux?

A. You can mount NTFS or FAT windows partition with mount command.

=> Click on Applications
=> Select Accessories
=> Select Terminal
=> Now terminal window will be on screen.

First you need to create directory where you can attach windows partition using mount command (for example /media/c for C:):# sudo mkdir -p /media/cNow find out list of partition (click on System > Administration > Disks ) or use following command:# sudo fdisk -l

Output:

Device Boot Start End Blocks Id System
/dev/hdb1 * 1 2432 19535008+ 86 NTFS
/dev/hdb2 2433 2554 979965 82 Linux swap / Solaris
/dev/hdb3 2555 6202 29302560 83 Linux

As you see /dev/hdb1 is NTFS partition. Now type following command:# sudo mount -t ntfs -o nls=utf8,umask=0222 /dev/hdb1 /media/cTo unmount Windows NTFS partition type command:# sudo umount /media/cTo mount FAT partition type command:# sudo mkdir -p /media/d
# sudo mount -t vfat -o iocharset=utf8,umask=000 /dev/hda1 /media/d

To unmount Windows FAT (mounted at /media/d) partition type command:# sudo umount /media/d

Where,

-t : Specify file system type (such as NTFS or FAT)
umask=VALUE: Set the umask (the bitmask of the permissions that are not present). The default is the umask of the current process. The value is given in octal.
iocharset=VALUE: Character set to use for converting between 8 bit characters and 16 bit Unicode characters. The default is iso8859-1. Long filenames are stored on disk in Unicode format.

http://www.cyberciti.biz/faq/mounting-windows-partition-onto-ubuntu-linux/

Howto mount windows partition onto ubuntu Linux
http://www.psychocats.net/ubuntu/mountlinux

Install sun java on ubuntu

Java Downloads for Linux

JRE - http://java.com/en/download/linux_manual.jsp?locale=en

JDK - http://www.oracle.com/technetwork/java/javase/downloads/index.html

JAVA Installation

https://help.ubuntu.com/community/Java

http://askubuntu.com/questions/56104/how-can-i-install-oracle-java-jre-7

http://askubuntu.com/questions/55848/how-do-i-install-oracle-java-jdk-7

Extract a gzip compressed tar archive in Linux

The version of tar in most Linux distributions supports gzip compression. This means that a gzipped tar file can be extracted in one simple command.


To extract the archive filename.tar.gz into the current directory:

tar xzf filename.tar.gz

If this fails, the version of tar may not support gzip compression. In this case, you can use the traditional two-stage command:

gzip -dc filename.tar.gz | tar xf -

http://www.tech-recipes.com/rx/138/extract-a-gzip-compressed-tar-archive-in-linux/

Kill process in Linux

Q. How do I kill process in Linux?
A. Linux and all other UNIX like oses comes with kill command. The command kill sends the specified signal (such as kill process) to the specified process or process group. If no signal is specified, the TERM signal is sent.

Kill process using kill command under Linux/UNIX

kill command works under both Linux and UNIX/BSD like operating systems.

Step #1: First, you need to find out process PID (process id)

Use ps command or pidof command to find out process ID (PID). Syntax:
ps aux | grep processname
pidof processname
For example if process name is lighttpd, you can use any one of the following command to obtain process ID:
# ps aux | grep lighttpdOutput:

lighttpd  3486  0.0  0.1   4248  1432 ?        S    Jul31   0:00 /usr/sbin/lighttpd -f /etc/lighttpd/lighttpd.conf
lighttpd  3492  0.0  0.5  13752  3936 ?        Ss   Jul31   0:00 /usr/bin/php5-cg

OR use pidof command which is use to find the process ID of a running program:
# pidof lighttpdOutput:

3486

Step #2: kill process using PID (process id)

Above command tell you PID (3486) of lighttpd process. Now kill process using this PID:
# kill 3486
OR
# kill -9 3486
Where,

• -9 is special Kill signal, which will kill the process.

killall command examples

DO NOT USE killall command on UNIX system (Linux only command). You can also use killall command. The killall command kill processes by name (no need to find PID):
# killall -9 lighttpd
Kill Firefox process:
# killall -9 firefox-bin
As I said earlier killall on UNIX system does something else. It kills all process and not just specific process. Do not use killall on UNIX system (use kill -9).

http://www.cyberciti.biz/faq/kill-process-in-linux-or-terminate-a-process-in-unix-or-linux-systems/

Show All Running Processes in Linux

How do I see all running process in Linux?

You need to use the ps command. It provide information about the currently running processes, including their process identification numbers (PIDs). Both Linux and UNIX support ps command to display information about all running process. ps command gives a snapshot of the current processes. If you want a repetitive update of this status, use top command.

ps command

Type the following ps command to display all running process:
# ps aux | less
Where,

• -A: select all processes
• a: select all processes on a terminal, including those of other users
• x: select processes without controlling ttys

Task: see every process on the system

# ps -A
# ps -e


Task: See every process except those running as root

# ps -U root -u root -N

Task: See process run by user vivek

# ps -u vivek

Task: top command

The top program provides a dynamic real-time view of a running system. Type the top at command prompt:
# top

Task: display a tree of processes

pstree shows running processes as a tree. The tree is rooted at either pid or init if pid is omitted. If a user name is specified, all process trees rooted at processes owned by that user are shown.
$ pstree

Task: Print a process tree using ps

# ps -ejH
# ps axjf

Task: Get info about threads

Type the following command:
# ps -eLf
# ps axms

Task: Get security info

Type the following command:
# ps -eo euser,ruser,suser,fuser,f,comm,label
# ps axZ
# ps -eM

Task: Save Process Snapshot to a file

Type the following command:
# top -b -n1 > /tmp/process.log
Or you can email result to yourself:
# top -b -n1 | mail -s 'Process snapshot' you@example.com

Task: Lookup process

Use pgrep command. pgrep looks through the currently running processes and lists the process IDs which matches the selection criteria to screen. For example display firefox process id:
$ pgrep firefox
Following command will list the process called sshd which is owned by root user.
$ pgrep -u root sshd

Say hello to htop and atop

htop is interactive process viewer just like top, but allows to scroll the list vertically and horizontally to see all processes and their full command lines. Tasks related to processes (killing, renicing) can be done without entering their PIDs. To install htop type command:
# apt-get install htop
or
# yum install htop
Now type the htop command at the shell prompt:
# htop

atop program

The program atop is an interactive monitor to view the load on a Linux system. It shows the occupation of the most critical hardware resources (from a performance point of view) on system level, i.e. cpu, memory, disk and network. It also shows which processes are responsible for the indicated load with respect to cpu- and memory load on process level; disk- and network load is only shown per process if a kernel patch has been installed. Type the following command to start atop:
# atop


http://www.cyberciti.biz/faq/show-all-running-processes-in-linux/