Copyright (C) 2000  M K Saravanan
http://www.mksarav.org
Written on 15th June 2000.
Last modified on Sat Nov 15 02:23:43 SGT 2003


Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or any
later version published by the Free Software Foundation; with no Invariant
Sections, no Front-Cover Texts and no Back-Cover Texts.  You can download
a copy of the license from http://www.gnu.org/copyleft/fdl.txt

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1.  To change your password:

	passwd

	Type your current password and then your new password.

2.  Instead of man pages you can also use a help facility called
"info".  Try:

	info sort
	info bash

3.  The shell you are using by default, under Linux is called "bash" shell
stands for "Bourne Again SHell".  "bash" has a rich set of inbuilt shell
programming commands.  for more info about shell programming "info bash".

4.  You can use the grep command to search a particular piece of text in
a file.  For e.g do the following exercise:

	cat > temp.txt
My name is Saravanan.
I have a good friend called Ranjan.
Press ^D to save the above two lines in the file temp.txt.  This way you
can indirectly use your cat as a simple editor.

	grep called temp.txt	

	What is the output you got?  Now try the following:

	who | grep <type your login name here>
	finger | grep <type your login name here>


5.  There is a wonderful and universally highly used editor called "vi"
(otherwise called as "vim" )  in linux.  Actually it is an improved
version of original "vi" editor. You can invoke "vi" by typing:

	vi  (or) vim

Try the following:

	vi test2.c
Press "i" to get into "insert" mode.  vi uses two modes called "command
mode" and "normal typing mode".  To return to command mode Press Esc.  To
return to normal typing mode press "i" (for insert) or "a" (for append).

type:

God is Great.

Press Esc
type a colon and "wq" (for write and quit).

:wq

To comeout without saving you can use:

:q!


6.  If you want to locate the pathname of a command use:

	whereis date
	whereis ls
	whereis cp

7.  The command "which" will also produce similar result:

	which date
	which mv

8.  If you don't know a command name but know the keyword use the
following to find out in which man pages those keyword appear:

	man -k sort
	apropos sort

Both "man -k" and "apropos" command will produce the same result.

9.  All the process running in Linux is otherwise called as jobs.  To
view the currently running process under Linux:

	ps
	ps -aux  //list all the running process of all the users
	ps -aux | grep ranjan   //process belongs to ranjan.

In Unix each process will have a Process Id.  called "pid".  The ps
command will list the pid.  Suppose if some program got hang, then you
can kill the coresponding process using it pid.  Try the follwing:

	pico test.txt  // run this command in one window

Login in another window.  use 

	ps -aux | grep "pico test.txt"
Note down the pid.  Let's say it is 1029.

	kill -9 1029

will kill the process.


10.  To logout from a system you can use any one of the following:

	logout
	exit
	^D

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