The document provides an overview of the Linux kernel, its open-source nature, and various distributions like Ubuntu and Fedora. It explains the Linux filesystem structure, detailing key directories and their purposes, as well as common commands and software for users. The document highlights the importance of understanding user permissions and system commands to effectively navigate and utilize Linux systems.

1. Linux: Introduction

2. Ohk.
● Linux – Know anything?
● What you expect to do by the end of the
lecture??

3. Linux : Kernel Not OS !!
● Kernel : Application layer <=> data layer
.
● Linux kernel is the underlying layer below all
operating systems like android, ubuntu ,
fedora , OpenInnova , OpenSUSE..
● Linus Torvalds (1991) – unix like kernel

4. Different
Flavors Of Linux.
● Linux kernel is open-source.
● Anyone is allowed to pick up the source code
and modify it to suit his own needs.
● Various differences you'll notice :
from different Window Managers
(gnome,kde,xfce,lfce )
to different flavors altogether
(OpenSUSE,Fedora, Ubuntu )

5. OpenSUSE
Kubuntu Ubuntu

6. Installing Ubuntu
● - Install with Wubi- DO NOT DO IT.
(More trouble than you can afford)
● - Install in new Partition
LiveUSB,LiveCD
Data security and safe.
Follow the steps given on Ubuntu.com or any
website.

7. Linux Filesystem

8. ● /bin - Executable programs.
● /boot -The startup files , the kernel and grub .
● /dev - CPU peripherals.
● /etc - System Configuration (** Control Panel )
● /home -Your files.
● /initrd -boot
● /lib Library files
● /lost+found Files that were saved during failures are here.
● /misc For miscellaneous purposes.
● /mnt Standard mount point : External temporarily mounted file
systems, e.g. a CD-ROM or a digital camera.
● /media Standard mount point : External removable media : pendrives .
● /net Standard mount point : Entire remote file systems
● /opt Typically contains extra and third party software.

9. ● /root The administrative user's home directory. Note: / and /root.
● /sbin Programs for use by the system and the system administrator.
● /tmp Temporary space , cleaned upon reboot.
● /usr Programs, libraries, documentation etc. for all user-related
programs.
● /var Storage for all variable files and temporary files created by
users, such as log files, the mail queue, the print spooler area, space
for temporary storage of files downloaded from the Internet, or to
keep an image of a CD before burning it.
● /proc A virtual file system containing information about system
resources. More information about the meaning of the files in proc is
obtained by entering the command man proc in a terminal window.
The file proc.txt discusses the virtual file system in detail.

10. Who's using it?
● Usable 2 – your user and superuser(root).
● You are unable to do most processes like
installing a new program or execute certain files
● In order to do so you must give the root
password.
● It's the same as the account password that you
enter during installation.

11. ● Standard Desktop

12. Some common Software you will Use
● man
the manual pages.
Usage: man gedit
● cd
- change directory.
● Sudo
Superuser do.
eg. sudo program

13. ● ls
- list the contents of the directory you are currently
in.
- ls -a : list hidden(begin with .) files also.
- ls -l : list files with permissions.
● Pwd
- print working directory.
● Gedit
- simple text editor with gui.

14. ● cp
-To copy files or directory from one place to another.
- cp source file location current file location
- For copying directory use cp –r instead (recursive).
● mv
- To move files or directories from one place to another.
- mv source destination
- mv –r to move directories.
● mkdir:
- To create a directory

15. ● rmdir:
- To delete an empty directory.
● rm:
-To delete files and directories.
- rm filename
- rm –r to delete directory.
● chmod
- Change File Permission
eg: chmod 777 filename.

16. ● The 777 in the example refer to the permissions
in binary.
- 001 = execute only (1 binary)
- 010 = write only (2 binary)
- 100 = read only (4 binary)
- 011 = write and execute only ( 2 + 1 = 3 )
- the order is user , group , others.

17. ● Top
- system's current running applications.
- Task manager.
● head
- display the first few lines of a file.
● tail
- display the last few lines of a file.

18. ● ssh
- secure shell : allows you to remotely access
any other computer allowing this protocol.
● sftp
- secure file transfer protocol .
● nano
- simple command line text editor.

19. ● cat
- Print contents of file to standard out.
- eg: cat filename.
● more and less
- page files one screen at a time

20. ● apt-get
- The best way to install anything . Ever.
eg. Sudo apt-get install program.
● synaptic
- Synaptic package manager .
- Repairs packages .
- Install more than one at a time.
● vim
- complete command line text editor.

21. ● Some Extra Things to know:
- Keep Googling.
- During installation some folders can be
located to a different partition altogether.
- Advantage :
Your linux operating may crash without taking
all your files with it.