Linux: Introduction

Ohk.

● Linux – Know anything?

● What you expect to do by the end of the lecture??

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

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 )

OpenSUSE

Kubuntu Ubuntu

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.

Linux Filesystem

● /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.

● /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.

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.

● Standard Desktop

● man

the manual pages.

Usage: man gedit

● cd

- change directory.

● Sudo

Superuser do.

eg. sudo program

Some common Software you will UseSome common Software you will Use

● 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.

● 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

● 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.

● 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.

● 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.

● 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.

● cat

- Print contents of file to standard out.

- eg: cat filename.

● more and less

- page files one screen at a time

● 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.

● 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.