Lesson 9-Linux

1. Lesson 9-Linux

2. Overview • Introduction to Linux. • Working with Linux. • Managing files and folders in Linux. • Using the Gnome desktop. • Configuring Linux. • Troubleshooting common Linux problems.

3. Introduction to Linux • Linus Torvalds developed an open source version of UNIX, called Linux, in 1991. • Open source software is software that is distributed with all its source code, and can be customized by the user as required. • Slack Ware and Red Hat Linux versions included C++ compilers, TCP/IP functionality, and primitive Web servers.

4. Introduction to Linux • Benefits of Linux. • Drawbacks of Linux.

5. Benefits of Linux • All versions of Linux can be freely downloaded from the Web. • Linux can run on older equipment. • Linux programs are very efficient, lean, and use lesser resources.

6. Benefits of Linux • Linux codes, being well written, provide higher speeds and better stability to the operating system. • Linux is an open source software, implying that the source code can be read and modified as required.

7. Drawbacks of Linux • The source code can be read as Linux is an Open Source License. This leads to easy hacking of the system. • Linux is compatible only with limited software and hardware. • Linux does not provide extensive documentation and support to fix vulnerabilities. • Linux is difficult to use.

8. Working With Linux • Access to Linux. • DOS versus Linux. • Logoff and shutdown in Linux.

9. Access to Linux • Authenticated login using a Linux account is required to access a Linux system. • The Linux prompt will be shown only if the authentication information is right. • The Linux prompt includes the user name, followed by a @machine name.

10. Access to Linux • The Linux command syntax is very basic, and starts with a Linux command separated by spaces, and followed by optional parameters and switches. • A switch changes the way a command runs.

11. DOS versus Linux • Case sensitivity – DOS is case-insensitive, while Linux is case-sensitive. • Switches – DOS switches start with a slash (/), and Linux switches start with a hyphen (-). • Spaces – DOS commands can work with or without a space, while all parts of the Linux command line must be separated by a space.

12. DOS versus Linux • Path – DOS uses the backslash (\) character to indicate a path to a folder, and Linux uses the forward slash (/) to indicate a path to a folder. • Output – DOS provides a very descriptive output, while Linux provides only the minimum output.

13. Logoff and Shutdown in Linux • The exit command or the CTRL-D key combination can be used to log out of Linux. • The shutdown –h now command is used to shut down the Linux machine immediately, and halt after shutting down. • The –r switch can be used with the command to reboot the Linux system after shutdown.

14. Managing Files and Folders in Linux • Listing the contents of a folder. • Creating a file with Pico. • Displaying the contents of a file. • Copying files in Linux.

15. Managing Files and Folders in Linux • Deleting a file in Linux. • Renaming or moving files in Linux. • Working with folders in Linux. • Changing file permissions.

16. Listing the Contents of a Folder • The ‘ls’ command is used to list the contents of a folder. • By default, the ls command only provides the names of visible files in the current folder.

17. Listing the Contents of a Folder File Management Commands

18. Creating a File With Pico • Linux treats folders, Web pages, and even devices as files. • Text editors are required to write a file. • Pico is the easiest editor to use and provides a series of commands at the bottom of the screen.

19. Creating a File With Pico Common Pico Commands

20. Displaying the Contents of a File • The ‘more’ command displays the contents of a file one page at a time. • The ‘head’ command displays the first ten lines of a file. • The ‘tail’ command displays the last ten lines of a file. • The ‘cat’ command displays the entire contents of a file.

21. Copying Files in Linux • The ‘cp’ command is used for copying files. • The command requires two parameters – the source file and the destination where the file has to be copied.

22. Deleting a File in Linux • The ‘rm’ command is used for deleting a file. • The command requires at least one parameter – the name of the file to be deleted.

23. Renaming or Moving Files in Linux • The ‘mv’ command is used to rename a file or to move a file from one folder to another. • The command required two parameters – the name of the original file and the new name or location of the file.

24. Working With Folders in Linux The folder structure in Linux is divided into two types: • Folders that can be changed, called home folders. • Folders that cannot be changed, and often consisting of system folders like /etc and /bin.

25. Working With Folders in Linux • /home/username is the home directory path, if Linux is installed with the defaults. • The /bin folder contains many of the Linux commands. • The /etc folder contains the settings and configuration data for Linux.

26. Working With Folders in Linux • The ‘mkdir’ command is used to create a folder. • The ‘mkdir’ command requires at least one parameter – the name of the folder to be created.

27. Working With Folders in Linux • The ‘cd’ command is used to change a directory. • The cd command requires only one parameter – the name of the folder. • The ‘pwd’ (print working directory) command can be used to print the path to the current folder.

28. Changing File Permissions • The mode of a file must be changed to implement security for that file. • The ‘chmod’ command is used for changing a file’s mode. • The command requires two parameters – the access mode number and the file to change.

29. Changing File Permissions The chmod Permissions

30. Using the Gnome Desktop • The Gnome desktop is a version of X Windows. • The ‘startx’ command is used for starting the Gnome. • The Gnome uses the Gnome Windows Manager to keep applications open and make them easily accessible.

31. Configuring Linux • Root login is required to make changes to the Linux system. • A user who has logged in as a regular user can log in as a root user without logging out, using the ‘su root’ command. • The ‘su’ stands for substitute user.

32. Configuring Linux • Managing users. • Configuring a printer.

33. Managing Users Creating users: • The ‘useradd’ command is used to create a user. • The command requires at least one parameter – the name of the user to be added. • Several users can be added at a time using the syntax ‘useradd username1, username2, username3’ • The ‘finger’ command can be used find a user name.

34. Managing Users Changing user passwords: • The ‘passwd’ command can be used for changing a user’s password. • The command does not require any additional parameters. • Root login is required to change a user’s password.

35. Managing Users Deleting users: • The ‘userdel’ command can be used to remove a user from the Linux account. • The syntax used is – userdel username

36. Configuring a Printer • Printtool is a command-line program that starts a GUI configuration program for the printers. • Printtool allows the user to select the printer and the port to which the printer is attached. • In Linux, the port for the printers is represented by /dev/lp0.

37. Troubleshooting Common Linux Problems • The Xconfigurator program can be used to properly configure the video card and monitor, thereby preventing Gnome startup problems. • Ensure that necessary changes are made to the /etc/inittab file to log in from the Gnome instead of the command-line.

38. Troubleshooting Common Linux Problems • The problem of screen gibberish can be resolved by simply logging off. • The help program in Linux can be used to provide additional information on the required topics.

39. Summary • Linux is free, stable, and open source software. • A root login is required to shut down the Linux system. • File management is crucial since everything in Linux is treated as a file.

40. Summary • The ‘man’ command can be used to provide a complete list of switches associated with a particular command. • Read, write, and execute are the permissions available on files. • Gnome is an X Windows version.