Lesson 9Linux

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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.

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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.

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Introduction to Linux

• Benefits of Linux.
• Drawbacks of Linux.

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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.

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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.

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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.

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Working With Linux

• Access to Linux.
• DOS versus Linux.
• Logoff and shutdown in Linux.

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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 _at_machine name.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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Listing the Contents of a Folder
File Management Commands
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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.

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Creating a File With Pico
Common Pico Commands
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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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 files
  mode.
• The command requires two parameters the access
  mode number and the file to change.

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Changing File Permissions
The chmod Permissions
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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.

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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.

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Configuring Linux

• Managing users.
• Configuring a printer.

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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.

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Managing Users

• Changing user passwords
• The passwd command can be used for changing a
  users password.
• The command does not require any additional
  parameters.
• Root login is required to change a users
  password.

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Managing Users

• Deleting users
• The userdel command can be used to remove a
  user from the Linux account.
• The syntax used is userdel username

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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.

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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.

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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.

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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.

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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.