Introduction to Linux

What is Linux

• Linux is a term for all operating system which is based on Unix (Predecessor to Linux).
• First release of linux was in the year 1991.
• Linux is open source.
• Linux is secure.
• Linux is memory efficient and can even run on systems with low memory.

Basic Linux Commands

• echo - Prints the given text.
• whoami - Prints the currently logged in user name.
• ls - Lists files in the given path.
• cd - Change to the given directory.
• cat - Displays the contents of a file.
• pwd - Prints the path of current working directory.
• man - Shows manual page of the command.
• sudo -l - Check the commands that the current user can run.

Basic Flags and Switches

• ls -a - Lists files in the given path including the hidden ones.
• ls --help - Shows the help for the command.
• ls -h - Print in human readable format.
• ls -lh - Lists files including file permissions and metadata in human readable format..

Basic Operators

• & - Runs command in the background.
• && - Combine multiple commands in one line. The second command runs only if the first one is successful.
• > - Redirects the output of a command into a file.
• >> - Same as redirect operator but instead of overwriting this operator appends to the contents of the file.