Environment Variables: Define the behavior of the environment: Try:

• echo $HOME

• echo $USER

• echo $SHELL

• echo $PATH

File searching/manipulation

• sed: stream editor for filtering and transforming text

  • $ sed 's/windows/linux/2' fav_os.txt

  • Above command would substitute the 2nd instance of string ‘windows’ in each line of the fav_os.txt file with string ‘linux’, but leave the any following instances of ‘windows’ alone in the file.

• gawk: pattern scanning and processing language

  • Scan specifying field separators, assign variables, specif source type, etc.

Ability to update file permission and ownership: chmod/chown

• User-case of sharing files/folders.