Use set -e to exit the script immediately if a command fails, enhancing reliability.

Used to store data. In shell, all variables are treated as strings. Example: name="John" ; echo $name (access variable with $ ). Control Structures:

grep (search), sed (stream editor), awk (data manipulation), cat (view content), cut , sort .

A Unix shell is a command-line interpreter that acts as an interface between the user and the operating system. Shell programming (or scripting) involves writing a series of commands in a plain text file, which the shell executes sequentially. It enables automation of repetitive tasks, system management, and complex data processing. 2. Key Components of Shell Scripts