Linux Shell Script
Linux Shell Script
A Linux shell script is a file containing a sequence of commands executed by a shell interpreter in the Linux operating system. These scripts help automate tasks, ranging from simple commands to complex tasks. The most commonly used shell for scripting in Linux is Bash (Bourne Again Shell), but others like Zsh (Z Shell) or Sh (Bourne Shell) can also be used.
Key Components
Shebang (#!): The first line of a shell script typically begins with #!, followed by the path to the shell interpreter. This line tells the system which interpreter to use to execute the script. For example, #! /bin/bash specifies that the script should be run using Bash.
Comments: Lines beginning with # (except the shebang) are comments and are not executed. They are used to explain or annotate the script.
Commands: These are the actual instructions that the script executes. They can be anything you normally type into the command line, such as ls to list directory contents or echo to print text.
Variables: Shell scripts can store data in variables. Variables are defined by assigning a value to a name, like my_var=”Hello,” and are accessed with $my_var.
Control Structures: Shell scripts can include control structures such as loops (for, while), conditionals (if, else), and case statements to control the execution flow.
Functions: You can define functions in shell scripts to encapsulate reusable code blocks. Functions are defined using the function_name() { … } syntax.
Ubuntu tutorials on this website:
