You probably heard about Bash scripting if you are familiar with Linux. A Bash script plays an essential role in the automation of commands in Linux. It can save a lot of time because you don’t need to write the commands one by one in the terminal. Thus, Bash scripting can increase your work efficiency by automatically executing the commands.
Moreover, a keen knowledge of Bash scripting is also necessary to get the Linux administrator job. That’s why you must learn Bash scripting to boost your career on a whole new level. If you are a beginner, read this guide to get a brief information about Bash scripting in Linux.
Your First Day of Bash Scripting
Before moving to the concepts of Bash scripting, let’s have a look at the basics of Bash in Linux:
What Is Bash?
Bash or Bourne Again Shell is a command language interpreter which is widely available on different Linux distros. Bash is an upgraded version of the Bourne shell that includes additional features like command-line editing. Nowadays, Bash comes as a default command interpreter on various Linux systems.
Brian Fox developed Bash in 1989 to improve the Bourne shell for interactive uses. It has different options including key bindings, command line editing, and command history support.
What Is Shell?
Shell reads and executes the commands that a user enters. In other words, it is a macro processor that works between the user and the system for the command execution. Shell’s ultimate ability to interact with the system (kernel) makes it a powerful tool.
You can create the shell file either from the CLI or GUI. There are various variants of shells, and every variant has its abilities and function to automate the command execution.
What Is Scripting?
Scripting offers an automatic command execution environment. It allows a user to write and execute the set of commands from the terminal. Scripts are text files that you can create either from the terminal or the Text Editor. With the scripts, you can execute multiple commands simultaneously, saving you a lot of time and effort.
Bash Scripting: Why Should You Use It?
As mentioned, Bash scripts can improve the workflow and simplify the process. Bash scripts are preferred by network engineers, scientists, system administrators, developers, and Linux experts.
You can use the Bash scripting in different tasks, including data crunching, automated backups, web app deployment, and custom script development for various pages. Moreover, here are a few reasons why you should use the Bash script for your daily tasks:
- Task Automation: You can automate the daily task with automatic command execution. The Bash script also supports the cron’s time-based scheduler to automate the execution of the Bash script.
- Simplify the Work: You don’t need to remember the sequence of the commands because the Bash script executes the commands one by one in the correct order. Hence, you only require to write the commands once in the sequence.
- Transferable Support: Bash script works well on every system. If you transfer a Bash script from one Linux OS to another, it still works correctly.
- Transparent: You can quickly check the script’s content since it is available in the human-readable text format.
Bash Scripting: The Basics
Initially, “.sh” is the extension of the Bash script. But there are a few more ways to identify these scripts quickly.
- Sometimes, Bash scripts end with the “.shebang” extension, a combination of Bash and bang. Shebang contains #! (bash# and bang!) that indicates an interpreter for the execution. This #! Shebang tells which interpreter does a system must use to run the Bash script commands.
- If you open a directory in the terminal which contains the Bash script, it appears in different colors from the rest of the files. You can identify the Bash script as per their colors.
- You can check the rights of the scripts because these files contain the execution right like x. Hence, you can use that script in the terminal if a file contains execution rights.
How to Create Bash Script in Linux
You can create the Bash script file through CLI and GUI approach. Let’s go through each of them separately:
Create a Bash Script through Nano Editor
First, open the Linux terminal and execute the touch command to create a Bash script:
You can check the path of the Bash file using the “which” command:
In case you want to save the script in a specific directory, execute the following commands:
You can also provide the execution rights to the script through the chmod command:
Now, use the nano command to enter the details in the Bash script:
In the nano editor, you can enter the details accordingly. For example, we insert a specific text into it:
Finally, run the following command to open the Bash script in the terminal:
There are a ton of Bash scripts that you can create in Linux. Check out 30 Bash Script Examples to learn everything about Bash scripting.
Commands that You Can Try for Bash Scripting
There are a few commands that you can try while writing Bash scripts in Linux:
The ls command is used to list the directory contents so that you can check the file’s contents quickly.
The grep command is used for searching the text in a specific pattern. It can be a useful command to search for a particular script from the directory.
You can use the mkdir command to create the directories. This command is useful when creating a Bash script in a new directory.
You can use the pwd to print the current working directory in the terminal. It is helpful when you are working in multiple terminals.
With man command, you can get the details about the commands that you are executing. You can try a few options such as -w, -b, -f, etc.
You rename or move the directories right from the terminal with the mv command.
This command is used for copying the directories and files.
The cat command creates, reads, displays, and concatenates a file.
You can use the exit command to end the currently running process and close the terminal window.
This is all about the things you should consider on your first day of Bash scripting. The Bash scripts are useful to improve your efficiency, whether you are a Linux administrator or a programmer. The concept of Bash script is not limited to a single guide. That’s why we wrote hundreds of guides and tutorials, so be sure to check out Linuxhint to know more.