Bash Scripting for Beginners + Downloadable Free Cheat Sheet

You can redirect output of any command to a file this way. For loops allow you to execute statements a specific number of times. This saves you time because you don’t have to write certain commands again and again. You can perform daily tasks efficiently and even schedule them for automatic execution. A shell is a program that is used for interacting with the system.

Don’t Fear the Learning Curve

It allows you to perform a series of actions, such as navigating to a specific directory, creating a folder, and launching a process using the command line. Once the loop completes, the function outputs the calculated factorial with a message indicating the original number. The script prompts the user to enter a number using the read command, and the entered number is stored in the number variable. Finally, the calculate_factorial function is called with the number Bash Scripting variable as an argument to compute and display the factorial of the input number.

C. Passing Arguments

To capture keyboard input without having it echoed to the terminal window, use the -s (silent) option. Note that unlike with echo, you must tell printf to start a new line with the “\n” token. This is important because if you’ve written a script to run in Bash, you don’t want it to be interpreted by a different shell. Bash—like most shells—has its own quirks of syntax and functionality that other shells won’t have, or will have implemented differently.

Echo -e “The -e option lets us use\nformatting directives\nto split the string.” Writing text to the terminal is a common requirement. This script is launched by the current shell and passed to the cat command.

Intro to Bash Scripting

By default, it finds both the loopback and private IP of the device. The script uses the ifconfig command and to gather interface information and then employs awk to filter and extract the line containing the IP address. Finally, it echoes the interface name with the corresponding IP address. The script utilizes the format %y to retrieve year (YY), %m for the month (MM) and %d for the day (DD). After substituting the date command in the variable “today“, it outputs the value of the variable using the echo command. Security tasks, such as monitoring unauthorized logins or managing firewall rules, can be automated with Bash scripts.