Jul 30, 2024 · Logical OR (||): This is a binary operator, which returns true if either of the operands is true or if both the operands are true. It returns false only if both operands are false. Not Equal to (!): This is a unary operator which returns true if the operand is false and returns false if the operand is true. 4.

May 2, 2025 · This variable is useful for creating shell scripts that need to manage multiple processes or create unique file names. For example, suppose you have a script called “log.sh” that logs information to a file with a unique name based on the process ID.

Most often, you use the hash or number sign (#) to tell the shell what follows is a comment, and it should not act on it. You can use it in shell scripts and---less usefully---on the command line.

Dec 8, 2013 · Rule of thumb: Use -a and -o inside square brackets, && and || outside. It's important to understand the difference between shell syntax and the syntax of the [ command. && and || are shell operators. They are used to combine the results of two commands.

Understanding Bash Operators. This section provides an overview of operators used in Bash scripting, including comparison, string, arithmetic, logical, and file test operators.

In this tutorial, you will learn about all of the operators that can be used in a Bash script on a Linux system. We will go over examples so you can learn how to use each type of operator in real context. In this tutorial you will learn: Privileged access to your Linux system as root or via the sudo command.

Apr 26, 2025 · Command chaining is a technique where multiple commands are executed in a sequence, based on the success or failure of previous commands. The Logical OR operator (||) is used to execute the command following it only if the previous command fails (returns a …

May 16, 2024 · Shell variables are an essential part of shell scripting. Shell variables allow us to use them anywhere in the script. In this article we have discussed the rules for defining scalar variables, unsetting variables, read-only variables and accessing variables.

$ followed by numbers (e.g. $1, $2, etc.) represents the parameters in the shell script.

Jan 23, 2024 · Bash provides several types of operators that allow you to perform various operations within shell scripts. Here I will talk about six different types of Bash operators with their relevant examples.