Introduction

The expr command is a powerful tool in Linux that allows users to perform arithmetic and logical operations on numerical values. It is a built-in command that is available in most Linux distributions and can be used to perform calculations, compare strings, and evaluate logical expressions. It is a versatile command that can be used to perform a variety of tasks, from simple calculations to complex operations. This guide will provide an overview of the expr command and how to use it.

Examples

Expr is a Linux command used to evaluate expressions. It can be used to perform arithmetic operations, compare strings, and perform pattern matching.

Syntax:

expr EXPRESSION

Examples:

1. To perform arithmetic operations:

$ expr 5 + 5
10

2. To compare strings:

$ expr “hello” = “hello”
1

3. To perform pattern matching:

$ expr match “hello world” “hello*”
6

Using the expr Command in Linux

The expr command in Linux is a powerful tool for performing mathematical operations and string manipulation. It is a built-in command that is part of the GNU Core Utilities package, and is available on most Linux distributions. The expr command can be used to evaluate expressions, perform arithmetic operations, compare strings, and more.

Syntax

The syntax for the expr command is as follows:

expr [options] expression

Options

The expr command has several options that can be used to modify its behavior. These include:

• -e: Evaluate the expression and print the result.
• -i: Interpret the expression as an integer.
• -f: Interpret the expression as a floating-point number.
• -s: Interpret the expression as a string.

Examples

Here are some examples of how to use the expr command:

• To evaluate an arithmetic expression:

  expr 2 + 2

• To compare two strings:

  expr "hello" = "hello"

• To evaluate an expression as an integer:

  expr -i 2 + 2

• To evaluate an expression as a floating-point number:

  expr -f 2.5 + 3.5

• To evaluate an expression as a string:

  expr -s "hello" + "world"

For more information about the expr command, consult the man page.