Bash If Statement

Bash If Statement

In Bash scripting, the if statement allows you to make decisions based on conditions. It executes commands based on whether a specified condition is true or false.

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Syntax

if [ condition ]; then
    # commands
fi

The basic syntax involves using if followed by the condition in square brackets and the commands to execute.

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Example Bash If Statements

Let's look at some examples of how to use if statements in Bash:

1. Simple If Statement to Compare Numbers

This script checks if the variable number is equal to 5 and prints a message if it is.

#!/bin/bash

number=5

if [ $number -eq 5 ]; then
    echo "The number is equal to 5."
fi

In this script, the variable number is assigned the value 5. The if statement checks if number is equal to 5 using the -eq operator, and if true, prints a message.

2. Simple If Statement to Compare Strings

This script checks if the variable string is equal to 'hello' and prints a message if it is.

#!/bin/bash

string="hello"

if [ "$string" = "hello" ]; then
    echo "The string is 'hello'."
fi

In this script, the variable string is assigned the value 'hello'. The if statement checks if string is equal to 'hello' using the = operator, and if true, prints a message.

3. Simple If Statement to Check if a Number is Greater

This script checks if the variable number is greater than 5 and prints a message if it is.

#!/bin/bash

number=10

if [ $number -gt 5 ]; then
    echo "The number is greater than 5."
fi

In this script, the variable number is assigned the value 10. The if statement checks if number is greater than 5 using the -gt operator, and if true, prints a message.

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Conclusion

The Bash if statement is a crucial tool for conditional operations in shell scripting. Understanding how to use simple if statements can help you create more dynamic and responsive scripts.