In Bash, if statements are used to make decisions and execute different blocks of code based on certain conditions. They allow you to control the flow of your script based on the evaluation of expressions or variables. Here’s the basic syntax of an if statement in Bash:
if condition
then
# code to execute if the condition is true
else
# code to execute if the condition is false
fi
The condition is an expression or command that evaluates to either true or false. If the condition is true, the code block following the then keyword will be executed. Otherwise, if the condition is false, the code block following the else keyword (if provided) will be executed.
Here’s an example that demonstrates the usage of an if statement in Bash:
#!/bin/bash
number=10
if ((number > 5))
then
echo "The number is greater than 5."
else
echo "The number is not greater than 5."
fi
In this example, the if statement checks if the value of the number variable is greater than 5. If it is, the script will execute the code block following the then keyword, which outputs “The number is greater than 5.” If the condition is false, the code block following the else keyword is executed, and it outputs “The number is not greater than 5.”
When you run this script, it will output:
The number is greater than 5.
You can modify the condition and the code blocks inside the if statement based on your specific requirements. if statements are fundamental for controlling the flow of your Bash scripts and executing different code paths based on conditions.