Bash - check if string is empty

This article will show you how to check if the string is empty in Bash.

Quick solution:

#!/bin/bash

variable="Sample text"
[ -z "$variable" ] && echo "variable is empty" || echo "variable is not empty"

Example output:

variable is not empty

Practical examples

1. With control operators

#!/bin/bash

variable="Sample text"
empty_variable=""

[ -z "$variable" ] && echo "variable is empty" || echo "variable is not empty"
[ -z "$empty_variable" ] && echo "empty_variable is empty" || echo "empty_variable is not empty"

Example output:

variable is not empty
empty_variable is empty

2. With if statement

#!/bin/bash

variable="Sample text"

if [ -z "$variable" ] 
then 
	echo "variable is empty"
else 
	echo "variable is not empty"
fi

Output:

variable is not empty

Alternative if statement example

#!/bin/bash

variable="Sample text"

if test -z "$variable"
then 
	echo "variable is empty"
else 
	echo "variable is not empty"
fi

Output:

variable is not empty