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How to check if a string is empty in Bash

How to check if a string is empty in Bash
Photo by Gabriel Heinzer / Unsplash

To check if a string is empty in a Bash script, use the -z conditional which returns 0 (true) if the length of the string is 0 and 1 (false) if it is greater than 0.

myVar="hello"

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

Alternatively, you can check if a bash string is NOT empty using -n and take the opposite using !.

myVar=""

if [[ ! -n "$myVar" ]]; then
	echo "myVar is empty"
else
	echo "myVar is not empty"
fi

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