How to check if a string is empty in Bash

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

Related

• All my posts on Bash

Did you find this information useful? If so, consider heading over to my donation page and drop me some support.

Want to ask a question or just chat? Contact me here