Bash Shell: Check If A Function Exists Or Not (Find Out If a Function Is Defined Or Not)

To check if a function exists or not in Bash shell, you can use the type command with the -t option.

Here's an example:

if [ $(type -t myfunction) = function ]; then
 echo "myfunction is defined"
else
 echo "myfunction is not defined"
fi

In this example, we use the type command with the -t option to get the type of myfunction. If the type is function, then we know that the function is defined, and we print the message "myfunction is defined". Otherwise, we print the message "myfunction is not defined".

You can replace myfunction with the name of the function you want to check.