Nested if statements

If a single level of if statements is not enough and you would like to have additional logic within an if statement, you can create nested conditional statements. This can be done in the following way:

#!/bin/bash
USER_AGE=18
AGE_LIMIT=18
NAME="Bob" # Change to your username if you want to execute the nested logic
HAS_NIGHTMARES="true"

if [ "${USER}" == "${NAME}" ]; then
    if [ ${USER_AGE} -ge ${AGE_LIMIT} ]; then
        if [ "${HAS_NIGHTMARES}" == "true" ]; then
            echo "${USER} gets nightmares, and should not see the movie"
        fi
    fi
else
    echo "Who is this?"
fi