Root Check

While trying to add a script which would install tmate, but for me to be able to put executables under bin folder would require a root permission. So, before trying to put the executables in the bin, permission check was a must. Though, checking if running as root isn't that hard using whoami command.

if [[ "${USER}" -ne "root" ]]; then
    echo "Can only run as root"
    exit 1
fi

I would've used this approach, but as an answer on StackOverFlow stated

"As a warning, do not check if a user is root by using the root username. Nothing guarantees that the user with ID 0 is called root. It's a very strong convention that is broadly followed but anybody could rename the superuser another name."

which I think does makes sense. So, that's why the other way around do the same is to check EUID variable, which is, in fact, read-only variable initialized at shell start-up.

if [[ "${EUID}" -ne "0" ]]; then
    echo "Can only run as root"
    exit 1
fi

Which pretty much worked for me the way I intended it to.

See the original question on StackOverFlow here