`$0`: Refers to the name of the script if it's being run as a script. If you're in an interactive shell session, `$0` will typically give the name of the shell.
who$@ami
echo whoami|$0Source: Command Injection/README.md in PayloadsAllTheThings. From PayloadsAllTheThings by Swissky and contributors. MIT License, Copyright (c) 2019 Swissky.