I want to be able to execute a bash script located in my home directory with the command ~/script_name.sh from any directory and then in the script, get the directory that it was ran from.
eg. I'm in the directory /foo/bar/baz, and execute /foo/script.sh, and it prints out /foo/bar/baz
pwd and $0/$BASH_SOURCE give me the directory my shell starts in and the path to the script in my home directory respectively.