External commands are not executed in an interactive shell so your .bash_profile is not read. To make your custom command available you must turn that it into an actual shell script, put it in your $PATH, and make it executable:

#!/usr/bin/env bash

echo "Hello world!"

But there's a much better way to "compile something": :help :make.

External commands are not executed in an interactive shell so your .bash_profile is not read. To make your custom command available you must turn it into an actual shell script, put it in your $PATH, and make it executable:

#!/usr/bin/env bash

echo "Hello world!"

But there's a much better way to "compile something": :help :make.