This assumes you have installed OpenResty on a Linux system.
The resty command line tool can be used to issue in line commands, like this.
~]# resty -e 'print("Hello World")' Hello World
Another approach is to create a resty script. Let's say foo.resty contains the following.
#!/bin/resty print("Hello World")
Invoking this script should return Hello World.
~]# resty foo.resty Hello World