NodeJS scripts

If we want to use NodeJS as a scripting language without going to the trouble of setting up an NPM-based development environment, we can use the following architecture.

#!/usr/bin/env node

const process = require("process");

const actualScript = (firstParam, secondParam) => {
  // Do something
};

if (require.main === module) {
  const [, param1, param2] = process.argv;
  actualScript(param1, param2).catch(console.error);
}

Basically we have a function that contains the main actions of the script. This is then invoked within main in the manner of a Bash or Python script

This obviously requires the Node binary to be in your path and the script must be run with executable privileges.

If you use any module not in the Node core, you will need to have this installed globally for it to work. (There are ways around this for Node scripts you publish but for personal scripts this doesn’t matter.)

require.main

This construction checks that the script is being directy invoked via the ‘node’ command in the terminal rather than called by another module.

This is equivalent to the following construct in Python:

if __name__ == "__main__":
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