It requires at least two PHP files. One that ACTUALLY DOES WHAT YOU WANT and the library files.
Since you have to write a new PHP file anyway, composer allows you to pull in the latest version (or update it) with semver constraints.
Then you can package it as a phar and call it that way.
This is a library, not a file to run, and so it should have composer support.
Or, if you don't want to package it as a PHAR - since I have no idea how to do that, you'd implement your version in some directory and probably alias a command to it.
TL;DR: This is a library, not a script. It should have composer support.
I don't want to automatically pull the latest version. I would only use this after I studied the code and made sure it is not doing anything harmful. That's why this has to be as simple as possible.
> I don't want to automatically pull the latest version.
You don't have to. Composer allows you to pick a particular package version if you like, and it's only going to fetch a more recent version if your composer.json permits it and if you explicitly run composer update.
Since you have to write a new PHP file anyway, composer allows you to pull in the latest version (or update it) with semver constraints.
Then you can package it as a phar and call it that way.
This is a library, not a file to run, and so it should have composer support.
Or, if you don't want to package it as a PHAR - since I have no idea how to do that, you'd implement your version in some directory and probably alias a command to it.
TL;DR: This is a library, not a script. It should have composer support.