tmpdir

The ruby/tmpdir project is a small utility for Ruby applications that need to create temporary folders on the fly. It gives developers a straightforward way to generate a short-lived directory, use it for whatever they need, and have it automatically cleaned up afterward.

The main feature is a function called Dir.mktmpdir that creates a fresh temporary directory with restricted permissions — only the person who created it can read or write to it. Developers can optionally customize the folder name by adding a prefix or suffix (like prefixing it with "foo" so the folder looks like "foo...random"). They can also choose where on the computer the folder gets created, defaulting to the system's standard temporary location but allowing alternatives like /var/tmp. The directory is designed to be used within a block of code and then removed automatically once that block finishes running.

This tool would be used by Ruby developers building applications that need scratch space — for example, a web app that processes uploaded files might stash them in a temporary folder while working on them, or a script that downloads and extracts data might need a holding area. It is essentially infrastructure plumbing that handles the messy details of creating and tearing down temporary storage safely.

One notable design choice is the emphasis on security. The folder is created with 0700 permissions, meaning only the owner can access it, and the README explicitly warns against changing this. This prevents a common pitfall where temporary files accidentally become visible to other users on the same machine — a real concern on shared servers. The project is maintained under the official Ruby organization, making it part of the broader Ruby ecosystem rather than an independent library.