Ruby Standard Library

Batteries included

Basically every programming language that you’ll use in practice has some kind of standard library that is shipped with the language itself.

When you install Ruby on your computer this will also install the Ruby Standard Library. This means you can simply require and use the things it includes.

Its documentation isn’t the most pretty website on earth, but if you look at the “package” (library) names on the left you see things mentioned like:

• benchmark: tools to test how performant your code is
• debug: tools to make debugging code easier
• digest, openssl, securerandom: tools for encryption and security
• erb: Ruby’s standard templating system
• net/imap, net/pop, net/smtp: stuff for sending and receiving emails
• zlib: tools for compressing files (you know zip files, don’t you?)

And a lot of other things. These are fairly low-level tools, of course. You do not see a library for “logging in via Twitter or Google”. They’re more like nuts and bolts, rather than bicycles or cars, but they’re super useful nonetheless.

In order to make one of these libraries available in your code you don’t have to do anything else other than use require. E.g. require "zlib" would make the zlib library available, which means you could now use the methods deflate and inflate in order to compress and decompress files.