Pry (software)

Pry REPL

Developer(s)	John Mair (banisterfiend), Conrad Irwin, …many more
Stable release	0.10.0 / June 9, 2014 (2014-06-09)
Repository	github.com/pry/pry
Written in	Ruby
Operating system	Cross-platform
Platform	Ruby interpreter
Type	Ruby shell
License	[1] MIT License
Website	http://www.pryrepl.org/

Pry is an interactive shell for the Ruby programming language. It is notable for its Smalltalk-inspired ability to start a REPL within a running program. This lets programmers debug and modify the current state of a system.

Features

Pry exposes most of its introspective capabilities using a filesystem metaphor. For example, it has a cd command to start interacting with a particular object, and uses ls to list methods and variables.

It is possible to start Pry at any point inside a running program. Due to the reflective nature of Ruby, this lets the programmer inspect the program, change its current state, or correct the source code without restarting the process.

A number of third party plugins are available for Pry, these add tighter integration with other Ruby projects, enhance the abilities of Pry itself, and make Pry available over a remote connection.

Competitors

The main competitor to Pry is IRB, a standalone interactive shell that is packaged with releases of the Ruby programming language. There are a reasonable number of third-party plugins that add features to make IRB behave more like Pry, packaged as irbtools.

There are other projects to bring a better-than-IRB REPL to Ruby, such as ripl, but they are yet to see widespread adoption.

See also

• Comparison of computer shells
• IPython — A similar piece of software for the Python programming language
• SLIME — An interactive Lisp shell for Emacs
• Tweak — A Smalltalk programming environment

External links

• Official website
• Wiki documentation
• Introductory video