---
title: 2.5 Ways to Execute a Shell Command
teaser:
tags: web,ruby
author: Gabe Berke-Williams
published_on: 2011-08-03
---

I always get confused by the difference between `%x{}`, backticks, and `system
"command"`, so I wrote down what the difference was. `%x{}` is actually the
exact same thing as backticks, but it's useful because you can nest backticks
inside it.

`system "command"` echoes to `STDOUT`, and returns true if the command succeeded.

    irb > system "echo ABC"
    ABC
     => true 

Backticks and `%x{ }` do not echo to STDOUT, and return the result of
running the command.

    irb > `echo ABC`
     => "ABC\n" 
    irb > %x{echo ABC}
     => "ABC\n"
    irb > %x{echo `which ruby`}
     => "/Users/gabe/.rvm/rubies/ruby-1.9.2-p290/bin/ruby\n"