Execute external bash command in Ruby

Tue, 03 Feb 2026 14:07:26 +0000

Most of the Ruby gems that you develop need to interact with the operating system or invoke external commands. To do this, Ruby provides many built-in methods: exec, system, spawn, ```, %x[], etc. There are also many different libraries that encapsulate all the complexity of working with parameter escaping, input/output, passing environment variables, getting exit codes, etc. One of my favorite gems is qbash. It is a simple and powerful wrapper over open3, which extends the Kernel module with only one qbash method. The source code and usage examples can be found here. What gems do you use for these purposes?

Rails runner: export tables row count

Wed, 28 Jan 2026 05:15:01 +0000

Anyone who works with Rails has heard of and used the runner command with a single-line code argument that executes in the application context. While working on my application the other day, I needed to list all tables with their row counts. The code for listing the number of table rows on a single line looks rather ugly and unmaintainable. If you read the runner help (bin/rails runner -h), you’ll see that runner can also read code from stdin. To pass multi-line code to runner, you can use a heredoc. To me, this looks absolutely stunning!

Bash on Artem Yegorov

Execute external bash command in Ruby

Rails runner: export tables row count