`rbexec`

Execute commands against different Ruby interpreters.

In the spirit of chruby's README:

Features

Even fewer than chruby!

Distributed as a single executable (plus a manual page).
Can be used as an executable or as a shell function.
Supports ash, bash, dash, ksh, mksh, pdksh, and zsh. Maybe other shells, too, but those are the only tested ones.
Auto-detects Rubies installed in /opt/rubies, ~/.rbfu/rubies, ~/.rbenv/versions, ~/.rvm/rubies, and ~/.rubies.

Doesn't change your current shell's environment (instead, it starts a new process).
Doesn't do pretty much anything else.

ash, bash, dash, ksh, mksh, pdksh, or zsh. Probably works with other shells, too.

You don't have to do much, as rbexec is designed to work as a standalone executable and Do The Right Thing under common circumstances. Just

$ rbexec 2.5.0 do-something

and you're cooking with Ruby 2.5.0! (assuming you have Ruby 2.5.0 installed)

Please see the manual page for information on how to fine-tune rbexec's behavior.