Question

I’m working on a Sidekiq worker that’s sole purpose is to make several long-running system calls. I have the following requirements:

• Able to set environment variables
• Real-time output (stdout, stderr) stream
• Block thread until finished
• Get exit code
• Thread-safe, since sidekiq is multi-threaded (read: no $?)

I’m running on Ruby 1.9.2. Thanks for your input!

Answer 1

$? (as well as most other “magical” variables like $1 etc.) is local to the current thread and thus using system and $? is perfectly thread-safe and meets all your criteria.