Run a process, capture its output and exit code

Here is a way to get this out.

#!/usr/bin/env ruby

require 'open3'

Open3.popen3("ls -l") do |stdin, stdout, stderr, wait_thr|
  puts stdout.read
  puts wait_thr.value.exitstatus 
end

# >> total 52
# >> -rw-r--r-- 1 arup users    0 Aug  5 09:32 a.rb
# >> drwxr-xr-x 2 arup users 4096 Jul 20 20:37 FSS
# >> drwxr-xr-x 2 arup users 4096 Jul 20 20:37 fss_dir
# >> -rw-r--r-- 1 arup users   42 Jul 19 01:36 out.txt
# .....
#...
# >> 0

Doco is very clear of ::popen3. stdout gives IO object. So, we need to use IO#read method. And wait_thr.value gives us Process::Status. Now once we have that object, we can use #exitstatus method for the same.