Ruby script to run commands in parallel, print the output with different colors, and provide a summary.

multi_command.rb

#!/usr/bin/env ruby

# Run commands in parallel, print the output with different colors,
# and provide a summary.

COMMANDS = [
  "curl -v www.google.com",
  "curl -v www.yahoo.com",
  "dig www.google.com",
  "hoo",
  "dig www.yahoo.com",
]

COLORS = %w[31m 32m 33m 34m 35m 36m 91m 92m 93m 94m 95m 96m]

require 'open3'

def run_command(command, color: COLORS.sample)
  Open3.popen3(command) do |_stdin, stdout, stderr, wait_thr|
    # Process stdout
    stdout_thread = Thread.new do
      stdout.each_line do |line|
        puts "\e[#{color}#{command}\e[0m: #{line.chomp}" # Prefix with the command and print
      end
    end

    # Process stderr
    stderr_thread = Thread.new do
      stderr.each_line do |line|
        warn "\e[#{color}#{command} (stderr)\e[0m: #{line.chomp}" # Prefix with the command and print
      end
    end

    # Wait for the threads to finish
    stdout_thread.join
    stderr_thread.join

    # Wait for the process to finish
    wait_thr.value # exit_status
  end
end

# Run each command in a separate process
processes = COMMANDS.each_with_index.map do |command, index|
  fork do
    color = COLORS[index % COLORS.size]
    status = run_command(command, color: color)

    if status.success?
      exit 0
    else
      exit 1
    end
  end
end

# Wait for all processes to finish
statuses = processes.map do |pid|
  Process.wait(pid)

  $?
end

puts

# Check the exit status of each process
COMMANDS.each_with_index do |command, index|
  status = statuses[index]
  if status.success?
    puts "✅ #{command}"
  else
    puts "❌ #{command}"
  end
end

if statuses.all?(&:success?)
  exit 0
else
  exit 1
end