run shell commands and redirect output to stdout/stderr and seperate files stdout.log and stderr.log

command.rb

require 'open3'


class MultiIO #stolen from here: http://stackoverflow.com/a/6407200/828277
  def initialize(*targets)
     @targets = targets
  end

  def write(*args)
    @targets.each {|t| t.write(*args)}
  end

  def close
    @targets.each(&:close)
  end

  def flush(*args)
    @targets.each(&:flush)
  end
end

$stdout = MultiIO.new(STDOUT, File.open("stdout.log", "w"))
$stderr = MultiIO.new(STDERR, File.open("stderr.log", "w"))

def c command
  stdin, stdout, stderr, wait_thr = Open3.popen3(command)

  while (line = stdout.gets)
    $stdout.write line
  end

  while (line = stderr.gets)
    $stderr.write line
  end
end


c "ls -la"
c "ls -la notthere/"