def what_can_i_do?
sys = Process::Sys
puts "UID=#{sys.getuid}, GID=#{sys.getgid}"
puts "Effective UID=#{sys.geteuid}, Effective GID=#{sys.getegid}"
file = '/bin/ls'
can_do = [:readable?, :writable?, :executable?].inject([]) do |arr, method|
arr << method if File.send(method, file); arr
end
puts "To you, #{file} is: #{can_do.join(', ')}"
end
what_can_i_do?
Process.uid = 1000
what_can_i_do?