Execute external command which does not need standard input/output.
Ruby has several method to execute external command.
This sample shows three patterns to execute touch command on Linux to create a file.

#!/usr/bin/ruby
`touch panda.txt`

system("touch giant_panda.txt")

exec("touch cute_panda.txt")

      

$ ls
command.rb
$ ruby command.rb
$ ls
command.rb  cute_panda.txt  giant_panda.txt  panda.txt