UNIX lets you connect the stdout of one command with the stdin of another command. This is known as pipes.


  • The most common use of pipes is to view output from a command with more because it scrolls off the screen too fast otherwise:
    % man -k shell
    (too much output!)
    % !! | more
  • You can string as many commands as desired together with pipes:
    % cmd1 | cmd2 | cmd3 | cmd4
  • This is often how UNIX's simple utility programs get combined to do complicated tasks.