====== Command line redirection ======

There are a couple of useful tips for using the command line:

  * The pipe ''|'' allows commands to send their output to another, example: ''ls | grep pdf'' would only list pdf file in the current directory.
  * The tilde ''`'', not to be confused with the single quote ''''', allows a command to be executed and its output inserted into another, for example: ''yelp `pwd`/internet.xml'' would send the complete filename and path to yelp.