A very nice (but a bit academic) way to look at "cat" as a monadic "return" on unix pipes : http://okmij.org/ftp/Computation/monadic-shell.html http://okmij.or

A very nice (but a bit academic) way to look at "cat" as a monadic "return" on unix pipes : http://okmij.org/ftp/Computation/monadic-shell.html http://okmij.org/ftp/Computation/monadic-shell.html