From: utzoo!decvax!decwrl!sun!megatest!fortune!hpda!hplabs!sri-unix!mark.umcp-cs@UDel-Relay
Newsgroups: net.unix-wizards
Title: controlling standard input in a forked process
Article-I.D.: sri-arpa.907
Posted: Thu Mar 31 15:41:35 1983
Received: Tue Apr 19 06:03:28 1983

From:  Mark Weiser <mark.umcp-cs@UDel-Relay>

Date: 28 Mar 1983 0340-PST
Just fork off the child with a pipe connected to standard input, 
and the other end of the pipe under the control of the parent.
Use dup2() to move the pipe file descripter to 0 (which is standard in)
after the fork but before the exec.

Make sure to close all unused descripters in each process to make
things clean.