cial redirection. No new file descriptor
is allocated. The child process simply inherits the channel from the
parent.</p>
</li>
<li>
<p>Specify -1 to have a pipe allocated; start_command() replaces -1
by the pipe FD in the following way:</p>
<div class="literalblock">
<div class="content">
<pre>.in: Returns the writable pipe end into which the caller writes;
	the readable end of the pipe becomes the child's stdin.</pre>
</div>
</div>
<div class="literalblock">
<div class="content">
<pre>.out, .err: Returns 