the readable pipe end from which the caller
	reads; the writable end of the pipe end becomes child's
	stdout/stderr.</pre>
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<pre>The caller of start_command() must close the so returned FDs
after it has completed reading from/writing to it!</pre>
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</li>
<li>
<p>Specify a file descriptor &gt; 0 to be used by the child:</p>
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<div class="content">
<pre>.in: The FD must be readable; it becomes child's stdin.
.ou