&gt;  In what way?<p>You&#x27;re right to ask that. I thought the question was about how they are implemented at the OS level, where the answer would be an operating system book like &quot;Advanced Programming in the Unix Environment&quot;.<p>(It&#x27;s been a while; I&#x27;ve forgotten how that book treats pipes and don&#x27;t know if it&#x27;s an appropriate answer to the question I thought was being posed.)