Alexander Gromnitsky's Blog

No real-life input looks like that

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Date: Tue, 6 Sep 2022 11:07:19 -0400
From: Douglas McIlroy <>
Subject: Re: Has this been discussed on-list? How Unix changed Software.
Message-ID: <>

> (Research) Unix ... 'shipped' with zero known bugs.

It wasn't a Utopia. Right from the start man pages reported BUGS,
though many were infelicities, not implementation errors.

Dennis once ran a demo of a ubiquitous bug: buffer overflow. He fed a
2000-character line on stdin to every program in /bin. Many crashed.
Nobody was surprised; and nobody was moved to fix the offenders. The
misdesign principle that "no real-life input looks like that" fell
into disrepute, but the bad stuff lived on. Some years down the road a
paper appeared (in CACM?) that repeated Dennis's exercise.

The paper: An Empirical Study of the Reliability of UNIX Utilities, originally appeared in Communications of the ACM, December 1990, this one with the comments from 2000.

Tags: quote, ойті
Authors: ag