Error Messages and Error Checking, NOT! 31and alias (where did those long names come from?), are examples of com-
mands that live in a shell and therefore have no man pages of their own.
A novice told to use “man command” to get the documentation on a com-
mand rapidly gets confused as she sees some commands documented, and
others not. And if she’s been set up with a shell different from the ones
documented in third-party books, there’s no hope of enlightenment without
consulting a guru.
Error Messages and Error Checking, NOT! ................................
Novices are bound to make errors, to use the wrong command, or use the
right command but the wrong options or arguments. Computer systems
must detect these errors and report them back to the user. Unfortunately,
Unix programs seldom bother. To the contrary, Unix seems to go out of its
way to make errors compound each other so that they yield fatal results.
In the last section, we showed how easy it is to accidentally delete a file
with rm. But you probably wouldn’t realize how easy it is to delete a file
without even using the rm command.
To Delete Your File, Try the Compiler
Some versions of cc frequently bite undergraduates by deleting previous
output files before checking for obvious input problems.
Date: Thu, 26 Nov 1992 16:01:55 GMT
From: [email protected] (Tommy Kelly)
Subject: HELP!
Newsgroups: cs.questions^9
Organization: Lab for the Foundations of Computer Science,
Edinburgh UKI just did:(^8) We are careful to say “a shell” rather than “the shell.” There is no standard shell in
Unix.
(^9) Forwarded to UNIX-HATERS by Paul Dourish, who adds “I suppose we should
take it as a good sign that first-year undergraduates are being exposed so early in
their career to the canonical examples of bad design practice.”