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From: idallen@watmath.UUCP
Newsgroups: net.unix,net.lang.c,net.unix-wizards
Subject: Qualified Names mean you don't break the C Library
Message-ID: <8430@watmath.UUCP>
Date: Mon, 23-Jul-84 19:54:57 EDT
Article-I.D.: watmath.8430
Posted: Mon Jul 23 19:54:57 1984
Date-Received: Tue, 24-Jul-84 04:17:11 EDT
References: <2065@rlgvax.UUCP>, <142@pyuxt.UUCP>, <8241@watmath.UUCP>, <297@watdcsu.UUCP>, <8248@watmath.UUCP>
Organization: U of Waterloo, Ontario
Lines: 27

If you don't have unique names for things like printf and getchar,
names that are identifiable so that no programmer will use them by
mistake, then you can never have one C Library routine call another C
Library routine, because the called routine might have been
accidentally redefined to do something that the Library doesn't
expect.  If I write a do-nothing function called malloc() and put it in
my program, every C Library routine that uses malloc() breaks.  This is
a bad thing.  I do not want to have to learn all the names of every
routine that ever is, was, or will be put in the C Library.  I want to
be told "if you never use an external name like such-and-so, you will
never break the library".  The C Library should be calling a special
internal name for malloc(); not a simple external name that you
are likely to stumble across.  If you *really* want to redefine the
Library's malloc, you redefine the internal name -- but, it is very
clear (by the form of the name) that you are doing something special.

The B Programming Language has reserved identifiers containing a
period for internal system use.  My programs call printf() -- the
library always calls .prntf().  If I never use an external with a
period in it, I never mess up the library.

Of course, this only works like this because most programs are
two-tiered -- my source, and the library.  When you start to apply
this to different libraries, each needing its own convention for
identifiers...  argh.
-- 
        -IAN!  (Ian! D. Allen)      University of Waterloo