Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!mimsy!chris
From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.unix.wizards
Subject: off_t (was unix question: files per directory)
Message-ID: <16901@mimsy.UUCP>
Date: 13 Apr 89 12:48:01 GMT
References: <24110@beta.lanl.gov> <8420@xanth.cs.odu.edu> <1430@auspex.auspex.com>
Distribution: na
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 12

In article <1430@auspex.auspex.com> guy@auspex.auspex.com (Guy Harris) writes:
>since [lseek] can use [its off_t] argument ... as a
>possibly-negative offset relative to the current position in the file or
>to the end of the file, it has to be signed. 

Well, no, not really.  Unsigned arithmetic is modular arithmetic;
this produces the same result, although not in as intuitive a manner.
If (off_t) is (unsigned long) and if that is 32 bits, -(off_t)100 is
4294967196, and (off_t)150 + -(off_t)100 is 50.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris