Path: utzoo!mnetor!uunet!vsi!friedl
From: friedl@vsi.UUCP (Stephen J. Friedl)
Newsgroups: comp.lang.c
Subject: Re: a couple of random questions
Message-ID: <541@vsi.UUCP>
Date: 15 Apr 88 01:23:26 GMT
References: <530@vsi.UUCP> <10426@steinmetz.ge.com>
Distribution: comp
Organization: V-Systems, Inc. -- Santa Ana, CA
Lines: 23

In an article, davidsen@steinmetz.ge.com (William E. Davidsen Jr) writes:
< In the first article  friedl@vsi.UUCP (Stephen J. Friedl) writes:
< |      Second, what is the portable way to rewind a Unix file
< | descriptor?  On almost every machine I have ever used:
< | 
< |         lseek(fd, (off_t)0, SEEK_SET);
< 
< Any implementation which doesn't use 
< 	lseek(int, long, int)
< In the K&R manner (pg 164) will break virtually every program which uses
< the feature. I have to check dpANS on this, or someone can post and tell
< me that they found some way to justify doing something else.

I believe that dpANS does not address lseek(2) because it is an
operating system function; they specify fseek(3) instead, where
the offset is defined to be in characters.  Presumably the stdio
library is required to "just figure it out" on a record-based
system.  I've seen it written somewhere that the only portable
way to get an lseek(2) offset is as a result from a previous lseek(2).

-- 
Steve Friedl   V-Systems, Inc.   "Yes, I'm jeff@unh's brother"
friedl@vsi.com  {backbones}!vsi.com!friedl  attmail!vsi!friedl