Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.bugs.sys5
Subject: Re: What's a system call ( Was: 'what' doesn't use perror...)
Message-ID: <1603@auspex.auspex.com>
Date: 10 May 89 07:54:35 GMT
References: <3759@sugar.hackercorp.com> <10156@smoke.BRL.MIL> <1153@aplcen.apl.jhu.edu> <1350@frog.UUCP> <11506@ulysses.homer.nj.att.com>
Reply-To: guy@auspex.auspex.com (Guy Harris)
Organization: Auspex Systems, Santa Clara
Lines: 8

>Actually, a system call is an entry point which is a one-for-one mapping to a
>particular kernel service.  Open(2) is a system call which returns a file
>descriptor, which is a kernel data structure. 

On *some* implementations of the UNIX system interface, "open" is a
system call which returns a file descriptor, which is a kernel data
structure.  I don't think it is in Apollo's DOMAIN/OS (or is that
"Domain/OS"?) implementation, for example.