Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!sun-barr!rutgers!psuvax1!schwartz@shire.cs.psu.edu From: schwartz@shire.cs.psu.edu (Scott Schwartz) Newsgroups: comp.unix.wizards Subject: Re: getcwd() and friends. Message-ID: <4523@psuvax1.cs.psu.edu> Date: 30 Apr 89 02:27:49 GMT References: <3675@ficc.uu.net> <14689@rpp386.Dallas.TX.US> <16758@mimsy.UUCP> <144@titania.warwick.ac.uk> <824@necisa.necisa.oz> Sender: news@psuvax1.cs.psu.edu Reply-To: schwartz@shire.cs.psu.edu (Scott Schwartz) Organization: Pennsylvania State University, Computer Science Lines: 24 In-reply-to: boyd@necisa.necisa.oz (Boyd Roberts) In article <824@necisa.necisa.oz>, boyd@necisa (Boyd Roberts) writes: >What we really need is /dev/time. Opening it returns a descriptor refering >to the system time inode. You can fstat() it and determine the current >time from the modification time. Its modification time would be updated >by clock(). More logical to read it to get the time, don't you think? >This would move us ever closer to a true descriptor based OS... I think we need a good dose of Multics: Reading the time should be equivalent to accessing an object in virtual memory. In fact, the whole operating system system should behave like that, filesystem, system calls, and so on. Recently there was a discussion about the SysV shm* namespace vs the file descriptor namespace. The answer to the question "is this a good thing" is no. A real OS (taking no prisoners, here :-) needs only virtual memory. Everything else should be part of that. Shared memory should be part of the filesystem because the filesystem and memory are identical. In that case it is unnatural to have a separate access mechanism like the shm* stuff. -- Scott Schwartz