Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!cs.utexas.edu!uunet!mcvax!ukc!axion!fulcrum!tjo From: tjo@Fulcrum.BT.CO.UK (Tim Oldham) Newsgroups: comp.unix.questions Subject: Re: Fine grained sync policy control (was: What I want in GNU OS) Message-ID: <217@cat.Fulcrum.BT.CO.UK> Date: 7 Jul 89 16:52:33 GMT References: <18410@mimsy.UUCP> Reply-To: tjo@fulcrum.bt.co.uk (Tim Oldham) Organization: BT IT Systems, Birmingham, England Lines: 25 In article <18410@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes: >SysV has an open() flag that causes writes to be immediate. Presumably >this can also be set and cleared with fcntl(F_SETFL). [yes - Tim] Not a correction, but an addition and word of warning-ish. O_SYNC, the flag in question, is only defined in the SVID addendum (V.3). The word of warning, at the risk of teaching grandma to suck eggs: many companies say "hey, we're SVID conformant". But check the SVID conformance level. Sometimes it's without the addendum features. Even then, check the kernel extensions conformance, otherwise you might be in for a shock when you come to use things like ptrace(2). This is particularly true of systems that aren't derived from AT&T source, and just look like SysV *IX. As a quick question, why does the SVID say that the sticky bit is `reserved'? Usually this means that "no, you're not allowed to use that - we're going to say what it's for later". They seem to mean "do what you want to with this bit", which is usually described as `undefined'. Comments? Tim. -- Tim Oldham tjo@fulcrum.bt.co.uk or ...!mcvax!ukc!axion!fulcrum!tjo #include Why have coffee, when caffeine tastes this good?