Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!haven!adm!smoke!gwyn From: gwyn@smoke.BRL.MIL (Doug Gwyn ) Newsgroups: comp.unix.questions Subject: Re: tail -f Message-ID: <9098@smoke.BRL.MIL> Date: 7 Dec 88 15:16:45 GMT References: <412@fedeva.UUCP> Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB)) Organization: Ballistic Research Lab (BRL), APG, MD. Lines: 8 In article <412@fedeva.UUCP> jbr0871@fedeva.UUCP (Blaine Robertson) writes: >Can someone please tell me how 'tail -f' works?. Obviously, it does not >do a busy loop while doing a stat on the file. All it does is to sleep for a short time (around one second), then copy out everything past the last high water mark via read/write. There is no statting, no asynchronous notification, no nonblocking I/O, etc. It IS a "busy loop" (except for the short sleep).