Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!cs.utexas.edu!uunet!mcvax!kth!sunic!dkuug!dde!kbe
From: kbe@dde.uucp (Kjeld Borch Egevang)
Newsgroups: comp.unix.wizards
Subject: Re: Tail
Keywords: Tail, Wait, Length
Message-ID: <155@mother.dde.uucp>
Date: 17 May 89 13:47:35 GMT
References: <11701@eddie.MIT.EDU>
Organization: Dansk Data Elektronik A/S, Herlev, Denmark
Lines: 13

rich@eddie.MIT.EDU (Richard Caloggero) writes:



>     How is "tail -1f" implemented?  Is there an IOCTL or FCNTRL
>parameter which allows one to wait for some sort of status event (like
>size change), or does tail just keep checking and sleeping?

I've been told that in our SysV-implementation (3.1) there is a loop
with a read (from the file), a write (to the terminal) and a sleep(1).

| UUCP: kbe@dde.dk      (Kjeld Borch Egevang) | Dansk Data Elektronik
| or  ...mcvax!enea!dkuug!dde!kbe             | Denmark