Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!hplabs!hpfcso!hpfelg!koren
From: koren@hpfelg.HP.COM (Steve Koren)
Newsgroups: comp.sys.amiga.tech
Subject: Re: forcing a flush w/ AmigaDos I/O
Message-ID: <13920053@hpfelg.HP.COM>
Date: 2 Mar 90 14:50:49 GMT
References: <13920051@hpfelg.HP.COM>
Organization: HP Elec. Design Div. -FtCollins
Lines: 37


One more for the AmigaDos I/O gurus:

How can I tell whether I have reached eof without actually reading
anything from the file?  That is, I am aware that if Read() returns
<= 0 when you asked for a positive number of byte, you either hit the
end of the file or had an error.  But what if (for a reason that is
not important here - you'll have to trust me that it's necessary) I
have a file pointer but don't want to call Read() to check eof status?
I can't seem to find an Feof() call for AmigaDos I/O.

   thanks for any help....

        - steve

PS - the motivation for my recent AmigaDos I/O questions is this:  I
     was very unsatisfied with both the size and performance of the
     SKsh external commands.  I have already changed them to AmigaDos
     I/O (from Lattice), and they are now much smaller and from 5
     to 10 times faster.  That part was easy, since the external
     commands (even the new 1.4 ones such as grep) are quite simple.
     However, I am planning to implement *real* pipes in SKsh 1.4
     using the 'cmd | cmd' syntax and the AmigaDos pipe device.  To
     do this, I need to convert at least some of SKsh to AmigaDos
     I/O (from ansi).  I've found a few capabilities that I need but
     can't find, such as this and the Fflush() call.  Any help would
     be greatly appriciated!

PPS- I am still hoping to finish SKsh 1.4 by late march or early
     april, although it depends on 1) how much time I can devote to
     it, and 2) how long I get stuck on stuff like this.

PPPS - So far, empirical results seem to suggest that the AmigaDos 
     Read() call is from 5 to 10 times faster than the Lattice read()
     call.  A file which used to take 17 seconds to 'wc -c' now
     takes 2 seconds with the SKsh 1.4 wc command.  I wonder how the
     Lattice call is implemented?