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From: rokicki@navajo.STANFORD.EDU (Tomas Rokicki)
Newsgroups: net.micro.amiga
Subject: Re: AmigaDOS problem
Message-ID: <788@navajo.STANFORD.EDU>
Date: Mon, 18-Aug-86 14:59:49 EDT
Article-I.D.: navajo.788
Posted: Mon Aug 18 14:59:49 1986
Date-Received: Wed, 20-Aug-86 00:00:32 EDT
References: <1646@well.UUCP>
Organization: Stanford University
Lines: 79
Summary: Huh?

In article <1646@well.UUCP>, crunch@well.UUCP (John Draper) writes:
> AMIGADOG PROBLEM
> ----------------
>   I am trying to whip up a simple directory display program and want to
> be able to detect when the last file has been displayed.   According
> to the manual  which is INCORRECT and INACCURATE (Thank you, MetaCompco,
> take a bow),  I quote from page 2-5 of the developers DOS (dog?) 
> manual:
> "ExNext gives a return code of zero if it fails for some reason.   One
>  reason for failure is reaching the last entry of the directory.  However,
>  IoErr() holds a code that may give more information on the exact cause of
>  a failure.   WHEN ExNext FINISHES AFTER THE LAST ENTRY, IT RETURNS:
>  ERROR_NO_MORE_ENTRIES (232)".   

Well, I just tested this, and wrote the following code fragment,
which seems to work as documented under 1.1.  The code is at the end
of the article.  (Compile under Manx without +l).

When run on the directory it was created in, it outputs:

df0:tdir entrytype 2
 tdir ioerr() 205
 tdir.c ioerr() 205
 tdir.o ioerr() 205
Exited with ioerr() 232

205 is couldn't find object; I don't know where this came from.
But it does finish with a zero result from ExNext() and an IoErr()
of NoMoreEntries.

Enjoy!                                                  -tom rokicki

---cut here---
/*
 *   Test of the directory finding functions.  Written by
 *   Tomas Rokicki of Radical Eye Software; feel free to
 *   use in any way you see fit.
 */
#include "stdio.h"
#include "libraries/dos.h"
struct FileInfoBlock fib ;
main(argc, argv)
int argc ;
char *argv[] ;
{
   long lock = 0 ;
   extern long CurrentDir(), ExNext(), Examine(), IoErr(), Lock() ;

   if (argc > 1) {
      argc-- ;
      argv++ ;
   } else {
      argc = 1 ;
      **argv = 0 ;
   }
   for (; argc > 0; argc--, argv++) {
      lock = Lock(*argv, ACCESS_READ) ;
      if (lock == 0) {
         printf("Error locking %s\n", *argv) ;
      } else {
         Examine(lock, &fib) ;
         printf("%s entrytype %ld\n", *argv, fib.fib_EntryType) ;
         if (fib.fib_EntryType > 0) {
            int fc = 0 ;
            while (ExNext(lock, &fib) != 0) {
               printf(" %s ioerr() %ld\n", fib.fib_FileName, IoErr()) ;
               fc++ ;
            }
            if (fc == 0)
               printf(" (empty)\n") ;
            printf("Exited with ioerr() %ld\n", IoErr()) ;
         } else {
            printf(" (file)\n") ;
         }
         UnLock(lock) ;
      }
   }
}
---cut here---