iostat

[Daniel Franke]

Hi all.

I tried to work out a way to provide meaningful error messages besides "open 
failed". While checking iostat, I found it VERY difficult to distiguish 
between different errors, ENOENT and EACCESS for example. Both iostat numbers 
are simply '1':

$> ls
iostat.f90
$> cat iostat.f90
PROGRAM test_iostat
  INTEGER :: ierr
  OPEN(UNIT = 42, FILE = "file", ACTION = "READ", STATUS = "OLD", IOSTAT=ierr)
  WRITE (*,*) ierr
END PROGRAM

$> gfortran-4.1.1 -g -Wall iostat.f90
$> ./a.out
           1
$> touch file
$> ./a.out
           0
$> chmod 0 file
$> ./a.out
           1

Removing the IOSTAT clause results in
    Fortran runtime error: No such file or directory
and
    Fortran runtime error: Permission denied
respectively.

If I am not completely mistaken, the numbers returned in "ierr"
should be distinguishable?

Regards
	Daniel


P.S. Related thread in comp.lang.fortran:
http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/a9d9bffdce73d9cd/