gw18@prism.gatech.edu (Williams, Greg) (06/06/90)
I have a FORTRAN program on a SPARCstation 1 that I am having difficulty
with. I am beginning to believe that the problem is a compiler bug and
not the program. The program used to work fine with f77 v1.2, but it will
not work properly with f77 v1.3. The program is too long to include here,
but here's the gist of what it does.
The program is supposed to allow the user to read and edit a 512 byte
header from a data file. What it does is open the file using
OPEN (UNIT= UNIT,FILE=NAME,STATUS='UNKNOWN',
& RECL = 512, ACCESS = 'DIRECT',
& FORM = 'UNFORMATTED')
and then allows the user to look at and possibly change some values. The
entire file is not read in; only the header is changed. Once the user
has made whatever changes he wants, they are written back out, and the
file is closed. What used to happen with v1.2 is the new header is
written out and the rest of the file (about .5Mb worth of data) is not
ever touched. What happens now is the header is written out and the rest
of the data is deleted.
I suppose I could modify the program to read in the entire file and write
the entire file back out when its done. However, I would prefer not to do
that. Does anyone know if this is a bug, or if I'm just doing something
wrong?