The reminds me of some problems with Fortran many years ago.
(Before OPEN was added, though I believe it is still optional.)

It seems that Fortran opens the DDNAME for INOUT by default.
That is true even if the first operation is READ, as one is allowed
to REWIND (or BACKSPACE) and then WRITE.

There were some cases where that was not desired, and the
solution, if I remember it right, is LABEL=(,,,IN).
(I could get out a JCL book.)

As for the question, I don't know how common it is to open
for INOUT (or OUTIN), but that will restrict the ability to
test for input only.

-- glen

Reply via email to