Dennis Bartlett wrote:
Following up on the common thread, can one OPENSEQ to a COMMON variable?
Absolutely.
COMMON is merely a method of sharing data between programs without
argument passing as is commonly done with subroutines. Note that common
in this fashion is accessible among programs for the individual user,
not to be confused with "shared common", (such as the catalog uses,
which allows users to access the same info).
So, any variable can be stuffed into a common block, and it's best to
use what's called NAMED COMMON so that you don't collide with anyone
else's definitions, (particularly if you're running vendor code which
you can't read the source code to).
And then any program or routine that has that COMMON block defined
within it has acccess to the variables within it.
With file pointers, the trick is to set flags so that you know that
they're open or closed. Which can be followed through to other
variables, set flags to show that they've been initialized or not.
Always set them to show non-initialized first, set them, set the flags,
then in any routine that uses them, check the flags before you use them,
and if the flags aren't set, you can't use the values.
One very common way of dealing with this is to call a program from the
VOC LOGIN PA which sets common.
As has been mentioned previously, watch out for accounts, as showing
that your PAYMASTER file is open, and having your user log from TEST to
LIVE will give you some very real problems...
--
Allen Egerton
aegerton at pobox dot com
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