The Question is:
I am trying to write a command file that reads tape that was mounted as
foriegn. A good tape would have 4 records where the first three are empty. If
the system that generates these tapes (+25 year old HP computer) has a problem
then it sometimes over wr
ites the tape and usually causes a 5th record to contain data some valid data.
I have written a command file that reads the tape and store the data into
files. I am trying to test for the possibility of a 5 record and there are
three possible conditions
that could occurs. 1st there is not data in the 5th record (blank - this is
GOOD) 2nd there is a parity error (tapes recycled may have been at different
density) and third there is valid data. When the tape drive reads either a
blank tape or parity erro
r I can capture the $STATUS into a LOG file which only indicated a read error.
What I really would like to do is capture the specific error message that
indicated either "incomplete read" or "parity error".
Any help would be greatly appreciated. I was a former assistant VMS system
manager too many years ago to remember how to do this. I have been reading
the system manuals but have not found the key to solve this problem.
The Answer is :
Assuming the error code is not stored in the $STATUS symbol, then a
program will likely be required. You will also want to declare an
ON ERROR handler, or use SET NOON.
Note that DCL is not particularly suited for reading binary data.