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[lenovo]

Hi,
Could anybody please help or provide some ideas on how to validate header and trailer records in a mainframe file using generic cobol program?
By Generic program I meant it should process different files with different file lengths and each can have different header and trailer.
I know this sounds some vague but in our system we have different input files coming in from other systems with different file length and different header and trailer and we have written seperate programs validating the same information and I planning to write some generic program to validate the header and trailer.
For instance, I will pass '1' from the JCL to program to process FILE1 and '2' to process FILE2

FILE1 with file length 500

[gene montgomery]

I would submit that it's not possible in COBOL.
In COBOL, you MUST know the characteristics of a file before you open it.
Otherwise, the OPEN fails. Anybody disagree?
_________________
Gene

[William Collins]

I disagree.

RECORD CONTAINS 0 in the FD for fixed-length records, 01 at maximum record-size (not of files, but system maximum).

LRECL=maximum-LRECL-for-system on the DSN for the input for variable-length records. Similar 01 to above.

However, it can be done with SORT without the messing about.

lenovo, don't fall into the trap of validating the files only when you receive them. Everything which reads those files must validate them. There's no point validating independently, then feeding the wrong file into your system.

You get a false sense of security if you validate on receipt and then forget about it. You'll get bit.

[lenovo]

Thanks Gene and William.

William - I understand your point for validation.

[kolusu]

Lenovo,

As William suggested you can use SORT product to perform the validation for any LRECL and it is quite easy to do it which can set a return code based on the validation.
_________________
Kolusu
www.linkedin.com/in/kolusu

[Nic Clouston]

On the other hand you have to change the existing programs to ignore the header and trailer records so instead of ignoring them - validate them. Besides which, trailers should have a record count on them so that your program knows that it has read all the records - not too few and not too many.
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Utility and Program control cards are NOT, repeat NOT, JCL.

[misi01]

you might also want (as we do here at the bank) code that checks:-

1) whether the file has already been processed once (based on the starter record which contains a timestamp)
2) whether the number of records sent in is the same as the number read in
3) the fact that various totals (accounts or whatever) sent in are the same as the totals read in
_________________
Michael

[William Collins]

I think if you are pre-verifying and also verifying in the individual programs, I'd go for a SORT solution.

I'd look at using SORT symbols, or generating the sort cards, to keep things as simple as possible, but could be done using IFTHEN, if a somewhat generic error if file-name is unidentifiable.