How to read,write records form bottom from a sequential file



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How to read,write records form bottom from a sequential file

Postby krishnanramesh » Sun Oct 03, 2010 1:31 pm

How to read,write records form bottom from a sequential file in cobol?
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Re: How to read,write records form bottom from a sequential file

 

Re: How to read,write records form bottom from a sequential file

Postby enrico-sorichetti » Sun Oct 03, 2010 1:43 pm

as already told gazillions times... it cannot be done ( the reading )

please explain better about the write

to process backwards You will have to <sort> in reverse order using a real / virtual sequence key
and sort again in the original sequence

but if the need is <real> the process should be revisited
cheers
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Re: How to read,write records form bottom from a sequential file

Postby dick scherrer » Sun Oct 03, 2010 9:48 pm

Hello,

write records form bottom from a sequential file
When records are written to a sequential file, they are always written at the "bottom".

As Enrico requested - explain better so someone can help.
Hope this helps,
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Re: How to read,write records form bottom from a sequential file

Postby steve-myers » Mon Oct 04, 2010 12:22 am

What an idiot I can be! Of course you write to the "bottom" of a sequential data set!

As for reading from the end of a sequential data set, write it to tape and then reread the tape in backwards mode. Or, as enrico-sorichetti said, sort it into reverse order to a new data set and read the new data set normally.
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