Accessing flat files on the mainframe

Fuism has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Accessing flat files on the mainframe by jZed (Prior) on Sep 02, 2004 at 22:42 UTC
DBD::AnyData works with many types of flatfiles including CSV, fixed length, XML, etc. If you have LWP installed, DBD::AnyData can use it to access flatfiles through either FTP or HTTP transparently. You just specify the URL of the file when you load the table, then use DBI and SQL on it as though it were a local database table.	[reply]
Re: Accessing flat files on the mainframe by DamnDirtyApe (Curate) on Sep 02, 2004 at 21:57 UTC
My question is how do I access these flat files using a perl script to run these queries? Depends on the file, but one common approach is: `open FILE, '<', $filename; while (<FILE>) { # ... do something here ... }` [download] Can I use DBD and DBI to hit these flat files using the access I have available? Possibly. It's tough to give any specific help without knowing what your queries look like, and what the files look like. If you were to post samples both, the value of the responses here will increase substantially. _______________ DamnDirtyApe Those who know that they are profound strive for clarity. Those who would like to seem profound to the crowd strive for obscurity. --Friedrich Nietzsche	[reply] [d/l]
Re^2: Accessing flat files on the mainframe by Fuism (Beadle) on Sep 02, 2004 at 23:02 UTC
OK guys, heres the information. Some of the data is packed so it doesnt look like a CSV file or anything like that. Supposely some of the packed information are read vertically rather than horizontally. An example of what the file looks like : Read more... (892 Bytes)	[reply] [d/l] [select]
Re^3: Accessing flat files on the mainframe by Old_Gray_Bear (Bishop) on Sep 02, 2004 at 23:19 UTC
WHEEEE! If you have a SAS proc to access your data, then change the Proc Print statements to put the packed-decimal fields out in zoned-decimal (printable character) format. That solves one of your biggest issues right off the top -- If you have a MainFrame format problem, use MainFrame re-formatting tools before you grab the file. Now use your favorite FTP to get the file over from the Big Iron World into the small iron world. Procede to read the resultant file as the normal string-of-characters that Unix expects. You will have to use substr or something simular to break up the string into records (unless you remembered to have the SAS code write the new lines for you...) and then attack each record with substr and crow-bar to get the fields pulled out of the record correctly. Wheee what fun. (And don't even think about trying to create a MainFrame readable record on your Unix system. Send SAS a flat file and have it rebuild the pack-decimal for you.) (Personally, I do the whole problem over on the MF using PL/1. But.) ---- I Go Back to Sleep, Now. OGB	[reply]
Re: Accessing flat files on the mainframe by jbodoni (Monk) on Sep 02, 2004 at 22:12 UTC
We have an IBM 825 iSeries (aka an AS/400) where I work. I regularly access DB2 files on it by using the ODBC driver that comes with iSeries Access (aka Client Access). It's an optional component, so you might to install it... and of course, this is ~~assum~~ taking for granted that your environment is at least a little bit like mine. I'm running Windows XP and ActiveState. Using DBI and the ODBC driver, I'm able to retrieve the data with normal SQL statements, and it's great! John	[reply]
Re: Accessing flat files on the mainframe by VSarkiss (Monsignor) on Sep 02, 2004 at 21:56 UTC
If these are flat files and you have access to the host via FTP, your best bet is to use Net::FTP or something similar. If they're not truly flat files (such as VSAM datasets or libraries or some such), there's not much point in copying them off the mainframe because you won't be able to do anything with them anyway. To my knowledge DBI doesn't support any type of hierarchical data store -- although I haven't checked.	[reply]