Re: Driving TN5250 non-interactively

Can you use a web service instead?

If the reports to be transfered are easy to build, you can generate a 
web page and retrieve it automaticlay.
If you need the output of a "batch" program, you can run it from a web 
page (automaticaly, by using something like wget) and retrive the spoll 
file after.

Richard Nolde wrote:

>TN5250 list members:
>
>I've been tasked with writing an interface between an application that 
>runs on a remote iSeries host, accessible with TN5250 over a private 
>network, and our application that would query the iSeries in real time 
>without human interaction. My application will run on a Linux or AIX 
>box, and act like a broker between the local application and the remote 
>iSeries host application that contains the database we are querying.
>
>I've been studying the current TN5250 source code to get a feel for what 
>I'm up against and clearly this is no simple task. Can anyone recommend 
>one or more books/online sources about how the TN5250 interface on 
>iSeries works. eg format fields, data types, etc. I can generate the 
>requests manually with TN5250 and get the desired results back as a 
>spool file with lp5250d, so my main objective is how to replace the 
>curses interface with one that reads from a file or other 
>non-interactive source. Eventually, I will provide a daemon that handles 
>requests from multiple clients over a socket interface and serializes 
>them for submission to the iSeries host, but that isn't necessary for now.
>
> From what I've read and seen by playing with the remote application, I 
>will need to know the position, length, and data types for each field of 
>each screen that I wish to use, and Action or Function Key definitions 
>for each screen. Assuming I can build a map that identifies each 
>component of each screen, and the sequence of screens that will be 
>encountered, I would then load each field with the appropriate value and 
>call one of the TN5250 functions to send the data on the stream to the 
>remote host application.  If the application screen produces output, I 
>may or may not chose to parse it directly if I can get everything I want 
>from the print spool that is returned via lp5250d.  In the sample cases 
>that I have looked at, the screen output simulates bold printing by 
>issuing a carriage return and then resending the data for selected 
>fields a second time, as might have been done with ancient line printers 
>of yore. I can probably parse this out but it would be nice to be able 
>to disable this altogether.  I'm currently not using a Host Print 
>Transform on the print spool output, only scs2ascii as there are no 
>graphics involved. The returned data is in a format that I should be 
>able to parse on my end as long as I know the parameters that were used 
>to generate the query and the screen from which the output is derived.
>
>I note that the TN5250 application can be compiled without ncurses 
>support, but doing so produced an executable that will not interact with 
>the remote host. I assume that this is due to the field position 
>requirements of the remote application.
>
>My initial approach is to build a profile of all the function calls in 
>the tn5250 interactive application and see which ones call functions 
>from the ncurses library. Once I understand how/where the screen 
>co-ordinates are being set/read, I may be able to write a function that 
>will read the appropriate values from my template files and the input 
>data stream.
>
>Any ideas/suggestions and online documentation references would be 
>welcome.  I have no access to the iSeries host except through the remote 
>application. My servers run Linux or AIX 5.3.
>
>Thanks,
>Richard Nolde
>  
>

-- 
This is the Linux 5250 Development Project (LINUX5250) mailing list
To post a message email: LINUX5250-Zwy7GipZuJhWk0Htik3J/[email protected]
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/linux5250
or email: LINUX5250-request-Zwy7GipZuJhWk0Htik3J/[email protected]
Before posting, please take a moment to review the archives
at http://archive.midrange.com/linux5250.