I'm working in a migration from Mainframe to Linux using SAS AF, I don't know much about this application, but as I understand it, in the mainframe there are some keyboards that are entered by the user, with some functions to change screens, exit, go to left/right, navigate, etc. Apparently there are some catalogs already created where those keys are associated to one or more screens, using a kind of menu. In that case, how do I associate those keys that appear on the screen to its respective catalog (or key)?
I am leaving attached a print of the mainframe screen of the keys that I want to associate to the commands given by the user.
SAS/AF is very very old, deprecated technology. If you're working on a migration, you probably want to migrate to some other approach for developing a user interface to drive SAS code. Common choices would be using a web interface with SAS stored processes or Viya jobs or whatever as the backend, or for Windows using SAS integration technologies to integrate an interface built with .NET stuff with SAS. If you invest now in building a SAS/AF application, you're choosing to take on a ton of technical debt.
From what I remember, you need to create a KEYS entry in your SAS/AF catalog to contain your custom key definitions. To execute a specified AF program from a function key, you use the AF command followed by the catalog entry you want to start: af c=MyLib.Mycat.MApp.program
Don't bother trying to ride a horse which, in essence, is dead.
Redesign your application with stored processes or Viya jobs, as already suggested.
On top of avoiding technological debt, you will also save money because you no longer need the AF license.
Learn how use the CAT functions in SAS to join values from multiple variables into a single value.
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