ISPF and debugging applications

The QMF trace facility can help you trace QMF activity at various levels of detail. To help you more effectively debug applications that use ISPF you can also use the ISPF log service and PDF dialog test service. These services complement the QMF trace facility.

The ISPF log service

You can use the ISPF log service to write a message to the ISPF log file. For example, in REXX, the ISPF command to write a message to the ISPF log is:

In this statement, message-id is the identification code for the message that is to be retrieved from the message library and written to the log.

The PDF dialog test service

If your site has PDF, you can use the PDF dialog test service to log ISPF application service calls to the ISPF log file. Additionally, you can use the log option of the PDF dialog test service to browse the contents of the log file or data set. You can also print the log file or data set when you exit ISPF.

The dialog test service has many other useful options for debugging your application. For example, you can debug interactively. You can run all or portions of your application, examine the results, change your application, and rerun it. You can also use dialog test services to accomplish these goals:
  • Start selection panels, command procedures, and programs
  • Display panels
  • Add variables and modify variable values
  • Run ISPF dialog services
  • Add, modify, and delete breakpoint definitions
  • Add, modify, and delete function and variable trace definitions

To create, change, and delete trace definitions, use the trace (TRACES) option of the dialog test service. Also use this option to monitor dialog service calls and dialog variable usage. During processing, if any of the trace definitions are satisfied, trace output is written to the ISPF log. You can use the LOG option of the dialog test services to browse the ISPF log, or examine the printed output when you exit ISPF.