Starting QMF from an application

Before you can run any other command from an application, you must start QMF. When using the callable interface, you start QMF by issuing the START command. You can have only one QMF session at a time.

Your application can issue a START command to test if QMF has already been started. If QMF has not been previously started, it starts. If QMF was previously started, the return code is nonzero, and you receive the following message number and message:

DSQ50719 QMF already active.  Secondary session not permitted.

With the REXX callable interface, you also can run the following program:

/*  test to see if QMF is active   */
"SUBCOM QRW"
if rc = 0
  then say "QMF is active"
else say "QMF is not active"

If your START command results in an error that is not severe (a return code of 4 or 8), QMF starts with errors. In this case, you can issue the EXIT command to stop QMF. You might want to issue the START command again. If the error persists, inspect the contents of the interface communications area or the QMF trace data output for sources of the error.

To pass parameters to QMF, specify the desired command keywords on the START command.

For details about the syntax and keywords used with the start command, see START.