What is the Callable Interface?

Programming languages can use the QMF callable interface to run QMF commands. All SAA Query commands are supported through the callable interface. The QMF callable interface provides standard interfaces for different programming languages, and provides common storage and access to program variables.

When an application program needs to run a QMF command, it must first issue a call to a QMF-supplied routine to start communication between the program and QMF. This call is made to the QMF-supplied interface routine. QMF supplies a routine for each supported language.

The application program can issue one or more QMF commands after the initial start call. The application program calls the QMF-supplied routine to issue each QMF command.

After the QMF command finishes processing, QMF supplies a return code that indicates the status of QMF. The callable interface gathers other information about the processing of the command and stores this information in variables accessible to both QMF and the application program. These variables are contained in either a variable pool or in an interface communications area. When the callable interface returns control to the calling application program, the application can refer to these variables but should not alter them.

When the application program no longer needs to use QMF, the program issues a call to terminate communication between the program and QMF. This call is made to the QMF-supplied routine.