The external indicators are U1 through U8. These indicators can be set in a CL program or in an RPG IV program. In a CL program, they can be set by the SWS (switch-setting) parameter on the CL commands CHGJOB (Change Job) or CRTJOBD (Create Job Description). In an RPG IV program, they can be set as a resulting indicator or field indicator.
The status of the external indicators can be changed in the program by specifying them as resulting indicators on the calculation specifications or as field indicators on the input specifications. However, changing the status of the IBM i job switches with a CL program during processing of an RPG IV program has no effect on the copy of the external indicators used by the RPG IV program. Setting the external indicators on or off in the program has no effect on file operations. File operations function according to the status of the U1 through U8 indicators when the program is initialized. However, when a program ends normally with LR on, the external indicators are copied back into storage, and their status reflects their last status in the RPG IV program. The current status of the external indicators can then be used by other programs.