Types of File Descriptions

When identifying the file description your program will be using, you must indicate whether it is a program-described file or an externally described file.

Externally described files offer the following advantages:

If an externally described file (identified by an E in position 22 of the file description specification) is specified for the devices SEQ or SPECIAL, the RPG program uses the field descriptions for the file, but the interface to the operating system is as though the file were a program-described file. Externally described files cannot specify device-dependent functions such as forms control for PRINTER files because this information is already defined in the external description.



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