General information about REXX

REXX stands for the REstructured eXtended eXecutor language. REXX is a general purpose programming language, similar to PL/I. It includes extensive parsing capabilities for character manipulation, extensive mathematical capabilities, and numerous built-in functions that perform various processing, searching, and comparison functions.

REXX programs are typically run by a language processor (interpreter). That is, the program is run statement-by-statement, without first being converted to another form (compiled). Because of the interpretive nature of REXX, FM/Db2 is able to exploit the power of REXX when processing record selection criteria.

Although REXX is a powerful and versatile language, coding selection criteria using REXX is straightforward. You do not need to know how to write REXX programs. All you need to know is how to write REXX comparison expressions. FM/Db2 takes care of turning your selection criteria into a REXX program.

Much of the information in this section has been extracted from the OS/390® TSO/E REXX Reference and OS/390® TSO/E REXX User's Guide. For more detailed information about REXX, see those manuals.