The colon acts as a clause separator. Arguments are translated into uppercase before the parsing. In the following sections there is a description of all the built-in rexx functions. Internal functions are sequence of instructions inside the same program starting at the label that matches the name in the CALL instruction. If the function is not found in the current program, then REXX will search for a file that matches the name in the CALL instruction and the same extension like the current program, and will load it as an external rexx function.
External routines are like internal but written in a separate module that can be used as a library.
As external routines can be used any DOS command or program that uses standard input and output. Simple DO loop are used to execute a block of instructions often used with IF-THEN statements. Hello Vivi' END Simple repetitive loops. It returns them in their original uninitialized state. If a variable is enclosed in parenthesis then DROP resets all the variables that nameind contains as separate words.