REXX is a platform-independent Scripting Language. It uses extensively in the mainframe. It is a free-flow language.

Let us take a simple program (Reference “Informit”)

/* GUESSING GAME -- try guessing the randomly-generated number */

do while end_this_game <> ’N’
   the_number = random(1,5)  /* generate the random number */
   say "I’m thinking of a number between 1 and 5, what is it?"

   pull your_guess
    say "You entered: " your_guess

   if your_guess = the_number then
      say ’You guessed it! The number was: ’ the_number
    else do
      say ’Sorry, the number was: ’ the_number
      say ’We should have bet on this!’
    end

   say ’Try again? [Y or N]: ’
    pull end_this_game
 end

The above program is self-explanatory.

Points:

• REXX program always starts with /*…….*/ (No problem you can span comments in multi-lines)
• Variables initialization is optional
• There is a number of error-handling conditions available. Some of them are: novalue, error, failure, halt, notready, syntax, lastdigits  
• PULL means in Cobol it is Accept. Say- in Cobol it is Display. 

In my next posts, I will give details from starting of REXX and its usage in the mainframe.