/*REXX program demonstrates a  method  of  handling events  (this is a time─driven pgm).*/
signal on halt                                   /*allow the user to  HALT  the program.*/
parse arg timeEvent                              /*allow the  "event"  to be specified. */
if timeEvent=''  then timeEvent=5                /*Not specified?  Then use the default.*/

event?:  do forever                              /*determine if an event has occurred.  */
         theEvent=right(time(),1)                /*maybe it's an event, ─or─  maybe not.*/
         if pos(theEvent,timeEvent)\==0  then  signal happening
         end   /*forever*/

say 'Control should never get here!'             /*This is a logic  can─never─happen !  */
halt: say '════════════ program halted.';  exit  /*stick a fork in it,  we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
happening: say 'an event occurred at'  time()", the event is:"   theEvent
             do  while theEvent==right(time(),1)
             nop                                 /*replace NOP  with the "process" code.*/
             end   /*while*/                     /*NOP  is a special REXX statement.    */
signal event?                                    /*see if another event has happened.   */