You can use a Rexx program whenever you now use Windows batch files or Unix/Linux shell scripts. The following example shows a Windows batch file that processes user input to display a help message:
@echo off if %1.==. goto msg if %1 == on goto yes if %1 == off goto no if %1 == ON goto yes if %1 == OFF goto no if %1 == On goto yes if %1 == oN goto yes if %1 == OFf goto no if %1 == OfF goto no if %1 == Off goto no if %1 == oFF goto no if %1 == oFf goto no if %1 == ofF goto no helpmsg %1 goto exit :msg helpmsg goto exit :yes prompt $i[$p] goto exit :no cls prompt :exit
Here is the equivalent program in Rexx:
/* HELP.CMD -- Get help for a system message */
arg action .
select
  when action=""    then     "helpmsg"
  when action="ON"  then     "prompt $i[$p]"
  when action="OFF" then do
    "cls"
    "prompt"
  end
  otherwise "helpmsg" action
end
exit