Using SIGNAL ON ERROR

The following example shows how a program might use SIGNAL ON to trap a command error in a program that copies a file. In this example, an error occurs because the name of a nonexistent file is stored in the variable File1. Processing jumps to the clause following the label ERROR:

           /* example of error trap                                    */
           signal on error                  /* Set the trap.           */
                .
                .
                .
      ┌─── "COPY"  file1 file2              /* When an error occurs... */
      │         .
      │         .
      │    exit .
      └───error:                           /* ...REXX jumps to here   */
           say "Error" rc "at line" sigl
           say "Program cannot continue."
           exit                             /* and ends the program.   */