return [ n ]
       Causes a shell function or . script  to  return  to
       the  invoking  script with the return status speci-
       fied by n.  If n is omitted, the return  status  is
       that of the last command executed.

       If  return  was  executed  from a trap in a TRAPNAL
       function, the effect  is  different  for  zero  and
       non-zero return status.  With zero status (or after
       an implicit return at the end  of  the  trap),  the
       shell  will  return  to  whatever it was previously
       processing; with a non-zero status, the shell  will
       behave as interrupted except that the return status
       of the trap is retained.   Note  that  the  numeric
       value of the signal which caused the trap is passed
       as the first argument,  so  the  statement  `return
       $((128+$1))'  will return the same status as if the
       signal had not been trapped.
