export [ name[=value] ... ]
       The specified names are marked for automatic export
       to the environment of  subsequently  executed  com-
       mands.   Equivalent  to  typeset -x, except that no
       parameter will be created to hide an  existing  one
       in  an  outer scope.  If a parameter specified does
       not already exist, it  is  created  in  the  global
       scope.
