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.
