Just like print, but implicitly appends a
newline.  say LIST
 is simply an abbreviation for
{ local $\ = "\n"; print LIST }
.  To use FILEHANDLE without a LIST to
print the contents of $_  to it, you must use a bareword
filehandle like FH
, not an indirect one like $fh
.
say is available only if the
say feature is enabled or if it is
prefixed with CORE::
.  The
say feature is enabled automatically
with a use v5.10
 (or higher) declaration in the current scope.