Special Variables

Per-filehandle Special Variables
These variables never need to be mentioned in a local()because they always refer to some value pertaining to the currently selected output filehandle - each filehandle keeps its own set of values.
Variable	Contents	Mnemonic
$|	If set to nonzero, forces a flush after every write or print	When you want your pipes to be piping hot
$%	Current page number	% is page number in nroff
$=	Current page length	= has horizontal lines
$-	Number of lines left on the page	lines_on_page - lines_printed
$~	Name of the current report format	Closely related to $^
$^	Name of the current top-of-page format	Points to top of page