Hurricane Billy was a nickname the director William Friedkin acquired in his 1970s heyday. Not just for the turbulence of his creative energy; he had an awful temper, too. Now 83, Friedkin still makes pictures, but he also spends a good deal of time flogging his memoir and hosting screenings of varied restorations from his fascinating and still-vital filmography. The gems include “The French Connection,” “The Exorcist,” “Sorcerer,” “Cruising” and “To Live and Die In L.A.”

In his in-person, self-promoting persona, Friedkin adopts an avuncular mode that’s more voluble than volatile. That is the Friedkin on display in “Friedkin Uncut,” a worshipful documentary portrait directed by Francesco Zippel .