NEW YORK — Clint Eastwood will get the full two-hour biographical treatment in a new TV documentary that TNT has commissioned from Eastwood’s biographer Richard Schickel.Sources said Schickel, who will write, produce and direct the documentary, will get “unprecedented personal access” to Eastwood, the same access Schickel got for his massive bestselling volume “Clint Eastwood: A Biography.” TNT is expected to announce the docu on Monday. A series of in-depth interviews with Eastwood by Schickel will form the spine of the docu. Schickel has also gotten hold of film of some of Eastwood’s rare TV appearances, plus home movies and excerpts from many of his theatrical movies. Eastwood will also let TNT’s cameras film him on the set of “Midnight in the Garden of Good & Evil,” the movie he’s directing for Warner Bros. Schickel, a movie critic for Time magazine, has written and produced a number of other documentaries about movie history. His previous books include “D.W. Griffith: An American Life” and “Brando: A Life in Our Times.” Over the years, TNT has produced a number of docus about Hollywood stars, including Humphrey Bogart, Katharine Hepburn and James Cagney. Executive producer of the Eastwood docu is Carl H. Lindahl. It will run on TNT sometime in the fourth quarter of 1997.