NEW YORK — Alice Walker, who turns 70 this month, is thinking about her legacy.

Over the past few years, the Pulitzer Prize-winning author has donated her papers to Emory University, permitted “The Color Purple” to be released as an e-book and reached a deal with Simon & Schuster to publish excerpts from journals she has kept for decades. Walker also participated in the documentary “Alice Walker: Beauty in Truth,” scheduled to air Friday night on PBS stations as part of the “American Masters” series.

“I don’t have this feeling that 70 is really old,” said Walker, who noted that one ancestor lived to 125. “But I do feel it’s helpful if you’re thinking about the coming generations to leave your work in a form that people can relate to.”

Walker said one reason she agreed to appear in the film is because the director, Pratibha Parmar, is a friend.

Parmar said she was inspired to make the documentary a few years ago after viewing DVDs of other “American Masters” projects.

“It seemed crazy not to have a film on Alice, given the impact she’s had with her life and her writing,” said Parmar, who in the 1990s worked with Walker on the film and book “Warrior Marks,” about female genital mutilation in Africa.

The film closely tracks Walker’s childhood on a former Georgia plantation, when money was so scarce her mother lined her own bedroom with paper bags; her years as a scholarship student at Spelman College; her brief marriage to the Jewish civil rights activist Melvyn Leventhal (“We were prepared to die,” she says in the film); and her long and diverse career as an author.