The importance of alcohol to literary genius has always been exaggerated, particularly by literary geniuses. That seems to be the case with Charles Bukowski, the late Los Angeles poet and novelist who attracted a great following, helped, no doubt, by lurid public perceptions of him as a hell-raiser who read his work in a state of high, theatricalized inebriation and sometimes challenged hecklers to fistfights.

Yet the documentary "Bukowski: Born Into This" depicts a hidden Bukowski. All the rumors, it proves, are true; but it emphasizes what hasn't been emphasized before, which is that he was an extremely hard-working, disciplined craftsman who put in something just as important to success as genius and rotgut: butt time.

That's his butt, that's the chair in front of the typewriter. Take Part A, place it in Part B. Every day for 35 or so years, no matter his health, his sobriety, his emotional life, his poverty, his wealth, his fame, his infamy, no matter what condition his condition was in, he logged the butt time. Clackety-clack, tappity-tap; he ended up with at least 40 books of poetry, fiction and short fiction, modest fame, a nice little house, a movie made. The winner in that race is almost always the guy who sits the longest.

As to the value of that work, I won't bother you with my opinion if you don't bother me with yours. What is indisputable is that "Bukowski: Born Into This" is about as good a picture of a writer's real life as we are likely to get. It is wide-ranging, it is fair, it is thorough, and although it admires, it is also tough enough to condemn.

The director, John Dullaghan, is lucky in that over the years Bukowski attracted a lot of attention and, like a lot of writers, was a sucker for media focus. Thus he sat still for many hours of filmed or taped interviews over his life, giving the director enormous range from which to choose. Dullaghan can pluck footage of the angry, drunken Bukowski of 1977 and play it off against the placidity of the wiser, sadder, richer Bukowski of many years later. (He died in 1994 at age 74.)

But perhaps his most astonishing discovery is a bit of footage shot by the German director Barbet Schroeder, a Bukowski devotee who, while waiting to raise money for his feature version of the Bukowski novel "Barfly" (with Mickey Rourke -- not a very good film, actually), spent much time at the writer's domicile. There, one night, drunk, his demons in full prance, his inhibitions in full retreat, the old man beat up his third wife. Such squalor: the domestic tyrant in full ugly glory, without grace or restraint, blaspheming her over and over, then drawing his gnarly old feet (they were sitting together on the couch) up and driving them into her guts, so that she spills to the floor, broken by his rage. It happens just after a moment when the hymn of praise others were singing to the man is becoming unbearable to us in the audience; how nice to learn what a creep he really was.

The life story, told simply and well, is surprising in its banality. He was the son of a German American father, an ex-doughboy, and a German mother; he was beaten regularly, though possibly he overdramatizes some of these memories. His true nemesis seems to have been a virulent form of acne that all but destroyed his adolescence. (Hemingway: The one necessity to be a writer is an unhappy childhood.) He was utterly undistinguished at the start, a mediocre student, subject to bad health and insomnia. He wrote prose for years, sending out 5,000 stories, selling three or possibly four. He wandered the United States rootlessly for 10 years during the late '40s and early '50s and was a lifelong alcoholic. But he understood the importance of a job, and clung to a clerk's life in the U.S. postal system for 18 years.

After a serious health scare in the '50s, he began writing poetry. He had found himself, and the world soon found him. It's really a success story of the most fundamental Yankee go-getter kind; he followed all those bromides your daddy recited to you that were both cornball and correct: Stick to it. Work hard. Meet people. Genius is 99 percent perspiration and 1 percent inspiration. The harder you work, the luckier you'll get.

He benefited most propitiously from the explosion in the underground newspaper scene in the mid-'60s, when the L.A. Express ran a column of his, "Confessions of a Dirty Old Man," and made him famous in that strange city. Soon he was hobnobbing with movie stars and celebs: Dullaghan tracks down and interviews his pals Tom Waits, Sean Penn and Bono, among others, and all have affectionate recollections. His wives and girlfriends tell slightly different stories, of course. He wasn't any day at the beach to live with, evidently, drunk or sober. But the breaks, after a certain point, just kept on coming. A wealthy collector, John Martin, believed in him so passionately that he became a publisher; the books in hardback just sold and sold and sold. "Barfly" was made. Youth believed in him.

Of course he never got over his demons, but then nobody ever does. Until the very end, he drank grotesquely (the filmmaker uncovers brilliant footage of a few of his drunken readings) and smoked tiny little cigarettes, had a lot of sexual success and a fair amount of commercial success.

Hey. It was a fortunate life, all things considered. Most writers don't get a third of that.

Bukowski: Born Into This (113 minutes, at Landmark's E Street Cinema) is not rated but features extreme profanity and ugly scenes of domestic violence.

"Confessions of a Dirty Old Man," written in the L.A. Express, launched poet-novelist Charles Bukowski.The revealing documentary "Bukowski: Born Into This" both admires and condemns the theatrically alcoholic poet, who died in 1994.