Like so many others in the world of software, I was greatly saddened yesterday by the news of Dennis Ritchie's death. We have lost a great contributor to our world and a really fine man. I first read K&R in 1980—a free copy included with my first Unix licence—and it changed my life. The book and the C language both shared many virtues which are so widely-known that I won't repeat that story now.
My first direct connection with dmr was an email he wrote to me back in the days of Usenet, something he avoided. But somebody had alerted him to a piece I had written and he thought it would be good to disabuse me of a misunderstanding. His email to me was as clear and spare as the book and his tone was perfect—polite, respectful, generous and kind. Naturally, I corrected my error in the forum where I had first written.
A couple of years later, after K&R2 had been published, I pontificated about the correct way to do something in C and was shouted down by people who were conversant with the new edition—a book I owned but had not read carefully at that time. I said K&R was wrong if they disagreed with me, expecting to find that those people had mis-read the book. Subsequent research revealed to me that K&R did put things differently from my understanding. So I wrote to Dennis and asked him to help out. Initially he said he thought the book was right. But when I wrote back with a detailed explanation for my belief, he promptly replied that I was right and the book was wrong. This resulted in an extra item in the still short errata for K&R2. What impressed me most in that exchange of email was that dmr never acted as if he had all the answers, but was ready to listen carefully to anybody who had something to say. I have tried to learn that from him.
Later I had the opportunity to meet him in person at a conference where he gave a keynote about an early release of Plan 9. He wore his hat with a propeller on top and gave a great talk. In person, dmr is just as nice as I had expected from my other interactions with him. We had occasion to correspond about C and its directions several times after that and I'm very grateful for his thoughtful and amusing emails.
Although this is really about Dennis, it seems wrong not to also mention his collaborator on K&R. I never met Brian in person, but have had email correspondence with him too. He showed the same wonderful manner of communication as did Dennis. I think of them both as mentors.
So, thank you, Dennis Ritchie. You have made a powerful and admirable mark upon our world.