K & R

Orcblood · October 22, 2016

I've been browsing the internet the last couple of days on K & R and it seems that Dennis Ritchie is mentioned way more than Ken Thompson. Just curious why that is. Didn't they both share the same amount of work on creating C and Unix? Or did Ritchie do more of the work or was more of the brains? Just curious.

straight_stewie · October 22, 2016

1 hour ago, jman629 said:

Didn't they both share the same amount of work on creating C and Unix

No. Let me just explain the full story:

In the mid 1960s Ken Thompson and Dennis Ritchie had both finished their PHDs and were working on a new operating system called Multics for Bell Labs. During this time, Thompson created a new language called BON. During this time, Thompson also invented the first fully working implementation of regular expressions.

In 1969 Bell Labs left behind the Multics project, and Ken Thompson and Dennis Ritchie went with them, after all, they had very nice jobs. That same year, Thompson and Ritchie were put in charge of a new team, a team that was tasked with building a new kind of operating system. This OS would become UNIX. Now, Unix would be very complicated. It would need a hierarchical file system, computer processes and controls, a command line interpreter, built in functionality (like a text editor) the concept of multiple users, and the concept of user permissions. Thompson and Ritchie realized that this would be impossible without some kind of language that had the concept of data types and other such things, Unix was just to big and complicated to write in existing languages.

To fix this problem, Thompson wrote a new language called B. B had nice things, like lot's of useful "syntactic sugar" that makes writing some common things easier and less typing. However, B was interpreted: This means that B runs in a program called an interpreter and that it is the interpreter which executes the machine instructions. It's very nice for some things, but it loses some efficiency. This would not work for UNIX, it needed to be as efficient as possible.

Enter C: Arguably the most important programming language ever developed. C was the brainchild of Dennis Ritchie, although it was based on B. C would have all of the nice features and syntactic sugar of B (and even more), yet be a compiled language. This is excellent for performance. C was originally developed solely for writing UNIX. Necessity is the mother of invention after all.

ANSWER TO YOUR QUESTION: Ritchie is remembered as having invented C because it was his brain child, and therefore was the main "boss" guy on the project. He is remembered as also inventing UNIX partly because he says he did and partly because of the spilled over fame from C. It is important to remember that C likely wouldn't exist if it wasn't for Ken Thompson's BON, and later, Thompson's B. It is also important to remember that UNIX would not exist without C, and therefore, Unix would not exist without either Dennis Ritchie or Ken Thompson.