Brian Kernighan: UNIX, C, AWK, AMPL, and Go Programming | Lex Fridman Podcast #109 | Summary and Q&A

TL;DR

Brian Kernighan discusses the creation and impact of UNIX, the power of programming languages like C and awk, and the importance of examples in programming.

Key Insights

• 📽️ The creation of UNIX was a result of the need for a more advanced and accessible computing environment after the failure of the Multics project.
• 🔙 The success of programming languages like C and awk can be attributed to their balance of expressiveness and efficiency, making them versatile and user-friendly.
• ❓ Examples in programming are essential for both learning and problem-solving, as they provide practical demonstrations and enable programmers to better understand the language and its capabilities.

Transcript

the following is a conversation with Brian Kernighan a professor of computer science at Princeton University he was a key figure in the computer science community in the early UNIX days alongside UNIX creators Ken Thompson and Dennis Ritchie he co-authored the C programming language with Dennis Ritchie the creator of C and has written a lot of book... Read More

Questions & Answers

Q: How was UNIX created and what led to its development?

UNIX was created by a group of individuals at Bell Labs, who were looking for a replacement for the Multics project that had failed to deliver its promises. They wanted to create an operating system that provided comfortable computing and the facilities of Multics, leading to the development of UNIX.

Q: What were the key features that made C programming language successful?

C programming language found a sweet spot between expressiveness and efficiency. It allowed for more natural ways of expressing ideas while still being efficient on limited hardware. Additionally, its portability on various machines and association with UNIX made it widely available and widely used.

Q: How did awk contribute to text processing and what were its main features?

awk, co-created by Brian Kernighan, was a text processing language that made it easy to perform tasks like counting, selecting, and summarizing information from text files. Its key feature was the ability to process text in a shorter, more concise code, making it a powerful tool for data analysis.

Q: What role do examples play in programming?

Examples are crucial in programming as they provide practical demonstrations of how to accomplish specific tasks. Well-crafted examples not only show how to solve a problem but also guide programmers in understanding the core principles and syntax of a programming language. They serve as a valuable learning tool for both beginners and experienced programmers.

Q: How was UNIX created and what led to its development?

UNIX was created by a group of individuals at Bell Labs, who were looking for a replacement for the Multics project that had failed to deliver its promises. They wanted to create an operating system that provided comfortable computing and the facilities of Multics, leading to the development of UNIX.

More Insights

• The creation of UNIX was a result of the need for a more advanced and accessible computing environment after the failure of the Multics project.

• The success of programming languages like C and awk can be attributed to their balance of expressiveness and efficiency, making them versatile and user-friendly.

• Examples in programming are essential for both learning and problem-solving, as they provide practical demonstrations and enable programmers to better understand the language and its capabilities.

• Programming languages continue to evolve and new languages emerge, offering unique features and catering to specific needs within the programming community.

Summary

In this conversation, Lex Friedman interviews Brian Kernighan, a professor of computer science at Princeton University and one of the key figures in the early days of UNIX. They discuss the creation of UNIX, its philosophy, and its impact on the programming community. They also touch on other topics such as programming languages, the art and science of programming, and some of Kernighan's favorite tools like AWK and grep.

Questions & Answers

Q: Can you summarize the story of how UNIX was created?

In 1969, a group of people at Bell Labs who had just finished working on the Multics project started thinking about creating a new operating system. Ken Thompson, one of the team members, began experimenting with file systems on a little-used PDP-7 computer. When his wife went away for three weeks, he wrote the initial version of UNIX, which eventually became the foundation for the operating systems we use today.

Q: What was the philosophy behind UNIX?

The primary goal of UNIX was to provide an environment that made it easy for programmers to write code. It aimed to be a productive and cooperative community where people could develop software. The focus was on creating a simple and efficient system that could be used for a wide range of tasks.

Q: How did the collaboration and feedback process work at Bell Labs during the creation of UNIX?

Bell Labs had a very open and cooperative environment, which allowed for easy collaboration between researchers and engineers. People would often come into each other's offices to discuss problems and work on solutions. The feedback loop was short, with people providing critiques and suggestions for improvement. This close-knit community and the supportive environment led to the rapid development of UNIX.

Q: What features made UNIX a good operating system?

One of the key factors was the modest hardware on which it was initially developed. This forced the developers to create a minimal set of mechanisms and find generalizations that could serve multiple purposes. For example, the simple file system interface in UNIX was later extended to handle other resources like devices. This focus on efficiency and generalizability helped UNIX become a robust and versatile operating system.

Q: Is programming more of an art or a science?

Programming is a combination of both art and science. The art lies in figuring out what needs to be done and envisioning a good program. The science lies in finding the most efficient algorithms and data structures to implement that program. It's also an engineering field, as programmers need to consider constraints like time, scalability, and future maintenance.

Q: What is the process of writing a program like for you?

Since Kernighan often writes small programs or experiments, he follows an informal and incremental process. He usually starts coding right away and iteratively refines the program as he goes. He enjoys the puzzle-solving aspect of programming and finds joy in writing code that others can use.

Q: What do you love about AWK?

Kernighan loves AWK for its simplicity and elegance. It provides a powerful yet easy way to perform quick tasks like counting or rearranging data in text files. AWK's automatic selection of default behaviors, such as splitting data into fields, allows for concise programs that reveal insights about the data. Kernighan believes AWK is a valuable tool to learn due to its high productivity for small programs.

Q: What makes grep such a powerful tool?

Grep is a simple yet powerful tool for searching patterns in text files. It shares the pattern-action paradigm with AWK but with a simpler structure. Kernighan finds grep extremely useful for quickly finding and printing lines that match a specific pattern. It's a fundamental tool that he utilizes frequently.

Q: Why do you think the command-line tools like grep and awk are more prevalent in the UNIX and Linux environment?

Kernighan believes it's partly due to the weight of history. The UNIX environment, starting from MS-DOS, honed a command-line culture, emphasizing the use of tools like grep and awk. In contrast, the graphical interface in Windows emphasized a point-and-click approach more suitable for non-programmers. However, tools like Cygwin and WSL (Windows Subsystem for Linux) have enabled UNIX-like command-line environments on Windows.

Q: What is your perfect programming setup?

Kernighan uses a 13-inch MacBook Air as his primary computer, finding it to be a good balance of size, power, and portability. For his editor, he prefers Sam, an editor originally developed at Bell Labs. Kernighan appreciates Sam's simplicity and efficiency, making it his preferred choice for small programs. He also mentions the iMac in his office for use when a larger screen is needed.

Takeaways

Brian Kernighan's interview offers insights into the creation and philosophy of UNIX, the art and science of programming, and some of his favorite programming tools like AWK and grep. The collaborative and supportive environment at Bell Labs played a crucial role in the rapid development of UNIX. The UNIX philosophy focused on creating an environment that made it easy for programmers to write code and fostered a community of developers. Kernighan's love for programming shines through as he discusses the joy of writing code and the satisfaction of creating programs that others can use. The command-line tools like AWK and grep continue to be valuable tools for programmers, and Kernighan emphasizes the versatility and efficiency of these tools. Overall, the interview provides a glimpse into the early days of UNIX and the impact it has had on the programming community.

Summary & Key Takeaways

• Brian Kernighan recounts the development of UNIX and its origins as a solution for comfortable computing and information utility.

• He highlights the importance of creating programming languages like C and awk that are both expressive and efficient, allowing for greater productivity and accessibility in programming.

• Kernighan emphasizes the power of examples in programming, demonstrating how they can simplify complex tasks and provide valuable insights into data processing.