Dennis Ritchie (standing) and Ken Thompson at a PDP-11 in 1972. (Photo: Courtesy of Bell Labs)
And then some.
“When Steve Jobs died last week, there was a huge outcry, and that was very moving and justified. But Dennis had a bigger effect, and the public doesn’t even know who he is,” says Rob Pike, the programming legend and current Googler who spent 20 years working across the hall from Ritchie at the famed Bell Labs.
On Wednesday evening, with a post to Google+, Pike announced that Ritchie had died at his home in New Jersey over the weekend after a long illness, and though the response from hardcore techies was immense, the collective eulogy from the web at large doesn’t quite do justice to Ritchie’s sweeping influence on the modern world. Dennis Ritchie is the father of the C programming language, and with fellow Bell Labs researcher Ken Thompson, he used C to build UNIX, the operating system that so much of the world is built on — including the Apple empire overseen by Steve Jobs.
“Pretty much everything on the web uses those two things: C and UNIX,” Pike tells Wired. “The browsers are written in C. The UNIX kernel — that pretty much the entire Internet runs on — is written in C. Web servers are written in C, and if they’re not, they’re written in Java or C++, which are C derivatives, or Python or Ruby, which are implemented in C. And all of the network hardware running these programs I can almost guarantee were written in C.
“It’s really hard to overstate how much of the modern information economy is built on the work Dennis did.”
Even Windows was once written in C, he adds, and UNIX underpins both Mac OS X, Apple’s desktop operating system, and iOS, which runs the iPhone and the iPad. “Jobs was the king of the visible, and Ritchie is the king of what is largely invisible,” says Martin Rinard, professor of electrical engineering and computer science at MIT and a member of the Computer Science and Artificial Intelligence Laboratory.
“Jobs’ genius is that he builds these products that people really like to use because he has taste and can build things that people really find compelling. Ritchie built things that technologists were able to use to build core infrastructure that people don’t necessarily see much anymore, but they use everyday.”
From B to C
Dennis Ritchie built C because he and Ken Thompson needed a better way to build UNIX. The original UNIX kernel was written in assembly language, but they soon decided they needed a “higher level” language, something that would give them more control over all the data that spanned the OS. Around 1970, they tried building a second version with Fortran, but this didn’t quite cut it, and Ritchie proposed a new language based on a Thompson creation known as B.
Depending on which legend you believe, B was named either for Thompson’s wife Bonnie or BCPL, a language developed at Cambridge in the mid-60s. Whatever the case, B begat C.
B was an interpreted language — meaning it was executed by an intermediate piece of software running atop a CPU — but C was a compiled language. It was translated into machine code, and then directly executed on the CPU. But in those days, C was considered a high-level language. It would give Ritchie and Thompson the flexibility they needed, but at the same time, it would be fast.
That first version of the language wasn’t all that different from C as we know it today — though it was a tad simpler. It offered full data structures and “types” for defining variables, and this is what Richie and Thompson used to build their new UNIX kernel. “They built C to write a program,” says Pike, who would join Bell Labs 10 years later. “And the program they wanted to write was the UNIX kernel.”
Ritchie’s running joke was that C had “the power of assembly language and the convenience of … assembly language.” In other words, he acknowledged that C was a less-than-gorgeous creation that still ran very close to the hardware. Today, it’s considered a low-level language, not high. But Ritchie’s joke didn’t quite do justice to the new language. In offering true data structures, it operated at a level that was just high enough.
“When you’re writing a large program — and that’s what UNIX was — you have to manage the interactions between all sorts of different components: all the users, the file system, the disks, the program execution, and in order to manage that effectively, you need to have a good representation of the information you’re working with. That’s what we call data structures,” Pike says.
“To write a kernel without a data structure and have it be as consist and graceful as UNIX would have been a much, much harder challenge. They needed a way to group all that data together, and they didn’t have that with Fortran.”
At the time, it was an unusual way to write an operating system, and this is what allowed Ritchie and Thompson to eventually imagine porting the OS to other platforms, which they did in the late 70s. “That opened the floodgates for UNIX running everywhere,” Pike says. “It was all made possible by C.”
Apple, Microsoft, and Beyond
At the same time, C forged its own way in the world, moving from Bell Labs to the world’s universities and to Microsoft, the breakout software company of the 1980s. “The development of the C programming language was a huge step forward and was the right middle ground … C struck exactly the right balance, to let you write at a high level and be much more productive, but when you needed to, you could control exactly what happened,” says Bill Dally, chief scientist of NVIDIA and Bell Professor of Engineering at Stanford. “[It] set the tone for the way that programming was done for several decades.”
As Pike points out, the data structures that Richie built into C eventually gave rise to the object-oriented paradigm used by modern languages such as C++ and Java.
The revolution began in 1973, when Ritchie published his research paper on the language, and five years later, he and colleague Brian Kernighan released the definitive C book: The C Programming Language. Kernighan had written the early tutorials for the language, and at some point, he “twisted Dennis’ arm” into writing a book with him.
Pike read the book while still an undergraduate at the University of Toronto, picking it up one afternoon while heading home for a sick day. “That reference manual is a model of clarity and readability compared to latter manuals. It is justifiably a classic,” he says. “I read it while sick in bed, and it made me forget that I was sick.”
Like many university students, Pike had already started using the language. It had spread across college campuses because Bell Labs started giving away the UNIX source code. Among so many other things, the operating system gave rise to the modern open source movement. Pike isn’t overstating it when says the influence of Ritchie’s work can’t be overstated, and though Ritchie received the Turing Award in 1983 and the National Medal of Technology in 1998, he still hasn’t gotten his due.
As Kernighan and Pike describe him, Ritchie was an unusually private person. “I worked across the hall from him for more than 20 years, and yet I feel like a don’t knew him all that well,” Pike says. But this doesn’t quite explain his low profile. Steve Jobs was a private person, but his insistence on privacy only fueled the cult of personality that surrounded him.
Ritchie lived in a very different time and worked in a very different environment than someone like Jobs. It only makes sense that he wouldn’t get his due. But those who matter understand the mark he left. “There’s that line from Newton about standing on the shoulders of giants,” says Kernighan. “We’re all standing on Dennis’ shoulders.”
Ruler can do anything, so Born to rule the Galaxy
மத்திய அரசு, இயற்கை உரங்களுக்கு
முக்கியத்துவம் அளிக்க முடிவு செய்துள்ளது. அதேசமயம், ரசாயன உரத்திற்கான
மானியத்தை குறைக்க திட்டமிட்டுள்ளதாக, மத்திய வேளாண் அமைச்சர் சரத்பவார்,
பார்லிமென்டில் தெரிவித்தார்.இதுகுறித்து அவர் மேலும் கூறியதாவது:ரசாயன
உரங்களை தொடர்ந்து பயன்படுத்துவதால், மண் வளம் குறைந்து போவதுடன், வேளாண்
உற்பத்தியும் குறையத் துவங்கியுள்ளது. எனவே, ரசாயன உரத்திற்கு
அளிக்கப்படும் மானியத்தை குறைக்கவும், அதேசமயம் இயற்கை ரசாயன உர உற்பத்தியை
மேம்படுத்துவதற்கான, நடவடிக்கை மேற்கொள்ளவும்
திட்டமிடப்பட்டுள்ளது.நாட்டின் முதல் பசுமை புரட்சியின் போது, ரசாயன உர
பயன்பாட்டால், வேளாண் உற்பத்தி, 50 சதவீதத்திற்கும் அதிகமாக உயர்ந்தது.
ஆனால், ரசாயன உரங்களை தொடர்ந்து பயன்படுத்துவதால், மண் வளம் மிகவும்
பாதிக்கப்பட்டுள்ளது.குறிப்பாக, பஞ்சாப், ஹரியானா, உத்தர பிரதேசத்தின்
மேற்கு பகுதிகளில் அதிகளவு ரசாயன உரங்கள் பயன்படுத்தப்பட்டதால், தற்போது,
அப்பகுதிகளில், நெல் சாகுபடி மேற்கொள்ள முடியாத சூழ்நிலை உருவாகி
விட்டது.இதை கருத்தில் கொண்டு, மத்திய அரசு, இப்பகுதிகளில் பருப்பு வகைகள்,
கோதுமை, எண்ணெய் வித்துக்கள் போன்ற தானியங்களை அதிகளவில், பயிரிடும்
வகையில் விவசாயிகளுக்கு ஊக்கம் அளித்து வருகிறது.நாட்டின் கிழக்கு
பகுதிகளில் உள்ள பல மாநிலங்களில், நெல் சாகுபடிக்கு அதிக முக்கியத்துவம்
அளிக்கப்பட்டு வருகிறது.மத்திய அரசு, மண் வளத்தை மேம்படுத்தும் வகையில்,
பல்வேறு திட்டங்களை அமல்படுத்தி வருகிறது. நுண்ணூட்ட சத்து, உயிரி உரங்கள்,
இயற்கை உரங்கள், பசுந்தாள் உரங்கள் போன்றவற்றை மிக அதிகளவில் உற்பத்தி
செய்யும் வகையில், திட்டங்கள் மேற்கொள்ளப்பட்டு வருகின்றன.மேலும், பழங்கள்
மற்றும் காய்கறி கழிவுகள் வாயிலாக, இயற்கை உர வகைகளை உற்பத்தி செய்வதற்காக,
பெரிய அளவில் தொழில் பிரிவுகளை அமைக்க நிதி உதவி அளிக்கப்பட்டு
வருகிறது.இதன் வாயிலாக, எதிர்காலத்தில், இயற்கை உர வகைகள் உற்பத்தி
அதிகரிக்கும் என, எதிர்பார்க்கப்படுகிறது. இதனால், மண் வளம், மேலும்
மேம்படுவதுடன் இயற்கை சாகுபடியின் மூலம் அதிகளவில், வேளாண் பொருட்களை
உற்பத்தி செய்ய முடியும். இவ்வாறு அவர் கூறினார்.
