There are two ways you, a non-ancient-Greek speaker, could follow its directions. The first is if someone had already translated it into English for you.
You and anyone else who can speak English could read the English version of the recipe and make hummus. Think of this translated recipe as the compiled version. The second way is if you have a friend who knows ancient Greek. When you're ready to make hummus, your friend sits next to you and translates the recipe into English as you go, line by line. In this case, your friend is the interpreter for the interpreted version of the recipe.
Compiled languages are converted directly into machine code that the processor can execute. As a result, they tend to be faster and more efficient to execute than interpreted languages. They also give the developer more control over hardware aspects, like memory management and CPU usage.
In our hummus example, the entire translation is written before it gets to you. If the original author decides that he wants to use a different kind of olive oil, the entire recipe would need to be translated again and resent to you. Interpreters run through a program line by line and execute each command. If you do not have hundreds of dollars to spend on a commercial compiler, then you can use one of the free compilers available on the Web. We will start at the beginning with an extremely simple C program and build up from there.
I will assume that you are using the UNIX command line and gcc as your environment for these examples; if you are not, all of the code will still work fine -- you will simply need to understand and use whatever compiler you have available. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe.
Prev NEXT. Every program and driver in a Mac, as in Windows and Linux computers, is running on a C-powered kernel. So smartphones you use every day are running on a C kernel.
Databases are used in all kind of systems: financial, government, media, entertainment, telecommunications, health, education, retail, social networks, web, and the like. Those applications need to be very efficient and fast, since they handle a huge amount of data and do many calculations per second.
The more efficient they are, the less time it takes for the artists and animators to generate the movie shots, and the more money the company saves.
Imagine that you wake up one day and go shopping. The alarm clock that wakes you up is likely programmed in C. Then you use your microwave or coffee maker to make your breakfast. They are also embedded systems and therefore are probably programmed in C. You turn on your TV or radio while you eat your breakfast. Those are also embedded systems, powered by C.
When you open your garage door with the remote control you are also using an embedded system that is most likely programmed in C. You get to the store, park your car and go to a vending machine to get a soda. What language did they use to program this vending machine?
Probably C. Then you buy something at the store. The cash register is also programmed in C. And when you pay with your credit card? You guessed it: the credit card reader is, again, likely programmed in C. All those devices are embedded systems. That program must detect key presses and act accordingly, and also display information to the user. For example, the alarm clock must interact with the user, detecting what button the user is pressing and, sometimes, how long it is being pressed, and program the device accordingly, all while displaying to the user the relevant information.
The anti-lock brake system of the car, for example, must be able to detect sudden locking of the tires and act to release the pressure on the brakes for a small period of time, unlocking them, and thereby preventing uncontrolled skidding. All those calculations are done by a programmed embedded system. There are many programming languages, today, that allow developers to be more productive than with C for different kinds of projects.
There are higher level languages that provide much larger built-in libraries that simplify working with JSON, XML, UI, web pages, client requests, database connections, media manipulation, and so on.
But despite that, there are plenty of reasons to believe that C programming will remain active for a long time. In programming languages one size does not fit all. C is almost a portable assembly language. It is as close to the machine as possible while it is almost universally available for existing processor architectures.
There is at least one C compiler for almost every existent architecture. It is even used by compilers for other languages to communicate with the machine. For example, C is the intermediate language underlying Eiffel and Forth. This means that, instead of generating machine code for every architecture to be supported, compilers for those languages just generate intermediate C code, and the C compiler handles the machine code generation.
C has also become a lingua franca for communicating between developers. C is a great language for expressing common ideas in programming in a way that most people are comfortable with. Arbitrary memory address access and pointer arithmetic is an important feature that makes C a perfect fit for system programming operating systems and embedded systems.
System applications must read and write to those custom memory locations to communicate with the world. In other words: write the value of variable byte to memory address 0x In this line, we perform a bitwise OR operation on the value at address 0x and the value 0x08 in binary, i. In other words: we set bit 4 of the byte that is at address 0x We also declare that the value at address 0x is volatile.
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