Compile and Run C Program | Creating and Running C Program | Compiling and Executing C Program

The compilation and execution (running) process of C program follows multiple steps. A brief explanation of each step is given below:

Step 1: Creating Source Code

When we write a program in ‘C’, that program is called source code. Every c program source file is saved with .c extension. To create source code, we use any text editor. The instructions written in the source code must follow the C programming language rules.

Step 2: Compiling the program

The compilers job is to translate the instructions in the source file into instructions called executable code that the operating system can understand and execute.  The source code passes through a number of intermediate stages before it turns into executable code.  The source code is sent to the preprocessors first.

Preprocessor: 

Preprocessor processes the source code before compilation. It performs some task like removing comments, include header files, expand the macros etc. The preprocessor generates the expanded source code. Then the expanded source code is passed to the compiler.

Compiler: 

Compiler will compile the program. It first checks the program errors, if errors are found it returns a list of errors. If the compiler reports no error, then it converts source code into the object code and stores it as a file with extension .obj. Then the object code is given to the Linker.

Linker: 

Linker is another important part of the compilation process. It takes the object code and links it with required library files. After linking, the linker generates executable code with extension .EXE which is ready to execute. The executable code is sent to loader

Step 3: Executing / Running the program

Loader: 

Whenever we give the command to execute a particular program, the loader comes into work. Loader loads the executable file into the main/primary memory and then it is executed. After execution, output is sent to the monitor screen of the computer.

The following diagram will show how a C Source Code can be executed.