How to Compile C Program in Linux?

Compiling C programs in Linux is commonly done using the GCC (GNU Compiler Collection). It translates your .c source files into executable programs.

Setting Up Your Environment

1. Install GCC Compiler

GCC (GNU Compiler Collection) is the standard compiler for C in Linux. To install it, open your terminal and run:

sudo apt update
sudo apt install build-essential

This command installs GCC along with other essential tools like make and libraries required for compiling C programs.

2. Verify GCC Installation

After installation, confirm that GCC is installed correctly:

gcc --version

You should see the GCC version information displayed.

Writing Your First C Program

Use any text editor like nano, vim, or gedit to write your code.

nano quiz.c

Example: quiz.c

#include <stdio.h>
 
int main() {
    printf("Welcome to Sanfoundry Quiz!\n");
    return 0;
}

Compiling the C Program

1. Basic Compilation

To compile your C program, use the gcc command:

gcc quiz.c -o quiz

This command tells GCC to compile quiz.c and output an executable named quiz.

2. Run the Executable

After compiling, run the program:

./quiz

Output:

Welcome to Sanfoundry Quiz!

GCC Compilation Stages

GCC compiles C programs through several stages:

• Preprocessing: Handles directives like #include and #define.
• Compilation: Translates preprocessed code into assembly language.
• Assembly: Converts assembly code into machine code, producing object files.
• Linking: Combines object files and libraries into an executable.

You can observe these stages using GCC flags:

• Preprocessing Only:

gcc -E quiz.c -o quiz.i

• Compile to Assembly:

gcc -S quiz.c -o quiz.s

• Compile to Object File:

gcc -c quiz.c -o quiz.o

• Link Object File to Create Executable:

gcc quiz.o -o quiz

Optional GCC Flags:

Mini Compilation Example

#include <stdio.h>
#define test 100
 
int main() {
    printf("Sanfoundry test score = %d\n", test);
    return 0;
}

To compile:

gcc test.c -o test

To run:

./test

Output:

Sanfoundry test score = 100

Troubleshooting Common Issues

• Command Not Found: If you receive a “command not found” error for gcc, ensure that GCC is installed and added to your system’s PATH.
• Permission Denied: If you encounter a “permission denied” error when running your executable, ensure it has execute permissions:

chmod +x test

• Segmentation Fault: This indicates an error in your code, such as accessing invalid memory. Review your code for mistakes.

Sanfoundry Global Education & Learning Series – 1000 C Tutorials.