File Handling in C Programming – Complete Beginner Guide with Examples

File handling is an essential part of C programming when you want to store data permanently.

Instead of losing data when a program ends, file handling allows programs to read and write data into files.

In this article, you will learn file handling in C programming from scratch with clear explanations and beginner-friendly examples.

What Is File Handling in C?

File handling in C allows you to work with files stored on your system.

You can:

• Create files
• Read data from files
• Write data to files
• Append data to files

FILE Pointer in C

To work with files, C uses a FILE pointer.

FILE *fp;

Opening a File

The fopen() function is used to open a file.

fp = fopen("data.txt", "w");

File Modes in C

• r – Read mode
• w – Write mode
• a – Append mode
• r+ – Read and write

Writing to a File

You can write data using fprintf().

fprintf(fp, "Hello C Programming");

Reading from a File

Use fscanf() or fgets() to read data.

fgets(buffer, 100, fp);

Appending Data to a File

Append mode allows you to add new data without deleting existing content.

fp = fopen("data.txt", "a");

Closing a File

Always close a file after use to free resources.

fclose(fp);

Common File Handling Mistakes

• Not checking if file opened successfully
• Forgetting to close files
• Using wrong file mode

Why File Handling Is Important?

• Permanent data storage
• Database handling
• Log files

Interview Questions on File Handling

• What is FILE pointer?
• Difference between write and append mode?
• Why should files be closed?

Final Conclusion

File handling allows C programs to store and retrieve data efficiently. Mastering this concept helps you build real-world applications and improves your programming skills.