File modes in C - Mini Project: Build & Apply

File modes

📖 Scenario: You are working on a simple program that needs to create and write to a file. Understanding how to open files in different modes is important to control whether you create a new file, overwrite an existing file, or append to it.

🎯 Goal: Build a C program that opens a file in write mode, writes a line of text, and then prints a confirmation message.

📋 What You'll Learn

Create a file pointer variable

Open a file named example.txt in write mode

Write the exact text Hello, File Modes! to the file

Close the file properly

Print File written successfully. to the console

💡 Why This Matters

🌍 Real World

File modes are used in programs to control how files are accessed and modified, such as saving user data or logs.

💼 Career

Understanding file modes is essential for software developers working with file input/output operations in many applications.

1

Create a file pointer variable

Declare a file pointer variable called file of type FILE *.

C

# Declare a file pointer variable called file
// Your code here

Need a hint?

Use FILE * to declare a pointer for file operations.

2

Open the file in write mode

Open a file named example.txt in write mode using fopen and assign it to the variable file.

C

#include 

FILE *file;

// Open example.txt in write mode
// Your code here

Need a hint?

Use "w" mode in fopen to write to a file (creates or overwrites).

3

Write text to the file and close it

Use fprintf to write Hello, File Modes! to the file pointed by file. Then close the file using fclose.

C

#include 

FILE *file;

file = fopen("example.txt", "w");

// Write text to the file
// Close the file
// Your code here

Need a hint?

Use fprintf(file, "text") to write and fclose(file) to close the file.

4

Print confirmation message

Print File written successfully. to the console using printf.

C

#include 

FILE *file;

file = fopen("example.txt", "w");
fprintf(file, "Hello, File Modes!\n");
fclose(file);

// Print confirmation message
// Your code here

Need a hint?

Use printf("File written successfully.\n") to show the message.