In this source code example, we will see how to use the fopen() function in C programming with an example.

fopen() Function Overview

Source Code Example

#include <stdio.h> int main() { // Trying to open a file to write FILE *filePtr = fopen("sample.txt", "w"); // Seeing if the file opened right if (filePtr == NULL) { printf("Oops! Problem opening the file.\n"); return 1; } // Writing to the file fprintf(filePtr, "Hello, Ram!\n"); fprintf(filePtr, "This is C programming.\n"); // Remember to close the file fclose(filePtr); printf("Finished writing to the file!\n"); return 0; } 

Output

Finished writing to the file! 

Explanation

Here's what we did:

1. We tried to open a "sample.txt" file for writing.

2. Checked if the file opened without issues. If there was a problem, we let you know.

3. We then wrote two messages to the file.

4. Finally, we closed the file to save what we wrote.

When you run this, you should see a "sample.txt" file with our messages.