C ftell() Function 📝

beginner
9 min

C ftell() Function 📝

Welcome to our deep dive into the ftell() function in C programming! This function is a powerful tool that helps you navigate files more efficiently. Let's get started!

Understanding the ftell() Function 🎯

The ftell() function in C is used to determine the current position of the file pointer in a stream (file). It returns the number of characters currently positioned in the file.

Syntax

c
long ftell(FILE *stream);

Where stream is the name of the stream (file).

Why is ftell() Useful? 💡

Imagine you're reading a large text file, and you need to keep track of your position. ftell() comes to the rescue, allowing you to find out where you are in the file at any given moment. This can be particularly useful in situations where you're reading or writing to a file and want to resume from where you left off.

Practical Example 📝

Let's create a simple program that demonstrates the usage of ftell().

c
#include <stdio.h> int main() { FILE *file = fopen("example.txt", "w+"); // Write to the file fprintf(file, "Hello, World!"); // Get the current position long position = ftell(file); printf("Current position: %ld\n", position); // Move the file pointer to the beginning rewind(file); // Read from the file char buffer[20]; fgets(buffer, sizeof(buffer), file); printf("Content: %s\n", buffer); // Close the file fclose(file); return 0; }

In this example, we open a file, write a string to it, find the current position, move the file pointer to the beginning, read the content, and then close the file.

Quiz 🎯

Quick Quiz
Question 1 of 1

What does the `ftell()` function do in C programming?


In our next lesson, we'll dive deeper into file handling in C programming and explore more functions that will help you become a master of file manipulation. Stay tuned! 📝