Working with Text Files in C: An Easy, Fun, & Free C Tutorial

Hello there! Welcome to this fun, free, and easy tutorial on working with text files in C. In this tutorial, we’ll dive into the world of text files and how to manipulate them using C programming. So, buckle up and let’s get started!

Understanding Text Files in C

Text files in C are a type of file that contains alphabets and numbers, which are easily understood by humans. They are line-oriented, meaning each line is treated as a separate command. Text files in C are straightforward and easy to understand. All text file functions and types in C come from the stdio library.

#include <stdio.h>

Opening a Text File in C

To work with a text file in C, we first need to open it. We can do this using the fopen function. This function takes two arguments: the name of the file and the mode in which to open the file. For example, to open a file named “example.txt” in read mode, we would use the following code:

FILE *file = fopen("example.txt", "r");

Reading from a Text File in C

Once a file is open, we can read from it using the fscanf or fgets function. The fscanf function is similar to the scanf function but reads from a file instead of the standard input. The fgets function reads one line at a time from a file.

char line[100];
fgets(line, 100, file);

Writing to a Text File in C

To write to a text file in C, we can use the fprintf function. This function is similar to the printf function but writes to a file instead of the standard output.

fprintf(file, "Hello, World!\n");

Closing a Text File in C

After we’re done with a file, it’s important to close it using the fclose function. This function takes one argument: the file pointer of the file to close.

fclose(file);

Code Examples

Let’s look at some complete examples of reading from and writing to text files in C.

Example 1: Reading from a Text File

#include <stdio.h>

int main() {
    FILE *file = fopen("example.txt", "r");
    if (file == NULL) {
        printf("Error! Could not open file\n");
        return -1;
    }

    char line[100];
    while (fgets(line, 100, file) != NULL) {
        printf("%s", line);
    }

    fclose(file);

    return 0;
}

In this example, we open a file named “example.txt” in read mode, read each line of the file and print it to the standard output, and then close the file.

Example 2: Writing to a Text File

#include <stdio.h>

int main() {
    FILE *file = fopen("example.txt", "w");
    if (file == NULL) {
        printf("Error! Could not open file\n");
        return -1;
    }

    fprintf(file, "Hello, World!\n");

    fclose(file);

    return 0;
}

In this example, we open a file named “example.txt” in write mode, write a line to the file, and then close the file.

Wrapping Up

Working with text files in C is a fundamental skill for any C programmer. By understanding how to open, read from, write to, and close

text files, you can start to create more complex and useful programs. Remember, practice makes perfect. So, don’t be afraid to experiment with different file operations and see what you can create!

Frequently Asked Questions (FAQ)

Related Tutorials

• Introduction to File Handling in C
• Reading from and Writing to Files in C
• File Modes and Operations in C
• Working with Binary Files in C

That’s all for this tutorial. Keep practicing and happy coding!