How To Code A Login Page In C

C++ Programming

Hey there, fellow coders! Today, I want to share with you my experience of coding a login page in C. As a programmer, I’ve always found the process of designing and building login pages to be both challenging and rewarding. In this article, I’ll guide you through the step-by-step process of creating a login page in C, while also adding personal touches and commentary along the way.

Getting Started

The first thing we need to do is to set up a development environment for coding in C. You’ll need a text editor and a C compiler to get started. Personally, I prefer using Visual Studio Code as my text editor and the GNU Compiler Collection (GCC) as my compiler. However, feel free to use the tools that you’re most comfortable with.

Once you have your development environment set up, create a new C file and let’s dive into the code.

Creating the Login Page

First, let’s include the necessary header files:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

Next, we’ll define a struct to represent a user:

typedef struct {
char username[20];
char password[20];
} User;

In this struct, we have two character arrays, username and password, each with a maximum length of 20 characters. Feel free to adjust these lengths based on your specific requirements.

Now, let’s write a function to validate the user’s credentials:

int validateUser(User users[], int numUsers, char username[], char password[]) {
for (int i = 0; i < numUsers; i++) { if (strcmp(users[i].username, username) == 0 && strcmp(users[i].password, password) == 0) { return 1; // User found, credentials are valid } } return 0; // User not found, credentials are invalid }

This function takes an array of User structs, the number of users in the array, and the entered username and password as arguments. It iterates through the array and checks if there's a match for both the username and password. If a match is found, it returns 1; otherwise, it returns 0.

Now, let's write the main function where we'll implement the login functionality:

int main() {
// Create an array of User structs
User users[2];
strcpy(users[0].username, "myusername");
strcpy(users[0].password, "mypassword");
strcpy(users[1].username, "anotheruser");
strcpy(users[1].password, "anotherpassword");

char username[20];
char password[20];

printf("Enter your username: ");
scanf("%s", username);

printf("Enter your password: ");
scanf("%s", password);

if (validateUser(users, 2, username, password)) {
printf("Login successful!\n");
} else {
printf("Invalid username or password.\n");

return 0;

In this main function, we create an array of User structs and initialize it with some sample user data. Then, we prompt the user to enter their username and password using the scanf function. We pass the entered credentials to the validateUser function, which checks if they match any of the users in the array. Based on the validation result, we display an appropriate message.


And there you have it! We've successfully coded a login page in C. I hope this article has provided you with a solid foundation for implementing your own login pages in C. Remember, coding is all about practice, so don't be afraid to experiment and improve upon what you've learned here.

If you want to take your knowledge further, I recommend exploring topics like password hashing for enhanced security or integrating your login page with a database for storing user information. The possibilities are endless!

Now, go ahead and put your newfound skills to the test. Happy coding!