Login Form

PHP Programming

PHP Programming Examples

<!DOCTYPE html>
<html>
	<head>
		<title>Login Form</title>
	</head>
	<body>
		<form  method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
			<input type="text" name="username" placeholder="Username" />
			<input type="password" name="password" placeholder="Password" />
			<input type="submit" value="Login" />
		</form>


		<?php
			if(isset($_POST['username']) && isset($_POST['password'])) {

				/* Associative Array with md5 encrypted password */
				$loginfo = array("geek12" => md5("1234"), "abc4" => md5("abcd"), "jcb84" => md5("msk53"));
				
				/* Trim whitespace from the beginning and end */
				/* Compare with regular expression */
				if((trim($_POST['username']) == '') || (ereg ('[^a-zA-Z0-9]', $_POST['username'])))
					echo "Invalid username...Usernames only contain letters and digits.";
				else {
					if((trim ($_POST['password']) == '') || (ereg ('[^[:alnum:][:punct:][:space:]]', $_POST['password'])))
						echo "Invalid password...Passwords only contain letters, digits, punctuation and spaces.";
					else { 

						/* Checking username exist or not */
						if(isset($loginfo[$_POST['username']])) {

							/* Checking password associated with matched username */
							if($loginfo[$_POST['username']] == md5($_POST['password'])) {
								/* Set session */
								session_start();
								$_SESSION["user_id"] = $_POST['username'];
								echo "Authenticated!";
							}
							else
								echo "Password didn't match!";
						}
						else
							echo "Username didn't match!";
					}
				}
			}
		?>
	</body>
</html>


          /****** Output ******/
          

Input:

username = geek12

password = 1234


Authenticated!

Learn more about md5, trim and ereg