Here we are using 3 files for send OTP(One Time Password) through mail in PHP.
<!DOCTYPE html>
<html>
<header>
<title>HTML Form</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="http://studentstutorial.com/div/d.css">
<header>
<body>
<div class="w3-row">
<div class="w3-half w3-card-2 w3-round">
<div class="w3-container w3-center w3-green">
<h2>Sign In</h2>
</div>
<br>
<form class="w3-container" method="post" action="process.php">
<label class="w3-label w3-text-black"><b>Name</b></label>
<p><input class="w3-input w3-border w3-round" type="text" placeholder="name" name="name" required></p>
<label class="w3-label w3-text-black"><b>Email</b></label>
<p><input class="w3-input w3-border w3-round" type="text" placeholder="email" name="email"></p>
<label class="w3-label w3-text-black"><b>Phone</b></label>
<p><input class="w3-input w3-border w3-round" type="text" placeholder="phone" name="phone"></p>
<p class="w3-center"><button class="w3-btn w3-green w3-round" style="width:100%;height:40px" name="btn-save">Submit</button></p>
</form>
<div class="w3-container w3-center w3-light-grey">
<h4>Students Tutorial</h4>
</div>
</div>
<div class="w3-half">
</div>
</div>
</body>
</html>
<?php
session_start();
$rndno=rand(100000, 999999);//OTP generate
$message = urlencode("otp number.".$rndno);
$to=$_POST['email'];
$subject = "OTP";
$txt = "OTP: ".$rndno."";
$headers = "From: otp@studentstutorial.com" . "\r\n" .
"CC: divyasundarsahu@gmail.com";
mail($to,$subject,$txt,$headers);
if(isset($_POST['btn-save']))
{
$_SESSION['name']=$_POST['name'];
$_SESSION['email']=$_POST['email'];
$_SESSION['phone']=$_POST['phone'];
$_SESSION['otp']=$rndno;
header( "Location: otp.php" );
}
?>
<?php
session_start();
if(isset($_POST['save']))
{
$rno=$_SESSION['otp'];
$urno=$_POST['otpvalue'];
if(!strcmp($rno,$urno))
{
$name=$_SESSION['name'];
$email=$_SESSION['email'];
$phone=$_SESSION['phone'];
//For admin if he want to know who is register
$to="example@gmail.com";
$subject = "Thank you!";
$txt = "Some one show your demo Email id: ".$email." Mobile number : ".$phone."";
$headers = "From: studentstutorial@gmail.com" . "\r\n" .
"CC: divyasundarsahu@gmail.com";
mail($to,$subject,$txt,$headers);
echo "<p>Thank you for show our Demo.</p>";
//For admin if he want to know who is register
}
else{
echo "<p>Invalid OTP</p>";
}
}
//resend OTP
if(isset($_POST['resend']))
{
$message="<p class='w3-text-green'>Sucessfully send OTP to your mail.</p>";
$rno=$_SESSION['otp'];
$to=$_SESSION['email'];
$subject = "OTP";
$txt = "OTP: ".$rno."";
$headers = "From: otp@studentstutorial.com" . "\r\n" .
"CC: divyasundarsahu@gmail.com";
mail($to,$subject,$txt,$headers);
$message="<p class='w3-text-green w3-center'><b>Sucessfully resend OTP to your mail.</b></p>";
}
?>
<!DOCTYPE html>
<html>
<header>
<title>OTP</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="http://studentstutorial.com/div/d.css">
<style>
a{
text-decoration:none;
}
</style>
<header>
<body>
<br>
<div class="w3-row">
<div class="w3-half w3-card-2 w3-round">
<div class="w3-container w3-center w3-green">
<h2>OTP</h2>
</div>
<br>
<form class="w3-container" method="post" action="">
<br>
<br>
<p><input class="w3-input w3-border w3-round" type="password" placeholder="OTP" name="otpvalue"></p>
<p class="w3-center"><button class="w3-btn w3-green w3-round" style="width:100%;height:40px" name="save">Submit</button></p>
<p class="w3-center"><button class="w3-btn w3-green w3-round" style="width:100%;height:40px" name="resend">Resend</button></p>
</form>
<div><?php if(isset($message)) { echo $message; } ?>
</div>
<br>
<div class="w3-container w3-center w3-light-grey">
<h4><a href="studentstutorial.com">Students Tutorial</a></h4>
</div>
</div>
<div class="w3-half">
</div>
</div>
</body>
</html>