How to attach PDF to email using PHP mail function

I am sending an email using PHP mail function, but I would like to add a specified PDF file as a file attachment to the email. How would I do that?

Here is my current code:

$to = "[e-mail]";
$subject = "My message subject";
$message = "Hello,nnThis is sending a text only email, but I would like to add a PDF attachment if possible.";
$from = "Jane Doe <[e-mail]>";

$headers = "From:" . $from; 
mail($to,$subject,$message,$headers);

echo "Mail Sent!";

Answer

You should consider using a PHP mail library such as PHPMailer which would make the procedure to send mail much simpler and better.

Here’s an example of how to use PHPMailer, it’s really simple!

<?php

require_once('../class.phpmailer.php');

$mail             = new PHPMailer(); // defaults to using php "mail()"

$body             = file_get_contents('contents.html');
$body             = eregi_replace("[]",'',$body);

$mail->AddReplyTo("[e-mail]","First Last");

$mail->SetFrom('[e-mail]', 'First Last');

$mail->AddReplyTo("[e-mail]","First Last");

$address = "[e-mail]";
$mail->AddAddress($address, "John Doe");

$mail->Subject    = "PHPMailer Test Subject via mail(), basic";

$mail->AltBody    = "To view the message, please use an HTML compatible email viewer!"; // optional, comment out and test

$mail->MsgHTML($body);

$mail->AddAttachment("images/phpmailer.gif");      // attachment
$mail->AddAttachment("images/phpmailer_mini.gif"); // attachment

if(!$mail->Send()) {
  echo "Mailer Error: " . $mail->ErrorInfo;
} else {
  echo "Message sent!";
}

?>

An alternative to PHPMailer is http://swiftmailer.org/