How to add random fortune cookies to Gmail signatures

People used to write Greasemonkey scripts or exploit some long-forgotten Gmail Labs extensions… but there's an easier way: just generate images on the fly and refer them in signatures.

Here's my quick-and-dirty way of doing it:

// Set the content-type
header('Content-Type: image/png');

// Create the image
$image = imagecreatetruecolor(450, 200);

// Fill image with white
$white = imagecolorallocate($image, 255, 255, 255); 
imagefilledrectangle($image, 0, 0, 449, 199, $white); 

// Font settings
$font ='./UbuntuMono-R.ttf';
$font_size = 8;
$font_color =  0x4A4A4A;

// Get the cookie
$text = shell_exec('/usr/games/fortune fortune');                                                                                                                                                                                              

$lines = explode('\n', $text);

// Starting Y position
$y = 12;

// Loop through the lines and place them on the image
foreach ($lines as $line) {
    imagettftext($image, $font_size, 0, 12, $y, $font_color, $font, $line); 
    // Increment Y so the next line is below the previous line                                                                                                                                                                                 
    $y += 12;
}

// Dump the image on screen
imagepng($image);                                                                                                                                                                                                                              
imagedestroy($image);