convert plain text to formatted html

<?php

// set source file name and path
$source = "php-email.txt";

// read raw text as array
$raw = file($source) or die("Cannot read file");

// retrieve first and second lines (title and author)
$slug = array_shift($raw);
$byline = array_shift($raw);

// join remaining data into string
$data = join('', $raw);

// replace special characters with HTML entities
// replace line breaks with <br />
$html = nl2br(htmlspecialchars($data));

// replace multiple spaces with single spaces
$html = preg_replace('/\s\s+/', ' ', $html);

// replace URLs with <a href...> elements
$html = preg_replace('/\s(\w+:\/\/)(\S+)/', ' <a href="\\1\\2" target="_blank">\\1\\2</a>', $html);

// start building output page
// add page header
$output =<<< HEADER
<html>
<head>
<style>
.slug {font-size: 15pt; font-weight: bold}
.byline { font-style: italic }
</style>
</head>
<body>
HEADER;

// add page content
$output .= "<div class='slug'>$slug</div>";
$output .= "<div class='byline'>By $byline</div><p />";
$output .= "<div>$html</div>";

// add page footer
$output .=<<< FOOTER
</body>
</html>
FOOTER;

// display in browser
echo $output;

// AND/OR

// write output to a new .html file
file_put_contents(basename($source, substr($source, strpos($source, '.'))) . ".html", $output) or die("Cannot write file");
?>