[chrome 36.0.1985.143 m]
<?php
echo "1";
?>
<!doctype html>
<html>
<head>
<title>test</title>
<script>
alert();
</script>
</head>
<body>
</body>
</html>
输出：
1<!doctype html>
<html>
<head>
<title>test</title>
<script>
alert();
</script>
</head>
<body>
</body>
</html>
浏览器会解析成：
<html>
<head>
</head>
<body>
"1
"
<title>test</title>
<script>
alert();
</script>
</body>
</html>
