How can I make my php script insert at a specific spot?

[trimidium]

made a nifty little question and answer script on my website: http://www.thesmartass.info/index.php?main=oaq . It works by using fwrite to dump preformated html into a text file, then I include the text file into the site and manually answer the questions myself when they appear.

However it has really taken off and I have better plans for this script. To achieve them I need my script to output not to a text file, but to an Atom feed, I suppose rss would be alright as well....

At any rate, I have been attempting to make the script output to xml, however I can't figure out how to make my output insert in a specific spot in the atom feed. It only outputs at the end of the file, which causes the to cut off before the questions.

How can I tell my output to appear directly after the first ID tag:
<id>tag:thesmartass.info,2006:001</id>

I tried to put it inside a preg_match_all tag, but to be honest I don't understand how that works at all so It didn't place it right. Before I added that, it just outputed $html and it landed at the bottom of a text file.

Your help would be most appreciated, I have already asked at several other places and nobody has been able to fix the script, your site came highly reccomended.

<?php
header('Expires: ' . gmdate('D, d M Y H:i:s') . ' GMT');

header('Cache-Control: no-cache, must-revalidate, max-age=0');
header('Pragma: no-cache');

$phrases = array(
    "is left to wonder",

    "is pondering",
    "wants to know",
    "is curious to find out",
    "is dying to know",

    "desires the answer for",
    "has been meditating on the answer to"
);

// write the question to a separate HTML file

$question = stripslashes($_POST["question"]);
if ($question == "?") $question = "";

if ($question) {
    $author = ($_POST["name"]) ? $_POST["name"] : "Chicken ****";

    $website = ($_POST["url"]) ? $_POST["url"] : "";
    $filename = "aas.xml";
    // build the message

    if ($questions = fopen($filename, "r+t")) {
        $QA = fread($questions, filesize($filename));

        $id = preg_match_all("/tag:thesmartass.info,2006:00/", $QA, $match) + 1;
        // add the entry

        $html =
         "\n".
         "<entry>\n".
         "    <title>".htmlspecialchars($question)."</title>\n".

         "    <link href=\"http://thesmartass.info/index.php?main=oaq\" />\n".
         "    <id>tag:thesmartass.info,2006:00".$id."</id>\n".
         "    <updated>".date(DATE_ATOM)."</updated>\n".

         "    <contributor>\n".
         "     <name>".$author."</name>\n".
         "     <email>".$email."</email>\n".

         "     <foaf:topic rdf:resource=".$phrases[time() % count($phrases)].": />\n".

         "     <foaf:homepage rdf:resource=".$website." />\n".
         "    </contributor>\n".
         "    <content type=\"html\" xml:space=\"preserve\">\n".

         "     <![CDATA[ \n".
         "     <div class=\"answer\"></div>\n".
         "     ]]>\n".
         "    </content>\n".

         "</entry>\n".
         "\n";
        $insertspot = preg_match_all("/<id>tag:thesmartass.info,2006:001</id>/", $html, $match);

        $addhtml = "".$insertspot."\n".$html."";
        fwrite($questions, $addhtml);

        fclose($questions);
    }
    // send yourself an email
    $to = "qna@thesmartass.info"; 
    $subject = "New question on Ask-a-Smartass page"; 

    $contents = "Question #".$id.": ".$question."\n\n".$author."\n".$email."\n".$website."\n".$REMOTE_ADDR."\n";

    $mailheaders = "From: $author <$email> \n";
    $mailheaders .= "Reply-To: $email\n\n"; 
    @mail($to, $subject, $contents, $mailheaders);

}
?>

[faulkner132]

Read the file into a string using the file_get_contents function. Then you can use the string/xml functions to parse it.