<?php

/**

* parser.php

* Name: Jason Yue

* Student Number: 492329

* CMPT360 Spring 2015

* Assignment #6

* WebCrawler

*

* This script extracts all links from an URL

* given by the user and displays the link names,

* addresses, extensions (file format) and status

*/

echo "<title> Link Results </title>";

echo "<input type=\"button\" value=\"Back\" onClick=\"history.go(-1)\">", "<br>";

// Check for "http(s)://"

if (!filter_var($_POST["url"], FILTER_VALIDATE_URL) === true) {

echo("Invalid URL!");

return;

}

$linkCount = 0;

// A Web page is essentially a file so...

$html = file_get_contents($_POST["url"]);

$dom = new DOMDocument;

@$dom->loadHTML($html);

// Get all links

$links = $dom->getElementsByTagName("a");

$url = $_POST["url"];

// Make sure original link has a "/" at the end just in case

if (substr($_POST["url"], $_POST["url"].length-1, 1) !== "/") {

$url = $url . "/";

}

// Formatting

echo "<table style='width:100%'>

<tr>

<th><div style='text-align:left'>Link Name</div></th>

<th><div style='text-align:left'>Link Address</div></th>

<th><div style='text-align:left'>Link Extension</div></th>

<th><div style='text-align:left'>Link Status</div></th>

</tr>";

// Iterate over every link

foreach ($links as $link) {

// Reset original link (consistency)

$path = $url;

// This extracts the individual (partial?) link

$href = $link->getAttribute("href");

// Combine original link with (partial?) link

// assuming it is indeed partial

$fullLink = $path . $href;

// If (partial?) link starts with http, it's a complete link

// Or if (partial?) link has a "/" in front,

// remove the "/" from the original link

if (preg_match("%^(https?://)([a-z0-9-].?)+(:[0-9]+)?(/.*)?$%i", $href)) {

$fullLink = $href;

} else if (substr($href, 0, 1) === "/") {

$path = substr_replace($_POST["url"], "", ($_POST["url"] . length - 1), 1);

$fullLink = $path . $href;

}

// Attempt to visit page

if ($file = @fopen($fullLink, "r")) {

$page = "Available!";

fclose($file);

} else {

$page = "Unknown!";

}

// Formatting

echo "<tr>

<td>" . $link->nodeValue . "</td>

<td>" . $fullLink . "</td>;

<td>" . getMimeType(pathinfo($href, PATHINFO_EXTENSION)) . "</td>

<td>" . $page . "</td>

</tr>";

$linkCount++;

}

echo "</table>";

if ($linkCount > 0) {

echo $linkCount, " Links found!";

} else {

echo "No links found! <br> Empty/Non-Existent page!";

}

function getMimeType($file)