Pearson Successnet Downloader

downloader.php

<?php
/*
 * Pearson Successnet Downloader *
 * Fully mirrors a HTML-based textbook stored on Pearson Successnet for offline viewing.
 * Author: James Woglom <j@wogloms.net> (wogloms.com)
 */

require_once 'simple_html_dom.php'; /* http://simplehtmldom.sourceforge.net/ */
// Cookie information in form name=value; name2=value2
$cookies = "name=value; name2=value2";
// Content directory for the text
$prefix = "https://www.pearsonsuccessnet.com/snpapp/iText/products/ISBN/";
function get($url) {
    global $cookies, $prefix;
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_USERAGENT, "MSIE 6.0 Windows");
    curl_setopt($ch, CURLOPT_URL,$prefix.$url);
    curl_setopt($ch, CURLOPT_HTTPHEADER, array("Cookie: ".$cookies));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    $res = curl_exec($ch);
    curl_close($ch);
    return $res;
}
$files = array();
$fi = 0;
$prevpg = ""; // Second to last page downloaded at any given time.
function download($name) {
    global $files, $fi, $cookies, $prefix;
    $files[$fi] = get($name);
    // file_put_contents($name, $files[$fi]);
    $cmd = "wget -r -e robots=off -p -k --keep-session-cookies --cookies=on --header='Cookie: ".trim($cookies)."' ".$prefix.$name;
    echo $cmd;
    exec("wget $cmd | tee out-wget.txt 2> /dev/null > /dev/null");
    $nextpgs = explode('value="', $files[$fi]);
    echo $nextpgs[1]."\n".$nextpgs[2]."\n".$nextpgs[3];
    $nextpg = explode('"', $nextpgs[2])[0];
    if(strpos($nextpg, "html") === false && strlen($nextpg) < 80) {
        $nextpg = explode('"', $nextpgs[1])[0];
    }

    if($files[$fi] == $files[$fi-1] || $files[$fi] == $files[$fi-2]) {
        // Looping
        echo "\n\nReached loop.";
        return;
    }
    
    echo "\n\n\n\n\nNext page: $nextpg \n\n\n";
    $prevpg = $name;
    $fi++;
    download($nextpg);
}
// Start downloading the first page of the book
download("firstpage.html");
?>