I have an odd issue, all of my links on the shirts4mike website are working, except 'shirts'.

cd <?php

    require_once("../inc/config.php");
    require_once(ROOT_PATH . "inc/products.php");

    // retrieve current page number from query string; set to 1 if blank
    if (empty($_GET["pg"])) {
        $current_page = 1;
    } else {
        $current_page = $_GET["pg"];
    }
    // set strings like "frog" to 0; remove decimals
    $current_page = intval($current_page);

    $total_products = get_products_count();
    $products_per_page = 8;
    $total_pages = ceil($total_products / $products_per_page);

    // redirect too-large page numbers to the last page
    if ($current_page > $total_pages) {
        header("Location: ./?pg=" . $total_pages);
    }

    // redirect too-small page numbers (or strings converted to 0) to the first page
    if ($current_page < 1) {
        header("Location: ./");
    }

    // determine the start and end shirt for the current page; for example, on
    // page 3 with 8 shirts per page, $start and $end would be 17 and 24
    $start = (($current_page - 1) * $products_per_page) + 1;
    $end = $current_page * $products_per_page;
    if ($end > $total_products) {
        $end = $total_products;
    }

    $products = get_products_subset($start,$end);

?><?php 
$pageTitle = "Mike's Full Catalog of Shirts";
$section = "shirts";
include(ROOT_PATH . 'inc/header.php'); ?>

        <div class="section shirts page">

            <div class="wrapper">

                <h1>Mike&rsquo;s Full Catalog of Shirts</h1>

                <?php include(ROOT_PATH . "inc/partial-list-navigation.html.php"); ?>

                <ul class="products">
                    <?php
                        foreach($products as $product) {
                            include(ROOT_PATH . "inc/partial-product-list-view.html.php");
                        }
                    ?>
                </ul>

                <?php include(ROOT_PATH . "inc/partial-list-navigation.html.php"); ?>

            </div>

        </div>

<?php include(ROOT_PATH . 'inc/footer.php') ?>

<?php

/*
 * Returns the four most recent products, using the order of the elements in the array
 * @return   array           a list of the last four products in the array;
                             the most recent product is the last one in the array
 */
function get_products_recent() {
    $recent = array();
    $all = get_products_all();

    $total_products = count($all);
    $position = 0;

    foreach($all as $product) {
        $position = $position + 1;
        if ($total_products - $position < 4) {
            $recent[] = $product;
        }
    }
    return $recent;
}

/*
 * Loops through all the products, looking for a search term in the product names
 * @param    string    $s    the search term
 * @return   array           a list of the products that contain the search term in their name
 */
function get_products_search($s) {
    $results = array();
    $all = get_products_all();

    foreach($all as $product) {
        if (stripos($product["name"],$s) !== false) {
            $results[] = $product;
        }
    }
    return $results;
}

/*
 * Counts the total number of products
 * @return   int             the total number of products
 */
function get_products_count() {
    return count(get_products_all());
}

/*
 * Returns a specified subset of products, based on the values received,
 * using the order of the elements in the array .
 * @param    int             the position of the first product in the requested subset 
 * @param    int             the position of the last product in the requested subset 
 * @return   array           the list of products that correspond to the start and end positions
 */
function get_products_subset($positionStart, $positionEnd) {
    $subset = array();
    $all = get_products_all();

    $position = 0;
    foreach($all as $product) {
        $position += 1;
        if ($position >= $positionStart && $position <= $positionEnd) {
            $subset[] = $product;
        }
    }
    return $subset;
}

/*
 * Returns the full list of products. This function contains the full list of products,
 * and the other model functions first call this function.
 * @return   array           the full list of products
 */
function get_products_all() {

//    $products = array();
//    $products[101] = array(
//      "name" => "Logo Shirt, Red",
//      "img" => "img/shirts/shirt-101.jpg",
//      "price" => 18,
//      "paypal" => "9P7DLECFD4LKE",
//        "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[102] = array(
//      "name" => "Mike the Frog Shirt, Black",
//        "img" => "img/shirts/shirt-102.jpg",
//        "price" => 20,
//        "paypal" => "SXKPTHN2EES3J",
//        "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[103] = array(
//        "name" => "Mike the Frog Shirt, Blue",
//        "img" => "img/shirts/shirt-103.jpg",
//        "price" => 20,
//        "paypal" => "7T8LK5WXT5Q9J",
//        "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[104] = array(
//        "name" => "Logo Shirt, Green",
//        "img" => "img/shirts/shirt-104.jpg",
//        "price" => 18,
//        "paypal" => "YKVL5F87E8PCS",
//        "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[105] = array(
//        "name" => "Mike the Frog Shirt, Yellow",
//        "img" => "img/shirts/shirt-105.jpg",
//        "price" => 25,
//        "paypal" => "4CLP2SCVYM288",
//        "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[106] = array(
//        "name" => "Logo Shirt, Gray",
//        "img" => "img/shirts/shirt-106.jpg",
//        "price" => 20,
//        "paypal" => "TNAZ2RGYYJ396",
//        "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[107] = array(
//        "name" => "Logo Shirt, Teal",
//        "img" => "img/shirts/shirt-107.jpg",
//        "price" => 20,
//        "paypal" => "S5FMPJN6Y2C32",
//        "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[108] = array(
//        "name" => "Mike the Frog Shirt, Orange",
//        "img" => "img/shirts/shirt-108.jpg",
//        "price" => 25,
//        "paypal" => "JMFK7P7VEHS44",
//        "sizes" => array("Large","X-Large")
//    );
//    $products[109] = array(
//            "name" => "Get Coding Shirt, Gray",
//            "img" => "img/shirts/shirt-109.jpg",
//            "price" => 20,
//            "paypal" => "B5DAJHWHDA4RC",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[110] = array(
//            "name" => "HTML5 Shirt, Orange",
//            "img" => "img/shirts/shirt-110.jpg",
//            "price" => 22,
//            "paypal" => "6T2LVA8EDZR8L",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[111] = array(
//            "name" => "CSS3 Shirt, Gray",
//            "img" => "img/shirts/shirt-111.jpg",
//            "price" => 22,
//            "paypal" => "MA2WQGE2KCWDS",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[112] = array(
//            "name" => "HTML5 Shirt, Blue",
//            "img" => "img/shirts/shirt-112.jpg",
//            "price" => 22,
//            "paypal" => "FWR955VF5PALA",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[113] = array(
//            "name" => "CSS3 Shirt, Black",
//            "img" => "img/shirts/shirt-113.jpg",
//            "price" => 22,
//            "paypal" => "4ELH2M2FW7272",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[114] = array(
//            "name" => "PHP Shirt, Yellow",
//            "img" => "img/shirts/shirt-114.jpg",
//            "price" => 24,
//            "paypal" => "AT3XQ3ZVP2DZG",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[115] = array(
//            "name" => "PHP Shirt, Purple",
//            "img" => "img/shirts/shirt-115.jpg",
//            "price" => 24,
//            "paypal" => "LYESEKV9JWE3A",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[116] = array(
//            "name" => "PHP Shirt, Green",
//            "img" => "img/shirts/shirt-116.jpg",
//            "price" => 24,
//            "paypal" => "KT7MRRJUXZR34",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[117] = array(
//            "name" => "Get Coding Shirt, Red",
//            "img" => "img/shirts/shirt-117.jpg",
//            "price" => 20,
//            "paypal" => "5UXJG8PXRXFKE",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[118] = array(
//            "name" => "Mike the Frog Shirt, Purple",
//            "img" => "img/shirts/shirt-118.jpg",
//            "price" => 25,
//            "paypal" => "KHP8PYPDZZFTA",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[119] = array(
//            "name" => "CSS3 Shirt, Purple",
//            "img" => "img/shirts/shirt-119.jpg",
//            "price" => 22,
//            "paypal" => "BFJRFE24L93NW",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[120] = array(
//            "name" => "HTML5 Shirt, Red",
//            "img" => "img/shirts/shirt-120.jpg",
//            "price" => 22,
//            "paypal" => "RUVJSBR9FXXWQ",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[121] = array(
//            "name" => "Get Coding Shirt, Blue",
//            "img" => "img/shirts/shirt-121.jpg",
//            "price" => 20,
//            "paypal" => "PGN6ULGFZTXL4",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[122] = array(
//            "name" => "PHP Shirt, Gray",
//            "img" => "img/shirts/shirt-122.jpg",
//            "price" => 24,
//            "paypal" => "PYR4QH97W2TSJ",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[123] = array(
//            "name" => "Mike the Frog Shirt, Green",
//            "img" => "img/shirts/shirt-123.jpg",
//            "price" => 25,
//            "paypal" => "STDAUJJTSPT54",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[124] = array(
//            "name" => "Logo Shirt, Yellow",
//            "img" => "img/shirts/shirt-124.jpg",
//            "price" => 20,
//            "paypal" => "2R2U74KWU5RXG",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[125] = array(
//            "name" => "CSS3 Shirt, Blue",
//            "img" => "img/shirts/shirt-125.jpg",
//            "price" => 22,
//            "paypal" => "GJG7F8EW3XFAS",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[126] = array(
//            "name" => "Doctype Shirt, Green",
//            "img" => "img/shirts/shirt-126.jpg",
//            "price" => 25,
//            "paypal" => "QW2LFRYGU7L4Q",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[127] = array(
//            "name" => "Logo Shirt, Purple",
//            "img" => "img/shirts/shirt-127.jpg",
//            "price" => 20,
//            "paypal" => "GFV6QVRMJU7F8",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[128] = array(
//            "name" => "Doctype Shirt, Purple",
//            "img" => "img/shirts/shirt-128.jpg",
//            "price" => 25,
//            "paypal" => "BARQMHMB565PN",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[129] = array(
//            "name" => "Get Coding Shirt, Green",
//            "img" => "img/shirts/shirt-129.jpg",
//            "price" => 20,
//            "paypal" => "DH9GXABU3P8GS",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[130] = array(
//            "name" => "HTML5 Shirt, Teal",
//            "img" => "img/shirts/shirt-130.jpg",
//            "price" => 22,
//            "paypal" => "4LZ3EUVCBENE4",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[131] = array(
//            "name" => "Logo Shirt, Orange",
//            "img" => "img/shirts/shirt-131.jpg",
//            "price" => 20,
//            "paypal" => "7BNDYJBKWD364",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
//    $products[132] = array(
//            "name" => "Mike the Frog Shirt, Red",
//            "img" => "img/shirts/shirt-132.jpg",
//            "price" => 25,
//            "paypal" => "Y6EQRE445MYYW",
//            "sizes" => array("Small","Medium","Large","X-Large")
//    );
    // when creating a new product, create it first in PayPal and
    // then copy the product ID from PayPal to use here     

    // automated duplication to copy the product_id/sku from the array key
    // and duplicate it into the product details inside the array
//    foreach ($products as $product_id => $product) {
//        $products[$product_id]["sku"] = $product_id;
//    }

    try {
        $db = new PDO("mysql:host=localhost;dbname=shirts4mike;port=3306", "root", "hkh92304");
        $db->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);
        $db->exec("SET NAMES 'utf8'");
    } catch (Exception $e) {
        echo "Could not connect to the database.";
        exit;
    }

    try {
        $results = $db->query("SELECT name, price, img, sku, paypal FROM products ORDER BY sku ASC");

    } catch (Exception $e) {
        echo "Data could not be retrieved from the database.";
        exit;
    }
    $products = $results->fetchAll(PDO::FETCH_ASSOC);

    //foreach ($products as $product_id => $product) { $products[$product_id]["sku"] = $product_id; }

    return $products;
}

?>