Simple PHP functions to extract links and metadata from a webpage

html_attr_extraction_functions.php

<?php
//Created as an alternative to an article demonstrating the use of regular expressions to parse HTML:
// http://www.web-development-blog.com/archives/parse-html-with-preg_match_all/

/**
 * @param string $remoteUrl
 * @param string $yourLink
 * @return bool
 */
function check_back_link($remoteUrl, $yourLink)
{
    $document = new DOMDocument('1.1');
    $document->loadHtmlFile($remoteUrl);
    $linkQuery = new DOMXPath($document);
    $results = $linkQuery->evaluate('/html/body//a[@href="' . $yourLink . '"]/');
    return ($results->length > 0);
}

/**
 * @param string $remoteUrl
 * @param string $metaName
 * @return array
 */
function extract_meta_data($remoteUrl, $metaName)
{
    $document = new DOMDocument('1.1');
    $document->loadHtmlFile($remoteUrl);
    $linkQuery = new DOMXPath($document);
    $results = $linkQuery->evaluate('/html/head/meta[@name="' . $metaName . '"]/@content');

    $content = [];
    foreach($results as $domAttr) {
        $content[] = $domAttr->value;
    }
    return $content;
}