给CSDN极客和开发者头条增加RSS源

<?php
/**
 * Created by Codefine.site.
 * User: Shentar
 * Date: 2018/1/6
 * Time: 22:06
 */
parse_str($_SERVER['QUERY_STRING'], $queryString);
if (empty($queryString)) {
    echo '404 not found.';
    return;
}
$url = $queryString['url'];
if ($url != 'geek.csdn.net' && $url != 'toutiao.io') {
    echo '404 not supported the url now.';
    return;
}
if ($url == 'geek.csdn.net') {
    $url = 'http://' . $url;
    $content = getContent($url);
    $pattern = '/<span >\n?.*?<a href="(.*)" class="title" target="_blank">(.*)\n?.*?<\/a>/';
    if (!empty($content)) {
        $matches = array();
        if (preg_match_all($pattern, $content, $matches)) {
            if (count($matches) === 3) {
                $array_link = $matches[1];
                $array_text = $matches[2];
                if (is_array($array_text) && is_array($array_link) && count($array_link) === count($array_text)) {
                    $body = '<?xml version="1.0"?>' . '<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">'
                        . '<channel>' . '<title>CSDN极客</title>' . '<link>http://geek.csdn.net</link>'
                        . '<atom:link href="http://geek.csdn.net" rel="self" type="application/rss+xml" />'
                        . '<description>CSDN极客</description>' . '<language>zh-CN</language>'
                        . '<generator>码范|CodeFine</generator>';
                    for ($i = 0; $i < count($array_link); $i++) {
                        $item = '<item>' . '<link>' . '<![CDATA[' . $array_link[$i] . ']]>' . '</link>'
                            . '<title>' . '<![CDATA[' . $array_text[$i] . ']]>' . '</title>' . '</item>';
                        $body .= $item;
                    }
                    $body .= '</channel></rss>';
                    // RSS
                    header('Content-Type: application/xml; charset=utf-8');
                    echo $body;
                }
            }
        }
    }
}
if ($url == 'toutiao.io') {
    $url = 'https://' . $url;
    $content = getContent($url);
    $pattern = '/<div class="content" data-url=".*">\n?.*<h3 class="title">\n?.*?<a target="_blank" rel="external" title=".*" href="(.*)">(.*)<\/a>/';
    if (!empty($content)) {
        $matches = array();
        if (preg_match_all($pattern, $content, $matches)) {
            if (count($matches) === 3) {
                $array_link = $matches[1];
                $array_text = $matches[2];
                if (is_array($array_text) && is_array($array_link) && count($array_link) === count($array_text)) {
                    $body = '<?xml version="1.0"?>' . '<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">'
                        . '<channel>' . '<title>Top-DEV-News</title>' . '<link>https://toutiao.io</link>'
                        . '<atom:link href="https://toutiao.io" rel="self" type="application/rss+xml" />'
                        . '<description>Top-DEV-News</description>' . '<language>zh-CN</language>'
                        . '<generator>码范|CodeFine</generator>';
                    for ($i = 0; $i < count($array_link); $i++) {
                        $item = '<item>' . '<link>' . '<![CDATA[' . 'https://toutiao.io' . $array_link[$i] . ']]>'
                            . '</link>' . '<title>' . '<![CDATA[' . $array_text[$i] . ']]>' . '</title>' . '</item>';
                        $body .= $item;
                    }
                    $body .= '</channel></rss>';
                    // RSS
                    header('Content-Type: application/xml; charset=utf-8');
                    echo $body;
                }
            }
        }
    }
}
function getContent($url)
{
    $http = new WP_Http();
    $res = $http->get($url);
    $bodyStr = $res['body'];
    if (!empty($bodyStr)) {
        return $bodyStr;
    } else {
        return '';
    }
}