wordpress将已发布文章外链图片保存到本地的方法（亲测可批量操作）

想必每个做站的朋友都有转载文章的习惯，就算喜欢坚持写原创的人也会偶尔转载几篇，电脑屋小编就是如此，而原来用帝国CMS转载文章底部是有选项可直接将图片下载到本地的!

后来由于种种原因，改用wp玩玩，但发现在发布文章的时候，复制来的文章图片不能自动下载到本地，而且以前的文章一样不可以修改，这就很纠结了!

经过不断的查找，发现强大的functions.php可以实现太多强大的功能,当然最终还是PHP强大

最终找来一段代码，经过不段改良后如下：

function ecp_save_post($post_id, $post) {
    global $wpdb;
    if($post->post_status == "publish") {
        $p   = "/<img.*[\s]src=[\"|\"](.*)[\"|\"].*>/iU";
        $num = preg_match_all($p, $post->post_content, $matches);
        if ($num) {
            $wp_upload_dir = wp_upload_dir();
            set_time_limit(0);
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_HEADER, false);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
            curl_setopt($ch, CURLOPT_MAXREDIRS,20);
            curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
  
            $ecp_options = $_SERVER["HTTP_HOST"];
            foreach ($matches[1] as $src) {
                if (isset($src) && strpos($src, $ecp_options) === false) {
                    $file_info = wp_check_filetype(basename($src), null);
                    if ($file_info["ext"] == false) {
                        date_default_timezone_set("PRC");
                        $file_name = date("YmdHis-").dechex(mt_rand(100000, 999999)).".tmp";
                    } else {
                        $file_name = dechex(mt_rand(100000, 999999)) . "-" . basename($src);
                    }
                    curl_setopt($ch, CURLOPT_URL, $src);
                    $file_path = $wp_upload_dir["path"] . "/" . $file_name;
                    $img = fopen($file_path, "wb");
                    curl_setopt($ch, CURLOPT_FILE, $img);
                    $img_data  = curl_exec($ch);
                    fclose($img);
  
                    if (file_exists($file_path) && filesize($file_path) > 0) {
                        $t   = curl_getinfo($ch, CURLINFO_CONTENT_TYPE);
                        $arr = explode("/", $t);
                        if (pathinfo($file_path, PATHINFO_EXTENSION) == "tmp") {
                            $file_path = ecp_handle_ext($file_path, $arr[1], $wp_upload_dir["path"], $file_name, "tmp");
                        } elseif (pathinfo($file_path, PATHINFO_EXTENSION) == "webp") {
                            $file_path = ecp_handle_ext($file_path, $arr[1], $wp_upload_dir["path"], $file_name, "webp");
                        }
                        $post->post_content  = str_replace($src, $wp_upload_dir["url"] . "/" . basename($file_path), $post->post_content);
                        $attachment = ecp_get_attachment_post(basename($file_path), $wp_upload_dir["url"] . "/" . basename($file_path));
                        $attach_id = wp_insert_attachment($attachment, ltrim($wp_upload_dir["subdir"] . "/" . basename($file_path), "/"), 0);
                        $attach_data = wp_generate_attachment_metadata($attach_id, $file_path);
                        $ss = wp_update_attachment_metadata($attach_id, $attach_data);
                    }
                }
            }
            curl_close($ch);
            $wpdb->update( $wpdb->posts, array("post_content" => $post->post_content), array("ID" => $post->ID));
        }
    }
}
  
function ecp_handle_ext($file, $type, $file_dir, $file_name, $ext) {
    switch ($ext) {
        case "tmp":
            if (rename($file, str_replace("tmp", $type, $file))) {
                if ("webp" == $type) {
                    return ecp_image_convert("webp", "jpeg", $file_dir . "/" . str_replace("tmp", $type, $file_name));
                }
                return $file_dir . "/" . str_replace("tmp", $type, $file_name);
            }
        case "webp":
            if ("webp" == $type) {
                return ecp_image_convert("webp", "jpeg", $file);
            } else {
                if (rename($file, str_replace("webp", $type, $file))) {
                    return $file_dir . "/" . str_replace("webp", $type, $file_name);
                }
            }
        default:
            return $file;
    }
}
  
function ecp_image_convert($from="webp", $to="jpeg", $image) {
    $im = imagecreatefromwebp($image);
    if (imagejpeg($im, str_replace("webp", "jpeg", $image), 100)) {
        try {
            unlink($image);
        } catch (Exception $e) {
            $error_msg = sprintf("Error removing local file %s: %s", $image,
                $e->getMessage());
            error_log($error_msg);
        }
    }
    imagedestroy($im);
  
    return str_replace("webp", "jpeg", $image);
}
  
function ecp_get_attachment_post($filename, $url) {
    $file_info  = wp_check_filetype($filename, null);
    return array(
        "guid"           => $url,
        "post_type"      => "attachement",
        "post_mime_type" => $file_info["type"],
        "post_title"     => preg_replace("/\.[^.]+$/", "", $filename),
        "post_content"   => "",
        "post_status"    => "inherit"
    );
}
add_action("save_post", "ecp_save_post", 120, 2);

将以上代码放到模板目录里的functions.php里，然后再去发布文章即可自动保存外链图片了！

实现的原理就是在文章保存的时候自动下载外链图片到本地媒体库

有人要说了，那已经发布的文章怎么办，不可能一个一个去保存吧

问出这样的问题的朋友肯定是wp新手了，电脑屋小编开始也是纠结

后来发现，wp有批量编辑的功能，其实就可以解决这个问题，如果你的服务器足够强大，完全可以将文章列表改成每页一万条（当然可以更多）然后再批量编辑然后哪里都不要动直接点更新即可！再查看文章就会发现，图片已经自动保存到本地了!