WordPress网站批量将外链图片保存到本地（代码+插件）

今天老白博客给大家分享一个实用教程：WordPress网站批量将外链图片保存到本地，适用于小型站点（文章数量小于1000），插件和纯代码法。代码的优势就是没有插件，不过个人更推荐nicen-localize-image插件，操作简单，而且作者一直在更新。

1.纯代码法

添加功能代码

WordPress很多插件或者代码都可以实现在编辑文章中自动将外链图片下载到本地，最终我选择了一个叫：Easy Copy Paste的插件。大家可以自己后台下载下，此处提供一个代码版：
将下面代码加到当前主题函数模板 functions.php 中

// 自动保存外链图片
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);
// 自动保存外链图片

编辑文章只需要点击更新按钮，就可以将文章中的外链图片下载到本地并替换链接。

不过逐个编辑文章不仅繁琐而且工作量不小，这里教大家一个小技巧，可以批量下载文章中的外链图片。