自动将WordPress文章中的外链图片下载到本地

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);