These days I needed a script to backup only a part of a customers website using a CRON. Most of the control panels I know allow only a complete website backup and this is not what I needed. While plaaning the script, I thought about a solution for webmaster without full SSH access to their hosting account. A typical situation could be:

• A shared hosting account that allows only backups for the whole site incl. database, emails and other settings
• No administration rights via SSH
• A FTP host for the storage of the the backup files
• Support for cURL and a default PHP5 configuration (sorry no more code for PHP4).

First of all we need to create a variable to define the local source directory on your website where you like to start the backup from:

define('BASEPATH', $_SERVER['DOCUMENT_ROOT'].'/');

The next code is to create a new class including the constructor function and some variables used in that class:

class Curl_ftp_backup {
 
	public $basePath, $errors, $ftp_server, $ftp_user_pw , $msg, $email;
 
	public function __construct($ftp_server, $ftp_userpw, $email_adr) {
		$this->basePath = BASEPATH;
		$this->errors = '';
		$this->ftp_server = $ftp_server;
		$this->ftp_user_pw = $ftp_userpw;
		$this->email = $email_adr;
		$this->msg = '';
	}
}

Our class will store file and directories on the remote FTP server, the next function will create a directory if it not already exists:

	private function curl_create_ftp_directory($name, $curr_dir = '') {
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $this->ftp_server);
		curl_setopt($ch, CURLOPT_USERPWD, $this->ftp_user_pw);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		$cmd = array();
		if ($curr_dir != '') $cmd[] = 'CWD '.$curr_dir;
		$cmd[] = 'MKD '.$name;
		curl_setopt($ch, CURLOPT_POSTQUOTE, $cmd);
		curl_exec ($ch);
		return;
	}

The following function will open a file and uploads the data to specified directory on the target server. For each file that is not stored the error number is returned, this information is used later to build up an error string.

	private function curl_put_file($path) {
		$ch = curl_init();
		$fp = fopen($this->basePath.$path, "r");
		curl_setopt($ch, CURLOPT_URL, $this->ftp_server.$path);
		curl_setopt($ch, CURLOPT_USERPWD, $this->ftp_user_pw);
		curl_setopt($ch, CURLOPT_UPLOAD, 1);
		curl_setopt($ch, CURLOPT_INFILE, $fp);
		curl_setopt($ch, CURLOPT_INFILESIZE, filesize($this->basePath.$path));
		curl_exec ($ch);
		$error = curl_errno($ch);
		curl_close ($ch);
		if ($error != 0) $this->errors .= $path.PHP_EOL;
		return;
	}

Now we need a function that will loop through the specified base directory and will switch between directories and files; the previous functions will create the directory or upload the file.

	public function backupfiles($directory) {
		if ($handle = opendir($this->basePath.$directory)) {
			$this->curl_create_ftp_directory($directory);
			while (false !== ($file = readdir($handle))) {
				if (is_file($this->basePath.$directory.$file) && $file != '.htaccess') {
					$this->curl_put_file($directory.$file);
				} elseif ($file != '.' && $file != '..' && is_dir($this->basePath.$directory.$file)) {
					$this->backupfiles($directory.$file.'/', $directory);
				}
			}
			closedir($handle);
			if ($this->errors != '') {
				$this->msg = 'Missing files: '.PHP_EOL.$this->errors;
			} else {
				$this->msg = 'FTP upload successful.';
			}
		} else {
			$this->msg = 'Can\'t open local directory.';
		}
	}
 
	public function send_emailmsg() {
		if ($this->msg != '') {
			$body = PHP_EOL.'Backup result:'.PHP_EOL.PHP_EOL.$this->msg;
			mail($this->email, 'Your Backup on '.date('Y-m-d H:i:s'), $body);
		}
	}

At last there is a tiny function that will send you some short email message about the backup result. You can call the class in your PHP script:

$cb = new Curl_ftp_backup('ftp://ftp.yourserver.com/source_folder/', 'user:password', 'your@email.com');
$cb->backupfiles('includes/');
$cb->send_emailmsg();

Thats all, now you need to create a CRON job for the file that will execute the backup. If your hosting provider doesn’t provide CRON jobs, just google for “free cron jobs”.

Disclaimer:
We tested the script “successful” on two modern Linux web servers with ~100 files between 10kb and 300MB. If you have a backup with a lot of files you should think about a different solution. With every file or directory a new CURL function is called, this could result in a high server load. We are not responsible for any damage and/or data loss as the result off using this script.

Click here to download the PHP class script.Similar Posts:

• Tutorial: FTP Upload via cURL
• Curl: Location redirect while open_basedir is set
• Tutorial: Create a zip file from folders on the fly

FTP hosting is often much cheaper than regular web hosting. The upload with an ftp client is for sure the most common way, but could be a problem for people behind a firewall or without enough rights (capabilities) to install a FTP client. For those a upload via a web form is the best solution.

Upload limitations by your web server

The default value for file uploads within PHP is 2MB, if you need to upload bigger files you need to change your PHP configuration or need to create a .htaccess file with this code to upload files of max. 16MB:

php_value upload_max_filesize 16M
php_value post_max_size 20M

The value for the post_max_size is larger than the value for the upload_max_size because we want to be able to upload more than just a file (also other data via text fields or text areas). The .htaccess file needs to be in the same directory than your upload script.

Using cURL for file transmissions

cURL is a great library for file transmissions via different types of protocols. The library supports the transport via POST, GET, FTP upload and much more. cURL is also able to authenticate on the target server or website.

In this tutorial we want to upload a file to some (password protected) remote FTP server via a web form.

<form action="curlupload.php" method="post" enctype="multipart/form-data">
<div>
<label for="upload">Select file</label>
<input name="upload" type="file" />
<input type="submit" name="Submit" value="Upload" />
</div>
</form>

The form is simple and has only one file field and the submit button. Don’t forget to protect this kind of pages.

Next we need some PHP code to handle the upload and opens a stream to send the file via cURL to the remote FTP server (place this code above the html code):

if (isset($_POST['Submit'])) {
 if (!empty($_FILES['upload']['name'])) {
 	$ch = curl_init();
 	$localfile = $_FILES['upload']['tmp_name'];
 	$fp = fopen($localfile, 'r');
 	curl_setopt($ch, CURLOPT_URL, 'ftp://ftp_login:password@ftp.domain.com/'.$_FILES['upload']['name']);
 	curl_setopt($ch, CURLOPT_UPLOAD, 1);
 	curl_setopt($ch, CURLOPT_INFILE, $fp);
 	curl_setopt($ch, CURLOPT_INFILESIZE, filesize($localfile));
 	curl_exec ($ch);
 	$error_no = curl_errno($ch);
 	curl_close ($ch);
        if ($error_no == 0) {
        	$error = 'File uploaded succesfully.';
        } else {
        	$error = 'File upload error.';
        }
 } else {
    	$error = 'Please select a file.';
 }
}

After the user has selected a file, the data is uploaded to the web server. We open the temp file with fopen and the cURL session is initialized. Together with the URL for the remote FTP server, we send the FTP login and password to the target location. The other cURL settings are required to send the file via the FTP protocol to the target server. If the returned error code is equal “0″, the upload was successful.

This small PHP snippet is responsible for the upload to some remote FTP server. We suggest using more validation routines in a production environment.Similar Posts:

• Create custom backups from your website using cURL
• Uploading files with cURL?
• Curl: Location redirect while open_basedir is set