How to Create a PHP FTP Client

FTP which stands for File Transfer Protocol, is a computer protocol which is used to transfer files from one computer to another over a TCP network, like the internet for instance. In this tutorial, we will learn how to create a PHP FTP client to connect to a remote server, upload a file, and download a file.

Step 1: Connect to FTP Server

First, we need to establish a connection to the FTP server. We can use the ftp_connect() function to connect to the server. Here’s an example:


// FTP server details
$ftp_server = "ftp.example.com";
$ftp_username = "username";
$ftp_password = "password";

// connect to FTP server 
$conn_id = ftp_connect($ftp_server) or die("Could not connect to $ftp_server");

In the example above, we are connecting to the FTP server at ftp.example.com using the username username and password password.

Step 2: Login to FTP Server

Once we have established a connection to the FTP server, we need to login to the server using the ftp_login() function. Here’s an example:


// login to FTP server
if (@ftp_login($conn_id, $ftp_username, $ftp_password)) {
echo "Connected as $ftp_username@$ftp_server\n";
} else {
echo "Could not login to $ftp_server\n";
}

In the example above, we are logging in to the FTP server using the credentials we defined earlier. If the login is successful, we print a message to the console indicating that we are connected to the server.

Step 3: Upload File to FTP Server

Now that we are connected to the FTP server, we can upload a file to the server using the ftp_put() function. Here’s an example:


// upload file to FTP server
$file_to_upload = "local_file.txt";
$remote_file_path = "/remote/path/file.txt";
if (ftp_put($conn_id, $remote_file_path, $file_to_upload, FTP_ASCII)) {
echo "File uploaded successfully\n";
} else {
echo "Error uploading file\n";
}

In the example above, we are uploading a local file named local_file.txt to a remote path on the FTP server at /remote/path/file.txt. We are using the FTP_ASCII transfer mode to transfer the file.

Step 4: Download File from FTP Server

We can also download a file from the FTP server using the ftp_get() function. Here’s an example:


// download file from FTP server
$local_file_path = "downloaded_file.txt";
$remote_file_path = "/remote/path/file.txt";
if (ftp_get($conn_id, $local_file_path, $remote_file_path, FTP_BINARY)) {
echo "File downloaded successfully\n";
} else {
echo "Error downloading file\n";
}

In the example above, we are downloading a remote file at /remote/path/file.txt to a local file at downloaded_file.txt. We are using the FTP_BINARY transfer mode to transfer the file.

Step 5: Close FTP Connection

Finally, we need to close the connection to the FTP server using the ftp_close() function. Here’s an example:


// close FTP connection
ftp_close($conn_id);

In the example above, we are closing the connection to the FTP server.

Putting it All Together

Here’s the complete example of a PHP FTP client that connects to a remote server, uploads a file, and downloads a file:


// FTP server details
$ftp_server = "ftp.example.com";
$ftp_username = "username";
$ftp_password = "password";

// connect to FTP server $conn_id = ftp_connect($ftp_server) or die("Could not connect to $ftp_server");
// login to FTP server 
if (@ftp_login($conn_id, $ftp_username, $ftp_password)) { 
echo "Connected as $ftp_username@$ftp_server\n"; 
// upload file to FTP server
$file_to_upload = "local_file.txt"; 
$remote_file_path = "/remote/path/file.txt"; 
if (ftp_put($conn_id, $remote_file_path, $file_to_upload, FTP_ASCII)) {
 echo "File uploaded successfully\n";
 } else {
 echo "Error uploading file\n";
 }


// download file from FTP server
$local_file_path = "downloaded_file.txt";
$remote_file_path = "/remote/path/file.txt";
if (ftp_get($conn_id, $local_file_path, $remote_file_path, FTP_BINARY)) {
echo "File downloaded successfully\n";
} else {
echo "Error downloading file\n";
}
// close FTP connection
ftp_close($conn_id);
} else {
echo "Could not login to $ftp_server\n";
}
?>

Note: This is just an example and should be modified to fit your specific needs. Additionally, it’s important to ensure that the FTP server you are connecting to is secure and properly configured.

Conclusion

In this tutorial, we learned how to create a PHP FTP client to connect to a remote server, upload a file, and download a file. By using the functions provided by the FTP extension in PHP, we can easily transfer files between local and remote servers.