Ftp_nb_continue()

What is ftp_nb_continue()?

The ftp_nb_continue() function is a PHP built-in function that continues an asynchronous FTP operation. The function takes one parameter:

1. ftp_stream: The connection identifier returned by the ftp_connect() function.

The function returns true if the operation was successful. Otherwise, it returns false.

Syntax of ftp_nb_continue()

The syntax of the ftp_nb_continue() function is as follows:

int ftp_nb_continue ( resource $ftp_stream )

The ftp_nb_continue() function takes one parameter, ftp_stream. The ftp_stream parameter is the connection identifier returned by the ftp_connect() function.

Usage of ftp_nb_continue()

To use the ftp_nb_continue() function, you first need to initiate an asynchronous FTP operation using one of the following functions: ftp_nb_fget(), ftp_nb_fput(), ftp_nb_get(), ftp_nb_put(), or ftp_nb_mkdir(). Here's an example:

<?php

// Set up an FTP connection
$conn = ftp_connect('ftp.example.com');

// Login with your FTP credentials
ftp_login($conn, 'username', 'password');

// Initiate an asynchronous FTP operation
ftp_nb_get($conn, 'local_file.txt', 'remote_file.txt', FTP_BINARY);

// Continue the asynchronous FTP operation
while (ftp_nb_continue($conn)) {
    // Do something else while waiting for the FTP operation to complete
}

// Close the FTP connection
ftp_close($conn);

In this example, we establish a connection to the FTP server using the ftp_connect() function. Then we log in using our FTP credentials using the ftp_login() function. We initiate an asynchronous FTP operation using the ftp_nb_get() function and continue the operation using the ftp_nb_continue() function. Finally, we close the FTP connection.

Error handling in ftp_nb_continue()

It's important to handle errors properly when using the ftp_nb_continue() function. If the function returns false, it means that the asynchronous FTP operation failed. Here's an example of how to handle errors:

<?php

while (ftp_nb_continue($conn)) {
    $status = ftp_nb_continue($conn);
    if ($status === FTP_FAILED) {
        echo "FTP operation failed.\n";
        break;
    } else if ($status === FTP_MOREDATA) {
        // Do something else while waiting for the FTP operation to complete
    }
}

In this example, we check the return value of the ftp_nb_continue() function. If it's FTP_FAILED, we display an error message and break out of the loop. If it's FTP_MOREDATA, we continue doing something else while waiting for the FTP operation to complete.

Conclusion

The ftp_nb_continue() function is a useful PHP built-in function that allows you to continue an asynchronous FTP operation. By following the guidelines and best practices outlined in this article, you can use the ftp_nb_continue() function in your PHP projects with confidence. We hope this article has been helpful to you.