int ftp_nb_fput ( resource $ftp_stream , string $remote_file , resource $handle , int $mode [, int $startpos = 0 ] )
ftp_nb_fput() uploads the data from a file pointer to a remote file on the FTP server. The difference between this function and the ftp_fput() is that this function uploads the file asynchronously, so your program can perform other operations while the file is being uploaded.
Returns FTP_FAILED or FTP_FINISHED or FTP_MOREDATA.