The PHP ftp_delete() function deletes a file on the FTP server.

<?php
// connect and login to FTP server
$ftp_server = 'ftp.example.com';

$ftp_conn = ftp_connect($ftp_server) or die('Could not connect to ' . $ftp_server);
$login = ftp_login($ftp_conn, $ftp_username, $ftp_userpass);

$file = 'php/test.txt';

// try to delete file
if (ftp_delete($ftp_conn, $file)) {
    echo $file . ' deleted';
}
else {
    echo 'Could not delete' . $file;
}

// close connection
ftp_close($ftp_conn);
?>

// deletes a file on the FTP server

ftp_delete(ftp_conn, file)