Echo显示何时不应该[关闭]

Hello i am having problems with the code below for some reason the echo is showing when i load the file its showing on start up any ideas on how to fix this?

if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) {
    echo "<a href='http://$url/files/".  basename( $_FILES['uploadedfile']['name'])."'>Download</a>";
} else{
    echo "There was an error uploading the file, please try again!";
}
?>
<form enctype="multipart/form-data" action="" method="POST">
<input type="hidden" name="MAX_FILE_SIZE" value="99999999999999999">
<input name="uploadedfile" type="file"><br>
<input type="submit" value="Upload">
</form>

I'll just make it an answer, see if OP accepts it to close the question; since it did work for OP.

Name your submit button <input type="submit" value="Upload" name="submit"> then wrap your PHP inside if(isset($_POST['submit'])){...}

Another way to do this is to use two seperate files.

For example. HTML form

<form enctype="multipart/form-data" action="handler.php" method="POST">...</form>

handler.php (while keeping the named submit button)

if(isset($_POST['submit'])){

    if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) {
        echo "<a href='http://$url/files/".  basename( $_FILES['uploadedfile']['name'])."'>Download</a>";
    } else{
        echo "There was an error uploading the file, please try again!";
    }

} // brace for if(isset($_POST['submit']))

the echo show because you have a if statement and on load page it's always false. put a if with a isset first like this :

 if(isset($_POST['uploadedfile'])){
        if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) {
            echo "<a href='http://$url/files/".  basename( $_FILES['uploadedfile']['name'])."'>Download</a>";
        } else{
            echo "There was an error uploading the file, please try again!";
        }
    }
        ?>
        <form enctype="multipart/form-data" action="" method="POST">
        <input type="hidden" name="MAX_FILE_SIZE" value="99999999999999999">
        <input name="uploadedfile" type="file"><br>
        <input type="submit" value="Upload">
        </form>

Should do the trick if not post more information / code and specifie witch echo is showing... thx

Would be cleaner to add name to the button like name="submit" and do the isset on the button name OR a input type="hidden" with a name for the form.

You never bothered checking if a POST was actually performed, and you also don't bother checking if the upload actually succeeded. NEVER assume success. Always assume failure and treat success as a pleasant surprise:

if ($_SERVER['REQUEST_METHOD'] == 'POST') {
   if ($_FILES['uploadedfile']['error'] !== UPLOAD_ERR_OK) {
        die("Upload failed with error code {$_FILES['uploadedfile']['error']}");
   }
   ... do your upload processing here
}