PHP rename（）函数删除文件（如果已存在）

Question

I've been looking around and appearently the // if sucess should be executed when the file gets renamed:

if(rename("$filepath$oldfilename", "$filepath$filename")===true) { // if success }

Unfortunately, since this function renames the file even if another file is there with the same name, it's always a success.

But yet worse...since another file with same name already exists, it somehow gets deleted...

Anyone know a way how to prevent this? And why this is happening?!

Additional info:

Im giving the user the opportunity to change the file name through a textarea, when it's posted, the rename function will start:

        if(rename("$filepath$oldfilename", "$filepath$filename")===true)
        {
            $WhatToUpdateQueryResult = mysql_query($WhatToUpdateQuery) or die ("query fout ". mysql_error() );      

            if ($WhatToUpdateQueryResult == 1)
            {
                $uploadmsg = "Document name successfully updated.<br/> From: $oldfilename <br/> To: $filename.";
            }
        }
        else
        {
            $uploadmsg = "Can't update document. A file with the same name already exists.";
        }

Note: As long I change the name to something which doesn't already exists, it works fine. But still, it always ends up true.

Answer 1

You will have to make a function to check if filename already exists:

function rename_if_free($newPath, $oldPath) {
    if (file_exists($newPath)) return false;
    else {
        rename($oldPath, $newPath);
        return true;
    }
}

And put that function in your if statement.

Now it will be

if (rename_if_free($filepath.$oldfilename, $filepath.$filename) === true) { 
    $WhatToUpdateQueryResult = mysql_query($WhatToUpdateQuery) or die ("query fout ". mysql_error() );      

        if ($WhatToUpdateQueryResult == 1)
        {
            $uploadmsg = "Document name successfully updated.<br/> From: $oldfilename <br/> To: $filename.";
        }
}
else {
    $uploadmsg = "Can't update document. A file with the same name already exists.";
}

Answer 2

http://php.net/manual/en/function.move-uploaded-file.php

take move_uploaded_file instead. This will return false, if file can't be moved.

Edit: Ah you are not necessarily doing an upload? Then you would have to check if the destination file already exists manually i assume. check out file_exists()