auto rename of file when its already exist.. PHP CODE - php

Question

upload.php
<form enctype="multipart/form-data" action="uploader.php" method="POST">
Choose a file: <input name="uploadedfile" type="file" /><br />
Choose a file1: <input name="uploadedfile1" type="file" /><br />
<input type="submit" value="Upload File" />
</form>
^Image of the upload.php^
uploader.php
<?php
mysql_select_db("test");
$target_path = "uploads/" . basename( $_FILES['uploadedfile']['name']);
$target_path1 = "upload1/" . basename( $_FILES['uploadedfile1']['name']);
$currentfile = $_FILES['uploadedfile']['name'];
$currentfile1 = $_FILES['uploadedfile1']['name'];
$dbfiles = mysql_query("SELECT * FROM new WHERE amount='$currentfile' || amount='$currentfile1'");
if(mysql_num_rows($dbfiles) > 0 )
{
}
else
{
if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path))
{
echo "file1: ".$_FILES['uploadedfile']['name']."<br>";
$file1 = basename( $_FILES['uploadedfile']['name']);
mysql_query("insert into new (amount) values('$file1')");
}
if(move_uploaded_file($_FILES['uploadedfile1']['tmp_name'], $target_path1))
{
echo "file2: ".basename( $_FILES['uploadedfile1']['name']);
$file2 = basename( $_FILES['uploadedfile1']['name']);
mysql_query("insert into new (amount) values('$file2')");
}
}
?>
introduction and the problem
This code will allow the user to upload 2 files, then their respective file name will save to the new(name of table) , I need it to save in table so that i have history who was the uploader of the file and simply can retrieve it or download it. The first button is the uploadedfile where in the file will save in uploads folder, then the button below is the uploadedfile1 where in the file will save in upload1, when the user put 2 files in this 2 buttons, then the user click save, it will save to their prepared folder(uploads or upload1), when the user only attach one file whether in the button uploaderfile or uploaderfile1 and click Upload file/save/submit, it will still save its file name to table new and save the file in the following folder(uploads of upload1).
The Problem is when the user upload a same file name, For example abc.jpg is already exist in table new and in folder(uploads of upload1), but there some user also upload abc.jpg.. the problem is in the folder(uploads of upload1) the abc.jpg will only one(one pcs..) because same file name.. i think the solution is the rename, where in the abc.jpg that is currently uploaded will became abc_1.jpg, also in the table new abc_1.jpg will be save..

Answer 1

You shouldn't save the files by their original name.
It is better practise to assign the file a unique identifier in the database, and use this same identifier for the file name.
Then have a downloads page which retrieves the file path and original name from the database and send it to the user with readfile and set relevant headers:
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="'.basename($file_name).'"');
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: '.filesize($file_path));
ob_clean();
flush();
readfile($file_path);
die();
This is also better from a security point of view as the users no longer need to know or have access to the file location on the server so if they upload anything malicious, they will be unable to call the file directly.
Edit:
To apply this, you will need to have a table for your file uploads with an autoincrementing ID field.
You can then insert the original filename and other relevant information into the database using mysql_query (as you are already using it in your example). You then need to pass the query into mysql_insert_id which will give you the unique identifier for the row you just inserted. Use this to name your file, followed by a '.dat' extension in your uploads folder.
When it comes to downloading, have a download page which takes an id by either query string or post parameter and then use this to look up the information in the database. You can figure out the filename given the ID as this is what you used to store it in the first place.
Once you have the file path and original name, you can use the code above to present the user with the download (after replacing $file_name and $file_location with your own parameters if you call them something else).
The downloads page will also need to handle any checks on whether or not the user is allowed to download the file.