How can I overwrite a file, when the file I want to upload already exists?

Question

I want to overwrite a file, if it already exists in the folder. Here is my code:

index.php

<form action="check.php" method="post" enctype="multipart/form-data">
    <input type="file" name="file">
    <button type="submit" value="upload">Upload</button>
</form>

check.php

if(isset($_FILES['file'])) {
    $file = $_FILES['file'];
    $target_file = 'files/'.basename($_FILES["file"]["name"]);
    if (file_exists($target_file)) {
        echo "File already exist";                  
        echo "<form action='overwrite.php' method='post'>
                <button type='submit'> Overwrite</button>
            </form>";
    } 
}

overwrite.php

move_uploaded_file($_FILES["file"]["tmp_name"], $target_file);
echo "The file is overwritten";

Update: I did a mistake in my question. Now I changed it. On check.php there should only be the statement "File already exists" and a button which directs to the overwrite.php and overwrite the file. (No second input field)

Check your script has permission to overwrite the file. Alternatively, create a unique string as the file name so you avoid this issue. — Liam Sorsby, Jul 23 '15 at 13:40
possible duplicate of [PHP File upload and overwrite file with same name](http://stackoverflow.com/questions/8064618/php-file-upload-and-overwrite-file-with-same-name) — Liam Sorsby, Jul 23 '15 at 13:42

score 1 · Answer 1 · edited Jul 23 '15 at 13:38

1

when you are creating the form again you need to specify enctype="multipart/form-data"

 echo "<form action='overwrite.php' method='post' enctype='multipart/form-data'>
        <input type='file' name='file'>
        <button type='submit'> Overwrite</button>
    </form>";

without enctype="multipart/form-data"it wont let you perform file upload operation

other than that name should not be a value it should be static so you can use it

edited Jul 23 '15 at 13:38

Ben

8,894
7
44
80

answered Jul 23 '15 at 13:35

Meenesh Jain

2,532
2
19
29

1

Hi, I changed it, like you suggested, but it is still not working – peace_love Jul 23 '15 at 13:37
change the name to static `file` from `$target_file` – Meenesh Jain Jul 23 '15 at 13:38
1

This wouldn't overwrite the file if the script doesn't have permission to do so. – Liam Sorsby Jul 23 '15 at 13:39
I did. My change: ``. But still not working – peace_love Jul 23 '15 at 13:42
@jarla buddy you are doing it wrong, `enctype='multipart/form-data'` should be added to `form` tag and keep your input name as `` simply. see my answer i havent posted something like this – Meenesh Jain Jul 23 '15 at 13:44
Sorry I found out I did an important mistake in my question. Please see the change in my question – peace_love Jul 23 '15 at 14:00

score 0 · Answer 2 · answered Jul 23 '15 at 13:39

0

You're accessing $_FILES["file"] but, unless $target_file==="file", you're not finding anything.

Change the name attribute of the file upload from $target_file to just file:

        echo "<form action='overwrite.php' method='post'>
                <input type='file' name='file'>
                <button type='submit'> Overwrite</button>
            </form>";

answered Jul 23 '15 at 13:39

Ben

8,894
7
44
80

What do you see when you use `var_dump($_FILES)`? – Ben Jul 23 '15 at 13:46
Sorry, I did a mistake in my question. On check.php there shouldn't be a new input field, just a button to say overwrite. So on my check.php should only be the statement "File already exists" and a button which directs to the overwrite.php and overwrite the file. – peace_love Jul 23 '15 at 13:54
Do you know how to get the code working without an input field on check.php? – peace_love Jul 23 '15 at 14:12

How can I overwrite a file, when the file I want to upload already exists?

2 Answers2