PHP Image Uploaded Name won't change - php

Question

I have PHP function to upload file (image).
foreach($_FILES['wallpaperFile']['tmp_name'] as $key => $tmpName)
{
$file_name = $_FILES['wallpaperFile']['name'][$key];
$file_type = $_FILES['wallpaperFile']['type'][$key];
$file_size = $_FILES['wallpaperFile']['size'][$key];
$file_tmp = $_FILES['wallpaperFile']['tmp_name'][$key];
move_uploaded_file($file_tmp,"assets/img/wallpapers/".time().$file_name);
}
It's working and I can see the data image uploaded on my folder.
But now how can I set the image file name only time() without .$file_name
If I remove .$file_name, file uploaded is not correct without extension and only 1 file, even though I uploaded 3 files.
Example:
Image file name: 1510750186shubuh.jpg
What I want only
1510750186.jpg

Answer 1

You can use pathinfo() for this, with PATHINFO_EXTENSION flag, Like:
foreach($_FILES['wallpaperFile']['tmp_name'] as $key => $tmpName)
{
$file_name = $_FILES['wallpaperFile']['name'][$key];
$file_type = $_FILES['wallpaperFile']['type'][$key];
$file_size = $_FILES['wallpaperFile']['size'][$key];
$file_tmp = $_FILES['wallpaperFile']['tmp_name'][$key];
$ext = pathinfo($file_name, PATHINFO_EXTENSION);
move_uploaded_file($file_tmp,"assets/img/wallpapers/".time().'.'.$ext);
}
This will only add the extension and no the full file name.
Edit:
To upload multiple files at the same time try to use 1 of these:
$newFileName = time()."{$key}.{$ext}";
move_uploaded_file($file_tmp,"assets/img/wallpapers/".$newFileName);
Or
$newFileName = str_replace('.','',microtime(true)).".{$ext}";
move_uploaded_file($file_tmp,"assets/img/wallpapers/".$newFileName);

Answer 2

I don't think that the extension of the file is your problem here. It's that time() only has a one-second resolution. It's highly improbable that time() will have a different value in any iteration of that loop. As such all your files have the same name with just time().
It's probably better to use something like microtime(true), which has microsecond fidelity or uniqid() to get a higher resolution in the same request.
foreach($_FILES['wallpaperFile']['tmp_name'] as $key => $tmpName)
{
$file_name = $_FILES['wallpaperFile']['name'][$key];
$file_type = $_FILES['wallpaperFile']['type'][$key];
$file_size = $_FILES['wallpaperFile']['size'][$key];
$file_tmp = $_FILES['wallpaperFile']['tmp_name'][$key];
/* user either this */
move_uploaded_file($file_tmp,"assets/img/wallpapers/" . microtime(true));
/* or this */
move_uploaded_file($file_tmp,"assets/img/wallpapers/" . uniqid());
}
You can see the difference by simply printing the value of both time() and microtime(true) inside that loop to realize the problem that time() would pose on your requirements here.
foreach($_FILES['wallpaperFile']['tmp_name'] as $key => $tmpName)
{
echo "time(): ", time(), "<br>\n";
echo "microtime(true): ", microtime(true), "<br>\n";
echo "uniqid(): ", uniqid(), "<br>\n";
}
Warning
You should never rely on $_FILES['wallpaperFile']['name'] here, because it is user-supplied input, and as such it is vulnerable to manipulation. Avoid allowing the client to possibly exploit/manipulate your filesystem by handing them direct-access to it via this vector. Having a completely random filename on your filesystem, instead, and storing that random name in your database to associate it with some arbitrary user-supplied-input is preferrable, because it allows you to retain full-control over your server's file system while still allowing the user to retain control over their own data.