Artifacts in text file - php

Question

I have a test project which allows upload of various text(subs), then content of these text file gets displayed. Problem occurs when characters used, are not alphabet, i.e Cyrillic as in diacritics as ŠŽČĆ. Characters in text file are ok pre upload, but when i opened a uploaded file on server, all characters ŠŽČĆĐ get replaced by a . Yes, you saw it correctly, it's a rectangle thingy.
I use this line which work great on localhost, but on shared hosting throws a fit.
$temp = iconv(mb_detect_encoding($tmp, mb_detect_order(), true), "UTF-8", utf8_encode($tmp));
Where $temp variable is the string to be decoded.
Is it hosting thing, could i do something to prevent it?
PS: If i don't use utf8_encode on $tmp variable, server throws an error.
Edit1:
First image shows how it looks when file is opened on shared hosting.
And when i copy/paste that thing, it looks like this
sadly it doesn't get rendered on SO. Or lucky, depends of how you look at it ...
Above this sentence is an image, not typed out characters. It is how ever, a text i typed and character that is in a uploaded file copied then pasted when you making post on SO.
Edit2:
I sort a figured it out what's the problem. File is correctly saved as utf8 which contains previously said letters.
When file gets uploaded, these letters get changed to rectangle thing. So when i open file on server, instead ŠŽČĆĐ, i get rectangles. How to prevent server changing anything and to upload as is?
So it's not a formatting thing, athrough setting encoding to utf8 seems to help to at least display it and if i don't set encoding to utf8, it throws an error.
I'm using Laravel as backend.
Edit3:
If i test specific char after being read from file with this
mb_convert_encoding(file($path)[8][9])//It should be **š** character
It shows it's utf8, but if it was it will be shown.
If i try this line:
mb_convert_encoding(file($path)[8][9], "UTF-8", "ISO-8859-1")
then it shows rectangle thing like in file on server.
If i use to detect encoding with additional parameters like:
mb_detect_encoding(file($path)[8], "UTF-8", TRUE);
to determine if it's actual utf8, it says it's false.
And if i paste rectangle thing into google translate it shows an "š".
which is correct letter.
If i use bin2hex() to see hex code and for example argument is š letter, i get 9a hex code.
If anybody has any idea how to recreate function that will differentiate between these rectangles and show correct hex code or char itself, or how to upload to shared hosting without allowing it to change letters encoding in text file, or how to approach whole problem, it would be much obliged.

Answer 1

Do not use utf8-encode. It is only to converting from ISO-8859-1 and it doesn’t work with Windows-1252.
https://www.php.net/manual/en/function.utf8-encode.php
The second problem is that your code do a double encoding. I have marked two function that convert a string to UTF-8.
$temp = iconv(mb_detect_encoding($tmp, mb_detect_order(), true), "UTF-8", utf8_encode($tmp));
/* ^^^^^ ^^^^^^^^^^^ */
If the code below do not work, I would debug output of mb_detect_encoding($tmp, mb_detect_order(), true). The default values for mb_detect_order() may be far for optimal for Your situation.
https://www.php.net/manual/en/function.mb-detect-encoding.php
https://www.php.net/manual/en/function.mb-detect-order.php
$temp = iconv(mb_detect_encoding($tmp, mb_detect_order(), true), "UTF-8", $tmp);
You can use mb_convert_encoding() in place of iconv.
https://www.php.net/manual/en/function.mb-convert-encoding.php
For Your problem I would write this code:
/* If there are no Asian languages, the UTF-8 is the only encoding the mb_detect_encoding can recognize. */
if (mb_detect_encoding($tmp, 'UTF-8')) {
$temp = $tmp;
} else {
/* It is not UTF-8. Assume WINDOWS-1252. */
$temp = mb_convert_encoding($tmp, 'UTF-8', 'WINDOWS-1252');
}
It is very hard to reliably detect a particular single byte encoding. I am not aware of any build in PHP function for this.