// Created on savesnippets.com · https://savesnippets.com/rtWETph7yXj3Zz
<?php
const UTF8_BOM = "\xEF\xBB\xBF";

function hasBom(string $s): bool {
    return strncmp($s, UTF8_BOM, 3) === 0;
}

function stripBom(string $s): string {
    return hasBom($s) ? substr($s, 3) : $s;
}

// Useful when reading user-uploaded CSV files written from Excel.
$csv = stripBom(file_get_contents('upload.csv'));
$lines = explode("\n", $csv);