Currency

<?php

Class Currency
{
    public static $soldRow = 6;
    public static $url = "https://www.csob.cz/portal/lide/produkty/kurzovni-listky/kurzovni-listek/-/date/kurzy.txt";

    public function getActualSoldCurs($currency)
    {
        $output = false;
        $lines = @file($this::$url);

        if ($lines === FALSE) {
            throw new Exception("Currency list is inaccessible");
        }

        $matches = preg_grep("/" . $currency . "/", $lines);

        if (count($matches) > 0) {
            $contentLine = explode(";", reset($matches));
            if (isset($contentLine[$this::$soldRow])) {
                $output = $contentLine[$this::$soldRow];
            }
        } else {
            throw new Exception("Curse is not find in currency list.");
        }
        return $output;
    }
}

$currency = new Currency();
try {
    $course = $currency->getActualSoldCurs("USD");
    echo $course;
} catch (Exception $e) {
    echo "Error: " . $e->getMessage();
}