[PHP] Workaround for the absent "ereg()" function, in PHP 7+

ereg-workaround-for-php-7.php

//make sure the function is not already there ;-)
if (!function_exists('ereg'))
{
    //@see https://stackoverflow.com/questions/6270004/how-can-i-convert-ereg-expressions-to-preg-in-php
    //@see http://php.net/manual/en/function.ereg.php
    //@see http://php.net/manual/en/function.preg-match.php
    function ereg($pattern, $string, $matches = null)
    {
        //quote delimiters, if already present in the pattern (ereg does not have delimiters)
        $pattern = preg_quote($pattern, '~');
        
        //add delimiters to pattern
        $pattern = '~' . $pattern . '~';

        //check function's third parameter
        if (!isset($matches))
        {
            //there is no matches array
            $result = preg_match($pattern, $string);
        }
        else
        {
            $result = preg_match($pattern, $string, $matches);
        }
        
        
        //preg_match() returns 1 if the pattern matches given subject, 0 if it does not, or FALSE if an error occurred.
        //ereg() returns the length of the matched string if a match for pattern was found in string, or FALSE if no matches were found or an error occurred.
        //    If the optional parameter "regs" was not passed or the length of the matched string is 0, this function returns 1.
        if ($result === false)
        {
            //ok
            return false;
        }
        else if ($result === 0)
        {
            //ereg returns "false", if a match has not been found
            return false;
        }
        else
        {
            //ereg returns 1 if there was no "matches" array or lentgh of matched string is 0
            if (
                !isset($matches)
                || (strlen($matches[0]) === 0)
            )
            {
                //no matches array, so we just return "1"
                return 1;
            }
            else
            {
                //first element in $matches contains matched string
                return strlen($matches[0]);
            }
            
        }
    }
}