Read $limit lines from line $offset by PHP

function readLine($sfile, $offset, $limit = 1000) {
    $file = new SplFileObject($sfile);
    $file->seek($offset);
    $i = 1;
    $data = array();
    if ($limit == -1) {//read from line $offset to EOF
        while (!$file->eof()) {
            $line = $file->current(); $i++; $file->next();
            processData($line, $data);
        }
    } else {
        while (!$file->eof() && $i <= $limit) {
            $line = $file->current(); $i++; $file->next();
            processData($line, $data);
        }
    }