sub isThisADecimalNumber {
    my ($string) = @_;

    return $string =~ /^\s*
                        -?              # negative sign - optional
                        (?:
                            \d+         # digits
                            (?:\.\d*)?  # and an optional decimal and maybe more digits
                        |               # OR
                            \.\d+       # a decimal and some digits
                        )
                        \s*$/x;
}