Perl sprintf

        # Format number with up to 8 leading zeroes
        $result = sprintf("%08d", $number);

        # Round number to 3 digits after decimal point
        $rounded = sprintf("%.3f", $number);

Perl's sprintf permits the following universally-known conversions:

   %% a percent sign
 %c a character with the given number
 %s a string
 %d a signed integer, in decimal
 %u an unsigned integer, in decimal
 %o an unsigned integer, in octal
 %x an unsigned integer, in hexadecimal
 %e a floating-point number, in scientific notation
 %f a floating-point number, in fixed decimal notation
 %g a floating-point number, in %e or %f notation