RE: RE: Randomizing Unique ID?

[tye]

in reply to RE: Randomizing Unique ID?
in thread Randomizing Unique ID?

Note that this is barely adequate since a "typical" double has 53 bits of mantissa (not counting the sign bit) which can handle just under 16 decimal digits while time() currently returns 9 digits but will soon return 10, while $$ is typically no more than 5 digits (total will soon be 15 digits).

Doing the conversion to base-62 in two steps would give you lots of room (and different results).

        - tye (but my friends call me "Tye")

[Adam]

Well, If you want more room in the double, then do the base conversion before doing the concatenation, thusly:

# Generate a truly unique ID
sub GenerateBase
{
    my $base = shift;
    $base = 62 if $base > 62;
    my @nums = (0..9,'a'..'z','A'..'Z')[0..$base-1];

    return sub
    {
        my $number = shift;
        my $rep = ""; # this will be the end value.
        while( $number > 0 )
        {
            $rep = $nums[$number % $base] . $rep;
            $number = int( $number / $base );
        }
        return $rep;
    }
}
my $ToBase62 = GenerateBase( 62 );
my $ID = $ToBase62->( $$ ) . $ToBase62->( time );