Re: Restrict RAND to producing 63 random bits

[Robert Moskowitz <rgm@xxxxxxxxxxxxxxx>]

    I kind of like that.  I was thinking how to use a mask like you
    have, but I just don't have the skills in that direction to figure
    it out.
    
    I may document both ways.
    
    thanks

On 7/20/23 17:39, James wrote:

An alternative using openssl

$ printf "%016X\n" $((16#$(openssl rand -hex 8) & 0x7fffffffffffffff))

4B0193AE43934F09

To get the leading zeros so it will generate an 8-byte serial number, I added:

printf "%016X\n" $(shuf -rn 1 -i 1-9223372036854775807 --random-source=/dev/urandom)

an example output is:

0E12E1A664C30AE1

I had to run it a couple dozen times before it generated a small enough value to need to pad it.