[ILUG] how to answer the question: "how random?"

[Fergal Daly]

perl -e 'sysread(STDIN, $r, 4); print unpack("L", $r)."\n"' < /dev/random

prints a random number between 0 and 2^32-1
replace the 4 and L to get different ranges:
2, S gives 0 to 65535
1, C gives 0 to 255


On Sat, Apr 28, 2001 at 12:46:58PM +0100, kevin lyda wrote:
> On Sat, Apr 28, 2001 at 11:34:18AM +0100, Conor Daly wrote:
> > Errm,  so, how do I get numbers form /dev/random?  dd gives me ascii
> > garbage, so does cat.  Do I need to write a c proggie to read and what
> > should I read then?
> 
> an ugly pipeline:
> 
> dd if=/dev/urandom bs=10 count=1 2> /dev/null| od -x | sed 's/^[^ ]* *//'
> 
> play with flags to od to change the radix, change the bs= setting for dd
> to get different sized numbers.  oh, and i used /dev/urandom to generate
> the numbers as it always returns the amount requested (at the price of
> less randomness).
> 
> kevin
> 
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