randombash's Introduction

Bash RNG glitch

I generated three sets of random numbers using: MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports, 2,5 GHz Dual Core i7). First two sets were generated using commands:

watch -c 'echo $RANDOM >> bash1.txt'
watch -c 'echo $RANDOM >> bash2.txt'

There were generated parallel, in two separate tmux sessions.

bash1.txt

bash2.txt

The following Python script generated the third set:

from random import random

for x in range(0,10000):
    print(str(random()*32767).split('.')[0])

python.txt

In each file, let's subtract each number from the previous one. Next, we will count the frequencies of each subtraction:

cat python.txt | awk '{print prev-$1 ;prev=$1}' | sort | uniq -c | sed -e 's/^ *//' | sort -t ' '  -k 1rn,2rn > python_subtraction.txt
cat bash1.txt | awk '{print prev-$1 ;prev=$1}' | sort | uniq -c | sed -e 's/^ *//' | sort -t ' '  -k 1rn,2rn > bash1_subtraction.txt
cat bash2.txt | awk '{print prev-$1 ;prev=$1}' | sort | uniq -c | sed -e 's/^ *//' | sort -t ' '  -k 1rn,2rn > bash2_subtraction.txt

Results:

Columns 1-2: bash1_subtraction.txt
Columns 3-4: bash2_subtraction.txt
Columns 5-6: python_subtraction.txt

freq	number	freq	number	freq	number
4725	-2726	4900	-2726	4	-1322
922	-2725	951	-2725	4	-9356
802	13204	855	13204	4	9461
553	-19564	549	-19564	3	-10270
447	30042	417	30042	3	-10636
359	14112	365	14112	3	-13308
338	14113	361	14113	3	-13866
277	-18656	257	-18655	3	-14735
259	-1817	257	-18656	3	-1700
236	-18655	159	13203	3	-17671
168	-3634	156	-3634	3	-1794
142	-3635	145	-3635	3	-184
132	13203	120	-19565	3	-2186
89	-19565	84	30043	3	-2222
76	-1818	59	12295	3	-2254
73	30043	51	-4543	3	-3012
53	12295	32	-20473	3	-3020
48	-4543	25	29134	3	-3041
31	-20473	24	-1817	3	-3215
21	11386	19	10478	3	-326