Another thought - not all unixes have /dev/urandom and /dev/random.
You can read abou them, but they do provide a random bitstream. If your box has them (Soalris & Linux come to mind) read on -
An example of how to play with the bitstream using Corona's idea.:
This needs work but you get the idea.
Hi I want to genrate 10 random 32 bit binary numbers with hamming distance 4 and 8.
11010110010101010101010101010101
11010110010101010100010101010010
if we look carefully at these two binary numbers they differ at 4 places hence hamming distance 4. Now I want to genrate these numbers... (2 Replies)
Hi,
I am having trouble with generating random numbers. can this be done with awk?
So I have a file that looks like this:
23 30
24 40
26 34
So column1 is start and column2 is end. I want to generate 3 random #'s between start and stop:
So the output will look like this:
... (9 Replies)
Im new to C, and Im having a hard time getting a random number.
In bash, I would do something similar to the following to get a random number;
#!/bin/bash
seed1=$RANDOM
seed2=$RANDOM
seed3=$RANDOM
SEED=`expr $seed1 * $seed2 / $seed3`
echo ${SEED%.*}
Now, in online examples... (4 Replies)
Hello All, I am stuck up in a program where the rand functions ends up giving all the same integers. Tried sleep, but the numbers turned out to be same... Can anyone help me out how to fix this issue ? I have called the srand once in the program, but I feel like when I call fork the child process... (5 Replies)
Hi Unix Gurus,
I have a requirement to generate positive random 16 and 13 digit numbers.
Here is the script I have so far.....
number=$RANDOM$RANDOM$RANDOM$RANDOM;
let "number %= 10000000000000";
echo $number
But sometimes it is generating negative numbers and also 15 digit... (8 Replies)
Hi there I am trying to generate a random number between 40 and 70 using the shell here is my code so far and it keeps going above 70. all help much appreciated!
comp=$(( RANDOM%70+40 ))
echo $comp (4 Replies)
Having a hard time with this. Very new to scripting and linux. Spent all sunday trying to do this. Appreciate some help and maybe help breaking down what the syntax does.
Create a Bash program. It should have the following properties
• Creates a secret number between 1 and 100
i. The... (3 Replies)
Hi,
How can I generate a string of random characters (alpha+numeric) of a particular length ?
For e.g. for
n=5, output = 'kasjf'
n=10, output = 'hedbcd902k'
Also, please let me know if random (valid) dates could also be generated.
Thanks (7 Replies)
Hi Guys and gals...
As you know I am getting to grips with POSIX and hit this stumbling block.
Generating two random numbers 0 to 255 POSIXly. Speed in not important hence the 'sleep 1' command.
I have done a demo that works, but it sure is ugly! Is there a better way?
#!/bin/sh
# Random... (12 Replies)
Discussion started by: wisecracker
12 Replies
LEARN ABOUT DEBIAN
bup-random
bup-random(1) General Commands Manual bup-random(1)NAME
bup-random - generate a stream of random output
SYNOPSIS
bup random [-S seed] [-fv]
DESCRIPTION
bup random produces a stream of pseudorandom output bytes to stdout. Note: the bytes are not generated using a cryptographic algorithm and
should never be used for security.
Note that the stream of random bytes will be identical every time bup random is run, unless you provide a different seed value. This is
intentional: the purpose of this program is to be able to run repeatable tests on large amounts of data, so we want identical data every
time.
bup random generates about 240 megabytes per second on a modern test system (Intel Core2), which is faster than you could achieve by read-
ing data from most disks. Thus, it can be helpful when running microbenchmarks.
OPTIONS
the number of bytes of data to generate.
Can be used with the suffices k, M, or G to indicate kilobytes, megabytes, or gigabytes, respectively.
-S, --seed=seed
use the given value to seed the pseudorandom number generator. The generated output stream will be identical for every stream
seeded with the same value. The default seed is 1. A seed value of 0 is equivalent to 1.
-f, --force
generate output even if stdout is a tty. (Generating random data to a tty is generally considered ill-advised, but you can do if
you really want.)
-v, --verbose
print a progress message showing the number of bytes that has been output so far.
EXAMPLES
$ bup random 1k | sha1sum
2108c55d0a2687c8dacf9192677c58437a55db71 -
$ bup random -S1 1k | sha1sum
2108c55d0a2687c8dacf9192677c58437a55db71 -
$ bup random -S2 1k | sha1sum
f71acb90e135d98dad7efc136e8d2cc30573e71a -
$ time bup random 1G >/dev/null
Random: 1024 Mbytes, done.
real 0m4.261s
user 0m4.048s
sys 0m0.172s
$ bup random 1G | bup split -t --bench
Random: 1024 Mbytes, done.
bup: 1048576.00kbytes in 18.59 secs = 56417.78 kbytes/sec
1092599b9c7b2909652ef1e6edac0796bfbfc573
BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup unknown-bup-random(1)