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 ${SEED%.*}
Now, in online examples... (4 Replies)
I want to generate an awk function that generated a Gaussian distributed set of random numbers. I need to implement the thing below in awk. Rnd is just a uniform random number between 0 and 1
function rgaussian(r1, r2) {
Do
v1 = 2 * Rnd - 1
v2 = 2 * Rnd - 1
... (0 Replies)
Hi,
I hope someone can share there scripting fu on my problem,
I would like to delete the 3rd character from a random length of string starting from the end
Example
Output
Hope you can help me..
Thanks in advance.. (3 Replies)
Hello.
Could anyone help me with my little annoying problem?
I have to generate a 512 MB file made up with random data using DD. After some internet digging I found out that the command is:
dd if=/dev/urandom of=/exemple/file bs=512MB
After running this command the... (2 Replies)
Hi there I am trying to generate a random number between 40 and 70 using the shell here is my code so far and it keeps going above 70. all help much appreciated!
comp=$(( 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 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 OPENDARWIN
random
RANDOM(4) BSD Kernel Interfaces Manual RANDOM(4)NAME
random , urandom -- random data source devices.
SYNOPSIS
pseudo-device random
DESCRIPTION
The random device produces uniformly distributed random byte values of potentially high quality.
To obtain random bytes, open /dev/random for reading and read from it.
To add entropy to the random generation system, open /dev/random for writing and write data that you believe to be somehow random.
/dev/urandom is a compatibility nod to Linux. On Linux, /dev/urandom will produce lower quality output if the entropy pool drains, while
/dev/random will prefer to block and wait for additional entropy to be collected. With Yarrow, this choice and distinction is not necessary,
and the two devices behave identically. You may use either.
OPERATION
The random device implements the Yarrow pseudo random number generator algorithm and maintains its entropy pool. Addditional entropy is fed
to the generator regularly by the SecurityServer daemon from random jitter measurements of the kernel. SecurityServer is also responsible
for periodically saving some entropy to disk and reloading it during startup to provide entropy in early system operation.
You may feed additional entropy to the generator by writing it to the random device, though this is not required in a normal operating envi-
ronment.
LIMITATIONS AND WARNINGS
Yarrow is a fairly resilient algorithm, and is believed to be resistant to non-root. The quality of its output is however dependent on regu-
lar addition of appropriate entropy. If the SecurityServer system daemon fails for any reason, output quality will suffer over time without
any explicit indication from the random device itself.
Paranoid programmers can counter-act this risk somewhat by collecting entropy of their choice (e.g. from keystroke or mouse timings) and
seeding it into random directly before obtaining important random numbers.
FILES
/dev/random
/dev/urandom
HISTORY
A random device appeared in Linux operating system.
Darwin September 6, 2001 Darwin