RANDOM(6) BSD Games Manual RANDOM(6)NAME
random -- random lines from a file or random numbers
random [-er] [denominator]
random reads lines from the standard input and copies them to the standard output with a probability of 1/denominator. The default value for
denominator is 2.
The options are as follows:
-e If the -e option is specified, random does not read or write anything, and simply exits with a random exit value of 0 to
-r The -r option guarantees that the output is unbuffered.
SEE ALSO shuffle(1), fortune(6)BSD March 20, 2007 BSD
Check Out this Related Man Page
RANDOM(4) BSD Kernel Interfaces Manual RANDOM(4)NAME
random , urandom -- random data source devices.
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.
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-
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.
A random device appeared in Linux operating system.
Darwin September 6, 2001 Darwin
Hi, how do I use /dev/urandom to generate a single number between 1-100? I can od /dev/urandom but it gives me an endless list of random numbers, I just want 1 between 1-100. How can I get that? Thanks. (12 Replies)
Hi one and all,
I'm working on a Bash script that is designed to calculate how much IP traffic has passed through a port to determine traffic volume over a given amount of time.
I've currently been able to use the netstat -s command coupled with grep to write to a file the total packets... (13 Replies)
I'm coding on Ubuntu 9.04 standard shell.
I'm writing a script that needs to generate a random number at some point of its execution.
When I do
echo $RANDOMas a command inside shell, I clearly get some randomly generated number
However when I do
echo $ior even... (14 Replies)
Hi, im trying to make a shell script that basically runs a random shell script form a list of shell scripts i specify. Im not very good at writing shell scripts, and am new to linux.
Thanks in advance :) (15 Replies)
I have 200 pictures in a folder and I would like move 10 random pictures every week to given folder automatically.
I have this server on 1and1.com.
So I tried the following using Bash script for manual copy and paste for testing
mapfile -t -n 3 files < <(find... (13 Replies)
Is there a tool somewhat parallel to rev, but which randomizes instead of reverses?
I've tried rl, but I can only get it to randomize words.
I was hoping for something like this
echo "hello" | ran
less simpler solutions are also welcome.
Sorry if the question is... (21 Replies)
This is my code:
nb_lignes=`wc -l $1 | cut -d " " -f1`
for i in $(seq $nb_lignes)
m=`head $1 -n $i | tail -1`
Please how can i change it to get Get 20% of lines in File randomly to apply "command" on each line ? 20% or 40% or 60 % (it's a parameter)
Thank you. (15 Replies)
i want to generate a random number through a script, and even if anyone reads the script, they wont be able to figure out what the random number is. only the person who setup the script would know it.
something like this could work: random
the full thread is here:
... (13 Replies)
I have two files containing hundreds of different sequences with the same Identifiers (ID-001, ID-002, etc.,), something like this:
ID-003... (18 Replies)
I've been attempting to create a script that downloads web pages at random intervals to mimic typical user usage. However I'm struggling to link $url to the URL list and thus wget complains of a missing URL. Any ideas?
url1="http://www.bbc.co.uk"... (14 Replies)
I have a column which have 7200 numbers and I am deciding to pick up 1440 numbers randomly without any reputation? Could any one let me know which script in unix will be work for my case?
Sajjad (17 Replies)
I am in a terrible emergency. I have multiple cdr files with line count >6000.
I need to append |0| | | | | | | |random| to end of each line. The random number should never repeat.
Please help with a shell script to process all cdr's in a directory with above requirement. (23 Replies)
I just got my hands on a T5120 running Sol10. As far as I've read, the T2 chip has a built-in hardware number generator. My question is: how can I access it to get random numbers in either C or Fortran? I'm using Sun Studio 12.4.
I am currently trying to write an... (13 Replies)
first of all this is not homework...this is a new type of exercise for practicing vocabulary with my students.
I have a file consisting of two columns, separated by a tab, each line consisting of a word and its definition, separated by a line break.
What i need is to replace a... (15 Replies)