Would you please explain what do you mean by unsatisfactory? I suppose most applications generate random numbers with these functions for cross-platform compatibility as they are standard.
In the rand() manpage, somewhere in the bottom, there is a note that discusses how to use that properly. Did you use it like that?
On some systems there are other means for random number generation. For instance, on Linux PCs the /dev/hwrandom represents a hardware random number generator . But this is only present if this support is compiled and available in the kernel. You may also try /dev/random and /dev/urandom.
Hi all,
I have a doubt in SQL Loader.
We have SEQUENCE function in SQL Loader or can create Sequence in Oracle database for generating a number sequence for
a column while loading data using SQL Loader into table or multiple tables.
My requirment is this.
For the first run in SQL... (2 Replies)
I need to generate a random number in ksh everytime I run the script ,the range should be from 100 to 24800,I could use $RANDOM but I seem to have no control over the range of numbers ,could you please suggest some way I could implement this .Thanks.
Mervin (2 Replies)
Hi Folks,
Can you help me with this issue:
I have to generate the numbers say from 1001 for each record in a file based on a key field,
the catch is the generated number should be unique based on key column.
(EMP_NUMBER)
Example:
Input File:
EMP_NUMBER EMP_NAME
8908 ... (6 Replies)
HI
please help me in solving this issue.
I have a shell script which consists of ten statemnts ( i mean 10 executable statments)...........and if i run that script the 10 statmenst will execute continously ............
But now my probelm is i have to write another script --> to... (0 Replies)
Hi
I have the below code
MAXCOUNT=10
count=1
echo
echo "$MAXCOUNT random numbers:"
echo "-----------------"
while # Generate 10 ($MAXCOUNT) random integers.
do
number=$ + 1 ]
"echo $number"
let "count += 1" # Increment count.
done
But aftre executing this
... (8 Replies)
i tried to use $random function in unix
i simply typed print $random at shell and it returnted no value
is there any function in korn shell that i can use to generate random number
help is appreciated (2 Replies)
I need to generate and reuse a 5 digit random number every time my program is executed. But the following generates random numbers every time the function is called.
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <time.h>
... (12 Replies)
Hi - I have a word GTTCAGAGTTCTACAGTCCGACGAT
I need to extract all the possible "chunks" of 7 or above letter "words" from this.
SO, my out put should be
GTTCAGA
TTCAGAG
TCAGAGT
CAGAGTTCT
TCCGACGAT
CAGTCCGACG
etc.
How can I do that with awk or any other language? I have no... (2 Replies)
Hello,
I have created a script to generate a random password on Linux/Solaris, but I simply cannot use it on my AIX VMs since Bash isn't installed on them.
I need a password that is randomly created with the following... (12 Replies)
Discussion started by: gfroute
12 Replies
LEARN ABOUT OPENDARWIN
urandom
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