The quality of the output of the algorithm is also very sensitive to the value of seed (line 10).
I was well aware of this that is why I used a variable instead of a fixed value inside line 25.
The idea was to use the last byte read as the next "seed" but I didn't pursue it any further. "seed" must always
have a value greater than or equal to 1 and less than or equal to decimal value 256 added to the current byte in use.
(I assumed you guys would see the flaw and correct as you need.)
However if the current byte value would be zero then "seed" would have to be a minimum value of "1".
(This is taken care of with the limitation of fixing "seed" in the script shown.)
Not because of anything to do with binary zero in shell scripting per-se but it would just stop there until the
loop finished and give that character value at that point continuously ( <- if that sentence is lucid enough. ).
Bazza...
EDIT: Made more lucid.
This is a simple way of making it a little better without the complexity of storing the previous and current
bytes read. (Line 26.)
Last edited by wisecracker; 09-21-2013 at 06:27 PM..
Reason: Rewrite to make more lucid...
I am trying to find a way to generate random numbers within a shell script.
Does Solaris have a utility that will generate random numbers?
Thanks in advance.
B (3 Replies)
In my server migration requirement, I need to compare if one file on old server is exactly the same as the corresponding file on the new server.
For diff and comm, the inputs need to be sorted. But I do not want to disturb the content of the file and need to find byte-to-byte match.
Please... (4 Replies)
Hi,
I need to create a table with random sentences. I need lines that are upto 1000 characters in lenght. I need a random sentence generator that will create sentences and output it to a text file. The sentences should be of lenght varying from 1 to 1000.
Does anyone know how this can be... (7 Replies)
Hi,
I need a script that will generate a set of random strings in sequence, with the ability to predetermine the length, quantity, and alphabet of individual string, and to use the outputs of earlier strings in the sequence to define the parameters of later strings. For examples, I might want... (5 Replies)
I want to develop a script of the following form:
#!/bin/bash
# Function 'listen' opens a data stream
# which stores all incoming bytes in
# a buffer, preparing them to be
# grabbed by a following function
# which appears at random
# intervals during the execution of
# the script
... (11 Replies)
A very simple crude sinewave generator.
The file required is generated inside the code, is linear interpolated and requires /dev/audio to work. Ensure you have this device, if not the download oss-compat from your OS's repository...
It lasts for about 8 seconds before exiting and saves a... (5 Replies)
Hello
I created 3 files by:
dd if=/dev/urandom bs=1024 count=1000000 of=./testfile1
dd if=/dev/urandom bs=1024 count=5000000 of=./testfile2
dd if=/dev/urandom bs=1024 count=10000000 of=./testfile3
Now I want to know how to make a change in a specific byte and/or line of theses files? (2 Replies)
Dear UNIX Friends,
I was wondering if there is a random RGB color generator or any function in any unix platforms.
Please share your ideas.
Thanks (2 Replies)
I am using the below to random generate a password but I need to have 2 numeric characters and 6 alphabetic chars
head /dev/urandom | tr -dc A-Za-z0-9 | head -c 8 ; echo ''
6USUvqRB
------ Post updated at 04:43 PM ------
Any Help folks - Can the output be passed onto a sed command to... (9 Replies)
Discussion started by: infernalhell
9 Replies
LEARN ABOUT REDHAT
random
RANDOM(3) Linux Programmer's Manual RANDOM(3)NAME
random, srandom, initstate, setstate - random number generator.
SYNOPSIS
#include <stdlib.h>
long int random(void);
void srandom(unsigned int seed);
char *initstate(unsigned int seed, char *state, size_t n);
char *setstate(char *state);
DESCRIPTION
The random() function uses a non-linear additive feedback random number generator employing a default table of size 31 long integers to
return successive pseudo-random numbers in the range from 0 to RAND_MAX. The period of this random number generator is very large, approx-
imately 16*((2**31)-1).
The srandom() function sets its argument as the seed for a new sequence of pseudo-random integers to be returned by random(). These
sequences are repeatable by calling srandom() with the same seed value. If no seed value is provided, the random() function is automati-
cally seeded with a value of 1.
The initstate() function allows a state array state to be initialized for use by random(). The size of the state array n is used by init-
state() to decide how sophisticated a random number generator it should use -- the larger the state array, the better the random numbers
will be. seed is the seed for the initialization, which specifies a starting point for the random number sequence, and provides for
restarting at the same point.
The setstate() function changes the state array used by the random() function. The state array state is used for random number generation
until the next call to initstate() or setstate(). state must first have been initialized using initstate() or be the result of a previous
call of setstate().
RETURN VALUE
The random() function returns a value between 0 and RAND_MAX. The srandom() function returns no value. The initstate() and setstate()
functions return a pointer to the previous state array, or NULL on error.
ERRORS
EINVAL A state array of less than 8 bytes was specified to initstate().
NOTES
Current "optimal" values for the size of the state array n are 8, 32, 64, 128, and 256 bytes; other amounts will be rounded down to the
nearest known amount. Using less than 8 bytes will cause an error.
CONFORMING TO
BSD 4.3
SEE ALSO rand(3), srand(3)GNU 2000-08-20 RANDOM(3)