Hello All...
Can someone help me generate a random password which will be 7 characters long which contains alpha-numeric characters using shell script.
I am looking to store the output of the script that generates the password to a variable within a script and use it as the password.
... (5 Replies)
Hello,
For my weather station I have made a little perl script to put the data into cacti. The next problem I have.
I can only get positive numbers or negative numbers.
What do I do:
Though a shell scrip I call the perl script.
Shell script:
#!/bin/sh
cat data.txt | stats.pl
Perl... (4 Replies)
I saw this formula to generate random number between two specified values in shell script.the following.
$(((RANDOM%(max-min+divisibleBy))/divisibleBy*divisibleBy+min))
Give a example in book.
Generate random number between 6 and 30.like this.
$(((RANDOM%30/3+1)*3))
But I have a... (1 Reply)
Let, I have three numbers
+00123.25
-00256.54
+00489.23
I need to sum up all those three numbers, after storing them in three variables (say var1, var2, var3).
I used both expr and BC, but they didn't work for me.
But, I am not able to sum up them, as I don't have any idea how to... (13 Replies)
hi guys,
I am writing a c program that generates a two dimensional array to make matrix and a vector of random numbers and perform multiplication. I can't figure out whats wrong with my code. It generates a matrix of random numbers but all the numbers in the vector array is same and so is the... (2 Replies)
Dear All,
I have to split a tab delimited file in two files based on the presence of a positive or negative in column number 9 , for example
file:
A 1 5 erg + 6766 0.9889 0.9817 9.01882 erg inside upstream
B 1 8 erg2 + 6766 0.9889 0.9817 -9.22 erg2 inside... (3 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)
Need to use dd to generate a large file from a sample file of random data. This is because I don't have /dev/urandom.
I create a named pipe then:
dd if=mynamed.fifo do=myfile.fifo bs=1024 count=1024
but when I cat a file to the fifo that's 1024 random bytes:
cat randomfile.txt >... (7 Replies)
I have a file that is pipe delimited and in Column F they have number values, both positive and negative. I need to take the one file I am starting with and split it into two separate files based on negative and positive numbers. What is the command to do so? And then I need to also transfer... (4 Replies)
Discussion started by: cckaiser15
4 Replies
LEARN ABOUT FREEBSD
read_random
RANDOM(9) BSD Kernel Developer's Manual RANDOM(9)NAME
arc4rand, arc4random, random, read_random, srandom -- supply pseudo-random numbers
SYNOPSIS
#include <sys/libkern.h>
void
srandom(u_long seed);
u_long
random(void);
void
arc4rand(void *ptr, u_int length, int reseed);
uint32_t
arc4random(void);
#include <sys/random.h>
int
read_random(void *buffer, int count);
DESCRIPTION
The random() function will by default produce a sequence of numbers that can be duplicated by calling srandom() with '1' as the seed. The
srandom() function may be called with any arbitrary seed value to get slightly more unpredictable numbers. It is important to remember that
the random() function is entirely predictable, and is therefore not of use where knowledge of the sequence of numbers may be of benefit to an
attacker.
The arc4rand() function will return very good quality random numbers, slightly better suited for security-related purposes. The random num-
bers from arc4rand() are seeded from the entropy device if it is available. Automatic reseeds happen after a certain timeinterval and after
a certain number of bytes have been delivered. A forced reseed can be forced by passing a non-zero value in the reseed argument.
The read_random() function is used to return entropy directly from the entropy device if it has been loaded. If the entropy device is not
loaded, then the buffer is filled with output generated by random(). The buffer is filled with no more than count bytes. It is advised that
read_random() is not used; instead use arc4rand()
All the bits generated by random(), arc4rand() and read_random() are usable. For example, 'random()&01' will produce a random binary value.
The arc4random() is a convenience function which calls arc4rand() to return a 32 bit pseudo-random integer.
RETURN VALUES
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 (2**31)-1. The period of this random number generator is very large, approxi-
mately 16*((2**31)-1).
The arc4rand() function uses the RC4 algorithm to generate successive pseudo-random bytes. The arc4random() function uses arc4rand() to gen-
erate pseudo-random numbers in the range from 0 to (2**32)-1.
The read_random() function returns the number of bytes placed in buffer.
AUTHORS
Dan Moschuk wrote arc4random().
Mark R V Murray wrote read_random().
BSD September 25, 2000 BSD