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;
Now, in online examples for C everyone suggest seeding srandom with time, so I attempted seeding with time_t now. Which works great except this program will run probably 20-30 times a second... to seeding with time_t now wont work.. as I'll continually get the same random number.
How can a randomize better in c? IS there a way to get milliseconds or nanoseconds with time.h? I dont care if it's not 100% accurate I just need to figure out how to get a truly random number.
Hi I want to genrate 10 random 32 bit binary numbers with hamming distance 4 and 8.
11010110010101010101010101010101
11010110010101010100010101010010
if we look carefully at these two binary numbers they differ at 4 places hence hamming distance 4. Now I want to genrate these numbers... (2 Replies)
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)
Hello All, I am stuck up in a program where the rand functions ends up giving all the same integers. Tried sleep, but the numbers turned out to be same... Can anyone help me out how to fix this issue ? I have called the srand once in the program, but I feel like when I call fork the child process... (5 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,
How can I generate a string of random characters (alpha+numeric) of a particular length ?
For e.g. for
n=5, output = 'kasjf'
n=10, output = 'hedbcd902k'
Also, please let me know if random (valid) dates could also be generated.
Thanks (7 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 HPUX
srand
rand(3C)rand(3C)NAME
rand(), rand_r(), srand() - simple random-number generator
SYNOPSIS DESCRIPTION
uses a multiplicative, congruential, random-number generator with period 2^32 that returns successive pseudo-random numbers in the range
from 0 to 2^15-1.
can be called at any time to reset the random-number generator to a random starting point. The generator is initially seeded with a value
of 1.
returns a random number at the address pointed to by the randval parameter. The seed parameter can be set at any time to start the random-
number generator at an arbitrary point.
Note
The spectral properties of leave a great deal to be desired. provides a much better, though more elaborate, random-number generator (see
drand48(3C)).
RETURN VALUE
If seed or randval is NULL, returns 0. Otherwise, returns a psuedo-random integer.
EXAMPLES
The following:
int x, y;
srand(10);
x = rand();
y = rand();
would produce the same results as:
int x, y, s = 10;
x=rand_r(&s);
y=rand_r(&s);
WARNINGS
Users of should note that rand_r() now conforms with POSIX.1c. The old prototype of is supported for compatibility with existing DCE
applications only.
SEE ALSO drand48(3C), random(3M), thread_safety(5), random(7).
STANDARDS CONFORMANCE rand(3C)