Generate random number


 
Thread Tools Search this Thread
Top Forums Programming Generate random number
Prev   Next
# 1  
Old 05-16-2010
Generate random number

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 question , how to get a divisibleBy number is ok.
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. OS X (Apple)

Generate a random number in a fully POSIX compliant shell, 'dash'...

Hi all... Apologies for any typos, etc... This took a while but it didn't beat me... Although there are many methods of generating random numbers in a POSIX shell this uses integer maths and a simple C source to create an executable to get epoch to microseconds accuracy if it is needed. I take... (8 Replies)
Discussion started by: wisecracker
8 Replies

2. Shell Programming and Scripting

Help with generate a pair of random number

Hi, Is anybody experience generate a pair of random number by using awk command? I wanna to generate a pair of random number (range from 1 to 4124) and repeats it 416 times. Desired output 2 326 123 1256 341 14 3245 645 . . . I did write the below command: awk... (5 Replies)
Discussion started by: perl_beginner
5 Replies

3. Shell Programming and Scripting

Need to generate a file with random data. /dev/[u]random doesn't exist.

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)
Discussion started by: Devyn
7 Replies

4. UNIX for Dummies Questions & Answers

how to generate random number as as the first column of a txt file

Dear all, I have a question. I have a txt file say 4000 rows X 1800 Column. I 'd like to creat a new column as the first column which is a column of random numbers (n=4000) thanks a lot! Lin (2 Replies)
Discussion started by: forevertl
2 Replies

5. Shell Programming and Scripting

generate random base 16

How would you use bash to generate a random 32 digit number base 16? Like this one: 0cc06f2fa0166913291afcb788717458 (8 Replies)
Discussion started by: locoroco
8 Replies

6. Shell Programming and Scripting

Unix random number generate in given range

Hi All, I have extracted some report from database for few activities done. Now I have a requirement to add some random time(In range of 10-35) in front of each activity. Can be generated random numbers in any bash/sh shell within a given number range, let's say in between 10-30. ... (10 Replies)
Discussion started by: gr8_usk
10 Replies

7. Shell Programming and Scripting

generate random number in perl

Could any one tell how can I generate random number from (0, 100..200) in perl? Thanks! (2 Replies)
Discussion started by: zx1106
2 Replies

8. Shell Programming and Scripting

Generate a random password

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)
Discussion started by: chiru_h
5 Replies

9. Shell Programming and Scripting

generate random number in korn shell

I want to be able to generate a random number within a korn shell script.. Preferably i would like to be able to state how many digits should be in this random number... ie 4 digits or 5 digits etc Any ideas? (2 Replies)
Discussion started by: frustrated1
2 Replies

10. Programming

How to generate a random number?

How to generate a random integer with specific range(for example, from 1 to 1000)? Also, how to convert a floating point number into a integer? (2 Replies)
Discussion started by: MacMonster
2 Replies
Login or Register to Ask a Question
RAND(3) 								 1								   RAND(3)

rand - Generate a random integer

SYNOPSIS
int rand (void ) DESCRIPTION
int rand (int $min, int $max) If called without the optional $min, $max arguments rand(3) returns a pseudo-random integer between 0 and getrandmax(3). If you want a random number between 5 and 15 (inclusive), for example, use rand(5, 15). Caution This function does not generate cryptographically secure values, and should not be used for cryptographic purposes. If you need a cryptographically secure value, consider using random_int(3), random_bytes(3), or openssl_random_pseudo_bytes(3) instead. Note On some platforms (such as Windows), getrandmax(3) is only 32767. If you require a range larger than 32767, specifying $min and $max will allow you to create a range larger than this, or consider using mt_rand(3) instead. PARAMETERS
o $min - The lowest value to return (default: 0) o $max - The highest value to return (default: getrandmax(3)) RETURN VALUES
A pseudo random value between $min (or 0) and $max (or getrandmax(3), inclusive). EXAMPLES
Example #1 rand(3) example <?php echo rand() . " "; echo rand() . " "; echo rand(5, 15); ?> The above example will output something similar to: 7771 22264 11 SEE ALSO
srand(3), getrandmax(3), mt_rand(3), random_int(3), random_bytes(3), openssl_random_pseudo_bytes(3). PHP Documentation Group RAND(3)