I am writing a unix shell script that will generate random numbers each time through a loop to store in two shell variables, which are then used later by a different program. The problem is, I can't seem to get the random numbers to generate correctly! I am not very experienced using the awk language, is there anyway i can call rand from awk to generate numbers between 0 and n, which are then stored in a variable? Or am I going about this the wrong way?

If it's a shell script, use the shell variable $RANDOM to create your random number. Use the modulus operator (%) if you want your values within a range.

e.g.

To generate a random number between 0 and 9 use...

myRandomNumber=$((RANDOM%10))

If it's an awk script, you will need to 'seed' your random number initially using 'srand()'. The function rand() will then generate a random number between 0 and 1, so if you want a number between 0 and 9 (inclusive), multiply the value by 10. Use the int() function or sprintf or whatever to attain an integer

e.g.

awk 'BEGIN {srand();myRandomNumber=sprintf("%d",rand()*10); print myRandomNumber}'

awk 'BEGIN {srand();myRandomNumber=int(*10); print myRandomNumber}'

HTH

Thanks for the help... but thats about what I've been finding on other threads and it's not working.

I can't use $RANDOM because I'm using a c-shell. (I tried to convert my script to bash but that was a whole other headache so I'm pursuing this first).

Perhaps I'm being stupid (or inexperienced, or both), but the awk lines you wrote do not work when i try to insert them in my code or type them into a command prompt.

Is there an easier way to call a random number in a c-shell than awk scripting? Something along the lines of using $RANDOM in the bash shells?

Thanks again for any help

try something like this:

# on Solaris
nawk 'BEGIN {srand();myRandomNumber=int(rand()*10); print myRandomNumber}'

OR

/usr/xpg4/bin/awk 'BEGIN {srand();myRandomNumber=int(rand()*10); print myRandomNumber}'

Thanks, the first thing works.

HOWEVER... my main problem I guess is that I don't want to just print the random number. I want to assign it to a variable I have previously declared in my script.

here's the area w/ the problem:

#!/bin/csh
...
set xcenter
set ycenter

while ($i < 1000)
nawk 'BEGIN {srand();xcenter=int(rand()*5000)}'
nawk 'BEGIN {srand();ycenter=int(rand()*5000)}'
echo $xcenter
echo $ycenter
...
and then I need to use these two variables in following programs I call, which part of the script is working fine. The problem is assigning the variables w/ diff random numbers each time through the loop.
I've tried (aimlessly) to pipe the outcome of the awk lines, but I think I'm blindly looking for a way to do this. Any help is GREATLY appreciated!

not being a big fan of csh (to say the least). but try this:

THANKS! it worked finally.

i hate csh too, never again will i script in it.