topic Re: puzzle no - 2 in Operating System - HP-UX

puzzle no - 2

U.SivaKumar_2 — Fri, 16 Aug 2002 04:01:02 GMT

Hi,
Can anybody write a shell script which can
generate random numbers and append to a output
file ?.

CONDITION: Should NOT use echo $RANDOM

regards,
U.SivaKumar

Re: puzzle no - 2

Paula J Frazer-Campbell — Fri, 16 Aug 2002 06:07:23 GMT

HI

Try these:-

Get a randon number in scripts
NOTE: produce a number 0 - $LIMIT-1
nawk:
set num=`nawk 'BEGIN { srand();
printf "%d", rand()*$LIMIT
}' /dev/null`

date:
set date=`date +%j%H%M%S`
set num=`expr $date \% $LIMIT`

(k/z/ba)sh
$RANDOM produces a number from 0.0 to 1.0
-----------------------------------------------------
Use a psudo random number generator
#!/bin/csh -f
#
# Random limit -- produce random number from 1 to limit
#
set multiplier = 25173
set increment = 13849
set modulus = 65536
set seedfile = $HOME/.rnd # seed file to use

if ( ! -f $seedfile ) then
echo '17' > $seedfile
endif

@ number = ( `cat $seedfile` * $multiplier + $increment ) % $modulus
echo $number > $seedfile

@ number = $number % $1 + 1
echo $number

Paula

Re: puzzle no - 2

Stefan Farrelly — Fri, 16 Aug 2002 06:10:35 GMT

perl -e 'srand(time()^$$);while (1){print int(rand(1)*255);}'

This will print random numbers from 1-255 seeded by the current time when invoked, you can redirect output to a file. You will need perl installed though.

Re: puzzle no - 2

Tom Danzig — Fri, 16 Aug 2002 13:00:31 GMT

echo "" | awk '{srand();printf("%3d\n",rand()*100)}' >> /tmp/randfile

Re: puzzle no - 2

A. Clay Stephenson — Fri, 16 Aug 2002 13:18:50 GMT

Okay, pure POSIX or Korn

OUTFILE="myfile.out"
RANDY=$((${$} + ${SECONDS}))
while [[ 1 -eq 1 ]]
do
RANDY=$(((${RANDY} * 13107) + 25171))
echo ${RANDY} >> ${OUTFILE}
done