I wrote a simple ksh script that’s gone bad. At the end of a quiz the script calculates the Marines quiz scores, with the following:

((a=100 / $b)) # $b equals # of questions.
((c=100 - ($a * $e))) # $e equals # of missed
# questions.

All is well as long as the number of quiz questions ($b) isn't greater than 100.

Unfortunate for me, but great for the Marines, there are 3 quizzes that are greater than 150 questions and when the Marines run those quizzes, the value of ($b=.66) is rounded to 0 and they all make 100's regradless of the number of wrong answers.

Does any one have a fix? Oh, one last thing, I am stuck with the shells that come bundled with Solaris 9.

mike

If you are using #!/bin/ksh, that is the '88 version of the Korn shell, and floats are not supported. They are not supported until the '93 version. On Solaris 9, the desk top version, dtksh, is 93 compliant:

#!/usr/dt/bin/dtksh

Use it, and it should work for you.

Nails, thanks for the info on dtksh, but with the above script, my problem continues. Maybe it's the way I put it on the command line. i.e.,

# /usr/dt/bin/dtksh
# b=100
# c=151
# ((a=$b / $c))
# print $a
0
#

"a" should return a vaule of .66.

mike

#!/usr/dt/bin/dtksh

The dtksh is brain dead as it doesn't know you are working with floats. I had to append a .0 in order to get this to work.

b=100.0
c=151.0

f=$(($b / $c))
print $f

One way of forcing your integer to a float is to use the external printf comand to format it:

d=100
e=151
d=$(printf "%4.1f" $d)
e=$(printf "%4.1f" $e)
g=$(($d / $e))
print $g

Have you considered using something other than the shell for your float arithmetic - such as awk or bc?

Here is an example using bc:

m=100
n=151
v=$(bc << MSG
scale=2
$m / $n
MSG
)
echo $v

Nails, that worked great! I used the dtsk example. One last request if I might. Is there a way of having the return be only two space holders after the decimal point? i.e.,

From

92.3759736192

to just

92.37

Thanks for your help.

mike

If you use the bc command to perform the arithmetic, you can use the scale command as I did in the above example. If you don't, the printf command can be used to format a number:

x=92.3759736192

x=$(printf "%3.2f" $x)

Nails thank you very much, that worked great!
In this world of knowledge is power, its refreshing to know that some people are still willing to share they're intellect.

mike

Mike:

Thank you for the compliment, but it's more experience than intellect. I'm just replying to the kindness paid me. I believe the young people call it "paying it forward".

Nails