Question

I just started learning shell scripting.

I’m trying to read from a file structured like:

harddrive1 10 20 30 40
harddrive2 20 30 40 50
harddrive3 30 40 50 60

I want to save the average of each row in a separate variable somehow…there will only be 3 rows, 5 columns.
So my output would be:

hd_AVG1=20
hd_AVG2=35
hd_AVG3=45

How can I accomplish that?

EDIT: I need to save it in DIFFERENT variable so that i can call the variable…for example

if [[ $hd_AVG1 -eq 20 ]];
    then 
    do something...
elif [[ $hd_AVG2 -gt 40 ]];
    then
    do something...
fi

Answer 1

This bash script should do what you want. It calls bc to do the float arithmetics since bash cannot do it itself.

#!/bin/bash
while read -a line ; do
    sum=0
    for ((i=1; i<${#line[@]}; i++)) ; do
        let sum+=line[i]
    done;
    hd[j++]=$(bc -l <<< "$sum/($i-1)")
done < input
echo ${hd[0]} ${hd[1]} ${hd[2]}