I'm trying to study for a test and one of the subjects are bash scripts. I have the following txt file :
123456 100
654321 50
203374111 86
I need to get the averages of the scores (the numbers in the second column).
This is what I have written :
cat $course_name$end | while read line; do
sum=`echo $line | cut -f2 -d" "`
let total+=$sum
done
I have tried with
while read -a line
and then
let sum+=${line[1]}
But I'm still getting the same error mentioned in the header.
I love AWK:
awk -F\* '{sum+=$3} END {print sum/NR}' x.txt
So in x.txt are values are stored. Please note that many answers don't actually compute the average, as they need to divide by the line numbers in the end. Often it will be performed by a wc -l < x.txt but in my solution you will get it almost for free.
I'm trying to study for a test and one of the subjects are bash scripts, so we can guess that is basically looking for a pure bash solution. By the way, I also love awk, it is such a powerful language!
sum+=$2 and there's no need to change the input separator - it looks like the OP was trying to make the numbers bold using **number** but it doesn't work in a code block.cat your_file_name.txt | cut -f2 -d" " | paste -sd+ | bc
This should do the job!
You are very close, this works for me:
while read line; do
sum=$(echo $line | cut -f2 -d" ")
echo "sum is $sum"
let total+=$sum
echo "total is $total"
done < file
echo "total is $total"
As you can see, there is no need to use cat $course_name$end, it is enough to do
while read line
do
done < file
Also, it is more recommendable to use
sum=$(echo $line | cut -f2 -d" ")
rather than
sum=`echo $line | cut -f2 -d" "`
Or even
sum=$(cut -f2 -d" " <<< "$line")
There's no need to use cat as well as read; you can redirect the contents of the file into the loop. You also don't need to use let for arithmetic.
sum = 0
count = 0
while read id score; do
(( sum += score )) && (( ++count ))
done < "$course_name$end"
echo $(( sum / count ))
This will give you an integer result, as bash doesn't do floating point arithmetic. To get a floating point result, you could use bc:
bc <<< "scale=2;$a/$b"
This will give you a result correct to 2 decimal places.
cut;readcan handle the word splitting for you withwith read id sum; do let total+=sum; done.idis just a placeholder for whatever the first column is.