Question

trying to sum elements in an array using bc,i have a file with names and thier vaules if the names appears 3 times i should multiply its value with 3 then find the sum of all the elements together,im seeing standard input error

$ cat foo.txt

max 2.3 
henry 3
fransis 4.5
max 2.3
henry 3
max 2.3

it should show on the terminal

max 6.9
henry 6 
fransis 4.5

then

total 17.9

declare -A array

while read name value; do

     array[$name]=$( echo "${array[$name]:-0} + $value" | bc )

done < cat foo.txt

for name in "${!array[@]}"; do

     echo "$name ${array[$name]}"

done

Answer 1

I’m not sure if you’re required to use bc but this could be done with the following awk command:

awk '{names[$1]=$1;vals[$1]+=$2} END {for(i in names){sum+=vals[i];print i, vals[i]}; print "total " sum}' foo.txt