syntax error: invalid arithmetic operator (error token is “”)

Question

I am trying to write a function the checks a text file, line by line, checking each field by certain cretirias, and then sums it all up. I am using the exact same way to sum

Answer 1

Your input file contains CR+LF line endings. As such, the variable ${line[4]} isn't a number like 10 but 10\r which causes the error.

Remove carriage returns from the input file using a tool such as dos2unix.

Alternatively, you could change your script to handle it by modifying

done < "$1"

to

done < <(tr -d '\r' < "$1")