# Read an input file and find the sum/count/average/median

averages.sh

#!/bin/bash

# Read an input file and find the sum/count/average/median
# ! Does not do any validation of the input !

FILE='numbers.txt' # where the file is just a list of numbers, one per line

# Read input file line-by-line
while IFS= read -r num; do
	sum=$((sum + num))
	count=$((count + 1))
done < "$FILE"

# Print results
printf "Count is %s\n" $count
printf "Sum is %s\n" $sum

# Use `bc` command to do float math with the average
printf "Average is %.2f\n" "$(bc -l <<< "$sum/$count")"

# Find median
if [[ $((count % 2)) == 1 ]]; then
	# Odd number of lines
	middle=$(( (count + 1) / 2))
	median=$(head -n${middle} "$FILE" | tail -n1)
else
	# Even number of lines
	middle=$((count / 2))
	medians=$(head -n${middle} "$FILE" | tail -n2)

	first=$(echo $medians | cut -d' ' -f1)
	second=$(echo $medians | cut -d' ' -f2)

	median=$(bc -l <<< "$first+$second / 2")
fi

printf "Median is %.2f\n" "$median"