Groupby is a project mainly written in C and SHELL, it's free.
CLI tool to perform sort of sort|uniq + apply an aggregate function to each field of the CSV.
Main parameter is -a :
-a field-spec[:func]
if not specified, func is rem
field-spec: n | n-m | -m | n- | field-spec,field-spec | !field-spec
where n and m are positive integers (fields are numbered from 1)
func : rem | avg | min | max | sum | first | last | smaller | greatest
sum, avg, min and max require numeric values parsable by strtoll().