Getting the count of how many times a route has been hit

Question

I have this log file (example below) and I'm trying to find the number of times a particular route is called.

Example log file:

2019-05-29 11:00:00 192.168.1.1 POST /route1 200  100000

2019-05-29 11:00:01 10.1.1.2 POST /route1 200  100000

2019-05-29 11:00:01 192.168.1.2 GET /route2 404 200000

2019-05-29 11:00:02 192.168.1.3 GET /route3 200  100000

2019-05-29 11:00:03 10.1.1.3 GET /route4 200  200000

2019-05-29 11:00:04 192.168.1.1 POST /route1 200 100000

Here is the code I've written:

route_count = Hash.new(0)
File.open('test.log').each do |line|
  temp_array = line.split(" ")
  route = temp_array[4]
  if route_count.has_key?(route)
    route_count[route] = route_count[route] + 1
  else
    route_count[route] = 1
  end
end
puts( route_count.map{ |k,v| "#{k},#{v}" })

and it gives the output:

/route1,3

/route2,1

/route3,1

/route4,1

I wanted to know if there is a better way to do this.

Answer 1

The Enumerable.group_by method is perfect for situations like this. The method takes the items in the enumerable, evaluates a block on them to yield a key, and inserts them into a hash under that key. Using this the code is very short:

puts(File.open('test.log').entries
    .group_by { |line| line.split(" ")[4] }
    .map { |k, v| "#{k},#{v.count}" })