Question

I’m looking for a ruby script that will use something like last to count the login frequency of each user and output it to a csv file so I can make a bar graph with most frequent logins.

I want it to save the CSV output like this:

user2,19
user6,20
user3,18 

Normally last looks like this:

user3     :1001        192.1.20.17   Sun Nov 30 15:01   still logged in
user8    :1000        192.1.20.15   Sun Nov 30 10:00 - 11:52  (01:52)    
user2     tty7         :0               Tue Nov 25 19:43 - 21:09  (01:25)    
user0   tty7         :0               Tue Nov 25 16:46 - 18:06  (01:19) 

Is there something that already does this, or how can I do this?

Answer 1

maybe this way:

file = `last`
hash = {}
file.each_line { |x| hash[x.split("     ")[0].split("    ")[0]] = 0 unless hash[x.split("     ")[0].split("    ")[0]]; hash[x.split("     ")[0].split("    ")[0]] += 1 }
output = ""
hash.each_pair { |key, value| output += "#{key},#{value}\n" }
File.open('last.csv', 'w') {|f| f.write(output) }

you should check content of “” in split to be correct.
also you should check exact output of your last command – you maybe need to take some of the garbage out before writing to file 😉