load csv via ruby into hash then selecting element from hash

Question

I am learning ruby today and got stuck with extracting single element from the hash.

login1.csv

role,uName,passwd
adm,admin1,a1
mgr,manager,m
user,user1,u1
adm,admin2,a2

ruby code

def csvIntoHash
  # load csv Into hash
  $table = []
  File.open("logIn1.csv") do|f|
    columns = f.readline.chomp.split(',')
    until f.eof?
      row = f.readline.chomp.split(',')
      row = columns.zip(row).flatten #build hash from array
      $table << Hash[*row]
    end
  end
end
#
#main
csvIntoHash
#pulls all hash elements when role=mgr
puts $table.select {|rEntry| rEntry["role"]=="mgr"} 

How do i extract only the uName when role=mgr then assign it to a variable?

Thanks for any assistance.

Answer 1

select() returns an Array, so look at the first (only, in your case?) entry, which is a Hash as you constructed it:

mgrh = $table.select {|rEntry| rEntry["role"]=="mgr"}
mgr_role = mgrh.first["uName"] # => "manager"

Answer 2

You should look into the CSV library in Core

From the format of your CSV on here, if what you really want it to get the uName of the manager, I have the following solution.

manager = ""
CSV.read("file.csv").each_with_index do |arr, index|
  role_column = arr.index("role") if index == 0
  if arr[role_column.to_i] == "mgr"
    manager = arr[role_column.to_i + 1]
  end
end

EDIT:
Obviously this assums there is only one manager in the CSV sheet. You can modify the code to assign an array of managers if so required.