How to valid input to matches data in CSV file - ruby

Question

I'm using Ruby 2.7 above. I've been working this task and still learning. I'm pretty sure that I am not using the right code. This task require me to do a mimic atm program. One of the requirements is where I need to check user valid inputs are matches the data in the CSV.file before user can access the program.
I'm using ruby (not allowed to use rails or any advance ruby code). I searched for similar program anywhere for reference but mostly does not involve with CSV file. How do I check that input from user is valid and matches in CSV file? I'm having trouble on how to do a validation and how to valid with two inputs (username and password). This program is run on command-line. Apologies if im not being clear enough. Can you tell me from my code where I'm going wrong please?
I have three .rb files and two csv files. I am not sure if I'm supposed to create two separate csv files.
function.rb (where all the functions)
login.rb (verify username and password from 'user.csv' file before proceed to system.rb file)
system.rb (the main where all data save or changes in 'account.csv' file)
below is function.rb file.
require 'csv'
class Function
def log_in(user)
CSV.foreach('user.csv', 'r', headers => true) do |row|
#check the user is valid, else error
if row[0] == uname && row[1] == pwd
puts "succesfully login"
ATMSystem.main_menu
end
end
if login == false
puts "invalid credentials."
Login.log_menu
end
end
login.rb file
require './function'
class Inn
def signin
function = AtmFunction.new
puts "Account login"
puts "Enter username"
uname = gets.chomp
puts "Enter password"
pwd = gets.chomp
user = [uname, pwd]
function.log_in(user)
end
end

Answer 1

Let's say this is your users.csv file:
name,password
bob,1234
alice,5678
This is one possible option.
Load the file into an array of hashes Enumerable#to_h and Hash#transform_keys:
require 'csv'
data_file = 'user.csv'
user_map = CSV.foreach(data_file, headers: true).map do |row|
row.to_h.transform_keys(&:to_sym)
end
user_map
#=> [{:name=>"bob", :password=>"1234"}, {:name=>"alice", :password=>"5678"}]
Then, given the input from the user:
input_username = 'bob'
input_password = '1234'
Check if user exists and in case compare the password:
user = user_map.find { |h| h[:name] == input_username }
#=> {:name=>"bob", :password=>"1234"}
user[:password] == input_password
#=> true
Check the password if Enumerable#find returns a non nil value: the user doesn't exist:
input_username = 'ron'
user = user_map.find { |h| h[:name] == input_username }
user
#=> nil
Following your implementation you can also write:
login_passed = false
CSV.foreach(data_file, headers: true) do |row|
login_passed = row['name'] == input_username && row['password'] == input_password
break if login_passed
end
login_passed
#=> true (or false)