Substitute character values in a password file, generating new strings. Save to the desired file. -- Not very efficient

substitute.rb

#!/usr/bin/ruby

@convert = {
  "e" => ["e", "3"], "l" => ["l", "1"], "o" => ["o", "0"],
  "a" => ["a", "4"], "t" => ["t", "7"], "s" => ["s", "5", "$"],
  "c" => ["c", "("], "g" => ["g", "6"], "p" => ["p", "9"],
  "b" => ["b", "8"]
}

@arrays = @convert.values # Grab all arrays in the hash
@elements = @arrays.first.product(*@arrays.drop(1)) # Grab each element value

def perms(input)
  perms = []
  @elements.each do |value|
    perms << [@convert.keys, value].transpose.each_with_object(input.dup){|sub, str| str.gsub!(*sub)}
  end
  return perms.uniq
end

print "Password File: "
password_file = gets.chomp

print "Save File: "
save_file = gets.chomp

outfile = File.open(save_file, 'a+') # File to write perms to
passfile = File.open(password_file, "r") # Regular dictionary

passfile.each_line do |line|
  values = perms(line)
  values.each do |perm|
    outfile.write("#{perm}")
  end
end
passfile.close
outfile.close