fix (WIP): Use File.stream!

This seems to avoid memory issues, but means that we can't stream lines
in from stdin.

scripts/sanitize_db_dump.exs

@@ -4,16 +4,18 @@ defmodule SanitizeDbDump do
 
   NOTE: Currently we are "cheating" by relying on the knowledge that email addresses and phone numbers come one after the other in our users table definition. This lets us limit where we look for 10-digit numbers and avoid timestamps and other items that aren't actually phone numbers but look the same.
 
-  To dump from production, sanitize, and load into dev locally:
+  Run like:
 
   ```
-  PGPASSWORD=<PROD PASSWORD> pg_dump --host=alerts-concierge-prod.cw84s0ixvuei.us-east-1.rds.amazonaws.com --port=5432 --username=alerts_concierge --dbname=alerts_concierge_prod --table=users --table=trips --table=subscriptions --no-owner --data-only | elixir ./scripts/sanitize_db_dump.exs | psql -d alert_concierge_dev
+  elixir ./scripts/sanitize_db_dump.exs /path/to/input_file.sql
   ```
   """
 
-  def run() do
-    :stdio
-    |> IO.stream(:line)
+  @chars ~c(abcdefghijklmnopqrstuvwxyz0123456789)
+
+  def run(file) do
+    file
+    |> File.stream!()
     |> Stream.map(&sanitize_an_email_addresses_followed_by_a_phone_number/1)
     |> Stream.map(&sanitize_an_email_addresses_followed_by_null/1)
     |> Enum.each(&IO.write(&1))
@@ -32,16 +34,10 @@ defmodule SanitizeDbDump do
   end
 
   defp mock_email() do
-    chars = String.split("abcdefghijklmnopqrstuvwxyz0123456789", "")
-
-    address =
-      Enum.reduce(1..10, [], fn _i, acc ->
-        [Enum.random(chars) | acc]
-      end)
-      |> Enum.join("")
-
+    address = for _ <- 1..10, into: "", do: <<Enum.random(@chars)>>
     "#{address}@example.com"
   end
 end
 
-SanitizeDbDump.run()
+file = System.argv() |> List.first()
+SanitizeDbDump.run(file)