all the old tests pass... moving on

cli/src/gsc_cli.erl

@@ -75,8 +75,35 @@ do(Args) ->
 
 do_doi() ->
     FP = zx:get_home() ++ "/priv/doi.txt",
-    Cmd = "less " ++ FP,
-    io:format("~s~n", [Cmd]).
+    page_file(FP).
+
+% thank you chatgpt
+% os:cmd didnt do nuffin because that's for running
+% stuff in the background and capturing the output, not
+% for taking over the screen
+page_file(FilePath) ->
+    Less = os:find_executable("less"),
+    case Less of
+        false -> cat_file(FilePath);
+        _     -> less_file(Less, FilePath)
+    end.
+
+cat_file(FilePath) ->
+    {ok, Bytes} = file:read_file(FilePath),
+    io:format("~ts", [Bytes]).
+
+less_file(Less, FilePath) ->
+    Port = open_port({spawn_executable, Less},
+                     [{args, [FilePath]},
+                      nouse_stdio, exit_status]),
+    receive
+        {Port, {exit_status, 0}} ->
+            ok;
+        {Port, {exit_status, N}} ->
+            error({less_exit_status, N});
+        {'EXIT', Port, Reason} ->
+            error(Reason)
+    end.
 
 do_tests() ->
     io:format("TestModules = ~p~n", [known_modules_with_prefix("ts")]),
@@ -134,7 +161,7 @@ do_eshell() ->
     end.
 
 tokenizers_agree(File) ->
-    so_tokens(File) =:= tokens(File).
+    gso_tokens(File) =:= so_tokens(File).
 
 
 do_tokens(FilePath) ->