Fix problems when reading from stdin and "-noshell" was passed to erl (or used through an escript)

lib/kernel/doc/src/kernel_app.xml

@@ -614,7 +614,25 @@ MaxT = NetTickTime + NetTickTime / NetTickIntensity</code>
 	</p>
 
       </item>
-    </taglist>
+    <tag><marker id="standard_io_encoding"/><c>standard_io_encoding = Encoding</c></tag>
+      <item>
+        <p>Set whether bytes sent or received via standard_io should be interpreted as unicode or latin1.
+        By default input and output is interpreted as Unicode if it is supported on the host. With this flag
+        you may configure the encoding on startup.</p>
+        <p>This works similarly to <seemfa marker="stdlib:io#setopts/2"><c>io:setopts(standard_io, {encoding, Encoding})</c></seemfa>
+        but is applied before any bytes on standard_io may have been read.</p>
+        <p>Encoding is one of:</p>
+        <taglist>
+          <tag><c>unicode</c></tag>
+          <item><p>Configure standard_io to use unicode mode.</p></item>
+          <tag><c>latin1</c></tag>
+          <item><p>Configure standard_io to use latin1 mode.</p></item>
+          <tag><c>_</c></tag>
+          <item><p>Anything other than unicode or latin1 will be ignored and the system will
+            configure the encoding by itself, typically unicode on modern systems.</p></item>
+        </taglist>
+      </item>
+          </taglist>
   </section>
 
   <section>

lib/kernel/src/group.erl

@@ -20,9 +20,16 @@
 -module(group).
 
 %% A group leader process for user io.
+%% This process receives input data from user_drv in this format
+%%   {Drv,{data,unicode:charlist()}}
+%% It then keeps that data as unicode in its state and converts it
+%% to latin1/unicode on a per request basis. If any data is left after
+%% a request, that data is again kept as unicode.
 
 -export([start/2, start/3, whereis_shell/0, server/4]).
 
+-export([server_loop/3]).
+
 start(Drv, Shell) ->
     start(Drv, Shell, []).
 
@@ -108,26 +115,29 @@ start_shell1(Fun) ->
 	    exit(Error)				% let the group process crash
     end.
 
+-spec server_loop(UserDrv :: pid(), Shell:: pid(),
+                  Buffer :: unicode:chardata()) ->
+          no_return().
 server_loop(Drv, Shell, Buf0) ->
     receive
         {io_request,From,ReplyAs,Req} when is_pid(From) ->
             %% This io_request may cause a transition to a couple of
             %% selective receive loops elsewhere in this module.
             Buf = io_request(Req, From, ReplyAs, Drv, Shell, Buf0),
-            server_loop(Drv, Shell, Buf);
+            ?MODULE:server_loop(Drv, Shell, Buf);
         {reply,{From,ReplyAs},Reply} ->
             io_reply(From, ReplyAs, Reply),
-	    server_loop(Drv, Shell, Buf0);
+	    ?MODULE:server_loop(Drv, Shell, Buf0);
 	{driver_id,ReplyTo} ->
 	    ReplyTo ! {self(),driver_id,Drv},
-	    server_loop(Drv, Shell, Buf0);
+	    ?MODULE:server_loop(Drv, Shell, Buf0);
 	{Drv, echo, Bool} ->
 	    put(echo, Bool),
-	    server_loop(Drv, Shell, Buf0);
+	    ?MODULE:server_loop(Drv, Shell, Buf0);
 	{'EXIT',Drv,interrupt} ->
 	    %% Send interrupt to the shell.
 	    exit_shell(interrupt),
-	    server_loop(Drv, Shell, Buf0);
+	    ?MODULE:server_loop(Drv, Shell, Buf0);
 	{'EXIT',Drv,R} ->
 	    exit(R);
 	{'EXIT',Shell,R} ->
@@ -139,7 +149,7 @@ server_loop(Drv, Shell, Buf0) ->
 			 (tuple_size(NotDrvTuple) =/= 2) orelse
 			 (element(1, NotDrvTuple) =/= Drv) ->
 	    %% Ignore this unknown message.
-	    server_loop(Drv, Shell, Buf0)
+	    ?MODULE:server_loop(Drv, Shell, Buf0)
     end.
 
 exit_shell(Reason) ->
@@ -497,13 +507,14 @@ get_chars_loop(Pbs, M, F, Xa, Drv, Shell, Buf0, State, LineCont0, Encoding) ->
                  true ->
                      get_line(Buf0, Pbs, LineCont0, Drv, Shell, Encoding);
                  false ->
-                     %% get_line_echo_off only deals with lists
-                     %% and does not need encoding...
-                     get_line_echo_off(Buf0, Pbs, Drv, Shell)
+                     %% get_line_echo_off only deals with lists,
+                     %% so convert to list before calling it.
+                     get_line_echo_off(cast(Buf0, list, Encoding), Pbs, Drv, Shell)
              end,
     case Result of
         {done,LineCont1,Buf} ->
-            get_chars_apply(Pbs, M, F, Xa, Drv, Shell, Buf, State, LineCont1, Encoding);
+            get_chars_apply(Pbs, M, F, Xa, Drv, Shell, append(Buf, [], Encoding),
+                            State, LineCont1, Encoding);
 
         interrupted ->
             {error,{error,interrupted},[]};
@@ -537,10 +548,8 @@ get_chars_apply(Pbs, M, F, Xa, Drv, Shell, Buf, State0, LineCont, Encoding) ->
 
 get_chars_n_loop(Pbs, M, F, Xa, Drv, Shell, Buf0, State, Encoding) ->
     try M:F(State, cast(Buf0, get(read_mode), Encoding), Encoding, Xa) of
-        {stop,Result,eof} ->
-            {ok,Result,eof};
         {stop,Result,Rest} ->
-            {ok,Result,append(Rest, [], Encoding)};
+            {ok, Result, append(Rest,[],Encoding)};
         State1 ->
             case get_chars_echo_off(Pbs, Drv, Shell) of
                 interrupted ->
@@ -604,13 +613,12 @@ get_line1({undefined,{_A,Mode,Char},Cs,Cont,Rs}, Drv, Shell, Ls0, Encoding)
             send_drv_reqs(Drv, edlin:erase_line()),
             {more_chars,Ncont,Nrs} = edlin:start(edlin:prompt(Cont)),
             send_drv_reqs(Drv, Nrs),
-            get_line1(edlin:edit_line1(string:to_graphemes(lists:sublist(Lcs,
-                                                                         1,
-                                                                         length(Lcs)-1)),
-                                       Ncont),
-                      Drv,
-                      Shell,
-                      Ls, Encoding)
+            get_line1(
+              edlin:edit_line1(
+                string:to_graphemes(
+                  lists:sublist(Lcs, 1, length(Lcs)-1)),
+                Ncont),
+              Drv, Shell, Ls, Encoding)
     end;
 get_line1({undefined,{_A,Mode,Char},Cs,Cont,Rs}, Drv, Shell, Ls0, Encoding)
   when Mode =:= none, Char =:= $\^N;
@@ -800,7 +808,8 @@ more_data(What, Cont0, Drv, Shell, Ls, Encoding) ->
             send_drv_reqs(Drv, edlin:redraw_line(Cont0)),
             more_data(What, Cont0, Drv, Shell, Ls, Encoding);
         {Drv,{data,Cs}} ->
-            get_line1(edlin:edit_line(Cs, Cont0), Drv, Shell, Ls, Encoding);
+            get_line1(edlin:edit_line(cast(Cs, list), Cont0),
+                      Drv, Shell, Ls, Encoding);
         {Drv,eof} ->
             get_line1(edlin:edit_line(eof, Cont0), Drv, Shell, Ls, Encoding);
         {io_request,From,ReplyAs,Req} when is_pid(From) ->
@@ -831,7 +840,7 @@ get_line_echo_off(Chars, Pbs, Drv, Shell) ->
 get_line_echo_off1({Chars,[]}, Drv, Shell) ->
     receive
 	{Drv,{data,Cs}} ->
-	    get_line_echo_off1(edit_line(Cs, Chars), Drv, Shell);
+	    get_line_echo_off1(edit_line(cast(Cs, list), Chars), Drv, Shell);
 	{Drv,eof} ->
 	    get_line_echo_off1(edit_line(eof, Chars), Drv, Shell);
 	{io_request,From,ReplyAs,Req} when is_pid(From) ->
@@ -860,7 +869,7 @@ get_chars_echo_off(Pbs, Drv, Shell) ->
 get_chars_echo_off1(Drv, Shell) ->
     receive
         {Drv, {data, Cs}} ->
-            Cs;
+            cast(Cs, list);
         {Drv, eof} ->
             eof;
         {io_request,From,ReplyAs,Req} when is_pid(From) ->
@@ -1008,7 +1017,7 @@ get_password_line(Chars, Drv, Shell) ->
 get_password1({Chars,[]}, Drv, Shell) ->
     receive
 	{Drv,{data,Cs}} ->
-	    get_password1(edit_password(Cs,Chars),Drv,Shell);
+	    get_password1(edit_password(Cs,cast(Chars,list)),Drv,Shell);
 	{io_request,From,ReplyAs,Req} when is_pid(From) ->
 	    io_request(Req, From, ReplyAs, Drv, Shell, []), %WRONG!!!
 	    %% I guess the reason the above line is wrong is that Buf is
@@ -1048,20 +1057,18 @@ edit_password([Char|Cs],Chars) ->
 prompt_bytes(Prompt, Encoding) ->
     lists:flatten(io_lib:format_prompt(Prompt, Encoding)).
 
-cast(L, binary,latin1) when is_list(L) ->
-    list_to_binary(L);
-cast(L, list, latin1) when is_list(L) ->
-    binary_to_list(list_to_binary(L)); %% Exception if not bytes
-cast(L, binary,unicode) when is_list(L) ->
-    unicode:characters_to_binary(L,utf8);
-cast(Other, _, _) ->
-    Other.
-
-append(B, L, latin1) when is_binary(B) ->
-    binary_to_list(B)++L;
-append(B, L, unicode) when is_binary(B) ->
-    unicode:characters_to_list(B,utf8)++L;
-append(L1, L2, _) when is_list(L1) ->
-    L1++L2;
-append(_Eof, L, _) ->
-    L.
+cast(Buf, Type) ->
+    cast(Buf, Type, utf8).
+cast(eof, _, _) ->
+    eof;
+cast(L, binary, ToEnc) ->
+    unicode:characters_to_binary(L, utf8, ToEnc);
+cast(L, list, _ToEnc) ->
+    unicode:characters_to_list(L, utf8).
+
+append(eof, [], _) ->
+    eof;
+append(eof, L, _) ->
+    L;
+append(B, L, FromEnc) ->
+    unicode:characters_to_list(B, FromEnc) ++ L.

lib/kernel/src/prim_tty.erl

@@ -115,6 +115,8 @@
        sizeof_wchar/0, tgetent_nif/1, tgetnum_nif/1, tgetflag_nif/1, tgetstr_nif/1,
        tgoto_nif/2, tgoto_nif/3, tty_read_signal/2]).
 
+-export([reader_loop/6, writer_loop/2]).
+
 %% Exported in order to remove "unused function" warning
 -export([sizeof_wchar/0, wcswidth/1, tgoto/2, tgoto/3]).
 
@@ -218,7 +220,7 @@ init(UserOptions) when is_map(UserOptions) ->
     {ok, TTY} = tty_create(),
 
     %% Initialize the locale to see if we support utf-8 or not
-    UnicodeMode =
+    UnicodeSupported =
         case setlocale(TTY) of
             primitive ->
                 lists:any(
@@ -228,6 +230,11 @@ init(UserOptions) when is_map(UserOptions) ->
             UnicodeLocale when is_boolean(UnicodeLocale) ->
                 UnicodeLocale
         end,
+    IOEncoding = application:get_env(kernel, standard_io_encoding, default),
+    UnicodeMode = if IOEncoding =:= latin1 -> false;
+                     IOEncoding =:= unicode -> true;
+                     true -> UnicodeSupported
+                  end,
     {ok, ANSI_RE_MP} = re:compile(?ANSI_REGEXP, [unicode]),
     init_term(#state{ tty = TTY, unicode = UnicodeMode, options = Options, ansi_regexp = ANSI_RE_MP }).
 init_term(State = #state{ tty = TTY, options = Options }) ->
@@ -252,7 +259,12 @@ init_term(State = #state{ tty = TTY, options = Options }) ->
     ReaderState =
         case {maps:get(input, Options), TTYState#state.reader} of
             {true, undefined} ->
-                {ok, Reader} = proc_lib:start_link(?MODULE, reader, [[State#state.tty, self()]]),
+                DefaultReaderEncoding = if State#state.unicode -> utf8;
+                                           not State#state.unicode -> latin1
+                                        end,
+                {ok, Reader} = proc_lib:start_link(
+                                 ?MODULE, reader,
+                                 [[State#state.tty, DefaultReaderEncoding, self()]]),
                 WriterState#state{ reader = Reader };
             {true, _} ->
                 WriterState;
@@ -421,22 +433,23 @@ call(Pid, Msg) ->
             {error, Reason}
     end.
 
-reader([TTY, Parent]) ->
+reader([TTY, Encoding, Parent]) ->
     register(user_drv_reader, self()),
     ReaderRef = make_ref(),
     SignalRef = make_ref(),
+
     ok = tty_select(TTY, SignalRef, ReaderRef),
     proc_lib:init_ack({ok, {self(), ReaderRef}}),
     FromEnc = case os:type() of
-                  {unix, _} -> utf8;
+                  {unix, _} -> Encoding;
                   {win32, _} ->
                       case isatty(stdin) of
                           true ->
                               {utf16, little};
                           _ ->
                               %% When not reading from a console
                               %% the data read is utf8 encoded
-                              utf8
+                              Encoding
                       end
               end,
     reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, <<>>).
@@ -448,20 +461,20 @@ reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc) ->
             receive
                 {EnableAlias, enable} ->
                     EnableAlias ! {EnableAlias, ok},
-                    reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc)
+                    ?MODULE:reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc)
             end;
         {select, TTY, SignalRef, ready_input} ->
             {ok, Signal} = tty_read_signal(TTY, SignalRef),
             Parent ! {ReaderRef,{signal,Signal}},
-            reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc);
+            ?MODULE:reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc);
         {Alias, {set_unicode_state, _}} when FromEnc =:= {utf16, little} ->
             %% Ignore requests on windows
             Alias ! {Alias, true},
-            reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc);
+            ?MODULE:reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc);
         {Alias, {set_unicode_state, Bool}} ->
             Alias ! {Alias, FromEnc =/= latin1},
             NewFromEnc = if Bool -> utf8; not Bool -> latin1 end,
-            reader_loop(TTY, Parent, SignalRef, ReaderRef, NewFromEnc, Acc);
+            ?MODULE:reader_loop(TTY, Parent, SignalRef, ReaderRef, NewFromEnc, Acc);
         {_Alias, stop} ->
             ok;
         {select, TTY, ReaderRef, ready_input} ->
@@ -471,7 +484,7 @@ reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc) ->
                     ok;
                 {ok, <<>>} ->
                     %% EAGAIN or EINTR
-                    reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc);
+                    ?MODULE:reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc);
                 {ok, UtfXBytes} ->
 
                     {Bytes, NewAcc, NewFromEnc} =
@@ -486,7 +499,7 @@ reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc) ->
                                         Alias ! {Alias, true}
                                 end,
                                 receive
-                                    {Parent, set_unicode_state, true} -> ok
+                                    {Parent, set_unicode_state, _} -> ok
                                 end,
                                 Latin1Chars = unicode:characters_to_binary(Error, latin1, utf8),
                                 {<<B/binary,Latin1Chars/binary>>, <<>>, latin1};
@@ -496,7 +509,7 @@ reader_loop(TTY, Parent, SignalRef, ReaderRef, FromEnc, Acc) ->
                                 {B, <<>>, FromEnc}
                         end,
                     Parent ! {ReaderRef, {data, Bytes}},
-                    reader_loop(TTY, Parent, SignalRef, ReaderRef, NewFromEnc, NewAcc)
+                    ?MODULE:reader_loop(TTY, Parent, SignalRef, ReaderRef, NewFromEnc, NewAcc)
             end
     end.
 
@@ -518,18 +531,18 @@ write(#state{ writer = {WriterPid, _WriterRef}}, Chars, From) ->
 writer_loop(TTY, WriterRef) ->
     receive
         {write, []} ->
-            writer_loop(TTY, WriterRef);
+            ?MODULE:writer_loop(TTY, WriterRef);
         {write, Chars} ->
             _ = write_nif(TTY, Chars),
-            writer_loop(TTY, WriterRef);
+            ?MODULE:writer_loop(TTY, WriterRef);
         {write, From, []} ->
             From ! {WriterRef, ok},
-            writer_loop(TTY, WriterRef);
+            ?MODULE:writer_loop(TTY, WriterRef);
         {write, From, Chars} ->
             case write_nif(TTY, Chars) of
                 ok ->
                     From ! {WriterRef, ok},
-                    writer_loop(TTY, WriterRef);
+                    ?MODULE:writer_loop(TTY, WriterRef);
                 {error, Reason} ->
                     exit(self(), Reason)
             end

lib/kernel/src/user_drv.erl

@@ -421,8 +421,7 @@ server({call, From}, {start_shell, _Args}, _State) ->
     keep_state_and_data;
 server(info, {ReadHandle,{data,UTF8Binary}}, State = #state{ read = ReadHandle })
   when State#state.current_group =:= State#state.user ->
-    State#state.current_group !
-        {self(), {data, unicode:characters_to_list(UTF8Binary, utf8)}},
+    State#state.current_group ! {self(), {data,UTF8Binary}},
     keep_state_and_data;
 server(info, {ReadHandle,{data,UTF8Binary}}, State = #state{ read = ReadHandle }) ->
     case contains_ctrl_g_or_ctrl_c(UTF8Binary) of
@@ -435,7 +434,7 @@ server(info, {ReadHandle,{data,UTF8Binary}}, State = #state{ read = ReadHandle }
             keep_state_and_data;
         none ->
             State#state.current_group !
-                {self(), {data, unicode:characters_to_list(UTF8Binary, utf8)}},
+                {self(), {data, UTF8Binary}},
             keep_state_and_data
     end;
 server(info, {ReadHandle,eof}, State = #state{ read = ReadHandle }) ->

lib/kernel/test/Makefile

@@ -150,7 +150,7 @@ TARGET_FILES= $(MODULES:%=$(EBIN)/%.$(EMULATOR))
 INSTALL_PROGS= $(TARGET_FILES)
 
 EMAKEFILE=Emakefile
-COVERFILE=kernel.cover logger.cover
+COVERFILE=kernel.cover logger.cover tty.cover
 
 # ----------------------------------------------------
 # Release directory specification

lib/kernel/test/tty.cover

@@ -0,0 +1,3 @@
+%% -*- erlang -*-
+{incl_mods,[prim_tty, user_drv, group, shell, edlin, edlin_expand, io_lib]}.
+