Teach file:write/read/read_line about named io_servers

2 files changed, 86 insertions, 4 deletions

diff --git a/lib/kernel/src/file.erl b/lib/kernel/src/file.erl
index a694ed0708..a37614e424 100644
--- a/lib/kernel/src/file.erl
+++ b/lib/kernel/src/file.erl
@@ -369,7 +369,7 @@ advise(_, _, _, _) ->
 -spec read(File :: io_device(), Size :: non_neg_integer()) ->
 	'eof' | {'ok', [char()] | binary()} | {'error', posix()}.
 
-read(File, Sz) when is_pid(File), is_integer(Sz), Sz >= 0 ->
+read(File, Sz) when (is_pid(File) orelse is_atom(File)), is_integer(Sz), Sz >= 0 ->
     case io:request(File, {get_chars, '', Sz}) of
 	Data when is_list(Data); is_binary(Data) ->
 	    {ok, Data};
@@ -385,7 +385,7 @@ read(_, _) ->
 -spec read_line(File :: io_device()) ->
 	'eof' | {'ok', [char()] | binary()} | {'error', posix()}.
 
-read_line(File) when is_pid(File) ->
+read_line(File) when (is_pid(File) orelse is_atom(File)) ->
     case io:request(File, {get_line, ''}) of
 	Data when is_list(Data); is_binary(Data) ->
 	    {ok, Data};
@@ -439,7 +439,7 @@ pread(_, _, _) ->
 -spec write(File :: io_device(), Byte :: iodata()) ->
 	'ok' | {'error', posix()}.
 
-write(File, Bytes) when is_pid(File) ->
+write(File, Bytes) when (is_pid(File) orelse is_atom(File)) ->
     case make_binary(Bytes) of
 	Bin when is_binary(Bin) ->
 	    io:request(File, {put_chars,Bin});
diff --git a/lib/kernel/test/file_SUITE.erl b/lib/kernel/test/file_SUITE.erl
index 1d652679b0..15bab0dccd 100644
--- a/lib/kernel/test/file_SUITE.erl
+++ b/lib/kernel/test/file_SUITE.erl
@@ -84,6 +84,8 @@
 
 -export([advise/1]).
 
+-export([standard_io/1,mini_server/1]).
+
 %% Debug exports
 -export([create_file_slow/2, create_file/2, create_bin/2]).
 -export([verify_file/2, verify_bin/3]).
@@ -103,7 +105,8 @@ all(suite) ->
       compression, links, copy,
       delayed_write, read_ahead, segment_read, segment_write,
       ipread, pid2name, interleaved_read_write, 
-      otp_5814, large_file, read_line_1, read_line_2, read_line_3, read_line_4],
+      otp_5814, large_file, read_line_1, read_line_2, read_line_3, read_line_4,
+      standard_io],
      fini}.
 
 init(Config) when is_list(Config) ->
@@ -172,6 +175,85 @@ time_dist({_D1, _T1} = DT1, {_D2, _T2} = DT2) ->
 	- calendar:datetime_to_gregorian_seconds(DT1).
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+mini_server(Parent) ->
+    receive
+	die ->
+	    ok;
+	{io_request,From,To,{put_chars,Data}} ->
+	    Parent ! {io_request,From,To,{put_chars,Data}},
+	    From ! {io_reply, To, ok},
+	    mini_server(Parent);
+	{io_request,From,To,{get_chars,'',N}} ->
+	    Parent ! {io_request,From,To,{get_chars,'',N}},
+	    From ! {io_reply, To, {ok, lists:duplicate(N,$a)}},
+	    mini_server(Parent);
+	{io_request,From,To,{get_line,''}} ->
+	    Parent ! {io_request,From,To,{get_line,''}},
+	    From ! {io_reply, To, {ok, "hej\n"}},
+	    mini_server(Parent)
+    end.
+
+standard_io(suite) ->
+    [];
+standard_io(doc) ->
+    ["Test that standard i/o-servers work with file module"];
+standard_io(Config) when is_list(Config) ->
+    %% Really just a smoke test
+    ?line Pid = spawn(?MODULE,mini_server,[self()]),
+    ?line register(mini_server,Pid),
+    ?line ok = file:write(mini_server,<<"hej\n">>),
+    ?line receive
+	     {io_request,_,_,{put_chars,<<"hej\n">>}} ->
+		  ok
+	  after 1000 ->
+		  exit(noreply)
+	  end,
+    ?line {ok,"aaaaa"} = file:read(mini_server,5),
+    ?line receive
+	     {io_request,_,_,{get_chars,'',5}} ->
+		  ok
+	  after 1000 ->
+		  exit(noreply)
+	  end,
+    ?line {ok,"hej\n"} = file:read_line(mini_server),
+    ?line receive
+	     {io_request,_,_,{get_line,''}} ->
+		  ok
+	  after 1000 ->
+		  exit(noreply)
+	  end,
+    ?line OldGL = group_leader(),
+    ?line group_leader(Pid,self()),
+    ?line ok = file:write(standard_io,<<"hej\n">>),
+    ?line group_leader(OldGL,self()),
+    ?line receive
+	     {io_request,_,_,{put_chars,<<"hej\n">>}} ->
+		  ok
+	  after 1000 ->
+		  exit(noreply)
+	  end,
+    ?line group_leader(Pid,self()),
+    ?line {ok,"aaaaa"} = file:read(standard_io,5),
+    ?line group_leader(OldGL,self()),
+    ?line receive
+	     {io_request,_,_,{get_chars,'',5}} ->
+		  ok
+	  after 1000 ->
+		  exit(noreply)
+	  end,
+    ?line group_leader(Pid,self()),
+    ?line {ok,"hej\n"} = file:read_line(standard_io),
+    ?line group_leader(OldGL,self()),
+    ?line receive
+	     {io_request,_,_,{get_line,''}} ->
+		  ok
+	  after 1000 ->
+		  exit(noreply)
+	  end,
+    Pid ! die,
+    receive after 1000 -> ok end.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 read_write_file(suite) -> [];
 read_write_file(doc) -> [];