%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2017. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
-module(error_logger_tty_h).
-behaviour(gen_event).
%%%
%%% A handler that can be connected to the error_logger
%%% event handler. Writes all events formatted to stdout.
%%%
%%% It can only be started from error_logger:swap_handler(tty)
%%% or error_logger:tty(true).
%%%
-export([init/1,
handle_event/2, handle_call/2, handle_info/2,
terminate/2, code_change/3]).
-export([write_event/2,write_event/3]).
-record(st,
{user,
prev_handler,
io_mod=io,
depth=unlimited,
modifier=""}).
%% This one is used when we takeover from the simple error_logger.
init({[], {error_logger, Buf}}) ->
User = set_group_leader(),
Depth = error_logger:get_format_depth(),
Modifier = modifier(),
State = #st{user=User,prev_handler=error_logger,
depth=Depth,modifier=Modifier},
write_events(State, Buf),
{ok, State};
%% This one is used if someone took over from us, and now wants to
%% go back.
init({[], {error_logger_tty_h, PrevHandler}}) ->
User = set_group_leader(),
{ok, #st{user=User,prev_handler=PrevHandler}};
%% This one is used when we are started directly.
init([]) ->
User = set_group_leader(),
Depth = error_logger:get_format_depth(),
Modifier = modifier(),
{ok, #st{user=User,prev_handler=[],depth=Depth,modifier=Modifier}}.
handle_event({_Type, GL, _Msg}, State) when node(GL) =/= node() ->
{ok, State};
handle_event(Event, State) ->
ok = do_write_event(State, tag_event(Event)),
{ok, State}.
handle_info({'EXIT', User, _Reason},
#st{user=User,prev_handler=PrevHandler}=State) ->
case PrevHandler of
[] ->
remove_handler;
_ ->
{swap_handler, install_prev, State,
PrevHandler, go_back}
end;
handle_info(_, State) ->
{ok, State}.
handle_call(_Query, State) -> {ok, {error, bad_query}, State}.
terminate(install_prev, _State) ->
[];
terminate(_Reason, #st{prev_handler=PrevHandler}) ->
{error_logger_tty_h, PrevHandler}.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%% Exported (but unoffical) API.
write_event(Event, IoMod) ->
do_write_event(#st{io_mod=IoMod}, Event).
write_event(Event, IoMod, {Depth, Enc}) ->
Modifier = modifier(Enc),
do_write_event(#st{io_mod=IoMod,depth=Depth,modifier=Modifier}, Event).
%%% ------------------------------------------------------
%%% Misc. functions.
%%% ------------------------------------------------------
set_group_leader() ->
case whereis(user) of
User when is_pid(User) ->
link(User),
group_leader(User,self()),
User;
_ ->
false
end.
tag_event(Event) ->
{erlang:universaltime(), Event}.
write_events(State, [Ev|Es]) ->
%% Write the events in reverse order.
_ = write_events(State, Es),
_ = do_write_event(State, Ev),
ok;
write_events(_State, []) ->
ok.
do_write_event(#st{modifier=M}=State, {Time, Event}) ->
case parse_event(Event,M) of
ignore ->
ok;
{Title,Pid,FormatList} ->
Header = header(Time, Title, M),
Body = format_body(State, FormatList),
AtNode = if
node(Pid) =/= node() ->
["** at node ",atom_to_list(node(Pid))," **\n"];
true ->
[]
end,
Str = [Header,AtNode,Body],
case State#st.io_mod of
io_lib ->
Str;
io ->
io:put_chars(user, Str)
end
end;
do_write_event(_, _) ->
ok.
format_body(#st{modifier=M}=State, [{Format,Args}|T]) ->
S = try format(State, Format, Args) of
S0 ->
S0
catch
_:_ ->
format(State, "ERROR: ~"++M++"p - ~"++M++"p\n", [Format,Args])
end,
[S|format_body(State, T)];
format_body(_State, []) ->
[].
format(#st{depth=unlimited}, Format, Args) ->
io_lib:format(Format, Args);
format(#st{depth=Depth}, Format0, Args) ->
Format1 = io_lib:scan_format(Format0, Args),
Format = limit_format(Format1, Depth),
io_lib:build_text(Format).
limit_format([#{control_char:=C0}=M0|T], Depth) when C0 =:= $p;
C0 =:= $w ->
C = C0 - ($a - $A), %To uppercase.
#{args:=Args} = M0,
M = M0#{control_char:=C,args:=Args++[Depth]},
[M|limit_format(T, Depth)];
limit_format([H|T], Depth) ->
[H|limit_format(T, Depth)];
limit_format([], _) ->
[].
parse_event({error, _GL, {Pid, Format, Args}},_) ->
{"ERROR REPORT",Pid,[{Format,Args}]};
parse_event({info_msg, _GL, {Pid, Format, Args}},_) ->
{"INFO REPORT",Pid,[{Format, Args}]};
parse_event({warning_msg, _GL, {Pid, Format, Args}},_) ->
{"WARNING REPORT",Pid,[{Format,Args}]};
parse_event({error_report, _GL, {Pid, std_error, Args}},M) ->
{"ERROR REPORT",Pid,format_term(Args,M)};
parse_event({info_report, _GL, {Pid, std_info, Args}},M) ->
{"INFO REPORT",Pid,format_term(Args,M)};
parse_event({warning_report, _GL, {Pid, std_warning, Args}},M) ->
{"WARNING REPORT",Pid,format_term(Args,M)};
parse_event(_,_) -> ignore.
format_term(Term,M) when is_list(Term) ->
case string_p(lists:flatten(Term)) of
true ->
[{"~"++M++"s\n",[Term]}];
false ->
format_term_list(Term,M)
end;
format_term(Term,M) ->
[{"~"++M++"p\n",[Term]}].
format_term_list([{Tag,Data}|T],M) ->
[{" ~"++M++"p: ~"++M++"p\n",[Tag,Data]}|format_term_list(T,M)];
format_term_list([Data|T],M) ->
[{" ~"++M++"p\n",[Data]}|format_term_list(T,M)];
format_term_list([],_) ->
[].
string_p([]) ->
false;
string_p(FlatList) ->
io_lib:printable_list(FlatList).
get_utc_config() ->
%% SASL utc_log configuration overrides stdlib config
%% in order to have uniform timestamps in log messages
case application:get_env(sasl, utc_log) of
{ok, Val} -> Val;
undefined ->
case application:get_env(stdlib, utc_log) of
{ok, Val} -> Val;
undefined -> false
end
end.
header(Time, Title, M) ->
case get_utc_config() of
true ->
header(Time, Title, "UTC ", M);
_ ->
header(calendar:universal_time_to_local_time(Time), Title, "", M)
end.
header({{Y,Mo,D},{H,Mi,S}}, Title, UTC, M) ->
io_lib:format("~n=~"++M++"s==== ~p-~s-~p::~s:~s:~s ~s===~n",
[Title,D,month(Mo),Y,t(H),t(Mi),t(S),UTC]).
t(X) when is_integer(X) ->
t1(integer_to_list(X));
t(_) ->
"".
t1([X]) -> [$0,X];
t1(X) -> X.
month(1) -> "Jan";
month(2) -> "Feb";
month(3) -> "Mar";
month(4) -> "Apr";
month(5) -> "May";
month(6) -> "Jun";
month(7) -> "Jul";
month(8) -> "Aug";
month(9) -> "Sep";
month(10) -> "Oct";
month(11) -> "Nov";
month(12) -> "Dec".
modifier() ->
modifier(encoding()).
modifier(latin1) ->
"";
modifier(_) ->
"t".
encoding() ->
proplists:get_value(encoding,io:getopts(),latin1).
