diff options
Diffstat (limited to 'lib/kernel/test/logger_env_var_SUITE.erl')
| -rw-r--r-- | lib/kernel/test/logger_env_var_SUITE.erl | 697 |
1 files changed, 697 insertions, 0 deletions
diff --git a/lib/kernel/test/logger_env_var_SUITE.erl b/lib/kernel/test/logger_env_var_SUITE.erl new file mode 100644 index 0000000000..9d2ad11be8 --- /dev/null +++ b/lib/kernel/test/logger_env_var_SUITE.erl @@ -0,0 +1,697 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2018. 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(logger_env_var_SUITE). + +-compile(export_all). + +-include_lib("kernel/include/logger.hrl"). +-include_lib("kernel/src/logger_internal.hrl"). + +-import(logger_test_lib,[setup/2,log/3,sync_and_read/3]). + +suite() -> + [{timetrap,{seconds,60}}, + {ct_hooks,[logger_test_lib]}]. + +init_per_suite(Config) -> + Config. + +end_per_suite(_Config) -> + ok. + +groups() -> + [{error_logger,[],[error_logger_tty, + error_logger_tty_sasl_compatible, + error_logger_false, + error_logger_false_progress, + error_logger_false_sasl_compatible, + error_logger_silent, + error_logger_silent_sasl_compatible, + error_logger_file]}, + {logger,[],[logger_file, + logger_file_sasl_compatible, + logger_file_log_progress, + logger_file_no_filter, + logger_file_no_filter_level, + logger_file_formatter, + logger_filters, + logger_filters_stop, + logger_module_level, + logger_disk_log, + logger_disk_log_formatter, + logger_undefined, + logger_many_handlers_default_first, + logger_many_handlers_default_last, + logger_many_handlers_default_last_broken_filter, + logger_proxy + ]}, + {bad,[],[bad_error_logger, + bad_level, + bad_sasl_compatibility]}]. + +all() -> + [default, + default_sasl_compatible, + sasl_compatible_false, + sasl_compatible_false_no_progress, + sasl_compatible, + all_logger_level, + {group,bad}, + {group,error_logger}, + {group,logger} + ]. + +default(Config) -> + {ok,#{primary:=P,handlers:=Hs,module_levels:=ML},_Node} = setup(Config,[]), + notice = maps:get(level,P), + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + false = exists(sasl,Hs), + [] = ML, + ok. + +default_sasl_compatible(Config) -> + {ok,#{primary:=P,handlers:=Hs,module_levels:=ML},_Node} = + setup(Config,[{logger_sasl_compatible,true}]), + info = maps:get(level,P), + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + true = exists(sasl,Hs), + [] = ML, + ok. + +error_logger_tty(Config) -> + {ok,#{primary:=P,handlers:=Hs,module_levels:=ML},_Node} = + setup(Config,[{error_logger,tty}]), + notice = maps:get(level,P), + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + false = exists(sasl,Hs), + [] = ML, + ok. + +error_logger_tty_sasl_compatible(Config) -> + {ok,#{primary:=P,handlers:=Hs,module_levels:=ML},_Node} = + setup(Config, + [{error_logger,tty}, + {logger_sasl_compatible,true}]), + info = maps:get(level,P), + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + true = exists(sasl,Hs), + [] = ML, + ok. + +error_logger_false(Config) -> + {ok,#{handlers:=Hs,primary:=P,module_levels:=ML},_Node} = + setup(Config, + [{error_logger,false}, + {logger_level,notice}]), + false = exists(?STANDARD_HANDLER,Hs), + #{module:=logger_simple_h} = SimpleC = find(simple,Hs), + all = maps:get(level,SimpleC), + notice = maps:get(level,P), + SimpleFilters = maps:get(filters,SimpleC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,SimpleFilters), + false = exists(sasl,Hs), + [] = ML, + ok. + +error_logger_false_progress(Config) -> + {ok,#{handlers:=Hs,primary:=P,module_levels:=ML},_Node} = + setup(Config, + [{error_logger,false}, + {logger_level,notice}]), + false = exists(?STANDARD_HANDLER,Hs), + #{module:=logger_simple_h} = SimpleC = find(simple,Hs), + all = maps:get(level,SimpleC), + notice = maps:get(level,P), + SimpleFilters = maps:get(filters,SimpleC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,SimpleFilters), + false = exists(sasl,Hs), + [] = ML, + ok. + +error_logger_false_sasl_compatible(Config) -> + {ok,#{handlers:=Hs,primary:=P,module_levels:=ML},_Node} = + setup(Config, + [{error_logger,false}, + {logger_level,notice}, + {logger_sasl_compatible,true}]), + false = exists(?STANDARD_HANDLER,Hs), + #{module:=logger_simple_h} = SimpleC = find(simple,Hs), + all = maps:get(level,SimpleC), + info = maps:get(level,P), + SimpleFilters = maps:get(filters,SimpleC), + {domain,{_,{log,super,[otp]}}} = lists:keyfind(domain,1,SimpleFilters), + true = exists(sasl,Hs), + [] = ML, + ok. + +error_logger_silent(Config) -> + {ok,#{handlers:=Hs},_Node} = setup(Config, + [{error_logger,silent}]), + false = exists(?STANDARD_HANDLER,Hs), + false = exists(simple,Hs), + false = exists(sasl,Hs), + ok. + +error_logger_silent_sasl_compatible(Config) -> + {ok,#{handlers:=Hs},_Node} = setup(Config, + [{error_logger,silent}, + {logger_sasl_compatible,true}]), + false = exists(?STANDARD_HANDLER,Hs), + false = exists(simple,Hs), + true = exists(sasl,Hs), + ok. + + +error_logger_file(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,_,Node} = setup(Config, + [{error_logger,{file,Log}}]), + check_default_log(Node,Log, + file,% dest + 0),% progress in std logger + ok. + + +logger_file(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{primary:=P,handlers:=Hs,module_levels:=ML},Node} + = setup(Config, + [{logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{config=>#{type=>{file,Log}}}}]}]), + check_default_log(Node,Log, + file,% dest + 0),% progress in std logger + + notice = maps:get(level,P), + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + false = exists(sasl,Hs), + [] = ML, + ok. + +logger_file_sasl_compatible(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{primary:=P,handlers:=Hs,module_levels:=ML},Node} + = setup(Config, + [{logger_sasl_compatible,true}, + {logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{config=>#{type=>{file,Log}}}}]}]), + check_default_log(Node,Log, + file,% dest + 0),% progress in std logger + + info = maps:get(level,P), + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + true = exists(sasl,Hs), + [] = ML, + ok. + +logger_file_log_progress(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{primary:=P,handlers:=Hs,module_levels:=ML},Node} + = setup(Config, + [{logger_level,info}, + {logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{config=>#{type=>{file,Log}}}}]}]), + check_default_log(Node,Log, + file,% dest + 6,% progress in std logger + info), + + info = maps:get(level,P), + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + false = exists(sasl,Hs), + [] = ML, + ok. + +logger_file_no_filter(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{handlers:=Hs},Node} + = setup(Config, + [{logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{filter_default=>log,filters=>[], + config=>#{type=>{file,Log}}}}]}]), + check_default_log(Node,Log, + file,% dest + 6),% progress in std logger + + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + [] = maps:get(filters,StdC), + false = exists(simple,Hs), + false = exists(sasl,Hs), + + ok. + +logger_file_no_filter_level(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{handlers:=Hs},Node} + = setup(Config, + [{logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{filters=>[],level=>error, + config=>#{type=>{file,Log}}}}]}]), + check_default_log(Node,Log, + file,% dest + 0,% progress in std logger + error),% level + + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + error = maps:get(level,StdC), + [] = maps:get(filters,StdC), + false = exists(simple,Hs), + false = exists(sasl,Hs), + + ok. + +logger_file_formatter(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{handlers:=Hs},Node} + = setup(Config, + [{logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{filters=>[], + formatter=>{logger_formatter,#{}}, + config=>#{type=>{file,Log}}}}]}]), + check_single_log(Node,Log, + file,% dest + 6),% progress in std logger + + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + [] = maps:get(filters,StdC), + false = exists(simple,Hs), + false = exists(sasl,Hs), + + ok. + +logger_filters(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{handlers:=Hs,primary:=P},Node} + = setup(Config, + [{logger_level,info}, + {logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{config=>#{type=>{file,Log}}}}, + {filters,log,[{stop_progress,{fun logger_filters:progress/2,stop}}]} + ]}]), + check_default_log(Node,Log, + file,% dest + 0,% progress in std logger + info), + + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + false = exists(sasl,Hs), + LoggerFilters = maps:get(filters,P), + true = lists:keymember(stop_progress,1,LoggerFilters), + + ok. + +logger_filters_stop(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{handlers:=Hs,primary:=P},Node} + = setup(Config, + [{logger_level,info}, + {logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{filters=>[], + config=>#{type=>{file,Log}}}}, + {filters,stop,[{log_error,{fun logger_filters:level/2,{log,gt,info}}}]} + ]}]), + check_default_log(Node,Log, + file,% dest + 0,% progress in std logger + info), + + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + [] = maps:get(filters,StdC), + false = exists(simple,Hs), + false = exists(sasl,Hs), + LoggerFilters = maps:get(filters,P), + true = lists:keymember(log_error,1,LoggerFilters), + + ok. + +logger_module_level(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{handlers:=Hs,module_levels:=ModuleLevels},Node} + = setup(Config, + [{logger_level,info}, + {logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{config=>#{type=>{file,Log}}}}, + {module_level,error,[supervisor]} + ]}]), + check_default_log(Node,Log, + file,% dest + 3,% progress in std logger + info), + + #{module:=logger_std_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + false = exists(sasl,Hs), + [{supervisor,error}] = ModuleLevels, + ok. + +logger_disk_log(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{handlers:=Hs},Node} + = setup(Config, + [{logger, + [{handler,?STANDARD_HANDLER,logger_disk_log_h, + #{config=>#{file=>Log}}}]}]), + check_default_log(Node,Log, + disk_log,% dest + 0),% progress in std logger + + #{module:=logger_disk_log_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + StdFilters = maps:get(filters,StdC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,StdFilters), + false = exists(simple,Hs), + false = exists(sasl,Hs), + + ok. + +logger_disk_log_formatter(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,#{handlers:=Hs},Node} + = setup(Config, + [{logger, + [{handler,?STANDARD_HANDLER,logger_disk_log_h, + #{filters=>[], + formatter=>{logger_formatter,#{}}, + config=>#{file=>Log}}}]}]), + check_single_log(Node,Log, + disk_log,% dest + 6),% progress in std logger + + #{module:=logger_disk_log_h} = StdC = find(?STANDARD_HANDLER,Hs), + all = maps:get(level,StdC), + [] = maps:get(filters,StdC), + false = exists(simple,Hs), + false = exists(sasl,Hs), + + ok. + +logger_undefined(Config) -> + {ok,#{handlers:=Hs,primary:=P},_Node} = + setup(Config,[{logger,[{handler,?STANDARD_HANDLER,undefined}]}]), + false = exists(?STANDARD_HANDLER,Hs), + #{module:=logger_simple_h} = SimpleC = find(simple,Hs), + all = maps:get(level,SimpleC), + notice = maps:get(level,P), + SimpleFilters = maps:get(filters,SimpleC), + {domain,{_,{log,super,[otp,sasl]}}} = lists:keyfind(domain,1,SimpleFilters), + false = exists(sasl,Hs), + ok. + + +%% Test that we can add multiple handlers with the default first +logger_many_handlers_default_first(Config) -> + LogErr = file(Config,logger_many_handlers_default_first_error), + LogInfo = file(Config,logger_many_handlers_default_first_info), + + logger_many_handlers( + Config,[{logger, + [{handler,?STANDARD_HANDLER,logger_std_h, + #{level=>error, + filters=>[], + formatter=>{logger_formatter,#{}}, + config=>#{type=>{file,LogErr}}} + }, + {handler,info,logger_std_h, + #{level=>info, + filters=>[{level,{fun logger_filters:level/2,{stop,gteq,error}}}], + config=>#{type=>{file,LogInfo}}} + } + ]}, + {logger_level,info}], LogErr, LogInfo, 6). + +%% Test that we can add multiple handlers with the default last +logger_many_handlers_default_last(Config) -> + LogErr = file(Config,logger_many_handlers_default_last_error), + LogInfo = file(Config,logger_many_handlers_default_last_info), + logger_many_handlers( + Config,[{logger, + [{handler,info,logger_std_h, + #{level=>info, + filters=>[{level,{fun logger_filters:level/2,{stop,gteq,error}}}], + config=>#{type=>{file,LogInfo}}} + }, + {handler,?STANDARD_HANDLER,logger_std_h, + #{level=>error, + filters=>[], + formatter=>{logger_formatter,#{}}, + config=>#{type=>{file,LogErr}}} + } + ]}, + {logger_level,info}], LogErr, LogInfo, 7). + +%% Check that we can handle that an added logger has a broken filter +%% This used to cause a deadlock. +logger_many_handlers_default_last_broken_filter(Config) -> + LogErr = file(Config,logger_many_handlers_default_first_broken_filter_error), + LogInfo = file(Config,logger_many_handlers_default_first_broken_filter_info), + + logger_many_handlers( + Config,[{logger, + [{handler,info,logger_std_h, + #{level=>info, + filters=>[{broken,{fun logger_filters:level/2,broken_state}}, + {level,{fun logger_filters:level/2,{stop,gteq,error}}}], + config=>#{type=>{file,LogInfo}}} + }, + {handler,?STANDARD_HANDLER,logger_std_h, + #{level=>error, + filters=>[], + formatter=>{logger_formatter,#{}}, + config=>#{type=>{file,LogErr}}} + } + ]}, + {logger_level,info}], LogErr, LogInfo, 7). + +logger_many_handlers(Config, Env, LogErr, LogInfo, NumProgress) -> + {ok,_,Node} = setup(Config,Env), + check_single_log(Node,LogErr, + file,% dest + 0,% progress in std logger + error), % level + ok = rpc:call(Node,logger_std_h,filesync,[info]), + {ok, Bin} = file:read_file(LogInfo), + ct:log("Log content:~n~s",[Bin]), + match(Bin,<<"info:">>,NumProgress,info,info), + match(Bin,<<"notice:">>,1,notice,info), + match(Bin,<<"alert:">>,0,alert,info), + + ok. + +logger_proxy(Config) -> + %% assume current node runs with default settings + DefOpts = logger_olp:get_opts(logger_proxy), + {ok,_,Node} = setup(Config, + [{logger,[{proxy,#{sync_mode_qlen=>0, + drop_mode_qlen=>2}}]}]), + Expected = DefOpts#{sync_mode_qlen:=0, + drop_mode_qlen:=2}, + Expected = rpc:call(Node,logger_olp,get_opts,[logger_proxy]), + Expected = rpc:call(Node,logger,get_proxy_config,[]), + + ok. + +sasl_compatible_false(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,_,Node} = setup(Config, + [{error_logger,{file,Log}}, + {logger_sasl_compatible,false}, + {logger_level,info}]), % to get progress + check_default_log(Node,Log, + file,% dest + 6,% progress in std logger + info), + ok. + +sasl_compatible_false_no_progress(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,_,Node} = setup(Config, + [{error_logger,{file,Log}}, + {logger_sasl_compatible,false}]), + check_default_log(Node,Log, + file,% dest + 0),% progress in std logger + ok. + +sasl_compatible(Config) -> + Log = file(Config,?FUNCTION_NAME), + {ok,_,Node} = setup(Config, + [{error_logger,{file,Log}}, + {sasl_compatible,true}]), + check_default_log(Node,Log, + file,% dest + 0),% progress in std logger + ok. + +all_logger_level(Config) -> + [all_logger_level(Config,Level) || Level <- [none, + emergency, + alert, + critical, + error, + warning, + notice, + info, + debug, + all]], + ok. + +all_logger_level(Config,Level) -> + {ok,#{primary:=#{level:=Level}},Node} = setup(Config,[{logger_level,Level}]), + true = test_server:stop_node(Node), + ok. + +bad_error_logger(Config) -> + error = setup(Config,[{error_logger,baddest}]). + +bad_level(Config) -> + error = setup(Config,[{logger_level,badlevel}]). + +bad_sasl_compatibility(Config) -> + error = setup(Config,[{logger_sasl_compatible,badcomp}]). + +%%%----------------------------------------------------------------- +%%% Internal +file(Config,Func) -> + filename:join(proplists:get_value(priv_dir,Config), + lists:concat([Func,".log"])). + +check_default_log(Node,Log,Dest,NumProgress) -> + check_default_log(Node,Log,Dest,NumProgress,notice). +check_default_log(Node,Log,Dest,NumProgress,Level) -> + + {ok,Bin1,Bin2} = check_log(Node,Log,Dest), + + match(Bin1,<<"PROGRESS REPORT">>,NumProgress,info,Level), + match(Bin1,<<"ALERT REPORT">>,1,alert,Level), + match(Bin1,<<"INFO REPORT">>,0,notice,Level), + match(Bin1,<<"DEBUG REPORT">>,0,debug,Level), + + match(Bin2,<<"INFO REPORT">>,1,notice,Level), + match(Bin2,<<"DEBUG REPORT">>,0,debug,Level), + ok. + +check_single_log(Node,Log,Dest,NumProgress) -> + check_single_log(Node,Log,Dest,NumProgress,notice). +check_single_log(Node,Log,Dest,NumProgress,Level) -> + + {ok,Bin1,Bin2} = check_log(Node,Log,Dest), + + match(Bin1,<<"info:">>,NumProgress,info,Level), + match(Bin1,<<"alert:">>,1,alert,Level), + match(Bin1,<<"debug:">>,0,debug,Level), + + match(Bin2,<<"info:">>,NumProgress+1,info,Level), + match(Bin2,<<"debug:">>,0,debug,Level), + + ok. + +check_log(Node,Log,Dest) -> + + ok = log(Node,alert,["dummy1"]), + ok = log(Node,debug,["dummy1"]), + + %% Check that there are progress reports (supervisor and + %% application_controller) and an error report (the call above) in + %% the log. There should not be any info reports yet. + {ok,Bin1} = sync_and_read(Node,Dest,Log), + ct:log("Log content:~n~s",[Bin1]), + + %% Then stop sasl and see that the info report from + %% application_controller is there + ok = rpc:call(Node,application,stop,[sasl]), + {ok,Bin2} = sync_and_read(Node,Dest,Log), + ct:log("Log content:~n~s",[Bin2]), + {ok,Bin1,Bin2}. + +match(Bin,Pattern,0,_,_) -> + nomatch = re:run(Bin,Pattern,[{capture,none}]); +match(Bin,Pattern,N,LogLevel,ConfLevel) -> + case logger:compare_levels(LogLevel,ConfLevel) of + lt -> match(Bin,Pattern,0,LogLevel,ConfLevel); + _ -> + {match,M} = re:run(Bin,Pattern,[{capture,all},global]), + N = length(M) + end. + +find(Id,Handlers) -> + case lists:search(fun(#{id:=Id0}) when Id0=:=Id-> true; + (_) -> false end, + Handlers) of + {value,Config} -> + Config; + false -> + false + end. + +exists(Id,Handlers) -> + case find(Id,Handlers) of + false -> + false; + _ -> + true + end. |