From b9d2cb688e562d200663bdbedfa65adc5a29aeae Mon Sep 17 00:00:00 2001
From: Siri Hansen
- This module is the main API for logging in Erlang/OTP. It
- contains functions that allow applications to use a single log
- API and the system to manage those log events independently. Use
- the This log event is then sent to the configured log handlers which
- by default means that it is be printed to the console. If you want
- your systems logs to be printed to a file instead of the console you
- must configure the default handler to do so. The simplest way is
- to include the following in your This module implements the main API for logging in
+ Erlang/OTP. To create a log event, use the
+ To configure the Logger backend,
+ use By default, the Kernel application installs one log handler at
+ system start. This handler is named If you want your systems logs to be printed to a file instead,
+ you must configure the default handler to do so. The simplest
+ way is to include the following in
+ your
For more information about:
The severity level for the message to be logged. Primary configuration data for Logger. The following
+ default values apply: Handler configuration data for Logger. The following
+ default values apply: In addition to these, the following fields are
+ automatically inserted by Logger, values taken from the
+ two first parameters
+ to Handler specific configuration data is inserted by the
+ handler callback itself, in a sub structure associated with
+ the field named See the A filter which can be installed as a handler filter, or as
+ a primary filter in Logger. The second argument to the filter fun. A unique identifier for a filter. The return value from the filter fun. Configuration data for the
+ formatter. See A unique identifier for a handler instance. The severity level for the message to be logged. When a log macro is used, Logger also inserts location
information: Configuration data for the logger part of Logger, or for a handler. The following default values apply: See the A unique identifier for a handler instance. A unique identifier for a filter. A filter which can be installed for the logger part of
- Logger, or for a handler. The second argument to the filter fun. The return value from the filter fun.
-?LOG_ERROR("error happened because: ~p",[Reason]). %% With macro
-logger:error("error happened because: ~p",[Reason]). %% Without macro
-
-
+?LOG_ERROR("error happened because: ~p", [Reason]). % With macro
+logger:error("error happened because: ~p", [Reason]). % Without macro
+
+
[{kernel,
[{logger,
- [{handler,default,logger_std_h,
- #{logger_std_h=>#{type=>{file,"path/to/file.log"}}}}]}]}].
+ [{handler, default, logger_std_h,
+ #{config => #{type => {file, "path/to/file.log"}}}}]}]}].
-
+
+
+
+
+
-
@@ -158,51 +235,15 @@ logger:error("error happened because: ~p",[Reason]). %% Without macro
-
-
Configuration data for the
- formatter. See
Equivalent to @@ -366,136 +402,21 @@ logger:error("error happened because: ~p",[Reason]). %% Without macro
Log the given message.
Look up the current configuration for the logger part of - Logger.
-Look up the current configuration for the given handler.
-Same as
Display or return all current Logger configurations.
-Return the pretty printed current Logger configuration - as iodata.
-Return the current Logger configuration as a term. The
- format of this term may change between releases. For a
- stable format use
The same as calling
Pretty print all the current Logger configuration to - standard out. Example:
- logger:i(print).
-Current logger configuration:
- Level: info
- Filter Default: log
- Filters:
- Handlers:
- Id: default
- Module: logger_std_h
- Level: info
- Formatter:
- Module: logger_formatter
- Config: #{legacy_header => true,single_line => false,
- template => [{logger_formatter,header},"\n",msg,"\n"]}
- Filter Default: stop
- Filters:
- Id: stop_progress
- Fun: fun logger_filters:progress/2
- Config: stop
- Id: remote_gl
- Fun: fun logger_filters:remote_gl/2
- Config: stop
- Id: domain
- Fun: fun logger_filters:domain/2
- Config: {log,super,[beam,erlang,otp,sasl]}
- Id: no_domain
- Fun: fun logger_filters:domain/2
- Config: {log,undefined,[]}
- Handler Config:
- logger_std_h: #{type => standard_io}
- Level set per module:
- Module: my_module
- Level: debug]]>
- Add a filter to the logger part of Logger.
-The filter fun is called with the log event as the first
- parameter, and the specified
The return value of the fun specifies if a log event is to - be discarded or forwarded to the handlers:
-The filter passed. The next logger filter, if - any, is applied. If no more logger filters exist, the - log event is forwarded to the handler part of Logger, - where handler filters are applied.
-The filter did not pass, and the log event is - immediately discarded.
-The filter has no knowledge of the log event. The next
- logger filter, if any, is applied. If no more logger
- filters exist, the value of the
See section
Some built-in filters exist. These are defined
- in
Add a handler with the given configuration.
+Remove the filter identified
- by
Remove the filter identified
- by
Add a handler with the given configuration.
-Remove the handler identified by
Set the log level for the
- specified
The log level for a module overrides the global log level - of Logger for log events originating from the module in - question. Notice, however, that it does not override the - level configuration for any handler.
-For example: Assume that the global log level for Logger
- is
With this configuration, no debug messages will be logged, - since they are all stopped by the global log level.
-If the level for
Debug events from other modules are still not logged.
-To change the global log level for Logger, use
-
To change the log level for a handler, use
-
The originating module for a log event is only detected
- if
Remove a module specific log setting. After this, the - global log level is used for the specified module.
-Reads the application configuration parameter
Set configuration data for the logger part of Logger. This - overwrites the current logger configuration.
-To modify the existing configuration,
- use
If a key is removed compared to the current configuration, - the default value is used.
+Add a primary filter to Logger.
+The filter fun is called with the log event as the first
+ parameter, and the specified
The return value of the fun specifies if a log event is to + be discarded or forwarded to the handlers:
+The filter passed. The next primary filter, if + any, is applied. If no more primary filters exist, the + log event is forwarded to the handler part of Logger, + where handler filters are applied.
+The filter did not pass, and the log event is + immediately discarded.
+The filter has no knowledge of the log event. The next
+ primary filter, if any, is applied. If no more primary
+ filters exist, the value of the
+ primary
See section
Some built-in filters exist. These are defined
+ in
Add or update configuration data for the logger part of
- Logger. If the given
Look up all current Logger configuration, including primary + and handler configuration, and module level settings.
Update configuration data for the logger part of - Logger. This function behaves as if it was implemented as - follows:
-
-{ok,Old} = logger:get_logger_config(),
-logger:set_logger_config(maps:merge(Old,Config)).
-
- To overwrite the existing configuration without any merge,
- use
Look up the current configuration for all handlers.
+Look up the current configuration for the given handler.
+Look up the identities for all installed handlers.
+Look up the current primary configuration for Logger.
+Look up all current module levels. Returns a list
+ containing one
Look up the current level for the given modules. Returns a
+ list containing one
Retrieve data set
+ with
Remove the handler identified by
Remove the filter identified
+ by
Remove the primary filter identified
+ by
Update configuration data for the specified handler. This function - behaves as if it was implemented as follows:
-
-{ok,{_,Old}} = logger:get_handler_config(HandlerId),
-logger:set_handler_config(HandlerId,maps:merge(Old,Config)).
-
- To overwrite the existing configuration without any merge,
- use Set primary configuration data for Logger. This
+ overwrites the current configuration. To modify the existing configuration,
+ use If a key is removed compared to the current configuration,
+ the default value is used.
Add or update primary configuration data for Logger. If the
+ given
Set the log level for the + specified modules.
+The log level for a module overrides the primary log level + of Logger for log events originating from the module in + question. Notice, however, that it does not override the + level configuration for any handler.
+For example: Assume that the primary log level for Logger
+ is
With this configuration, no debug messages will be logged, + since they are all stopped by the primary log level.
+If the level for
Debug events from other modules are still not logged.
+To change the primary log level for Logger, use
+
To change the log level for a handler, use
+
The originating module for a log event is only detected
+ if the key
Set metadata which Logger shall automatically insert in + all log events produced on the current process.
+Location data produced by the log macros, and/or metadata + given as argument to the log call (API function or macro), + are merged with the process metadata. If the same keys + occur, values from the metadata argument to the log call + overwrite values from the process metadata, which in turn + overwrite values from the location data.
+Subsequent calls to this function overwrites previous data
+ set. To update existing data instead of overwriting it,
+ see
Remove module specific log settings. After this, the + primary log level is used for all modules.
+Remove module specific log settings. After this, the + primary log level is used for the specified modules.
+Delete data set
+ with
The new configuration is merged with the existing formatter configuration.
To overwrite the existing configuration without any merge,
- use
+@@ -797,39 +834,41 @@ logger:set_handler_config(HandlerId,maps:merge(Old,Config)).set_handler_config(HandlerId, formatter, + {FormatterModule, FormatterConfig}) .
Update the formatter configuration for the specified handler.
-This is equivalent
- to
This is equivalent to
++update_formatter_config( HandlerId , #{Key =>Value })
Compare the severity of two log levels. Returns
Update configuration data for the specified handler. This function + behaves as if it was implemented as follows:
+
+{ok, {_, Old}} = logger:get_handler_config(HandlerId),
+logger:set_handler_config(HandlerId, maps:merge(Old, Config)).
+
+ To overwrite the existing configuration without any merge,
+ use
Set metadata which Logger shall automatically insert in - all log events produced on the current process.
-Location data produced by the log macros, and/or metadata - given as argument to the log call (API function or macro), - are merged with the process metadata. If the same keys - occur, values from the metadata argument to the log call - overwrite values from the process metadata, which in turn - overwrite values from the location data.
-Subsequent calls to this function overwrites previous data
- set. To update existing data instead of overwriting it,
- see
Update primary configuration data for Logger. This function + behaves as if it was implemented as follows:
+
+Old = logger:get_primary_config(),
+logger:set_primary_config(maps:merge(Old, Config)).
+
+ To overwrite the existing configuration without any merge,
+ use
If process metadata exists for the current process, this function behaves as if it was implemented as follows:
-logger:set_process_metadata(maps:merge(logger:get_process_metadata(),Meta)).
+logger:set_process_metadata(maps:merge(logger:get_process_metadata(), Meta)).
If no process metadata exists, the function behaves as
Retrieve data set
- with
Delete data set
- with
Compare the severity of two log levels. Returns
Convert a log message on report form to
This is the default report callback used +
Convert a log message on report form to
The function produces lines of
If the
If
This callback function is mandatory.
-The function is called when all global filters and all +
The function is called when all primary filters and all handler filters for the handler in question have passed for the given log event.
The handler identity is associated with the This callback function is optional. This callback function is optional. The function is called by a Logger when formatter
configuration is set or modified. The formatter must
validate the given configuration and return
The following Logger API functions can trigger this callback:
+See
+