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2 Error Logging

2.1 Error Information From the Runtime System

Error information from the runtime system, that is, information about a process terminating because of an uncaught error exception, is by default written to terminal (tty):

=ERROR REPORT==== 9-Dec-2003::13:25:02 ===
Error in process <0.27.0> with exit value: {{badmatch,[1,2,3]},[{m,f,1},{shell,eval_loop,2}]}

The error information is handled by the error logger, a system process registered as error_logger. This process receives all error messages from the Erlang runtime system as well as from the standard behaviours and different Erlang/OTP applications.

The exit reasons (such as badarg) used by the runtime system are described in Errors and Error Handling.

For information about the process error_logger and its user interface (with the same name), see the error_logger(3) manual page in Kernel. The system can be configured so that error information is written to file or to tty, or both. In addition, user-defined applications can send and format error information using error_logger.

2.2 SASL Error Logging

The standard behaviours (supervisor, gen_server, and so on) send progress and error information to error_logger. If the SASL application is started, this information is written to tty as well. For more information, see SASL Error Logging in the SASL User's Guide.

% erl -boot start_sasl
Erlang (BEAM) emulator version 5.4.13 [hipe] [threads:0] [kernel-poll]


=PROGRESS REPORT==== 31-Mar-2006::12:45:58 ===
          supervisor: {local,sasl_safe_sup}
             started: [{pid,<0.33.0>},
                       {name,alarm_handler},
                       {mfa,{alarm_handler,start_link,[]}},
                       {restart_type,permanent},
                       {shutdown,2000},
                       {child_type,worker}]

=PROGRESS REPORT==== 31-Mar-2006::12:45:58 ===
          supervisor: {local,sasl_safe_sup}
             started: [{pid,<0.34.0>},
                       {name,overload},
                       {mfa,{overload,start_link,[]}},
                       {restart_type,permanent},
                       {shutdown,2000},
                       {child_type,worker}]

=PROGRESS REPORT==== 31-Mar-2006::12:45:58 ===
          supervisor: {local,sasl_sup}
             started: [{pid,<0.32.0>},
                       {name,sasl_safe_sup},
                       {mfa,{supervisor,
                                start_link,
                                [{local,sasl_safe_sup},sasl,safe]}},
                       {restart_type,permanent},
                       {shutdown,infinity},
                       {child_type,supervisor}]

=PROGRESS REPORT==== 31-Mar-2006::12:45:58 ===
          supervisor: {local,sasl_sup}
             started: [{pid,<0.35.0>},
                       {name,release_handler},
                       {mfa,{release_handler,start_link,[]}},
                       {restart_type,permanent},
                       {shutdown,2000},
                       {child_type,worker}]

=PROGRESS REPORT==== 31-Mar-2006::12:45:58 ===
         application: sasl
          started_at: nonode@nohost
Eshell V5.4.13  (abort with ^G)
1> 

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