<?xml version="1.0" encoding="latin1" ?>
<!DOCTYPE chapter SYSTEM "chapter.dtd">

<chapter>
  <header>
    <copyright>
      <year>2003</year><year>2009</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      The contents of this file are subject to the Erlang Public License,
      Version 1.1, (the "License"); you may not use this file except in
      compliance with the License. You should have received a copy of the
      Erlang Public License along with this software. If not, it can be
      retrieved online at http://www.erlang.org/.
    
      Software distributed under the License is distributed on an "AS IS"
      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
      the License for the specific language governing rights and limitations
      under the License.
    
    </legalnotice>

    <title>Error Logging</title>
    <prepared></prepared>
    <docno></docno>
    <date></date>
    <rev></rev>
    <file>error_logging.xml</file>
  </header>

  <section>
    <title>Error Information From the Runtime System</title>
    <p>Error information from the runtime system, that is, information
      about a process terminating due to an uncaught error exception,
      is by default written to terminal (tty):</p>
    <code type="none"><![CDATA[
=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}]}]]></code>
    <p>The error information is handled by the <em>error logger</em>, a
      system process registered as <c>error_logger</c>. This process
      receives all error messages from the Erlang runtime system and
      also from the standard behaviours and different Erlang/OTP
      applications.</p>
    <p>The exit reasons (such as <c>badarg</c> above) used by
      the runtime system are described in
      <seealso marker="doc/reference_manual:errors#exit_reasons">Errors and Error Handling</seealso>
      in the Erlang Reference Manual.</p>
    <p>The process <c>error_logger</c> and its user interface (with
      the same name) are described in
      <seealso marker="kernel:error_logger">error_logger(3)</seealso>.
      It is possible to configure the system so that error information
      is written to file instead/as well as tty. Also, it is possible
      for user defined applications to send and format error
      information using <c>error_logger</c>.</p>
  </section>

  <section>
    <title>SASL Error Logging</title>
    <p>The standard behaviors (<c>supervisor</c>, <c>gen_server</c>,
      etc.) sends progress and error information to <c>error_logger</c>.
      If the SASL application is started, this information is written
      to tty as well. See
      <seealso marker="sasl:error_logging">SASL Error Logging</seealso>
      in the SASL User's Guide for further information.</p>
    <pre>
% <input>erl -boot start_sasl</input>
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,&lt;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,&lt;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,&lt;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,&lt;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> </pre>
  </section>
</chapter>