<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE chapter SYSTEM "chapter.dtd">

<chapter>
  <header>
    <copyright>
      <year>2003</year><year>2016</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      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.
    
    </legalnotice>

    <title>Error Logging</title>
    <prepared></prepared>
    <docno></docno>
    <date></date>
    <rev></rev>
    <file>error_logging.xml</file>
  </header>
  <marker id="error logging"></marker>

  <section>
    <title>Error Information From the Runtime System</title>
    <p>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):</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 as
      well as from the standard behaviours and different Erlang/OTP
      applications.</p>
    <p>The exit reasons (such as <c>badarg</c>) used by
      the runtime system are described in
      <seealso marker="doc/reference_manual:errors#exit_reasons">
      Errors and Error Handling</seealso>.</p>
    <p>For information about the process <c>error_logger</c> and its user
      interface (with the same name), see the
      <seealso marker="kernel:error_logger">error_logger(3)</seealso>
      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
      <c>error_logger</c>.</p>
  </section>

  <section>
    <title>SASL Error Logging</title>
    <p>The standard behaviours (<c>supervisor</c>, <c>gen_server</c>,
      and so on) send progress and error information to <c>error_logger</c>.
      If the SASL application is started, this information is
      written to tty as well. For more information, see
      <seealso marker="sasl:error_logging">SASL Error Logging</seealso>
      in the SASL User's Guide.</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>