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<!DOCTYPE erlref SYSTEM "erlref.dtd">

<erlref>
  <header>
    <copyright>
      <year>1996</year>
      <year>2020</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.

  The Initial Developer of the Original Code is Ericsson AB.
    </legalnotice>

    <title>log_mf_h</title>
    <prepared>Martin Bj&ouml;rklund</prepared>
    <responsible>Bjarne Dacker</responsible>
    <docno></docno>
    <approved>Bjarne D&auml;cker</approved>
    <checked>Martin Bj&ouml;rklund</checked>
    <date>1996-10-31</date>
    <rev>A</rev>
    <file>log_mf_h.xml</file>
  </header>
  <module since="">log_mf_h</module>
  <modulesummary>An event handler that logs events to disk.</modulesummary>
  <description>
    <p>This module is a <c>gen_event</c> handler module that can be installed
      in any <c>gen_event</c> process. It logs onto disk all events that are
      sent to an event manager. Each event is written as a binary, which makes
      the logging very fast. However, a tool such as the Report Browser
      (<seeerl marker="sasl:rb"><c>rb(3)</c></seeerl>) must be used to read
      the files. The events are written to multiple files. When all files have
      been used, the first one is reused and overwritten. The directory
      location, the number of files, and the size of each file are configurable.
      The directory will include one file called <c>index</c>, and report files
      <c>1, 2, ...</c>.</p>
  </description>

  <datatypes>
    <datatype>
      <name name="args"/>
      <desc><p>Term to be sent to <seemfa marker="gen_event#add_handler/3">
        <c>gen_event:add_handler/3</c></seemfa>.</p>
      </desc>
    </datatype>
  </datatypes>

  <funcs>
    <func>
      <name name="init" arity="3" since=""/>
      <name name="init" arity="4" since=""/>
      <fsummary>Initiate the event handler.</fsummary>
      <desc>
        <p>Initiates the event handler. Returns <c><anno>Args</anno></c>, which
          is to be used in a call to
          <c>gen_event:add_handler(EventMgr, log_mf_h, <anno>Args</anno>)</c>.
        </p>
        <p><c><anno>Dir</anno></c> specifies which directory to use for the log
          files. <c><anno>MaxBytes</anno></c> specifies the size of each
          individual file. <c><anno>MaxFiles</anno></c> specifies how many
          files are used. <c><anno>Pred</anno></c> is a predicate function used
          to filter the events. If no predicate function is specified, all
          events are logged.</p>
      </desc>
    </func>
  </funcs>

  <section>
    <title>See Also</title>
    <p><seeerl marker="gen_event"><c>gen_event(3)</c></seeerl>,
      <seeerl marker="sasl:rb"><c>rb(3)</c></seeerl></p>
  </section>
</erlref>

