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

<erlref>
  <header>
    <copyright>
      <year>2004</year><year>2021</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>snmpa</title>
    <prepared></prepared>
    <responsible></responsible>
    <docno></docno>
    <approved></approved>
    <checked></checked>
    <date></date>
    <rev></rev>
    <file>snmpa.xml</file>
  </header>
  <module since="">snmpa</module>
  <modulesummary>Interface Functions to the SNMP toolkit agent</modulesummary>
  <description>
    <p>The module <c>snmpa</c> contains interface functions to the 
      SNMP agent.</p>

    <marker id="data_types"></marker>
  </description>

  <section>
    <title>DATA TYPES</title>
    <code type="none"><![CDATA[
oid() = [byte()] 
atl_type() = read | write | read_write
notification_delivery_info() = #snmpa_notification_delivery_info{}
    ]]></code>

    <p>The <c>oid()</c> type is used to represent an ASN.1 OBJECT IDENTIFIER. </p>

    <p>The record <c><![CDATA[snmpa_notification_delivery_info]]></c> contains the following fields: </p>
    <taglist>
      <tag><c><![CDATA[tag = term()]]></c></tag>
      <item>
        <p>A user defined identity representing this notification send 
          operation.</p>
      </item>
      <tag><c><![CDATA[mod = module()]]></c></tag>
      <item>
        <p>A module implementing the 
          <seeerl marker="snmpa_notification_delivery_info_receiver">snmpa_notification_delivery_info_receiver</seeerl> 
          behaviour. The info functions of this module will be called at 
          various stages of delivery. </p>
      </item>
      <tag><c><![CDATA[extra = term()]]></c></tag>
      <item>
        <p>This is any extra info the user wants to have supplied 
          when the functions in the callback module is called. </p>
      </item>
    </taglist>
    
    <marker id="add_agent_caps"></marker>
  </section>

  <funcs>
    <func>
      <name since="">add_agent_caps(SysORID, SysORDescr) -> SysORIndex</name>
      <fsummary>Add an AGENT-CAPABILITY definition to the agent</fsummary>
      <type>
        <v>SysORID = oid()</v>
        <v>SysORDescr = string()</v>
        <v>SysORIndex = integer()</v>
      </type>
      <desc>
        <p>This function can be used to add an AGENT-CAPABILITY
          statement to the sysORTable in the agent.  The table is
          defined in the SNMPv2-MIB.</p>
        <marker id="del_agent_caps"></marker>
      </desc>
    </func>

    <func>
      <name since="">del_agent_caps(SysORIndex) -> void()</name>
      <fsummary>Delete an AGENT-CAPABILITY definition from the agent</fsummary>
      <type>
        <v>SysORIndex = integer()</v>
      </type>
      <desc>
        <p>This function can be used to delete an AGENT-CAPABILITY
          statement to the sysORTable in the agent.  This table is
          defined in the SNMPv2-MIB. </p>

          <marker id="get_agent_caps"></marker>
      </desc>
    </func>

    <func>
      <name since="">get_agent_caps() -> [[SysORIndex, SysORID, SysORDescr, SysORUpTime]]</name>
      <fsummary>Return all AGENT-CAPABILITY definitions in the agent</fsummary>
      <type>
        <v>SysORIndex = integer()</v>
        <v>SysORId = oid()</v>
        <v>SysORDescr = string()</v>
        <v>SysORUpTime = integer()</v>
      </type>
      <desc>
        <p>Returns all AGENT-CAPABILITY statements in the sysORTable
          in the agent.  This table is defined in the SNMPv2-MIB. </p>

        <marker id="get"></marker>
      </desc>
    </func>

    <func>
      <name since="">get(Agent, Vars) -> Values | {error, Reason}</name>
      <name since="">get(Agent, Vars, Context) -> Values | {error, Reason}</name>
      <fsummary>Perform a get operation on the agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Vars = [oid()]</v>
        <v>Context = string()</v>
        <v>Values = [term()]</v>
        <v>Reason = {atom(), oid()}</v>
      </type>
      <desc>
        <p>Performs a GET operation on the agent.  All loaded MIB
          objects are visible in this operation.  The agent calls the
          corresponding instrumentation functions just as if it was a
          GET request coming from a manager. </p>
        <p>Note that the request specific parameters (such as 
          <seeerl marker="#current_request_id">current_request_id</seeerl>) 
          are not accessible for the instrumentation functions if this 
          function is used. </p>

          <marker id="get_next"></marker>
      </desc>
    </func>

    <func>
      <name since="">get_next(Agent, Vars) -> Values | {error, Reason}</name>
      <name since="">get_next(Agent, Vars, Context) -> Values | {error, Reason}</name>
      <fsummary>Perform a get-next operation on the agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Vars = [oid()]</v>
        <v>Context = string()</v>
        <v>Values = [{oid(), term()}]</v>
        <v>Reason = {atom(), oid()}</v>
      </type>
      <desc>
        <p>Performs a GET-NEXT operation on the agent.  All loaded MIB
          objects are visible in this operation.  The agent calls the
          corresponding instrumentation functions just as if it was a
          GET request coming from a manager. </p>
        <p>Note that the request specific parameters (such as 
          <c>snmpa:current_request_id/0</c> are not accessible for the 
          instrumentation functions if this function is used. </p>

        <marker id="backup"></marker>
        <!-- <marker id="get_symbolic_store_db"></marker> -->
      </desc>
    </func>

<!--
    <func>
      <name since="">get_symbolic_store_db() -> Db</name>
      <fsummary>Retrieve the symbolic store database reference</fsummary>
      <type>
        <v>Db = term()</v>
      </type>
      <desc>
        <p>Retrieve the symbolic store database reference. This is used 
          for faster access to the database using the functions: 
          <c>int_to_enum/3</c>, <c>enum_to_int/3</c>, <c>name_to_oid/2</c>, 
          <c>oid_to_name/2</c>. </p>

        <marker id="backup"></marker>
      </desc>
    </func>

-->
    <func>
      <name since="">backup(BackupDir) -> ok | {error, Reason}</name>
      <name since="">backup(Agent, BackupDir) -> ok | {error, Reason}</name>
      <fsummary>Backup agent data</fsummary>
      <type>
        <v>BackupDir = string()</v>
        <v>Agent = pid() | atom()</v>
        <v>Reason = backup_in_progress | term()</v>
      </type>
      <desc>
        <p>Backup persistent/permanent data handled by the agent
          (such as local-db, mib-data and vacm). </p>
        <p>Data stored by mnesia is not handled. </p>
        <p>BackupDir cannot be identical to DbDir. </p>
        <p>Simultaneous backup calls are <em>not</em> allowed. 
	That is, two different processes cannot simultaneously 
	successfully call this function. One of them will be first, 
	and succeed. The second will fail with the error reason
	<c>backup_in_progress</c>. </p>

        <marker id="info"></marker>
      </desc>
    </func>
    <func>
      <name since="">info() -> [{Key, Value}]</name>
      <name since="">info(Agent) -> [{Key, Value}]</name>
      <fsummary>Return information about the agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
      </type>
      <desc>
        <p>Returns a list (a dictionary) containing information about
	the agent. Information includes loaded MIBs, registered
	sub-agents, some information about the memory allocation. </p>
        <marker id="load_mib"></marker>
      </desc>
    </func>

    <func>
      <name since="OTP R16B02">load_mib(Mib) -> ok | {error, Reason}</name>
      <name since="OTP R16B02">load_mib(Agent, Mib) -> ok | {error, Reason}</name>
      <fsummary>Load single MIB into the agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>MibName = string()</v>
        <v>Reason = already_loaded | term()</v>
      </type>
      <desc>
        <p>Load a single <c>Mib</c> into an agent. The <c>MibName</c> 
	is the name of the Mib, including the path to where the compiled 
	mib is found. For example: </p>
	<code type="none">
          Dir = code:priv_dir(my_app) ++ "/mibs/",
          snmpa:load_mib(snmp_master_agent, Dir ++ "MY-MIB").
        </code>

        <marker id="load_mibs"></marker>
      </desc>
    </func>

    <func>
      <name since="">load_mibs(Mibs) -> ok | {error, Reason}</name>
      <name since="">load_mibs(Mibs, Force) -> ok | {error, Reason}</name>
      <name since="">load_mibs(Agent, Mibs) -> ok | {error, Reason}</name>
      <name since="OTP R16B02">load_mibs(Agent, Mibs, Force) -> ok | {error, Reason}</name>
      <fsummary>Load MIBs into the agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Mibs = [MibName]</v>
        <v>Force = boolean()</v>
        <v>MibName = string()</v>
        <v>Reason = {'load aborted at', MibName, InternalReason}</v>
        <v>InternalReason = already_loaded | term()</v>
      </type>
      <desc>
        <p>Load <c>Mibs</c> into an agent.  If the agent cannot load all 
	MIBs (the default value of the <c>Force</c> argument is <c>false</c>), 
	it will indicate where loading was aborted. The <c>MibName</c> 
	is the name of the Mib, including the path to where the compiled 
	mib is found. For example,</p>
	<code type="none">
          Dir = code:priv_dir(my_app) ++ "/mibs/",
          snmpa:load_mibs(snmp_master_agent, [Dir ++ "MY-MIB"]).
        </code>
	<p>If <c>Force = true</c> then the agent will continue attempting
	to load each mib even after failing to load a previous mib. Use with 
	care. </p>

        <marker id="unload_mib"></marker>
      </desc>
    </func>

    <func>
      <name since="OTP R16B02">unload_mib(Mib) -> ok | {error, Reason}</name>
      <name since="OTP R16B02">unload_mib(Agent, Mib) -> ok | {error, Reason}</name>
      <fsummary>Unload single MIB from the agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>MibName = string()</v>
        <v>Reason = not_loaded | term()</v>
      </type>
      <desc>
        <p>Unload a single <c>Mib</c> from an agent. </p>

        <marker id="unload_mibs"></marker>
      </desc>
    </func>

    <func>
      <name since="">unload_mibs(Mibs) -> ok | {error, Reason}</name>
      <name since="">unload_mibs(Mibs, Force) -> ok | {error, Reason}</name>
      <name since="">unload_mibs(Agent, Mibs) -> ok | {error, Reason}</name>
      <name since="OTP R16B02">unload_mibs(Agent, Mibs, Force) -> ok | {error, Reason}</name>
      <fsummary>Unload MIBs from the agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Mibs = [MibName]</v>
        <v>Force = boolean()</v>
        <v>MibName = string()</v>
        <v>Reason = {'unload aborted at', MibName, InternalReason}</v>
        <v>InternalReason = not_loaded | term()</v>
      </type>
      <desc>
        <p>Unload <c>Mibs</c> from an agent. If it cannot unload all MIBs
	(the default value of the <c>Force</c> argument is <c>false</c>),
	it will indicate where unloading was aborted. </p>
	<p>If <c>Force = true</c> then the agent will continue attempting
	to unload each mib even after failing to unload a previous mib. 
	Use with care. </p>

        <marker id="which_mibs"></marker>
      </desc>
    </func>

    <func>
      <name since="">which_mibs() -> Mibs</name>
      <name since="">which_mibs(Agent) -> Mibs</name>
      <fsummary>Get a list of all the loaded mibs</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Mibs = [{MibName, MibFile}]</v>
        <v>MibName = atom()</v>
        <v>MibFile = string()</v>
      </type>
      <desc>
        <p>Retrieve the list of all the mibs loaded into this agent. Default 
          is the master agent. </p>
                    
        <marker id="whereis_mib"></marker>
      </desc>
    </func>

    <func>
      <name since="">whereis_mib(MibName) -> {ok, MibFile} | {error, Reason}</name>
      <name since="">whereis_mib(Agent, MibName) -> {ok, MibFile} | {error, Reason}</name>
      <fsummary>Get the path to the mib file</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>MibName = atom()</v>
        <v>MibFile = string()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Get the full path to the (compiled) mib-file. </p>

        <marker id="current_request_id"></marker>
        <marker id="current_context"></marker>
        <marker id="current_community"></marker>
        <marker id="current_address"></marker>
      </desc>
    </func>

    <func>
      <name since="">current_request_id() -> {value, RequestId} | false</name>
      <name since="">current_context() -> {value, Context} | false</name>
      <name since="">current_community() -> {value, Community} | false</name>
      <name since="">current_address() -> {value, Address} | false</name>
      <fsummary>Get the request-id, context, community and address of the current request</fsummary>
      <type>
        <v>RequestId = integer()</v>
        <v>Context = string()</v>
        <v>Community = string()</v>
        <v>Address = term()</v>
      </type>
      <desc>
        <p>Get the request-id, context, community and address of the 
          request currently being processed by the agent. </p>
        <p>Note that these functions is intended to be called by the 
          instrumentation functions and <em>only</em> if they are 
          executed in the context of the agent process (e.g. it does 
          not work if called from a spawned process).</p>

        <marker id="enum_to_int"></marker>
      </desc>
    </func>

    <func>
      <name since="">enum_to_int(Name, Enum) -> {value, Int} | false</name>
      <name since="">enum_to_int(Db, Name, Enum) -> {value, Int} | false</name>
      <fsummary>Convert an enum value to an integer</fsummary>
      <type>
        <v>Db   = term()</v>
        <v>Name = atom()</v>
        <v>Enum = atom()</v>
        <v>Int  = int()</v>
      </type>
      <desc>
        <p>Converts the symbolic value <c>Enum</c> to the
          corresponding integer of the enumerated object or type
          <c>Name</c> in a MIB.  The MIB must be loaded. 
          </p>
        <p><c>false</c> is returned if the object or type is not
          defined in any loaded MIB, or if it does not define the
          symbolic value as enumerated.
          </p>
        <p><c>Db</c> is a reference to the symbolic store database 
          (retrieved by a call to <c>get_symbolic_store_db/0</c>). </p>

        <marker id="int_to_enum"></marker>
      </desc>
    </func>

    <func>
      <name since="">int_to_enum(Name, Int) -> {value, Enum} | false</name>
      <name since="">int_to_enum(Db, Name, Int) -> {value, Enum} | false</name>
      <fsummary>Convert an integer to an enum value</fsummary>
      <type>
        <v>Db   = term()</v>
        <v>Name = atom()</v>
        <v>Int  = int()</v>
        <v>Enum = atom()</v>
      </type>
      <desc>
        <p>Converts the integer <c>Int</c> to the corresponding
          symbolic value of the enumerated object or type <c>Name</c> in
          a MIB.  The MIB must be loaded. 
          </p>
        <p><c>false</c> is returned if the object or type is not
          defined in any loaded MIB, or if it does not define the
          symbolic value as enumerated.
          </p>
        <p><c>Db</c> is a reference to the symbolic store database 
          (retrieved by a call to <c>get_symbolic_store_db/0</c>). </p>

        <marker id="name_to_oid"></marker>
      </desc>
    </func>

    <func>
      <name since="">name_to_oid(Name) -> {value, oid()} | false</name>
      <name since="">name_to_oid(Db, Name) -> {value, oid()} | false</name>
      <fsummary>Convert a symbolic name to an OID</fsummary>
      <type>
        <v>Db   = term()</v>
        <v>Name = atom()</v>
      </type>
      <desc>
        <p>Looks up the OBJECT IDENTIFIER of a MIB object, given the
          symbolic name.  Note, the OBJECT IDENTIFIER is given for the
          object, not for an instance. </p>
        <p><c>false</c> is returned if the object is not defined in any
          loaded MIB. </p>
        <p><c>Db</c> is a reference to the symbolic store database 
          (retrieved by a call to <c>get_symbolic_store_db/0</c>). </p>

        <marker id="oid_to_name"></marker>
      </desc>
    </func>

    <func>
      <name since="">oid_to_name(OID) -> {value, Name} | false</name>
      <name since="">oid_to_name(Db, OID) -> {value, Name} | false</name>
      <fsummary>Convert an OID to a symbolic name</fsummary>
      <type>
        <v>Db   = term()</v>
        <v>OID  = oid()</v>
        <v>Name = atom()</v>
      </type>
      <desc>
        <p>Looks up the symbolic name of a MIB object, given OBJECT
          IDENTIFIER. </p>
        <p><c>false</c> is returned if the object is not defined in any
          loaded MIB. </p>
        <p><c>Db</c> is a reference to the symbolic store database 
          (retrieved by a call to <c>get_symbolic_store_db/0</c>). </p>

        <marker id="which_aliasnames"></marker>
      </desc>
    </func>

    <func>
      <name since="">which_aliasnames() -> Result</name>
      <fsummary>Get all alias-names known to the agent</fsummary>
      <type>
        <v>Result = [atom()]</v>
      </type>
      <desc>
        <p>Retrieve all alias-names known to the agent.</p>
        <marker id="which_tables"></marker>
      </desc>
    </func>

    <func>
      <name since="">which_tables() -> Result</name>
      <fsummary>Get all tables known to the agent</fsummary>
      <type>
        <v>Result = [atom()]</v>
      </type>
      <desc>
        <p>Retrieve all tables known to the agent.</p>

        <marker id="which_transports"></marker>
      </desc>
    </func>

    <func>
      <name since="OTP 23.3">which_transports() -> Result</name>
      <fsummary>Get all configured transports</fsummary>
      <type>
        <v>Result = [{TDomain, TAddress} | {TDomain, TAddress, Kind}]</v>
        <v>TDomain = transportDomainUdpIpv4 | transportDomainUdpIpv6</v>
        <v>TAddress = {IpAddr, IpPort}</v>
        <v>IpAddr = inet:ip_address()</v>
        <v>IpPort = pos_integer()</v>
        <v>Kind = req_responder | trap_sender</v>
      </type>
      <desc>
        <p>Retrieve all configured transports.</p>

        <marker id="which_variables"></marker>
      </desc>
    </func>

    <func>
      <name since="">which_variables() -> Result</name>
      <fsummary>Get all variables known to the agent</fsummary>
      <type>
        <v>Result = [atom()]</v>
      </type>
      <desc>
        <p>Retrieve all variables known to the agent.</p>

        <marker id="which_notifications"></marker>
      </desc>
    </func>

    <func>
      <name since="">which_notifications() -> Result</name>
      <fsummary>Get all notifications known to the agent</fsummary>
      <type>
        <v>Result = [{Name, MibName, Info}]</v>
        <v>Name = atom()</v>
        <v>MibName = atom()</v>
        <v>Info = term()</v>
      </type>
      <desc>
        <p>Retrieve all notifications (and traps) known to the agent.</p>

        <marker id="log_to_txt"></marker>
      </desc>
    </func>

    <func>
      <name since="OTP R15B01">log_to_txt(LogDir)</name>
      <name since="">log_to_txt(LogDir, Block | Mibs)</name>
      <name since="">log_to_txt(LogDir, Mibs, Block | OutFile) -> ok | {ok, Cnt} | {error, Reason}</name>
      <name since="">log_to_txt(LogDir, Mibs, OutFile, Block | LogName) ->  ok | {ok, Cnt} | {error, Reason}</name>
      <name since="">log_to_txt(LogDir, Mibs, OutFile, LogName, Block | LogFile) ->  ok | {ok, Cnt} | {error, Reason}</name>
      <name since="">log_to_txt(LogDir, Mibs, OutFile, LogName, LogFile, Block | Start) ->  ok | {ok, Cnt} | {error, Reason}</name>
      <name since="">log_to_txt(LogDir, Mibs, OutFile, LogName, LogFile, Block, Start)  -> ok | {ok, Cnt} | {error, Reason}</name>
      <name since="">log_to_txt(LogDir, Mibs, OutFile, LogName, LogFile, Start, Stop)  -> ok | {ok, Cnt} | {error, Reason}</name>
      <name since="OTP R16B03">log_to_txt(LogDir, Mibs, OutFile, LogName, LogFile, Block, Start, Stop)  -> ok | {ok, Cnt} | {error, Reason}</name>
      <fsummary>Convert an Audit Trail Log to text format</fsummary>
      <type>
        <v>LogDir = string()</v>
        <v>Mibs = [MibName]</v>
        <v>MibName = string()</v>
        <v>Block = boolean()</v>
        <v>OutFile = string()</v>
        <v>LogName = string()</v>
        <v>LogFile = string()</v>
        <v>Start = Stop = null | calendar:datetime() | {local_time, calendar:datetime()} | {universal_time, calendar:datetime()} </v>
        <v>Cnt = {NumOK, NumERR}</v>
        <v>NumOK = non_neg_integer()</v>
        <v>NumERR = pos_integer()</v>
        <v>Reason = disk_log_open_error() | file_open_error() | term()</v>
        <v>disk_log_open_error() = {LogName, term()}</v>
        <v>file_open_error() = {OutFile, term()}</v>
      </type>
      <desc>
        <p>Converts an Audit Trail Log to a readable text file. 
	<c>OutFile</c> defaults to "./snmpa_log.txt". 
	<c>LogName</c> defaults to "snmpa_log". 
	<c>LogFile</c> defaults to "snmpa.log". </p>
	<p>The <c>Block</c> option indicates if the log should be blocked
	during conversion. This could be usefull when converting large 
	logs (when otherwise the log could wrap during conversion). 
	Defaults to <c>true</c>. </p>
	<p>See <seeerl marker="snmp#log_to_txt">snmp:log_to_txt</seeerl> 
	for more info.</p>

        <marker id="log_to_io"></marker>
      </desc>
    </func>

    <func>
      <name since="OTP R15B01">log_to_io(LogDir) ->  ok | {ok, Cnt} | {error, Reason}</name>
      <name since="OTP R15B01">log_to_io(LogDir, Block | Mibs) ->  ok | {ok, Cnt} | {error, Reason}</name>
      <name since="OTP R15B01">log_to_io(LogDir, Mibs, Block | LogName) ->  ok | {ok, Cnt} | {error, Reason}</name>
      <name since="OTP R15B01">log_to_io(LogDir, Mibs, LogName, Block | LogFile) -> ok | {ok, Cnt} | {error, Reason}</name>
      <name since="OTP R15B01">log_to_io(LogDir, Mibs, LogName, LogFile, Block | Start) -> ok | {ok, Cnt} | {error, Reason}</name>
      <name since="OTP R15B01">log_to_io(LogDir, Mibs, LogName, LogFile, Block, Start) -> ok | {ok, Cnt} | {error, Reason}</name>
      <name since="OTP R15B01">log_to_io(LogDir, Mibs, LogName, LogFile, Start, Stop) -> ok | {ok, Cnt} | {error, Reason}</name>
      <name since="OTP R16B03">log_to_io(LogDir, Mibs, LogName, LogFile, Block, Start, Stop) -> ok | {ok, Cnt} | {error, Reason}</name>
      <fsummary>Convert an Audit Trail Log to text format</fsummary>
      <type>
        <v>LogDir = string()</v>
        <v>Mibs = [MibName]</v>
        <v>MibName = string()</v>
        <v>Block = boolean()</v>
        <v>LogName = string()</v>
        <v>LogFile = string()</v>
        <v>Start = Stop = null | calendar:datetime() | {local_time, calendar:datetime()} | {universal_time, calendar:datetime()} </v>
        <v>Cnt = {NumOK, NumERR}</v>
        <v>NumOK = non_neg_integer()</v>
        <v>NumERR = pos_integer()</v>
        <v>Reason = disk_log_open_error() | file_open_error() | term()</v>
        <v>disk_log_open_error() = {LogName, term()}</v>
        <v>file_open_error() = {OutFile, term()}</v>
      </type>
      <desc>
        <p>Converts an Audit Trail Log to a readable format and 
	prints it on stdio. 
	<c>LogName</c> defaults to "snmpa_log". 
	<c>LogFile</c> defaults to "snmpa.log".</p>
	<p>The <c>Block</c> option indicates if the log should be blocked
	during conversion. This could be usefull when converting large 
	logs (when otherwise the log could wrap during conversion). 
	Defaults to <c>true</c>. </p>
	<p>See <seeerl marker="snmp#log_to_io">snmp:log_to_io</seeerl> 
	for more info.</p>

        <marker id="change_log_size"></marker>
      </desc>
    </func>

    <func>
      <name since="">change_log_size(NewSize) -> ok | {error, Reason}</name>
      <fsummary>Change the size of the Audit Trail Log</fsummary>
      <type>
        <v>NewSize = {MaxBytes, MaxFiles}</v>
        <v>MaxBytes = integer()</v>
        <v>MaxFiles = integer()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Changes the log size of the Audit Trail Log. The application must 
          be configured to use the audit trail log function. Please refer to 
          disk_log(3) in Kernel Reference Manual for a description of how to 
          change the log size. </p>
        <p>The change is permanent, as long as the log is not deleted. 
          That means, the log size is remembered across reboots. </p>

        <marker id="set_log_type"></marker>
      </desc>
    </func>

    <func>
      <name since="">set_log_type(NewType) -> {ok, OldType} | {error, Reason}</name>
      <name since="">set_log_type(Agent, NewType) -> {ok, OldType} | {error, Reason}</name>
      <fsummary>Change the type of the Audit Trail Log</fsummary>
      <type>
        <v>NewType = OldType = atl_type()</v>
        <v>Agent = pid() | atom()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Changes the run-time Audit Trail log type. </p>
        <p>Note that this has no effect on the application configuration as
          defined by configuration files, so a node restart will revert the 
          config to whatever is in those files. </p>
        <p>This function is primarily useful in testing/debugging 
          scenarios. </p>

        <marker id="mib_of"></marker>
      </desc>

    </func>

    <func>
      <name since="">mib_of(Oid) -> {ok, MibName} | {error, Reason}</name>
      <name since="">mib_of(Agent, Oid) -> {ok, MibName} | {error, Reason}</name>
      <fsummary>Which mib an Oid belongs to</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Oid = oid()</v>
        <v>MibName = atom()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Finds the mib corresponding to the <c>Oid</c>. If it is a
          variable, the Oid must be 
          &lt;Oid for var&gt;.0 and if it is a table, Oid must be 
          &lt;table&gt;.&lt;entry&gt;.&lt;col&gt;.&lt;any&gt;</p>

        <marker id="me_of"></marker>
      </desc>
    </func>

    <func>
      <name since="">me_of(Oid) -> {ok, Me} | {error, Reason}</name>
      <name since="">me_of(Agent, Oid) -> {ok, Me} | {error, Reason}</name>
      <fsummary>Retrieve the mib-entry of an Oid</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Oid = oid()</v>
        <v>Me = #me{}</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Finds the mib entry corresponding to the <c>Oid</c>. If it is a
          variable, the Oid must be 
          &lt;Oid for var&gt;.0 and if it is a table, Oid must be 
          &lt;table&gt;.&lt;entry&gt;.&lt;col&gt;.&lt;any&gt;</p>

        <marker id="invalidate_mibs_cache"></marker>
      </desc>
    </func>

    <func>
      <name since="">invalidate_mibs_cache() -> void()</name>
      <name since="">invalidate_mibs_cache(Agent) -> void()</name>
      <fsummary>Invalidate the mib server cache</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
      </type>
      <desc>
        <p>Invalidate the mib server cache. </p>
        <p>The entire contents of the cache will be deleted. </p>

        <marker id="enable_mibs_cache"></marker>
      </desc>
    </func>

    <func>
      <name since="">enable_mibs_cache() -> void()</name>
      <name since="">enable_mibs_cache(Agent) -> void()</name>
      <fsummary>Enable the mib server cache</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
      </type>
      <desc>
        <p>Enable the mib server cache. </p>

        <marker id="disable_mibs_cache"></marker>
      </desc>
    </func>

    <func>
      <name since="">disable_mibs_cache() -> void()</name>
      <name since="">disable_mibs_cache(Agent) -> void()</name>
      <fsummary>Disable the mib server cache</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
      </type>
      <desc>
        <p>Disable the mib server cache. </p>

        <marker id="which_mibs_cache_size"></marker>
      </desc>
    </func>

    <func>
      <name since="OTP R14B">which_mibs_cache_size() -> void()</name>
      <name since="OTP R14B">which_mibs_cache_size(Agent) -> void()</name>
      <fsummary>The size of the mib server cache</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
      </type>
      <desc>
        <p>Retreive the size of the mib server cache. </p>

        <marker id="gc_mibs_cache"></marker>
      </desc>
    </func>

    <func>
      <name since="">gc_mibs_cache() -> {ok, NumElementsGCed} | {error, Reason}</name>
      <name since="">gc_mibs_cache(Agent) -> {ok, NumElementsGCed} | {error, Reason}</name>
      <name since="">gc_mibs_cache(Age) -> {ok, NumElementsGCed} | {error, Reason}</name>
      <name since="">gc_mibs_cache(Agent, Age) -> {ok, NumElementsGCed} | {error, Reason}</name>
      <name since="">gc_mibs_cache(Age, GcLimit) -> {ok, NumElementsGCed} | {error, Reason}</name>
      <name since="">gc_mibs_cache(Agent, Age, GcLimit) -> {ok, NumElementsGCed} | {error, Reason}</name>
      <fsummary>Perform mib server cache gc</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Age = integer() > 0</v>
        <v>GcLimit = integer() > 0 | infinity</v>
        <v>NumElementsGCed = integer() >= 0</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Perform mib server cache gc. </p>
        <p>Manually performs a mib server cache gc. 
          This can be done regardless of the value of the 
          <c>autogc</c> option. 
          The <c>NumElementsGCed</c> value indicates how many 
          elements where actually removed from the cache. </p>

        <marker id="enable_mibs_cache_autogc"></marker>
      </desc>
    </func>

    <func>
      <name since="">enable_mibs_cache_autogc() -> void()</name>
      <name since="">enable_mibs_cache_autogc(Agent) -> void()</name>
      <fsummary>Enable automatic gc of the mib server cache</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
      </type>
      <desc>
        <p>Enable automatic gc of the mib server cache. </p>

        <marker id="disable_mibs_cache_autogc"></marker>
      </desc>
    </func>

    <func>
      <name since="">disable_mibs_cache_autogc() -> void()</name>
      <name since="">disable_mibs_cache_autogc(Agent) -> void()</name>
      <fsummary>Disable automatic gc of the mib server cache</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
      </type>
      <desc>
        <p>Disable automatic gc of the mib server cache. </p>

        <marker id="update_mibs_cache_age"></marker>
      </desc>
    </func>

    <func>
      <name since="">update_mibs_cache_age(NewAge) -> ok | {error, Reason}</name>
      <name since="">update_mibs_cache_age(Agent, NewAge) -> ok | {error, Reason}</name>
      <fsummary>Change the mib server cache age property</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>NewAge = integer() > 0</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Change the mib server cache <c>age</c> property. </p>

        <marker id="update_mibs_cache_gclimit"></marker>
      </desc>
    </func>

    <func>
      <name since="">update_mibs_cache_gclimit(NewGcLimit) -> ok | {error, Reason}</name>
      <name since="">update_mibs_cache_gclimit(Agent, NewGCLimit) -> ok | {error, Reason}</name>
      <fsummary>Change the mib server cache gclimit property</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>NewGcLimit = integer() > 0 | infinity</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Change the mib server cache <c>gclimit</c> property. </p>

        <marker id="register_notification_filter"></marker>
      </desc>
    </func>


    <func>
      <name since="">register_notification_filter(Id, Mod, Data) -> ok | {error, Reason}</name>
      <name since="">register_notification_filter(Agent, Id, Mod, Data) -> ok | {error, Reason}</name>
      <name since="">register_notification_filter(Id, Mod, Data, Where) -> ok | {error, Reason}</name>
      <name since="">register_notification_filter(Agent, Id, Mod, Data, Where) -> ok | {error, Reason}</name>
      <fsummary>Register a notification filter</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Id = filter_id()</v>
        <v>filter_id() = term()</v>
        <v>Mod = atom()</v>
        <v>Data = term()</v>
        <v>Where = filter_position()</v>
        <v>Reason = term()</v>
        <v>filter_position() = first | last | {insert_before, filter_id()} | {insert_after, filter_id()} </v>
      </type>
      <desc>
        <p>Registers a notification filter.
          </p>
        <p><c>Mod</c> is a module implementing the 
          <c>snmpa_notification_filter</c> behaviour.</p>
        <p><c>Data</c> will be passed on to the filter when calling the
          functions of the behaviour.</p>

        <marker id="unregister_notification_filter"></marker>
      </desc>
    </func>

    <func>
      <name since="">unregister_notification_filter(Id) -> ok | {error, Reason}</name>
      <name since="">unregister_notification_filter(Agent, Id) -> ok | {error, Reason}</name>
      <fsummary>Unregister a notification filter</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Id = filter_id()</v>
        <v>filter_id() = term()</v>
      </type>
      <desc>
        <p>Unregister a notification filter. </p>

        <marker id="which_notification_filter"></marker>
      </desc>
    </func>

    <func>
      <name since="">which_notification_filter() -> Filters</name>
      <name since="">which_notification_filter(Agent) -> Filters</name>
      <fsummary>Which notification filter</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Filters = [filter_id()]</v>
        <v>filter_id() = term()</v>
      </type>
      <desc>
        <p>List all notification filters in an agent.</p>

        <marker id="set_request_limit"></marker>
      </desc>
    </func>

   <func>
      <name since="">set_request_limit(NewLimit) -> {ok, OldLimit} | {error, Reason}</name>
      <name since="">set_request_limit(Agent, NewLimit) -> {ok, OldLimit} | {error, Reason}</name>
      <fsummary>Change the request limit</fsummary>
      <type>
        <v>NewLimit = OldLimit = infinity | integer() >= 0</v>
        <v>Agent = pid() | atom()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Changes the request limit. </p>
        <p>Note that this has no effect on the application configuration as
          defined by configuration files, so a node restart will revert the 
          config to whatever is in those files. </p>
        <p>This function is primarily useful in load regulation 
          scenarios. </p>

        <marker id="register_subagent"></marker>
      </desc>
    </func>

    <func>
      <name since="">register_subagent(Agent, SubTreeOid, Subagent) -> ok | {error, Reason}</name>
      <fsummary>Register a sub-agent under a sub-tree</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>SubTreeOid = oid()</v>
        <v>SubAgent = pid()</v>
      </type>
      <desc>
        <p>Registers a sub-agent under a sub-tree of another agent. </p>
        <p>It is easy to make mistakes when registering sub-agents and
          this activity should be done carefully.  For example, a
          strange behaviour would result from the following
          configuration:</p>
        <pre>
snmp_agent:register_subagent(MAPid,[1,2,3,4],SA1),
snmp_agent:register_subagent(SA1,[1,2,3], SA2).
        </pre>
        <p><c>SA2</c> will not get requests starting with object
          identifier <c>[1,2,3]</c> since <c>SA1</c> does not. </p>

        <marker id="unregister_subagent"></marker>
      </desc>
    </func>

    <func>
      <name since="">unregister_subagent(Agent, SubagentOidOrPid) -> ok | {ok, SubAgentPid} | {error, Reason}</name>
      <fsummary>Unregister a sub-agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>SubTreeOidorPid = oid() | pid()</v>
      </type>
      <desc>
        <p>Unregister a sub-agent.  If the second argument is a pid,
          then that sub-agent will be unregistered from all trees in
          <c>Agent</c>. </p>

          <marker id="send_notification2"></marker>
      </desc>
    </func>


    <func>
      <name since="OTP R14B03">send_notification2(Agent, Notification, SendOpts) -> void()</name>
      <fsummary>Send notification</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Notification = atom()</v>
        <v>SendOpts = [send_option()]</v>
	<v>send_option() = {receiver, receiver()} |
	                   {name, notify_name()} |
			   {context, context_name()} |
			   {varbinds, varbinds()} |
			   {local_engine_id, string()} |
	                   {extra, extra_info()}</v>
        <v>receiver() = no_receiver | {tag(), tag_receiver()} | notification_delivery_info()</v>
        <v>tag() = term(()</v>
        <v>tag_receiver() = pid() | registered_name() | {Mod, Func, Args}</v>
        <v>registered_name() = atom()</v>
        <v>Mod = atom()</v>
        <v>Func = atom()</v>
        <v>Args = list()</v>
        <v>notify_name() = string()</v>
        <v>context_name() = string()</v>
        <v>varbinds() = [varbind()]</v>
	<v>varbind() = {variable(), value()} |
	               {{process_oid(), variable()}, value()} |
	               {column(), row_index(), value()} |</v>
        <v>variable() = aliasname() | oid()</v>
        <v>aliasname() = atom()</v>
        <v>process_oid() = keep (default) | truncate</v>
        <v>value() = term()</v>
        <v>column() = atom()</v>
        <v>row_index() = [int()]</v>
        <v>extra_info() = term()</v>
      </type>
      <desc>
        <p>Send the notification <c>Notification</c> to the management 
	targets defined for notify-name (<c>name</c>) in the 
	<c>snmpNotifyTable</c> in SNMP-NOTIFICATION-MIB from the 
	specified <c>context</c>. </p>

	<p>If no <c>name</c> is specified (or if it is <c>""</c>), the
	notification is sent to all management targets. </p>

	<p>If no <c>context</c> is specified, the default context, <c>""</c>, 
	is used. </p>

        <p>The send option <c>receiver</c> specifies where information
	about delivery of Inform-Requests should be sent.  The agent
	sends Inform-Requests and waits for acknowledgments from the
	management targets. 
	The <c>receiver</c> can have three values: </p>

	<list type="bulleted">
          <item>
            <p><c>no_receiver</c> - No information is delivered. </p>
	  </item>

          <item>
	    <p><c>notification_delivery_info()</c> - The information is 
	    delivered via a function call according to this data. See the 
	    <seeerl marker="#data_types">DATA TYPES</seeerl> section 
	    above for details. </p>
	  </item>

          <item>
            <p><c>{tag(), tag_receiver()}</c> - The information is delivered 
	    either via messages or via a function call according to the value 
	    of <c>tag_receiver()</c>. </p>
	    <p>Delivery is done differently depending on the value
	    of <c>tag_receiver()</c>: </p>

	    <list>
	      <item>
		<p><c>pid() | registered_name()</c> - The info will be delivered in  
		the following messages: </p>
		<list>
		  <item>
		    <p><c>{snmp_targets, tag(), Addresses}</c></p>
		    <p>This informs the user which target addresses the 
		    notification was sent to. </p>
		  </item>
		  <item>
		    <p><c>{snmp_notification, tag(), {got_response, Address}}</c></p>
		    <p>This informs the user that this target address 
		    acknowledged the notification. </p>
		  </item>
		  <item>
		    <p><c>{snmp_notification, tag(), {no_response, Address}}</c></p>
		    <p>This informs the user that this target address 
		    did not acknowledge the notification. </p>
		  </item>
		</list>
		<p>The notification is sent as an Inform-Request to each 
		target address in <c>Addresses</c> and if there are no 
		targets for which an Inform-Request is sent, <c>Addresses</c> 
		is the empty list <c>[]</c>. </p>
		<p>The <c>tag_receiver()</c> will first be sent the 
		<c>snmp_targets</c> message, and then for each address in 
		<c>Addresses</c> list, one of the two <c>snmp_notification</c> 
		messages. </p>
	      </item>

	      <item>
		<p><c>{Mod, Func, Args}</c> - The info will be delivered via
		the function call: </p>
		<p><c>Mod:Func([Msg | Args])</c></p>
		<p>where <c>Msg</c> has the same content and purpose as the 
		messages descrived above.</p>
	      </item>

	    </list>
	  </item>
	</list>

	<p>The 'process oid' "tag" that can be provided with the
	variable name / oids is indended to be used for oid post
	processing. The value '<c>keep</c>', which is the default, leaves
	the oid as is. The value '<c>truncate</c>', will cause the oid
	to be "truncated". That is, any trailing ".0" will be removed. </p>

	<note>
	  <p>There is a way to exclude a varbind from the notification.
	  In the normal <c>varbinds</c> list, providing the special
	  value <c>'$ignore-oid'</c> (instead of a normal value) will
	  exclude this varbind from the notification. </p>
	  <p>A define for this has been added to the <c>snmp_types.hrl</c>
	  include file, <c>NOTIFICATION_IGNORE_VB_VALUE</c>. </p>
	</note>
	<note>
	  <p>The <c>extra</c> info is not normally interpreted by the agent, 
	  instead it is passed through to the 
	  <seeguide marker="snmp_agent_netif">net-if</seeguide> process. It is 
	  up to the implementor of that process to make use of this data. </p>
	  <p>The version of net-if provided by this application makes no use
	  of this data, with one exception: 
	  Any tuple containing the atom 
	  <c>snmpa_default_notification_extra_info</c> 
	  may be used by the agent and is therefor <em>reserved</em>. </p>
	  <p>See the net-if incomming messages for sending a 
	  <seeguide marker="snmp_agent_netif#im_send_pdu">
	  trap</seeguide> and 
	  <seeguide marker="snmp_agent_netif#im_send_pdu_req">
	  notification</seeguide> for more info. </p>
	</note>

	<marker id="send_notification"></marker>
      </desc>
    </func>


    <func>
      <name since="">send_notification(Agent, Notification, Receiver)</name>
      <name since="">send_notification(Agent, Notification, Receiver, Varbinds)</name>
      <name since="">send_notification(Agent, Notification, Receiver, NotifyName, Varbinds)</name>
      <name since="">send_notification(Agent, Notification, Receiver, NotifyName, ContextName, Varbinds) -> void() </name>
      <name since="OTP R14B">send_notification(Agent, Notification, Receiver, NotifyName, ContextName, Varbinds, LocalEngineID) -> void() </name>
      <fsummary>Send a notification</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
        <v>Notification = atom()</v>
        <v>Receiver = no_receiver | {Tag, Recv} | notification_delivery_info()</v>
        <v>Tag = term()</v>
        <v>Recv = receiver()</v>
        <v>receiver() = pid() | atom() | {Mod, Func, Args}</v>
        <v>Mod = atom()</v>
        <v>Func = atom()</v>
        <v>Args = list()</v>
        <v>NotifyName = string()</v>
        <v>ContextName = string()</v>
        <v>Varbinds = varbinds()</v>
        <v>varbinds() = [varbind()]</v>
        <v>varbind() = {Variable, Value} | {Column, RowIndex, Value} | {OID, Value}</v>
        <v>Variable = atom()</v>
        <v>Column = atom()</v>
        <v>OID = oid()</v>
        <v>Value = term()</v>
        <v>RowIndex = [int()]</v>
        <v>LocalEngineID = string()</v>
      </type>
      <desc>
        <p>Sends the notification <c>Notification</c> to the
	management targets defined for <c>NotifyName</c> in the
	<c>snmpNotifyTable</c> in SNMP-NOTIFICATION-MIB from the
	specified context.  </p>
	<p>If no <c>NotifyName</c> is specified (or if it is <c>""</c>), 
	the notification is sent to all management targets 
	(<c>Addresses</c> below).  </p>
	<p>If no <c>ContextName</c> is specified, the default <c>""</c> 
	context is used. </p>

        <p>The parameter <c>Receiver</c> specifies where information
	about delivery of Inform-Requests should be sent.  The agent
	sends Inform-Requests and waits for acknowledgments from the
	managers. <c>Receiver</c> can have three values: </p>

	<list type="bulleted">
          <item>
            <p><c>no_receiver</c> - No information is delivered. </p>
	  </item>

          <item>
            <p><c>notification_delivery_info()</c> - The information is 
              delivered via a function call according to this data. See the 
              <seeerl marker="#data_types">DATA TYPES</seeerl> section 
              above for details. </p>
	  </item>

          <item>
            <p><c>{Tag, Recv}</c> - The information is delivered either via 
	    messages or via a function call according to the value of 
	    <c>Recv</c>. </p>
	  </item>

        </list>


        <p>If <c>Receiver</c> has the value <c>{Tag, Recv}</c>, the delivery is
          done according to <c>Recv</c>: </p>

        <list>
          <item>
            <p><c>pid() | atom()</c> - The info will be delivered in  
              the following messages: </p>
            <list>
              <item>
                <p><c>{snmp_targets, Tag, Addresses}</c></p>
                <p>This inform the user which target addresses the 
                  notification was sent to. </p>
		  </item>
              <item>
                <p><c>{snmp_notification, Tag, {got_response, Address}}</c></p>
                <p>This informs the user that this target address 
                  acknowledged the notification. </p>
		  </item>
              <item>
                <p><c>{snmp_notification, Tag, {no_response, Address}}</c></p>
                <p>This informs the user that this target address 
                  did not acknowledge notification. </p>
		  </item>
		</list>
            <p>The notification is sent as an Inform-Request to each 
              target address in <c>Addresses</c> and if there are no 
              targets for which an Inform-Request is sent, <c>Addresses</c> 
              is the empty list <c>[]</c>. </p>
            <p>The <c>receiver</c> will first be sent the <c>snmp_targets</c> 
              message, and then for each address in <c>Addresses</c> list, 
              one of the two <c>snmp_notification</c> messages. </p>
	  </item>
          <item>
            <p><c>{Mod, Func, Args}</c> - The info will be delivered via
              the function call: </p>
            <p><c>Mod:Func([Msg | Args])</c></p>
            <p>where <c>Msg</c> has the same content and purpose as the 
              messages descrived above.</p>
	  </item>
	</list>

        <p><c>Address</c> is a management target address and <c>Addresses</c> is a 
          list of management target addresses. They are defined as followes: </p>

<pre>
        Addresses  = [address()]
        Address    = address()
        address()  = v1_address() | v3_address()
        v1_address() = {TDomain, TAddress}
        v3_address() = {{TDomain, TAddress}, V3MsgData}
        TDomain    = tdoamin()
        TAddress   = taddress()
        tdomain()  = The oid of snmpUDPDomain 
                     This is the only supported transport domain.
        taddress() = [A1, A2, A3, A4, P1, P3]
                     The 4 first bytes makes up the IP-address and the last 2,
                     the UDP-port number.
        V3MsgData  = v3_msg_data()
        v3_msg_data() = term()
</pre>

        <p>If <c>Receiver</c> is a <c>notification_delivery_info()</c> record,
          then the information about the notification delivery will be delivered 
          to the <c>receiver</c> via the callback functions defined by the 
          <seeerl marker="snmpa_notification_delivery_info_receiver">snmpa_notification_delivery_info_receiver</seeerl> 
          behaviour according to the content of the <c>notification_delivery_info()</c> 
          record. </p>

        <p>The optional argument <c>Varbinds</c> defines
          values for the objects in the notification.  If no value is
          given for an object, the <c>Agent</c> performs a get-operation
          to retrieve the value.
          </p>
        <p><c>Varbinds</c> is a list of <c>Varbind</c>, where each
          <c>Varbind</c> is one of:
          </p>
        <list type="bulleted">
          <item><c>{Variable, Value}</c>, where <c>Variable</c> is the
           symbolic name of a scalar variable referred to in the notification
           specification.
          </item>
          <item><c>{Column, RowIndex, Value}</c>, where <c>Column</c>
           is the symbolic name of a column variable.
          <c>RowIndex</c> is a list of indices for the specified
           element.  If this is the case, the OBJECT IDENTIFIER sent
           in the notification is the <c>RowIndex</c> appended to the OBJECT
           IDENTIFIER for the table column. This is the OBJECT
           IDENTIFIER which specifies the element.
          </item>
          <item><c>{OID, Value}</c>, where <c>OID</c> is the OBJECT
           IDENTIFIER for an instance of an object, scalar variable,
           or column variable.
          </item>
        </list>
        <p>For example, to specify that <c>sysLocation</c> should have the
          value <c>"upstairs"</c> in the notification, we could use one of:
          </p>
        <list type="bulleted">
          <item><c>{sysLocation, "upstairs"}</c> or</item>
          <item><c>{[1,3,6,1,2,1,1,6,0], "upstairs"}</c> or</item>
          <item><c>{?sysLocation_instance, "upstairs"}</c> (provided
           that the generated <c>.hrl</c> file is included)</item>
        </list>

        <p>If a variable in the notification is a table element, the
          <c>RowIndex</c> for the element must be given in the
          <c>Varbinds</c> list. In this case, the OBJECT IDENTIFIER sent
          in the notification is the OBJECT IDENTIFIER that identifies this
          element.  This OBJECT IDENTIFIER could be used in a get
          operation later.
          </p>

        <p>This function is asynchronous, and does not return any
          information.  If an error occurs, <c>user_err/2</c> of the error
          report module is called and the notification is discarded.
          </p>

        <note>
          <p>Note that the use of the LocalEngineID argument is only intended 
            for special cases, if the agent is to "emulate" multiple EngineIDs!
            By default, the agent uses the value of <c>SnmpEngineID</c> 
            (see SNMP-FRAMEWORK-MIB). </p>
	</note>

        <p><c>ExtraInfo</c> is not normally used in any way by the agent. 
	It is intended to be passed along to the net-if process, which is
	a component that a user can implement themself. The users own net-if
	may then make use of ExtraInfo. The net-if provided with this 
	application does not process ExtraInfo. </p>
	<p>There is one exception. <em>Any</em> tuple containing the atom
	<c>snmpa_default_notification_extra_info</c> will, in this context,
	be considered belonging to this application, and may be processed
	by the agent. </p>

	<marker id="discovery"></marker>
      </desc>
    </func>


    <func>
      <name since="">discovery(TargetName, Notification) -> {ok, ManagerEngineID} | {error, Reason}</name>
      <name since="">discovery(TargetName, Notification, Varbinds) -> {ok, ManagerEngineID} | {error, Reason}</name>
      <name since="">discovery(TargetName, Notification, DiscoHandler) -> {ok, ManagerEngineID} | {error, Reason}</name>
      <name since="">discovery(TargetName, Notification, ContextName, Varbinds) -> {ok, ManagerEngineID} | {error, Reason}</name>
      <name since="">discovery(TargetName, Notification, Varbinds, DiscoHandler) -> {ok, ManagerEngineID} | {error, Reason}</name>
      <name since="">discovery(TargetName, Notification, ContextName, Varbinds, DiscoHandler) -> {ok, ManagerEngineID} | {error, Reason}</name>
      <name since="">discovery(TargetName, Notification, ContextName, Varbinds, DiscoHandler, ExtraInfo) -> {ok, ManagerEngineID} | {error, Reason}</name>
      <fsummary>Initiate the discovery process with a manager</fsummary>
      <type>
        <v>TargetName = string()</v>
        <v>Notification = atom()</v>
        <v>ContextName = string() (defaults to "")</v>
        <v>Varbinds = varbinds()</v>
        <v>varbinds() = [varbind()]</v>
        <v>DiscoHandler = snmpa_discovery_handler()</v>
        <v>ExtraInfo = term()</v>
        <v>snmpa_discovery_handler() = Module implementing the snmpa_discovery_handler behaviour</v>
        <v>ManagerEngineID = string()</v>
        <v>varbind() = {Variable, Value} | {Column, RowIndex, Value} | {OID, Value}</v>
        <v>Variable = atom()</v>
        <v>Column = atom()</v>
        <v>OID = oid()</v>
        <v>Value = term()</v>
        <v>RowIndex = [int()]</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Initiate the discovery process with the manager identified by
          <c>TargetName</c> using the notification <c>Notification</c>. </p>

        <p>This function is synchronous, which means that it will return when
          the discovery process has been completed or failed. </p>

        <p>The <c>DiscoHandler</c> module is used during the discovery 
          process. See 
          <seeerl marker="snmpa_discovery_handler">discovery handler</seeerl>
          for more info. </p>

        <p>The <c>ExtraInfo</c> argument is passed on to the callback functions
          of the <c>DiscoHandler</c>. </p>

        <note><p>If we are not at security-level <c>noAuthNoPriv</c>,
          this could be complicated, since the agent will then continue 
          with stage 2, before which the usm-related updates must be 
          done. </p></note>

        <note><p>The default discovery handler will require 
          additional actions by the caller and the discovery will not work
          if the security-level is higher then <c>noAuthNoPriv</c>. </p></note>

          <marker id="convert_config"></marker>
      </desc>
    </func>

    <func>
      <name since="">convert_config(OldConfig) -> AgentConfig</name>
      <fsummary>Convert old snmp config to new agent config</fsummary>
      <type>
        <v>OldConfig = list()</v>
        <v>AgentConfig = list()</v>
      </type>
      <desc>
        <p>This off-line utility function can be used to convert
          the old snmp application config (pre snmp-4.0) to the 
          new snmp agent config (as of snmp-4.0).</p>
        <p>For information about the old config (<c>OldConfig</c>) 
          see the OTP R9C documentation.</p>
        <p>For information about the current agent config 
          (<c>AgentConfig</c>), see the 
          <seeguide marker="snmp_config#configuration_params">Configuring the application</seeguide> 
          chapter of the SNMP user's guide.</p>

        <marker id="restart_worker"></marker>
      </desc>
    </func>

    <func>
      <name since="">restart_worker() -> void()</name>
      <name since="">restart_worker(Agent) -> void()</name>
      <fsummary>Restart the worker process of a multi-threaded agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
      </type>
      <desc>
        <p>Restart the worker process of a multi-threaded agent.</p>
        <p>This is a utility function, that can be useful when
          e.g. debugging instrumentation functions.</p>

        <marker id="restart_set_worker"></marker>
      </desc>
    </func>

    <func>
      <name since="">restart_set_worker() -> void()</name>
      <name since="">restart_set_worker(Agent) -> void()</name>
      <fsummary>Restart the set worker process of a multi-threaded agent</fsummary>
      <type>
        <v>Agent = pid() | atom()</v>
      </type>
      <desc>
        <p>Restart the set worker process of a multi-threaded agent.</p>
        <p>This is a utility function, that can be useful when
          e.g. debugging instrumentation functions.</p>

        <marker id="print_mib_info"></marker>
      </desc>
    </func>

    <func>
      <name since="OTP R14B02">print_mib_info() -> void()</name>
      <fsummary>Print mib info</fsummary>
      <desc>
        <p>Prints the content of all the (snmp) tables and variables 
	for all mibs handled by the snmp agent. </p>

        <marker id="print_mib_tables"></marker>
      </desc>
    </func>

    <func>
      <name since="OTP R14B02">print_mib_tables() -> void()</name>
      <fsummary>Print mib tables</fsummary>
      <desc>
        <p>Prints the content of all the (snmp) tables 
	for all mibs handled by the snmp agent. </p>

        <marker id="print_mib_variables"></marker>
      </desc>
    </func>

    <func>
      <name since="OTP R14B02">print_mib_variables() -> void()</name>
      <fsummary>Print mib variables</fsummary>
      <desc>
        <p>Prints the content of all the (snmp) variables 
	for all mibs handled by the snmp agent. </p>

        <marker id="verbosity"></marker>
      </desc>
    </func>

    <func>
      <name since="">verbosity(Ref,Verbosity) -> void()</name>
      <fsummary>Assign a new verbosity for the process</fsummary>
      <type>
        <v>Ref = pid() | sub_agents | master_agent | net_if | mib_server | symbolic_store | note_store | local_db</v>
        <v>Verbosity = verbosity() | {subagents, verbosity()}</v>
        <v>verbosity() = silence | info | log | debug | trace </v>
      </type>
      <desc>
        <p>Sets verbosity for the designated process. For the lowest 
          verbosity <c>silence</c>, nothing is printed. The higher the
          verbosity, the more is printed. </p>
      </desc>
    </func>
  </funcs>

  <section>
    <title>See Also</title>
    <p>calendar(3), erlc(1) </p>
  </section>

  
</erlref>

