path: root/lib/common_test/doc/src/ct_telnet.xml

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

<erlref>
  <header>
    <copyright>
      <year>2010</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>ct_telnet</title>
    <prepared></prepared>
    <responsible></responsible>
    <docno></docno>
    <approved></approved>
    <checked></checked>
    <date></date>
    <rev>A</rev>
    <file>ct_telnet.xml</file>
  </header>
  <module>ct_telnet</module>
  <modulesummary>Common Test specific layer on top of Telnet client ct_telnet_client.erl</modulesummary>

  <description>

    <p><c>Common Test</c> specific layer on top of Telnet client
      <c>ct_telnet_client.erl</c>.</p>

    <p>Use this module to set up Telnet connections, send commands, and
      perform string matching on the result. For information about how to use
      <c>ct_telnet</c> and configure connections, specifically for UNIX hosts,
      see the
      <seealso marker="unix_telnet"><c>unix_telnet</c></seealso> manual page.
    </p>

    <p>Default values defined in <c>ct_telnet</c>:</p>
    <marker id="Default_values"/>

    <list type="bulleted">
      <item><p>Connection timeout (time to wait for connection) = 10
        seconds</p></item>
      <item><p>Command timeout (time to wait for a command to return) =
        10 seconds</p></item>
      <item><p>Max number of reconnection attempts = 3</p></item>
      <item><p>Reconnection interval (time to wait in between
        reconnection attempts) = 5 seconds</p></item>
      <item><p>Keep alive (sends NOP to the server every 8 sec if
        connection is idle) = <c>true</c></p></item>
      <item><p>Polling limit (max number of times to poll to get a
        remaining string terminated) = 0</p></item>
      <item><p>Polling interval (sleep time between polls) = 1 second</p>
      </item>
      <item><p>The TCP_NODELAY option for the telnet socket
        is disabled (set to <c>false</c>) per default</p></item>
    </list>

    <p>These parameters can be modified by the user with the following
      configuration term:</p>

    <pre>
 {telnet_settings, [{connect_timeout,Millisec},
                    {command_timeout,Millisec},
                    {reconnection_attempts,N},
                    {reconnection_interval,Millisec},
                    {keep_alive,Bool},
                    {poll_limit,N},
                    {poll_interval,Millisec},
                    {tcp_nodelay,Bool}]}.</pre>

    <p><c>Millisec = integer(), N = integer()</c></p>

    <p>Enter the <c>telnet_settings</c> term in a configuration file included
      in the test and <c>ct_telnet</c> retrieves the information
      automatically.</p>

    <p><c>keep_alive</c> can be specified per connection, if necessary. For
      details, see
      <seealso marker="unix_telnet"><c>unix_telnet</c></seealso>.</p>

  </description>

  <section>
    <title>Logging</title>
    <marker id="Logging"/>

    <p>The default logging behavior of <c>ct_telnet</c> is to print information
      about performed operations, commands, and their corresponding results to
      the test case HTML log. The following is not printed to the HTML
      log: text strings sent from the Telnet server that are not explicitly
      received by a <c>ct_telnet</c> function, such as <c>expect/3</c>.
      However, <c>ct_telnet</c> can be configured to use a special purpose
      event handler, implemented in <c>ct_conn_log_h</c>, for logging
      <em>all</em> Telnet traffic. To use this handler, install a <c>Common
      Test</c> hook named <c>cth_conn_log</c>. Example (using the test suite
      information function):</p>

    <pre>
 suite() -&gt;
     [{ct_hooks, [{cth_conn_log, [{conn_mod(),hook_options()}]}]}].</pre>

    <p><c>conn_mod()</c> is the name of the <c>Common Test</c> module
      implementing the connection protocol, that is, <c>ct_telnet</c>.</p>

    <p>The <c>cth_conn_log</c> hook performs unformatted logging of Telnet
      data to a separate text file. All Telnet communication is captured and
      printed, including any data sent from the server. The link to
      this text file is located at the top of the test case HTML log.</p>

    <p>By default, data for all Telnet connections is logged in one common
      file (named <c>default</c>), which can get messy, for example, if
      multiple Telnet sessions are running in parallel. Therefore a separate
      log file can be created for each connection. To configure this, use hook
      option <c>hosts</c> and list the names of the servers/connections
      to be used in the suite. The connections must be named for this to
      work (see
      <seealso marker="#open-1"><c>ct_telnet:open/1,2,3,4</c></seealso>).</p>

    <p>Hook option <c>log_type</c> can be used to change the
      <c>cth_conn_log</c> behavior. The default value of this option is
      <c>raw</c>, which results in the behavior described above. If the value
      is set to <c>html</c>, all Telnet communication is printed to the test
      case HTML log instead.</p>

    <p>All <c>cth_conn_log</c> hook options described can also be
      specified in a configuration file with configuration variable
      <c>ct_conn_log</c>.</p>

    <p><em>Example:</em></p>
 
    <pre>
 {ct_conn_log, [{ct_telnet,[{log_type,raw},
                            {hosts,[key_or_name()]}]}]}</pre>

    <note>
      <p>Hook options specified in a configuration file overwrite any
        hard-coded hook options in the test suite.</p>
    </note>

    <marker id="Logging_example"/>
    <p><em>Logging Example:</em></p>
 
    <p>The following <c>ct_hooks</c> statement causes printing of Telnet
      traffic to separate logs for the connections <c>server1</c> and
      <c>server2</c>. Traffic for any other connections is logged in the
      default Telnet log.</p>

    <pre>
 suite() -&gt;
     [{ct_hooks,
       [{cth_conn_log, [{ct_telnet,[{hosts,[server1,server2]}]}]}]}].</pre>
 
    <p>As previously explained, this specification can also be provided by an
      entry like the following in a configuration file:</p>

    <pre>
 {ct_conn_log, [{ct_telnet,[{hosts,[server1,server2]}]}]}.</pre>

    <p>In this case the <c>ct_hooks</c> statement in the test suite can look
      as follows:</p>

    <pre>
 suite() -&gt;
     [{ct_hooks, [{cth_conn_log, []}]}].</pre>
  </section>

  <section>
    <title>Data Types</title>
    <marker id="types"/>
    <taglist>
      <tag><c>connection() = handle() | {target_name(), connection_type()} | target_name()</c></tag>
      <item><marker id="type-connection"/>
        <p>For <c>target_name()</c>, see module
          <seealso marker="ct"><c>ct</c></seealso>.</p></item>

      <tag><c>connection_type() = telnet | ts1 | ts2</c></tag>
      <item><marker id="type-connection_type"/> </item>

      <tag><c>handle() = handle()</c></tag>
      <item><marker id="type-handle"/>
        <p>Handle for a specific Telnet connection, see module
          <seealso marker="ct"><c>ct</c></seealso>.</p></item>

      <tag><c>prompt_regexp() = string()</c></tag>
      <item><marker id="type-prompt_regexp"/>
        <p>Regular expression matching all possible prompts for a specific
          target type. <c>regexp</c> must not have any groups, that is, when
          matching, <c>re:run/3</c> (in STDLIB) must return a list with
          one single element.</p></item>
    </taglist>
  </section>

  <funcs>
    <func>
      <name>close(Connection) -&gt; ok | {error, Reason}</name>
      <fsummary>Closes the Telnet connection and stops the process managing
        it.</fsummary>
      <type>
        <v>Connection = connection()</v>
        <v>Reason = term()</v>
      </type>
      <desc><marker id="close-1"/>
        <p>Closes the Telnet connection and stops the process managing it.</p>

        <p>A connection can be associated with a target name and/or a handle.
          If <c>Connection</c> has no associated target name, it can only
          be closed with the handle value (see
          <seealso marker="#open-4"><c>ct_telnet:open/4</c></seealso>).</p>
      </desc>
    </func>

    <func>
      <name>cmd(Connection, Cmd) -&gt; {ok, Data} | {error, Reason}</name>
      <fsummary>Equivalent to cmd(Connection, Cmd, []).</fsummary>
      <desc><marker id="cmd-2"/>
        <p>Equivalent to
          <seealso marker="#cmd-3"><c>ct_telnet:cmd(Connection, Cmd,
          [])</c></seealso>.</p>
      </desc>
    </func>

    <func>
      <name>cmd(Connection, Cmd, Opts) -&gt; {ok, Data} | {error, Reason}</name>
      <fsummary>Sends a command through Telnet and waits for prompt.</fsummary>
      <type>
        <v>Connection = connection()</v>
        <v>Cmd = string()</v>
        <v>Opts = [Opt]</v>
        <v>Opt = {timeout, timeout()} | {newline, boolean()}</v>
        <v>Data = [string()]</v>
        <v>Reason = term()</v>
      </type>
      <desc><marker id="cmd-3"/>
        <p>Sends a command through Telnet and waits for prompt.</p>

        <p>By default, this function adds a new line to the end of the
          specified command. If this is not desired, use option
          <c>{newline,false}</c>. This is necessary, for example, when
          sending Telnet command sequences prefixed with character
          Interprete As Command (IAC).</p>

        <p>Option <c>timeout</c> specifies how long the client must wait
          for prompt. If the time expires, the function returns
          <c>{error,timeout}</c>. For information about the default value
          for the command timeout, see the
          <seealso marker="#Default_values">list of default values</seealso>
          in the beginning of this module.</p>
      </desc>
    </func>

    <func>
      <name>cmdf(Connection, CmdFormat, Args) -&gt; {ok, Data} | {error, Reason}</name>
      <fsummary>Equivalent to cmdf(Connection, CmdFormat, Args, []).</fsummary>
      <desc><marker id="cmdf-3"/>
        <p>Equivalent to
          <seealso marker="#cmdf-4"><c>ct_telnet:cmdf(Connection, CmdFormat,
          Args, [])</c></seealso>.</p>
      </desc>
    </func>

    <func>
      <name>cmdf(Connection, CmdFormat, Args, Opts) -&gt; {ok, Data} | {error, Reason}</name>
      <fsummary>Sends a Telnet command and waits for prompt (uses a format
        string and a list of arguments to build the command).</fsummary>
      <type>
        <v>Connection = connection()</v>
        <v>CmdFormat = string()</v>
        <v>Args = list()</v>
        <v>Opts = [Opt]</v>
        <v>Opt = {timeout, timeout()} | {newline, boolean()}</v>
        <v>Data = [string()]</v>
        <v>Reason = term()</v>
      </type>
      <desc><marker id="cmdf-4"/>
        <p>Sends a Telnet command and waits for prompt (uses a format string
          and a list of arguments to build the command).</p>

        <p>For details, see
          <seealso marker="#cmd-3"><c>ct_telnet:cmd/3</c></seealso>.</p>
      </desc>
    </func>

    <func>
      <name>expect(Connection, Patterns) -&gt; term()</name>
      <fsummary>Equivalent to expect(Connections, Patterns, []).</fsummary>
      <desc><marker id="expect-2"/>
        <p>Equivalent to
          <seealso marker="#expect-3"><c>ct_telnet:expect(Connections,
          Patterns, [])</c></seealso>.</p>
      </desc>
    </func>

    <func>
      <name>expect(Connection, Patterns, Opts) -&gt; {ok, Match} | {ok, MatchList, HaltReason} | {error, Reason}</name>
      <fsummary>Gets data from Telnet and waits for the expected
        pattern.</fsummary>
      <type>
        <v>Connection = connection()</v>
        <v>Patterns = Pattern | [Pattern]</v>
        <v>Pattern = string() | {Tag, string()} | prompt | {prompt, Prompt}</v>
        <v>Prompt = string()</v>
        <v>Tag = term()</v>
        <v>Opts = [Opt]</v>
        <v>Opt = {idle_timeout, IdleTimeout} | {total_timeout, TotalTimeout} | repeat | {repeat, N} | sequence | {halt, HaltPatterns} | ignore_prompt | no_prompt_check | wait_for_prompt | {wait_for_prompt, Prompt}</v>
        <v>IdleTimeout = infinity | integer()</v>
        <v>TotalTimeout = infinity | integer()</v>
        <v>N = integer()</v>
        <v>HaltPatterns = Patterns</v>
        <v>MatchList = [Match]</v>
        <v>Match = RxMatch | {Tag, RxMatch} | {prompt, Prompt}</v>
        <v>RxMatch = [string()]</v>
        <v>HaltReason = done | Match</v>
        <v>Reason = timeout | {prompt, Prompt}</v>
      </type>
      <desc><marker id="expect-3"/>
        <p>Gets data from Telnet and waits for the expected pattern.</p>

        <p><c>Pattern</c> can be a POSIX regular expression. The function
          returns when a pattern is successfully matched (at least one, in
          the case of multiple patterns).</p>

        <p><c>RxMatch</c> is a list of matched strings. It looks as
          follows <c>[FullMatch, SubMatch1, SubMatch2, ...]</c>, where
          <c>FullMatch</c> is the string matched by the whole regular
          expression, and <c>SubMatchN</c> is the string that matched
          subexpression number <c>N</c>. Subexpressions are denoted with
          <c>'(' ')'</c> in the regular expression.</p>

        <p>If a <c>Tag</c> is speciifed, the returned <c>Match</c> also
          includes the matched <c>Tag</c>. Otherwise, only <c>RxMatch</c>
          is returned.</p>

        <p><em>Options:</em></p>

        <taglist>
          <tag><c>idle_timeout</c></tag>
          <item><p>Indicates that the function must return if the Telnet
            client is idle (that is, if no data is received) for more than
            <c>IdleTimeout</c> milliseconds. Default time-out is 10
            seconds.</p></item>
          <tag><c>total_timeout</c></tag>
          <item><p>Sets a time limit for the complete <c>expect</c> operation.
            After <c>TotalTimeout</c> milliseconds, <c>{error,timeout}</c>
            is returned. Default is <c>infinity</c> (that is, no time
            limit).</p></item>
          <tag><c>ignore_prompt | no_prompt_check</c></tag>
          <item><p>>The function returns when a prompt is received, even if
            no pattern has yet been matched, and 
            <c>{error,{prompt,Prompt}}</c> is returned. However, this
            behavior can be modified with option <c>ignore_prompt</c> or
            option <c>no_prompt_check</c>, which tells <c>expect</c> to
            return only when a match is found or after a time-out.</p></item>
          <tag><c>ignore_prompt</c></tag>
          <item><p><c>ct_telnet</c> ignores any prompt found. This option is
            useful if data sent by the server can include a pattern
            matching prompt <c>regexp</c> (as returned by
            <c>TargedMod:get_prompt_regexp/0</c>), but is not to not cause
            the function to return.</p></item>
          <tag><c>no_prompt_check</c></tag>
          <item><p><c>ct_telnet</c> does not search for a prompt at all. This
            is useful if, for example, <c>Pattern</c> itself matches the
            prompt.</p></item>
          <tag><c>wait_for_prompt</c></tag>
          <item><p>Forces <c>ct_telnet</c> to wait until the prompt string
            is received before returning (even if a pattern has already been
            matched). This is equal to calling
            <c>expect(Conn, Patterns++[{prompt,Prompt}], [sequence|Opts])</c>.
            Notice that option <c>idle_timeout</c> and <c>total_timeout</c>
            can abort the operation of waiting for prompt.</p></item>
          <tag><c>repeat | repeat, N</c></tag>
          <item><p>The pattern(s) must be matched multiple times. If <c>N</c>
            is speciified, the pattern(s) are matched <c>N</c> times, and
            the function returns <c>HaltReason = done</c>. This option can be
            interrupted by one or more <c>HaltPatterns</c>. <c>MatchList</c>
            is always returned, that is, a list of <c>Match</c> instead of
            only one <c>Match</c>. Also <c>HaltReason</c> is returned.</p>
          </item>
          <tag><c>sequence</c></tag>
          <item><p>All patterns must be matched in a sequence. A match is not
            concluded until all patterns are matched. This option can be
            interrupted by one or more <c>HaltPatterns</c>. <c>MatchList</c>
            is always returned, that is, a list of <c>Match</c> instead of
            only one <c>Match</c>. Also <c>HaltReason</c> is returned.</p> 
          </item>
        </taglist>

        <p><em>Example 1:</em></p>

        <pre>
 expect(Connection,[{abc,"ABC"},{xyz,"XYZ"}],[sequence,{halt,[{nnn,"NNN"}]}])</pre>

        <p>First this tries to match <c>"ABC"</c>, and then <c>"XYZ"</c>, but
          if <c>"NNN"</c> appears,  the function returns
          <c>{error,{nnn,["NNN"]}}</c>. If both <c>"ABC"</c> and <c>"XYZ"</c>
          are matched, the function returns <c>{ok,[AbcMatch,XyzMatch]}</c>.</p>

        <p><em>Example 2:</em></p>

        <pre>
 expect(Connection,[{abc,"ABC"},{xyz,"XYZ"}],[{repeat,2},{halt,[{nnn,"NNN"}]}])</pre>

        <p>This tries to match <c>"ABC"</c> or <c>"XYZ"</c> twice. If
          <c>"NNN"</c> appears, the function returns
          <c>HaltReason = {nnn,["NNN"]}</c>.</p>

        <p>Options <c>repeat</c> and <c>sequence</c> can be combined to
          match a sequence multiple times.</p>
      </desc>
    </func>

    <func>
      <name>get_data(Connection) -&gt; {ok, Data} | {error, Reason}</name>
      <fsummary>Gets all data received by the Telnet client since the last
        command was sent.</fsummary>
      <type>
        <v>Connection = connection()</v>
        <v>Data = [string()]</v>
        <v>Reason = term()</v>
      </type>
      <desc><marker id="get_data-1"/>
        <p>Gets all data received by the Telnet client since the last
          command was sent. Only newline-terminated strings are returned.
          If the last received string has not yet been terminated, the
          connection can be polled automatically until the string is
          complete.</p>

        <p>The polling feature is controlled by the configuration values
          <c>poll_limit</c> and <c>poll_interval</c> and is by default
          disabled. This means that the function immediately returns all
          complete strings received and saves a remaining non-terminated
          string for a later <c>get_data</c> call.</p>
      </desc>
    </func>

    <func>
      <name>open(Name) -&gt; {ok, Handle} | {error, Reason}</name>
      <fsummary>Equivalent to open(Name, telnet).</fsummary>
      <desc><marker id="open-1"/>
        <p>Equivalent to
          <seealso marker="#open-2"><c>ct_telnet:open(Name,
          telnet)</c></seealso>.</p>
      </desc>
    </func>

    <func>
      <name>open(Name, ConnType) -&gt; {ok, Handle} | {error, Reason}</name>
      <fsummary>Opens a Telnet connection to the specified target
        host.</fsummary>
      <type>
        <v>Name = target_name()</v>
        <v>ConnType = connection_type()</v>
        <v>Handle = handle()</v>
        <v>Reason = term()</v>
      </type>
      <desc><marker id="open-2"/>
        <p>Opens a Telnet connection to the specified target host.</p>
      </desc>
    </func>

    <func>
      <name>open(KeyOrName, ConnType, TargetMod) -&gt; {ok, Handle} | {error, Reason}</name>
      <fsummary>Equivalent to open(KeyOrName, ConnType, TargetMod, []).</fsummary>
      <desc><marker id="open-3"/>
        <p>Equivalent to
          <seealso marker="#open-4"><c>ct_telnet:ct_telnet:open(KeyOrName,
          ConnType, TargetMod, [])</c></seealso>.</p>
      </desc>
    </func>

    <func>
      <name>open(KeyOrName, ConnType, TargetMod, Extra) -&gt; {ok, Handle} | {error, Reason}</name>
      <fsummary>Opens a Telnet connection to the specified target
        host.</fsummary>
      <type>
        <v>KeyOrName = Key | Name</v>
        <v>Key = atom()</v>
        <v>Name = target_name()</v>
        <v>ConnType = connection_type()</v>
        <v>TargetMod = atom()</v>
        <v>Extra = term()</v>
        <v>Handle = handle()</v>
        <v>Reason = term()</v>
      </type>
      <desc><marker id="open-4"/>
        <p>Opens a Telnet connection to the specified target host.</p>

        <p>The target data must exist in a configuration file. The connection
          can be associated with <c>Name</c> and/or the returned <c>Handle</c>.
          To allocate a name for the target, use one of the following
          alternatives:</p>

        <list type="bulleted">
          <item><p><seealso marker="ct#require-2"><c>ct:require/2</c></seealso>
             in a test case</p></item>
          <item><p>A <c>require</c> statement in the suite information
            function (<c>suite/0</c>)</p></item>
          <item><p>A <c>require</c> statement in a test case information
            function</p></item>
        </list>

        <p>If you want the connection to be associated with <c>Handle</c> only
          (if you, for example, need to open multiple connections to a host),
          use <c>Key</c>, the configuration variable name, to specify the
          target. Notice that a connection without an associated target name
          can only be closed with the <c>Handle</c> value.</p>

        <p><c>TargetMod</c> is a module that exports the functions
          <c>connect(Ip, Port, KeepAlive, Extra)</c> and
          <c>get_prompt_regexp()</c> for the specified <c>TargetType</c>
          (for example, <c>unix_telnet</c>).</p>

        <p>For <c>target_name()</c>, see module
          <seealso marker="ct"><c>ct</c></seealso>.</p>

        <p>See also
          <seealso marker="ct#require-2"><c>ct:require/2</c></seealso>.</p>
      </desc>
    </func>

    <func>
      <name>send(Connection, Cmd) -&gt; ok | {error, Reason}</name>
      <fsummary>Equivalent to send(Connection, Cmd, []).</fsummary>
      <desc><marker id="send-2"/>
        <p>Equivalent to
          <seealso marker="#send-3"><c>ct_telnet:send(Connection, Cmd,
          [])</c></seealso>.</p>
      </desc>
    </func>

    <func>
      <name since="OTP 17.4">send(Connection, Cmd, Opts) -&gt; ok | {error, Reason}</name>
      <fsummary>Sends a Telnet command and returns immediately.</fsummary>
      <type>
        <v>Connection = connection()</v>
        <v>Cmd = string()</v>
        <v>Opts = [Opt]</v>
        <v>Opt = {newline, boolean()}</v>
        <v>Reason = term()</v>
      </type>
      <desc><marker id="send-3"/>
        <p>Sends a Telnet command and returns immediately.</p>

        <p>By default, this function adds a newline to the end of the
          specified command. If this is not desired, option
          <c>{newline,false}</c> can be used. This is necessary, for example,
          when sending Telnet command sequences prefixed with character   
          Interprete As Command (IAC).</p>

        <p>The resulting output from the command can be read with
          <seealso marker="#get_data-1"><c>ct_telnet:get_data/2</c></seealso> or
          <seealso marker="#expect-2"><c>ct_telnet:expect/2,3</c></seealso>.</p>
      </desc>
    </func>

    <func>
      <name>sendf(Connection, CmdFormat, Args) -&gt; ok | {error, Reason}</name>
      <fsummary>Equivalent to sendf(Connection, CmdFormat, Args, []).</fsummary>
      <desc><marker id="sendf-3"/>
        <p>Equivalent to
          <seealso marker="#sendf-4"><c>ct_telnet:sendf(Connection, CmdFormat,
          Args, [])</c></seealso>.</p>
      </desc>
    </func>

    <func>
    <name since="OTP 17.4">sendf(Connection, CmdFormat, Args, Opts) -&gt; ok | {error, Reason}</name>
    <fsummary>Sends a Telnet command and returns immediately (uses a format
      string and a list of arguments to build the command).</fsummary>
      <type>
        <v>Connection = connection()</v>
        <v>CmdFormat = string()</v>
        <v>Args = list()</v>
        <v>Opts = [Opt]</v>
        <v>Opt = {newline, boolean()}</v>
        <v>Reason = term()</v>
      </type>
      <desc><marker id="sendf-4"/>
        <p>Sends a Telnet command and returns immediately (uses a format
          string and a list of arguments to build the command).</p>
      </desc>
    </func>
  </funcs>

  <section>
    <title>See Also</title>
      <p><seealso marker="unix_telnet"><c>unix_telnet</c></seealso></p>
  </section>

</erlref>