path: root/lib/inets/doc/src/ftp.xml

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

<erlref>
  <header>
    <copyright>
      <year>1997</year><year>2013</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>ftp</title>
    <prepared>Peter H&ouml;gfeldt</prepared>
    <docno></docno>
    <date>1997-11-05</date>
    <rev>B</rev>
    <file>ftp.xml</file>
  </header>
  <module>ftp</module>
  <modulesummary>A File Transfer Protocol client</modulesummary>

  <description>

    <p>The <c>ftp</c> module implements a client for file transfer
      according to a subset of the File Transfer Protocol (see <term
      id="RFC"></term>959). </p>

    <p>Starting from inets version 4.4.1 the ftp
      client will always try to use passive ftp mode and only resort
      to active ftp mode if this fails. There is a start option 
      <seealso marker="#mode">mode</seealso> where this default behavior 
      may be changed. </p>

    <marker id="two_start"></marker>

    <p>There are two ways to start an ftp client. One is using the 
      <seealso marker="#service_start">Inets service framework</seealso>
      and the other is to start it directy as a standalone process 
      using the <seealso marker="#open">open</seealso> function. </p>

    <p>For a simple example of an ftp session see 
      <seealso marker="ftp_client">Inets User's Guide.</seealso></p>

    <p>In addition to the ordinary functions for receiving and sending
      files (see <c>recv/2</c>, <c>recv/3</c>, <c>send/2</c> and
      <c>send/3</c>) there are functions for receiving remote files as
      binaries (see <c>recv_bin/2</c>) and for sending binaries to to be
      stored as remote files (see <c>send_bin/3</c>).</p>

    <p>There is also a set of functions for sending and receiving
      contiguous parts of a file to be stored in a remote file (for send
      see <c>send_chunk_start/2</c>, <c>send_chunk/2</c> and
      <c>send_chunk_end/1</c> and for receive see
      <c>recv_chunk_start/2</c> and <c>recv_chunk/</c>).</p>

    <p>The particular return values of the functions below depend very
      much on the implementation of the FTP server at the remote
      host. In particular the results from <c>ls</c> and <c>nlist</c>
      varies. Often real errors are not reported as errors by <c>ls</c>,
      even if for instance a file or directory does not
      exist. <c>nlist</c> is usually more strict, but some
      implementations have the peculiar behaviour of responding with an
      error, if the request is a listing of the contents of directory
      which exists but is empty.</p>

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

  <section>
    <title>FTP CLIENT SERVICE START/STOP </title>
    
    <p>The FTP client can be started and stopped dynamically in runtime by
      calling the Inets application API 
      <c>inets:start(ftpc, ServiceConfig)</c>,
      or <c>inets:start(ftpc, ServiceConfig, How)</c>, and
      <c>inets:stop(ftpc, Pid)</c>. 
      See <seealso marker="inets">inets(3)</seealso> for more info. </p>
    <p>Below follows a description of
      the available configuration options.</p>
    
    <taglist>
      <tag>{host, Host}</tag>
      <item>
        <marker id="host"></marker>
	<p>Host = <c>string() | ip_address()</c> </p>
      </item>

      <tag>{port, Port}</tag>
      <item>
        <marker id="port"></marker>
	<p>Port = <c>integer() > 0</c> </p>
	<p>Default is 21.</p>
      </item>

      <tag>{mode, Mode}</tag>
      <item>
        <marker id="mode"></marker>
	<p>Mode = <c>active | passive</c> </p>
	<p>Default is <c>passive</c>. </p> 
      </item>

      <tag>{verbose, Verbose}</tag>
      <item>
        <marker id="verbose"></marker>
	<p>Verbose = <c>boolean()</c> </p>
	<p>This determines if the FTP communication should be
	  verbose or not. </p>
	<p>Default is <c>false</c>. </p>
      </item>

      <tag>{debug, Debug}</tag>
      <item>
        <marker id="debug"></marker>
	<p>Debug = <c>trace | debug | disable</c> </p>
	<p>Debugging using the dbg toolkit. </p>
	<p>Default is <c>disable</c>. </p>
      </item>

      <tag>{ipfamily, IpFamily}</tag>
      <item>
        <marker id="ipfamily"></marker>
	<p>IpFamily = <c>inet | inet6 | inet6fb4</c> </p>
	<p>With <c>inet6fb4</c> the client behaves as before 
	  (it tries to use IPv6 and only if that does not work, it 
          uses IPv4). </p>
	<p>Default is <c>inet</c> (IPv4). </p>
      </item>

      <tag>{timeout, Timeout}</tag>
      <item>
        <marker id="timeout"></marker>
	<p>Timeout = <c>non_neg_integer()</c> </p>
	<p>Connection timeout. </p>
	<p>Default is 60000 (milliseconds). </p>
      </item>

      <tag>{dtimeout, DTimeout}</tag>
      <item>
        <marker id="dtimeout"></marker>
	<p>DTimeout = <c>non_neg_integer() | infinity</c> </p>
	<p>Data Connect timeout. 
	The time the client will wait for the server to connect to the 
	data socket. </p>
	<p>Default is infinity. </p>
      </item>

      <tag>{progress, Progress}</tag>
      <item>
        <marker id="progress"></marker>
	<p>Progress = <c>ignore | {CBModule, CBFunction, InitProgress}</c></p>
	<p>CBModule = <c>atom()</c>, CBFunction = <c>atom()</c> </p>
	<p>InitProgress = <c>term()</c> </p>
	<p>Default is <c>ignore</c>. </p>
      </item>  

    </taglist>
  
    <p>The progress option is intended to be used by applications that
      want to create some type of progress report such as a progress bar in
      a GUI.  The default value for the progress option is ignore
      e.i. the option is not used.  When the progress option is
      specified the following will happen when ftp:send/[3,4] or
      ftp:recv/[3,4] are called.</p>
    
    <list type="bulleted">
      <item>
	<p>Before a file is transfered the following call will
	  be made to indicate the start of the file transfer and how big
	  the file is. The return value of the callback function
	  should be a new value for the UserProgressTerm that will
	  bu used as input next time the callback function is
	  called.</p>
	<br></br>
	<p><c>
	  CBModule:CBFunction(InitProgress, File, {file_size, FileSize})
	</c></p>
	<br></br>
      </item>
      
      <item>
	<p>Every time a chunk of bytes is transfered the
	  following call will be made:</p>
	<br></br>
	<p><c>
	    CBModule:CBFunction(UserProgressTerm, File, {transfer_size, TransferSize})             </c></p>
	<br></br>
      </item>

      <item>
	<p>At the end of the file the following call will be
	  made to indicate the end of the transfer.</p>
	<br></br>
	<p><c>
	    CBModule:CBFunction(UserProgressTerm, File, {transfer_size, 0})             </c></p>
	<br></br>
      </item>
    </list>
    
    <p>The callback function should be defined as </p>

    <p><c>
	CBModule:CBFunction(UserProgressTerm, File, Size) -> UserProgressTerm        </c></p>
    
    <p><c>
	CBModule = CBFunction = atom()
      </c></p>

    <p><c>
	UserProgressTerm = term()
      </c></p>

    <p><c>
	File = string()
      </c></p>

    <p><c>
	Size = {transfer_size, integer()} | {file_size, integer()} | {file_size, unknown}        </c></p>
    
    <p>Alas for remote files it is not possible for ftp to determine the
      file size in a platform independent way. In this case the size
      will be <c>unknown</c> and it is left to the application to find
      out the size. </p>
    
    <note>
      <p>The callback is made by a middleman process, hence the
	file transfer will not be affected by the code in the progress
	callback function. If the callback should crash this will be
	detected by the ftp connection process that will print an
	info-report and then go one as if the progress option was set
	to ignore. </p>
    </note>
    
    <p>The file transfer type is set to the default of the FTP server
      when the session is opened. This is usually ASCCI-mode.
    </p>
    
    <p>The current local working directory (cf. <c>lpwd/1</c>) is set to
      the value reported by <c>file:get_cwd/1</c>. the wanted
      local directory.
    </p>
    
    <p>The return value <c>Pid</c> is used as a reference to the
      newly created ftp client in all other functions, and they should
      be called by the process that created the connection. The ftp
      client process monitors the process that created it and
      will terminate if that process terminates.</p>   
  </section>
  
  <section>
    <title>COMMON DATA TYPES </title>
    <p>Here follows type definitions that are used by more than one
      function in the FTP client API. </p>
    <p><c> pid() - identifier of an ftp connection.</c></p>
    <p><c> string() = list of ASCII characters.</c></p>
    <p><c> shortage_reason() = etnospc | epnospc</c></p>
    <p><c> restriction_reason() = epath | efnamena | elogin | enotbinary
      - note not all restrictions may always relevant to all functions
    </c></p>
    <p><c>common_reason() = econn | eclosed | term() - some kind of
      explanation of what went wrong.</c></p>

    <marker id="account"></marker>
  </section>

  <funcs>
    <func>
      <name>account(Pid, Account) -> ok | {error, Reason}</name>
      <fsummary>Specify which account to use.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Account = string()</v>
        <v>Reason = eacct | common_reason()</v>
      </type>
      <desc>
        <p>If an account is needed for an operation set the account
          with this operation.</p>

       <marker id="append"></marker>
       <marker id="append2"></marker>
       <marker id="append3"></marker>
      </desc>
    </func>

    <func>
      <name>append(Pid, LocalFile) -> </name>
      <name>append(Pid, LocalFile, RemoteFile) -> ok | {error, Reason}</name>
      <fsummary>Transfer file to remote server, and append it to Remotefile.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>LocalFile = RemoteFile = string()</v>
        <v>Reason = epath | elogin | etnospc | epnospc | efnamena | common_reason</v>
      </type>
      <desc>
        <p>Transfers the file <c>LocalFile</c> to the remote server. If 
          <c>RemoteFile</c> is specified, the name of the remote file that the
          file will be appended to is set to <c>RemoteFile</c>; otherwise 
          the name is set to <c>LocalFile</c> If the file does not exists the
          file will be created.</p>

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

    <func>
      <name>append_bin(Pid, Bin, RemoteFile) -> ok | {error, Reason}</name>
      <fsummary>Transfer a binary into a remote file.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Bin = binary()()</v>
        <v>RemoteFile = string()</v>
        <v>Reason =  restriction_reason()| shortage_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Transfers the binary <c>Bin</c> to the remote server and append 
          it to the file <c>RemoteFile</c>. If the file does not exists it 
          will be created.</p>

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

    <func>
      <name>append_chunk(Pid, Bin) -> ok | {error, Reason}</name>
      <fsummary>append a chunk to the remote file.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Bin = binary()</v>
        <v>Reason = echunk | restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Transfer the chunk <c>Bin</c> to the remote server, which 
          append it into the file specified in the call to 
          <c>append_chunk_start/2</c>. </p>
        <p>Note that for some errors, e.g. file system full, it is 
          necessary to to call <c>append_chunk_end</c> to get the 
          proper reason.</p>

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

    <func>
      <name>append_chunk_start(Pid, File) -> ok | {error, Reason}</name>
      <fsummary>Start transfer of file chunks for appending to File.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>File = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Start the transfer of chunks for appending to the file 
          <c>File</c> at the remote server. If the file does not exists 
          it will be created.</p>

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

    <func>
      <name>append_chunk_end(Pid) -> ok | {error, Reason}</name>
      <fsummary>Stop transfer of chunks for appending.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Reason = echunk | restriction_reason() | shortage_reason() </v>
      </type>
      <desc>
        <p>Stops transfer of chunks for appending to the remote server. 
          The file at the remote server, specified in the call to 
          <c>append_chunk_start/2</c> is closed by the server.</p>

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

    <func>
      <name>cd(Pid, Dir) -> ok | {error, Reason}</name>
      <fsummary>Change remote working directory.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Dir = string()</v>
        <v>Reason = restriction_reason() | common_reason() </v>
      </type>
      <desc>
        <p>Changes the working directory at the remote server to 
          <c>Dir</c>.</p>

       <marker id="close"></marker>
      </desc>
    </func>
    
    <func>
      <name>close(Pid) -> ok</name>
      <fsummary>End the ftp session.</fsummary>
      <type>
	<v>Pid = pid()</v>
      </type>
      <desc>
	<p>Ends an ftp session, created using the 
          <seealso marker="#open">open</seealso> function. </p>

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

    <func>
      <name>delete(Pid, File) -> ok | {error, Reason}</name>
      <fsummary>Delete a file at the remote server..</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>File = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Deletes the file <c>File</c> at the remote server.</p>

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

    <func>
      <name>formaterror(Tag) -> string()</name>
      <fsummary>Return error diagnostics.</fsummary>
      <type>
        <v>Tag = {error, atom()} | atom()</v>
      </type>
      <desc>
        <p>Given an error return value <c>{error, AtomReason}</c>,
          this function returns a readable string describing the error.</p>

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

    <func>
      <name>lcd(Pid, Dir) -> ok | {error, Reason}</name>
      <fsummary>Change local working directory.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Dir = string()</v>
        <v>Reason = restriction_reason()</v>
      </type>
      <desc>
        <p>Changes the working directory to <c>Dir</c> for the local client. </p>

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

    <func>
      <name>lpwd(Pid) -> {ok, Dir}</name>
      <fsummary>Get local current working directory.</fsummary>
      <type>
        <v>Pid = pid()</v>
      </type>
      <desc>
        <p>Returns the current working directory at the local client.</p>

       <marker id="ls"></marker>
       <marker id="ls1"></marker>
       <marker id="ls2"></marker>
      </desc>
    </func>

    <func>
      <name>ls(Pid) -> </name>
      <name>ls(Pid, Pathname) -> {ok, Listing} | {error, Reason}</name>
      <fsummary>List of files.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Pathname = string()</v>
        <v>Listing = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Returns a list of files in long format. </p>
        <p><c>Pathname</c> can be a directory, a group of files or 
          even a file. The <c>Pathname</c> string can contain wildcard(s). </p>
        <p><c>ls/1</c> implies the user's current remote directory. </p>
        <p>The format of <c>Listing</c> is operating system dependent 
          (on UNIX it is typically produced from the output of the 
          <c>ls -l</c> shell command).</p>

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

    <func>
      <name>mkdir(Pid, Dir) -> ok | {error, Reason}</name>
      <fsummary>Create remote directory.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Dir = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Creates the directory <c>Dir</c> at the remote server.</p>

       <marker id="nlist"></marker>
       <marker id="nlist1"></marker>
       <marker id="nlist2"></marker>
      </desc>
    </func>

    <func>
      <name>nlist(Pid) -> </name>
      <name>nlist(Pid, Pathname) -> {ok, Listing} | {error, Reason}</name>
      <fsummary>List of files.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Pathname = string()</v>
        <v>Listing = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Returns a list of files in short format. </p>
        <p><c>Pathname</c> can be a directory, a group of files or 
          even a file. The <c>Pathname</c> string can contain wildcard(s). </p>
        <p><c>nlist/1</c> implies the user's current remote directory. </p>
        <p>The format of <c>Listing</c> is a stream of
          file names, where each name is separated by &lt;CRLF&gt; or
          &lt;NL&gt;. Contrary to the <c>ls</c> function, the purpose of
          <c>nlist</c> is to make it possible for a program to
          automatically process file name information.</p>

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

    <func>
      <name>open(Host) -> {ok, Pid} | {error, Reason}</name>
      <name>open(Host, Opts) -> {ok, Pid} | {error, Reason}</name>
      <fsummary>Start an standalone ftp client.</fsummary>
      <type>
	<v>Host = string() | ip_address()</v>
	<v>Opts = options()</v>
	<v>options() = [option()]</v>
	<v>option() = start_option() | open_option()</v>
	<v>start_option() = {verbose, verbose()} | {debug, debug()}</v>
	<v>verbose() = boolean() (defaults to false)</v>
	<v>debug() = disable | debug | trace (defaults to disable)</v>
	<v>open_option() = {ipfamily, ipfamily()} | {port, port()} | {mode, mode()} | {tls, tls_options()} | {timeout, timeout()} | {dtimeout, dtimeout()} | {progress, progress()}</v>
	<v>ipfamily() = inet | inet6 | inet6fb4 (defaults to inet)</v>
	<v>port() = integer() > 0 (defaults to 21)</v>
	<v>mode() = active | passive (defaults to passive)</v>
	<v>tls_options() = [<seealso marker="ssl:ssl#type-ssloption">ssl:ssloption()</seealso>]</v>
	<v>timeout() = integer() > 0 (defaults to 60000 milliseconds)</v>
	<v>dtimeout() = integer() > 0 | infinity (defaults to infinity)</v>
	<v>pogress() = ignore | {module(), function(), initial_data()} (defaults to ignore)</v>
	<v>module() = atom()</v>
	<v>function() = atom()</v>
	<v>initial_data() = term()</v>
	<v>Reason = ehost | term()</v>
      </type>

      <desc>
	<p>This function is used to start a standalone ftp client process 
          (without the inets service framework) and 
          open a session with the FTP server at <c>Host</c>. </p>

	<p>If the option <c>{tls, tls_options()}</c> is present, the ftp session will be transported over tls (ftps, see 
<url href="http://www.ietf.org/rfc/rfc4217.txt">RFC 4217</url>). The list <c>tls_options()</c> may be empty. The function <seealso marker="ssl:ssl#connect/3"><c>ssl:connect/3</c></seealso> is used for securing both the control connection and the data sessions.
	</p>

        <p>A session opened in this way, is closed using the 
          <seealso marker="#close">close</seealso> function. </p>

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

    <func>
      <name>pwd(Pid) -> {ok, Dir} | {error, Reason}</name>
      <fsummary>Get remote current working directory.</fsummary>
      <type>
	<v>Pid = pid()</v>
	<v>Reason = restriction_reason() | common_reason() </v>
      </type>
      <desc>
	<p>Returns the current working directory at the remote server. </p>
      </desc>
    </func>

    <func>
      <name>pwd(Pid) -> {ok, Dir} | {error, Reason}</name>
      <fsummary>Get remote current working directory.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Reason = restriction_reason() | common_reason() </v>
      </type>
      <desc>
        <p>Returns the current working directory at the remote server.</p>

       <marker id="recv"></marker>
       <marker id="recv2"></marker>
       <marker id="recv3"></marker>
      </desc>
    </func>

    <func>
      <name>recv(Pid, RemoteFile) -> </name>
      <name>recv(Pid, RemoteFile, LocalFile) -> ok | {error, Reason}</name>
      <fsummary>Transfer file from remote server.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>RemoteFile = LocalFile = string()</v>
        <v>Reason = restriction_reason() | common_reason() | file_write_error_reason() </v>
        <v>file_write_error_reason() = see file:write/2</v>
      </type>
      <desc>
        <p>Transfer the file <c>RemoteFile</c> from the remote server
          to the the file system of the local client. If
          <c>LocalFile</c> is specified, the local file will be
          <c>LocalFile</c>; otherwise it will be
          <c>RemoteFile</c>.</p>
        <p>If the file write fails
          (e.g. enospc), then the command is aborted and <c>{error, file_write_error_reason()}</c> is returned. The file is
          however <em>not</em> removed.</p>

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

    <func>
      <name>recv_bin(Pid, RemoteFile) -> {ok, Bin} | {error, Reason}</name>
      <fsummary>Transfer file from remote server as a binary.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Bin = binary()</v>
        <v>RemoteFile = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Transfers the file <c>RemoteFile</c> from the remote server and 
          receives it as a binary.</p>

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

    <func>
      <name>recv_chunk_start(Pid, RemoteFile) -> ok | {error, Reason}</name>
      <fsummary>Start chunk-reading of the remote file.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>RemoteFile = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Start transfer of the file <c>RemoteFile</c> from the
          remote server.</p>

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

    <func>
      <name>recv_chunk(Pid) -> ok | {ok, Bin} | {error, Reason}</name>
      <fsummary>Receive a chunk of the remote file.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Bin = binary()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Receive a chunk of the remote file (<c>RemoteFile</c> of 
          <c>recv_chunk_start</c>). The return values has the following 
          meaning:</p>
        <list type="bulleted">
          <item><c>ok</c> the transfer is complete.</item>
          <item><c>{ok, Bin}</c> just another chunk of the file.</item>
          <item><c>{error, Reason}</c> transfer failed.</item>
        </list>

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

    <func>
      <name>rename(Pid, Old, New) -> ok | {error, Reason}</name>
      <fsummary>Rename a file at the remote server..</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>CurrFile = NewFile = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Renames <c>Old</c> to <c>New</c> at the remote server.</p>

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

    <func>
      <name>rmdir(Pid, Dir) -> ok | {error, Reason}</name>
      <fsummary>Remove a remote directory.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Dir = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Removes directory <c>Dir</c> at the remote server.</p>

       <marker id="send"></marker>
       <marker id="send2"></marker>
       <marker id="send3"></marker>
      </desc>
    </func>

    <func>
      <name>send(Pid, LocalFile) -></name>
      <name>send(Pid, LocalFile, RemoteFile) -> ok | {error, Reason}</name>
      <fsummary>Transfer file to remote server.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>LocalFile = RemoteFile = string()</v>
        <v>Reason = restriction_reason() | common_reason() | shortage_reason()</v>
      </type>
      <desc>
        <p>Transfers the file <c>LocalFile</c> to the remote server. If 
          <c>RemoteFile</c> is specified, the name of the remote file is set
          to <c>RemoteFile</c>; otherwise the name is set to <c>LocalFile</c>.</p>

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

    <func>
      <name>send_bin(Pid, Bin, RemoteFile) -> ok | {error, Reason}</name>
      <fsummary>Transfer a binary into a remote file.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Bin = binary()()</v>
        <v>RemoteFile = string()</v>
        <v>Reason = restriction_reason() | common_reason() | shortage_reason()</v>
      </type>
      <desc>
        <p>Transfers the binary <c>Bin</c> into the file <c>RemoteFile</c> 
          at the remote server.</p>

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

    <func>
      <name>send_chunk(Pid, Bin) -> ok | {error, Reason}</name>
      <fsummary>Write a chunk to the remote file.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Bin = binary()</v>
        <v>Reason = echunk | restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Transfer the chunk <c>Bin</c> to the remote server, which 
          writes it into the file specified in the call to 
          <c>send_chunk_start/2</c>. </p>
        <p>Note that for some errors, e.g. file system full, it is 
          necessary to to call <c>send_chunk_end</c> to get the 
          proper reason.</p>

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

    <func>
      <name>send_chunk_start(Pid, File) -> ok | {error, Reason}</name>
      <fsummary>Start transfer of file chunks.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>File = string()</v>
        <v>Reason = restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Start transfer of chunks into the file <c>File</c> at the 
          remote server.</p>

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

    <func>
      <name>send_chunk_end(Pid) -> ok | {error, Reason}</name>
      <fsummary>Stop transfer of chunks.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Reason = restriction_reason() | common_reason() | shortage_reason()</v>
      </type>
      <desc>
        <p>Stops transfer of chunks to the remote server. The file at the
          remote server, specified in the call to <c>send_chunk_start/2</c> 
          is closed by the server.</p>

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

    <func>
      <name>type(Pid, Type) -> ok | {error, Reason}</name>
      <fsummary>Set transfer type to <c>ascii</c>or <c>binary</c>.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Type = ascii | binary</v>
        <v>Reason = etype | restriction_reason() | common_reason()</v>
      </type>
      <desc>
        <p>Sets the file transfer type to <c>ascii</c> or <c>binary</c>. When
          an ftp session is opened, the default transfer type of the
          server is used, most often <c>ascii</c>, which is the default
          according to <url href="http://www.ietf.org/rfc/rfc959.txt">RFC 959</url>.</p>
       <marker id="user3"></marker>
      </desc>
    </func>

    <func>
      <name>user(Pid, User, Password) -> ok | {error, Reason}</name>
      <fsummary>User login.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>User = Password = string()</v>
        <v>Reason = euser | common_reason()</v>
      </type>
      <desc>
        <p>Performs login of <c>User</c> with <c>Password</c>.</p>

       <marker id="user4"></marker>
      </desc>
    </func>

    <func>
      <name>user(Pid, User, Password, Account) -> ok | {error, Reason}</name>
      <fsummary>User login.</fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>User = Password = string()</v>
        <v>Reason = euser | common_reason() </v>
      </type>
      <desc>
        <p>Performs login of <c>User</c> with <c>Password</c> to the account 
          specified by <c>Account</c>.</p>

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

    <func>
      <name>quote(Pid, Command) -> [FTPLine]</name>
      <fsummary>Sends an arbitrary FTP command. </fsummary>
      <type>
        <v>Pid = pid()</v>
        <v>Command = string()</v>
        <v>FTPLine = string() - Note the telnet end of line characters, from the ftp protocol definition, CRLF e.g. "\\r\\n" has been removed.</v>
      </type>
      <desc>
        <p>Sends an arbitrary FTP command and returns verbatimly a list
          of the lines sent back by the FTP server. This functions is
          intended to give an application accesses to FTP commands
          that are server specific or that may not be provided by
          this FTP client. </p>
        <note>
          <p>FTP commands that require a data connection can not be
            successfully issued with this function. </p>
        </note>
      </desc>
    </func>
  </funcs>

  <section>
    <title>ERRORS</title>
    <p>The possible error reasons and the corresponding diagnostic strings 
      returned by <c>formaterror/1</c> are as follows:
      </p>
    <taglist>
      <tag><c>echunk</c></tag>
      <item>
        <p>Synchronisation error during chunk sending. 
          </p>
        <p>A call has been made to <c>send_chunk/2</c> or
          <c>send_chunk_end/1</c>, before a call to
          <c>send_chunk_start/2</c>; or a call has been made to another
          transfer function during chunk sending, i.e. before a call
          to <c>send_chunk_end/1</c>.</p>
      </item>
      <tag><c>eclosed</c></tag>
      <item>
        <p>The session has been closed.</p>
      </item>
      <tag><c>econn</c></tag>
      <item>
        <p>Connection to remote server prematurely closed.</p>
      </item>
      <tag><c>ehost</c></tag>
      <item>
        <p>Host not found, FTP server not found, or connection rejected
          by FTP server.</p>
      </item>
      <tag><c>elogin</c></tag>
      <item>
        <p>User not logged in.</p>
      </item>
      <tag><c>enotbinary</c></tag>
      <item>
        <p>Term is not a binary.</p>
      </item>
      <tag><c>epath</c></tag>
      <item>
        <p>No such file or directory, or directory already exists, or
          permission denied.</p>
      </item>
      <tag><c>etype</c></tag>
      <item>
        <p>No such type.</p>
      </item>
      <tag><c>euser</c></tag>
      <item>
        <p>User name or password not valid.</p>
      </item>
      <tag><c>etnospc</c></tag>
      <item>
        <p>Insufficient storage space in system [452].</p>
      </item>
      <tag><c>epnospc</c></tag>
      <item>
        <p>Exceeded storage allocation (for current directory or
          dataset) [552].</p>
      </item>
      <tag><c>efnamena</c></tag>
      <item>
        <p>File name not allowed [553].</p>
      </item>
    </taglist>
  </section>

  <section>
    <title>SEE ALSO</title>
    <p>file, filename, J. Postel and J. Reynolds: File Transfer Protocol
      (<url href="http://www.ietf.org/rfc/rfc959.txt">RFC 959</url>).
      </p>
  </section>
  
</erlref>