path: root/lib/ssh/doc/src/ssh_sftp.xml

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

<erlref>
  <header>
    <copyright>
      <year>2005</year><year>2014</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      The contents of this file are subject to the Erlang Public License,
      Version 1.1, (the "License"); you may not use this file except in
      compliance with the License. You should have received a copy of the
      Erlang Public License along with this software. If not, it can be
      retrieved online at http://www.erlang.org/.

      Software distributed under the License is distributed on an "AS IS"
      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
      the License for the specific language governing rights and limitations
      under the License.

    </legalnotice>

    <title>ssh_sftp</title>
    <prepared>OTP</prepared>
    <date>2005-09-22</date>
    <file>ssh_sftp.sgml</file>
  </header>
  <module>ssh_sftp</module>
  <modulesummary>SFTP client.</modulesummary>
  <description>
    <p>This module implements an SFTP (SSH FTP) client. SFTP is a
    secure, encrypted file transfer service available for
    SSH.</p>
  </description>
  
 <section>
    <title>DATA TYPES </title>
    <p>Type definitions that are used more than once in this module
    and/or abstractions to indicate the intended use of the data type:
    </p>
    <p><c>ssh_connection_ref() - opaque to the user
    returned by ssh:connect/3</c></p>
    <p><c>timeout() =  infinity | integer() - in milliseconds.</c></p>    
   </section>

 <section>
    <title>TIMEOUTS </title>
    <p>If the request functions for the SFTP channel return {error, timeout}
    it does not guarantee that the request did not reach the server and was
    not performed, it only means that we did not receive an answer from the
    server within the time that was expected.</p>
   </section>

  <funcs>
    <func>
      <name>start_channel(ConnectionRef) -> </name>
      <name>start_channel(ConnectionRef, Options) -> </name>
      <name>start_channel(Host, Options) -></name>
      <name>start_channel(Host, Port, Options) -> {ok, Pid} | {ok, Pid, ConnectionRef} |
      {error, Reason}</name>
      <fsummary>Starts a SFTP client</fsummary>
      <type>
        <v>Host = string()</v>
        <v>ConnectionRef = ssh_connection_ref()</v>
        <v>Port = integer()</v>
        <v>Options = [{Option, Value}]</v>
        <v>Reason = term()</v>
      </type>
      <desc>
	<p>If no connection reference is provided, a connection is set
	up and the new connection is returned.  An SSH channel process
	is started to handle the communication with the SFTP server.
	The returned pid for this process should be used as input to
	all other API functions in this module.</p>

	<p>Options are:</p>
	<taglist>
          <tag><c><![CDATA[{timeout, timeout()}]]></c></tag>
	  <item>
	    <p>The timeout is passed to the ssh_channel start function,
	    and defaults to infinity.</p>
	  </item>
	  <tag>
	    <p><c><![CDATA[{sftp_vsn, integer()}]]></c></p>
	  </tag>
	  <item>
	    <p>
	      Desired SFTP protocol version.
	      The actual version will be the minimum of
	      the desired version and the maximum supported
	      versions by the SFTP server.
	    </p>
	  </item>
	</taglist>
	<p>All other options are  directly passed to
	<seealso marker="ssh">ssh:connect/3</seealso> or ignored if a
	connection is already provided. </p>
      </desc>
    </func>

    <func>
      <name>stop_channel(ChannelPid) -> ok</name>
      <fsummary>Stops the SFTP client channel.</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
      </type>
      <desc>
	<p>Stops an SFTP channel. Does not close the SSH connetion.
	Use <seealso marker="ssh">ssh:close/1</seealso> to close it.</p>
      </desc>
    </func>
  
    <func>
      <name>read_file(ChannelPid, File) -> </name>
      <name>read_file(ChannelPid, File, Timeout) -> {ok, Data} | {error, Reason}</name>
      <fsummary>Read a file</fsummary>
      <type>
	<v>ChannelPid = pid()</v>
	<v>File = string()</v>
        <v>Data = binary()</v>
	<v>Timeout = timeout()</v>
	<v>Reason = term()</v>
      </type>
      <desc>
        <p>Reads a file from the server, and returns the data in a binary,
          like <c><![CDATA[file:read_file/1]]></c>.</p>
      </desc>
    </func>
    <func>
      <name>write_file(ChannelPid, File, Iolist) -> </name>
      <name>write_file(ChannelPid, File, Iolist, Timeout) -> ok | {error, Reason}</name>
      <fsummary>Write a file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>File = string()</v>
        <v>Iolist = iolist()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Writes a file to the server, like
        <c><![CDATA[file:write_file/2]]></c>.  The file is created if
        it does not exist or is owerwritten if it does.</p>
      </desc>
    </func>
    <func>
      <name>list_dir(ChannelPid, Path) -> </name>
      <name>list_dir(ChannelPid, Path, Timeout) -> {ok, Filenames} | {error, Reason}</name>
      <fsummary>List directory</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Path = string()</v>
        <v>Filenames = [Filename]</v>
        <v>Filename = string()</v>
	<v>Timeout = timeout()</v>
	<v>Reason = term()</v>
      </type>
      <desc>
        <p>Lists the given directory on the server, returning the
          filenames as a list of strings.</p>
      </desc>
    </func>
    <func>
      <name>open(ChannelPid, File, Mode) -> </name>
      <name>open(ChannelPid, File, Mode, Timeout) -> {ok, Handle} | {error, Reason}</name>
      <fsummary>Open a file and return a handle</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>File = string()</v>
        <v>Mode = [Modeflag]</v>
        <v>Modeflag = read | write | creat | trunc | append | binary</v>
	<v>Timeout = timeout()</v>
	<v>Handle = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Opens a file on the server, and returns a handle that
          can be used for reading or writing.</p>
      </desc>
    </func>
    <func>
      <name>opendir(ChannelPid, Path) -> </name>
      <name>opendir(ChannelPid, Path, Timeout) -> {ok, Handle} | {error, Reason}</name>
      <fsummary>Open a directory and return a handle</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Path = string()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Opens a handle to a directory on the server, the handle
          can be used for reading directory contents.</p>
      </desc>
    </func>

    <func>
      <name>open_tar(ChannelPid, Path, Mode) -></name>
      <name>open_tar(ChannelPid, Path, Mode, Timeout) -> {ok, Handle} | {error, Reason}</name>
      <fsummary>Opens a tar file on the server to which <v>ChannelPid</v> is connected and returns a handle</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Path = string()</v>
	<v>Mode = [read] | [write] | [read,EncryptOpt] | [write,DecryptOpt] </v>
	<v>EncryptOpt = {crypto,{InitFun,EncryptFun,CloseFun}}</v>
	<v>DecryptOpt = {crypto,{InitFun,DecryptFun}}</v>
	<v>InitFun = (fun() -> {ok,CryptoState}) | (fun() -> {ok,CryptoState,ChunkSize}) </v>
	<v>CryptoState = any()</v>
	<v>ChunkSize = undefined | pos_integer()</v>
	<v>EncryptFun = (fun(PlainBin,CryptoState) -> EncryptResult)</v>
	<v>EncryptResult = {ok,EncryptedBin,CryptoState} | {ok,EncryptedBin,CryptoState,ChunkSize}</v>
	<v>PlainBin = binary()</v>
	<v>EncryptedBin = binary()</v>
	<v>DecryptFun = (fun(EncryptedBin,CryptoState) -> DecryptResult)</v>
	<v>DecryptResult = {ok,PlainBin,CryptoState} | {ok,PlainBin,CryptoState,ChunkSize}</v>
	<v>CloseFun = (fun(PlainBin,CryptoState) -> {ok,EncryptedBin})</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Opens a handle to a tar file on the server associated with <c>ChannelPid</c>. The handle
	can be used for remote tar creation and extraction as defined by the
	<seealso marker="stdlib:erl_tar#init/3">erl_tar:init/3</seealso> function.
	</p>
	<p>An example of writing and then reading a tar file:</p>
        <code type="none">
          {ok,HandleWrite} = ssh_sftp:open_tar(ChannelPid, ?tar_file_name, [write]),
          ok = erl_tar:add(HandleWrite, .... ),
          ok = erl_tar:add(HandleWrite, .... ),
              ...
          ok = erl_tar:add(HandleWrite, .... ),
          ok = erl_tar:close(HandleWrite),

          %% And for reading
          {ok,HandleRead} = ssh_sftp:open_tar(ChannelPid, ?tar_file_name, [read]),
          {ok,NameValueList} = erl_tar:extract(HandleRead,[memory]),
          ok = erl_tar:close(HandleRead),
        </code>

	<p>The <c>crypto</c> mode option is applied to the generated stream of bytes just prior to sending
	them to the sftp server.  This is intended for encryption but could of course be used for other
	purposes.
	</p>
	<p>The <c>InitFun</c> is applied once
	prior to any other crypto operation. The returned <c>CryptoState</c> is then folded into
	repeated applications of the <c>EncryptFun</c> or <c>DecryptFun</c>.  The binary returned
	from those Funs are sent further to the remote sftp server. Finally - if doing encryption
	- the <c>CloseFun</c> is applied to the last piece of data.  The <c>CloseFun</c> is
	responsible for padding (if needed) and encryption of that last piece.
	</p>
	<p>The <c>ChunkSize</c> defines the size of the <c>PlainBin</c>s that <c>EncodeFun</c> is applied
	to. If the <c>ChunkSize</c> is <c>undefined</c> the size of the <c>PlainBin</c>s varies because
	this is	inteded for stream crypto while a fixed  <c>ChunkSize</c> is intended for block crypto. It
	is possible to change the  <c>ChunkSize</c>s in the return from the <c>EncryptFun</c> or
	<c>DecryptFun</c>. It is in fact possible to change the value between <c>pos_integer()</c> and
	<c>undefined</c>.
	</p>
	<p>The write and read example above can be extended with encryption and decryption:</p>
        <code type="none">
          %% First three parameters depending on which crypto type we select:
          Key = &lt;&lt;"This is a 256 bit key. abcdefghi">>,
          Ivec0 = crypto:rand_bytes(16),
          DataSize = 1024,  % DataSize rem 16 = 0 for aes_cbc

          %% Initialization of the CryptoState, in this case it is the Ivector.
          InitFun = fun() -> {ok, Ivec0, DataSize} end,

          %% How to encrypt:
          EncryptFun = 
              fun(PlainBin,Ivec) -> 
                   EncryptedBin = crypto:block_encrypt(aes_cbc256, Key, Ivec, PlainBin),
                   {ok, EncryptedBin, crypto:next_iv(aes_cbc,EncryptedBin)}
              end,

          %% What to do with the very last block:
          CloseFun = 
              fun(PlainBin, Ivec) ->
                    EncryptedBin = crypto:block_encrypt(aes_cbc256, Key, Ivec, 
                                                     pad(16,PlainBin) %% Last chunk
                                                     ),
                    {ok, EncryptedBin} 
            end,

          Cw = {InitFun,EncryptFun,CloseFun},
          {ok,HandleWrite} = ssh_sftp:open_tar(ChannelPid, ?tar_file_name, [write,{crypto,Cw}]),
          ok = erl_tar:add(HandleWrite, .... ),
          ok = erl_tar:add(HandleWrite, .... ),
              ...
          ok = erl_tar:add(HandleWrite, .... ),
          ok = erl_tar:close(HandleWrite),

          %% And for decryption (in this crypto example we could use the same InitFun
          %% as for encryption):
          DecryptFun = 
              fun(EncryptedBin,Ivec) ->
                   PlainBin = crypto:block_decrypt(aes_cbc256, Key, Ivec, EncryptedBin),
                   {ok, PlainBin, crypto:next_iv(aes_cbc,EncryptedBin)}
              end,

          Cr = {InitFun,DecryptFun},
          {ok,HandleRead} = ssh_sftp:open_tar(ChannelPid, ?tar_file_name, [read,{crypto,Cw}]),
          {ok,NameValueList} = erl_tar:extract(HandleRead,[memory]),
          ok = erl_tar:close(HandleRead),
        </code>
      </desc>
    </func>

    <func>
      <name>close(ChannelPid, Handle) -> </name>
      <name>close(ChannelPid, Handle, Timeout) -> ok | {error, Reason}</name>
      <fsummary>Close an open handle</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Handle = term()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Closes a handle to an open file or directory on the server.</p>
      </desc>
    </func>
    <func>
      <name>read(ChannelPid, Handle, Len) -> </name>
      <name>read(ChannelPid, Handle, Len, Timeout) -> {ok, Data} | eof | {error, Error}</name>
      <name>pread(ChannelPid, Handle, Position, Len) -> </name>
      <name>pread(ChannelPid, Handle, Position, Len, Timeout) -> {ok, Data} | eof | {error, Error}</name>
      <fsummary>Read from an open file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Handle = term()</v>
        <v>Position = integer()</v>
        <v>Len = integer()</v>
	<v>Timeout = timeout()</v>
        <v>Data = string() | binary()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Reads <c><![CDATA[Len]]></c> bytes from the file referenced by
          <c><![CDATA[Handle]]></c>. Returns <c><![CDATA[{ok, Data}]]></c>, <c><![CDATA[eof]]></c>, or
          <c><![CDATA[{error, Reason}]]></c>. If the file is opened with <c><![CDATA[binary]]></c>,
          <c><![CDATA[Data]]></c> is a binary, otherwise it is a string.</p>
        <p>If the file is read past eof, only the remaining bytes
          will be read and returned. If no bytes are read, <c><![CDATA[eof]]></c>
          is returned.</p>
        <p>The <c><![CDATA[pread]]></c> function reads from a specified position,
          combining the <c><![CDATA[position]]></c> and <c><![CDATA[read]]></c> functions.</p>
      </desc>
    </func>
    <func>
      <name>aread(ChannelPid, Handle, Len) -> {async, N} | {error, Error}</name>
      <name>apread(ChannelPid, Handle, Position, Len) -> {async, N} | {error, Error}</name>
      <fsummary>Read asynchronously from an open file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Handle = term()</v>
        <v>Position = integer()</v>
        <v>Len = integer()</v>
        <v>N = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Reads from an open file, without waiting for the result. If the
          handle is valid, the function returns <c><![CDATA[{async, N}]]></c>, where N
          is a term guaranteed to be unique between calls of <c><![CDATA[aread]]></c>. 
          The actual data is sent as a message to the calling process. This
          message has the form <c><![CDATA[{async_reply, N, Result}]]></c>, where
          <c><![CDATA[Result]]></c> is the result from the read, either <c><![CDATA[{ok, Data}]]></c>,
          or <c><![CDATA[eof]]></c>, or <c><![CDATA[{error, Error}]]></c>.</p>
        <p>The <c><![CDATA[apread]]></c> function reads from a specified position,
          combining the <c><![CDATA[position]]></c> and <c><![CDATA[aread]]></c> functions.</p>
      </desc>
    </func>
    <func>
      <name>write(ChannelPid, Handle, Data) -></name>
      <name>write(ChannelPid, Handle, Data, Timeout) -> ok | {error, Error}</name>
      <name>pwrite(ChannelPid, Handle, Position, Data) -> ok </name>
      <name>pwrite(ChannelPid, Handle, Position, Data, Timeout) -> ok | {error, Error}</name>
      <fsummary>Write to an open file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Handle = term()</v>
        <v>Position = integer()</v>
        <v>Data = iolist()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Writes<c><![CDATA[data]]></c> to the file referenced by <c><![CDATA[Handle]]></c>.
          The file should be opened with <c><![CDATA[write]]></c> or <c><![CDATA[append]]></c>
          flag. Returns <c><![CDATA[ok]]></c> if successful or S<c><![CDATA[{error, Reason}]]></c>
          otherwise.</p>
        <p>Typical error reasons are:</p>
        <taglist>
          <tag><c><![CDATA[ebadf]]></c></tag>
          <item>
            <p>The file is not opened for writing.</p>
          </item>
          <tag><c><![CDATA[enospc]]></c></tag>
          <item>
            <p>There is a no space left on the device.</p>
          </item>
        </taglist>
      </desc>
    </func>
    <func>
      <name>awrite(ChannelPid, Handle, Data) -> ok | {error, Reason} </name>
      <name>apwrite(ChannelPid, Handle, Position, Data) -> ok | {error, Reason}</name>
      <fsummary>Write asynchronously to an open file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Handle = term()</v>
        <v>Position = integer()</v>
        <v>Len = integer()</v>
        <v>Data = binary()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Writes to an open file, without waiting for the result. If the
          handle is valid, the function returns <c><![CDATA[{async, N}]]></c>, where N
          is a term guaranteed to be unique between calls of
          <c><![CDATA[awrite]]></c>. The result of the <c><![CDATA[write]]></c> operation is sent
          as a message to the calling process. This message has the form
          <c><![CDATA[{async_reply, N, Result}]]></c>, where <c><![CDATA[Result]]></c> is the result
          from the write, either <c><![CDATA[ok]]></c>, or <c><![CDATA[{error, Error}]]></c>.</p>
        <p>The <c><![CDATA[apwrite]]></c> writes on a specified position, combining
          the <c><![CDATA[position]]></c> and <c><![CDATA[awrite]]></c> operations.</p>
      </desc>
    </func>
    <func>
      <name>position(ChannelPid, Handle, Location) -> </name>
      <name>position(ChannelPid, Handle, Location, Timeout) -> {ok, NewPosition | {error, Error}</name>
      <fsummary>Seek position in open file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Handle = term()</v>
        <v>Location = Offset | {bof, Offset} | {cur, Offset} | {eof, Offset} | bof | cur | eof</v>
        <v>Offset = integer()</v>
	<v>Timeout = timeout()</v>
        <v>NewPosition = integer()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Sets the file position of the file referenced by <c><![CDATA[Handle]]></c>.
          Returns <c><![CDATA[{ok, NewPosition}]]></c> (as an absolute offset) if
          successful, otherwise <c><![CDATA[{error, Reason}]]></c>. <c><![CDATA[Location]]></c> is
          one of the following:</p>
        <taglist>
          <tag><c><![CDATA[Offset]]></c></tag>
          <item>
            <p>The same as <c><![CDATA[{bof, Offset}]]></c>.</p>
          </item>
          <tag><c><![CDATA[{bof, Offset}]]></c></tag>
          <item>
            <p>Absolute offset.</p>
          </item>
          <tag><c><![CDATA[{cur, Offset}]]></c></tag>
          <item>
            <p>Offset from the current position.</p>
          </item>
          <tag><c><![CDATA[{eof, Offset}]]></c></tag>
          <item>
            <p>Offset from the end of file.</p>
          </item>
          <tag><c><![CDATA[bof | cur | eof]]></c></tag>
          <item>
            <p>The same as above with <c><![CDATA[Offset]]></c> 0.</p>
          </item>
        </taglist>
      </desc>
    </func>
    <func>
      <name>read_file_info(ChannelPid, Name) -> </name>
      <name>read_file_info(ChannelPid, Name, Timeout) -> {ok, FileInfo} | {error, Reason}</name>
      <fsummary>Get information about a file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Name = string()</v>
        <v>Handle = term()</v>
	<v>Timeout = timeout()</v>
        <v>FileInfo = record()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Returns a <c><![CDATA[file_info]]></c> record from the file specified by
          <c><![CDATA[Name]]></c> or <c><![CDATA[Handle]]></c>, like <c><![CDATA[file:read_file_info/2]]></c>.</p>
      </desc>
    </func>
    <func>
      <name>read_link_info(ChannelPid, Name) -> {ok, FileInfo} | {error, Reason}</name>
      <name>read_link_info(ChannelPid, Name, Timeout) -> {ok, FileInfo} | {error, Reason}</name>
      <fsummary>Get information about a symbolic link</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Name = string()</v>
        <v>Handle = term()</v>
	<v>Timeout = timeout()</v>
        <v>FileInfo = record()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Returns a <c><![CDATA[file_info]]></c> record from the symbolic
          link specified by <c><![CDATA[Name]]></c> or <c><![CDATA[Handle]]></c>, like
          <c><![CDATA[file:read_link_info/2]]></c>.</p>
      </desc>
    </func>
    <func>
      <name>write_file_info(ChannelPid, Name, Info) -> </name>
      <name>write_file_info(ChannelPid, Name, Info, Timeout) -> ok | {error, Reason}</name>
      <fsummary>Write information for a file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Name = string()</v>
        <v>Info = record()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Writes file information from a <c><![CDATA[file_info]]></c> record to the
          file specified by <c><![CDATA[Name]]></c>, like <c><![CDATA[file:write_file_info]]></c>.</p>
      </desc>
    </func>
    <func>
      <name>read_link(ChannelPid, Name) -> </name>
      <name>read_link(ChannelPid, Name, Timeout) -> {ok, Target} | {error, Reason}</name>
      <fsummary>Read symbolic link</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Name = string()</v>
        <v>Target = string()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Reads the link target from the symbolic link specified
          by <c><![CDATA[name]]></c>, like <c><![CDATA[file:read_link/1]]></c>.</p>
      </desc>
    </func>
    <func>
      <name>make_symlink(ChannelPid, Name, Target) -> </name>
      <name>make_symlink(ChannelPid, Name, Target, Timeout) -> ok | {error, Reason}</name>
      <fsummary>Create symbolic link</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Name = string()</v>
        <v>Target = string()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Creates a symbolic link pointing to <c><![CDATA[Target]]></c> with the
          name <c><![CDATA[Name]]></c>, like <c><![CDATA[file:make_symlink/2]]></c>.</p>
      </desc>
    </func>
    <func>
      <name>rename(ChannelPid, OldName, NewName) ->  </name>
      <name>rename(ChannelPid, OldName, NewName, Timeout) -> ok | {error, Reason}</name>
      <fsummary>Rename a file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>OldName = string()</v>
        <v>NewName = string()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Renames a file named <c><![CDATA[OldName]]></c>, and gives it the name
          <c><![CDATA[NewName]]></c>, like <c><![CDATA[file:rename/2]]></c></p>
      </desc>
    </func>
    <func>
      <name>delete(ChannelPid, Name) -> </name>
      <name>delete(ChannelPid, Name, Timeout) -> ok | {error, Reason}</name>
      <fsummary>Delete a file</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Name = string()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Deletes the file specified by <c><![CDATA[Name]]></c>, like
          <c><![CDATA[file:delete/1]]></c></p>
      </desc>
    </func>
    <func>
      <name>make_dir(ChannelPid, Name) -> </name>
      <name>make_dir(ChannelPid, Name, Timeout) -> ok | {error, Reason}</name>
      <fsummary>Create a directory</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Name = string()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
        <p>Creates a directory specified by <c><![CDATA[Name]]></c>. <c><![CDATA[Name]]></c> should
          be a full path to a new directory. The directory can only be
          created in an existing directory.</p>
      </desc>
    </func>
    <func>
      <name>del_dir(ChannelPid, Name) -> </name>
      <name>del_dir(ChannelPid, Name, Timeout) -> ok | {error, Reason}</name>
      <fsummary>Delete an empty directory</fsummary>
      <type>
        <v>ChannelPid = pid()</v>
        <v>Name = string()</v>
	<v>Timeout = timeout()</v>
        <v>Reason = term()</v>
      </type>
      <desc>
	<p>Deletes a directory specified by <c><![CDATA[Name]]></c>.
	Note that the directory must be empty before it can be successfully deleted
	</p>
      </desc>
    </func>
  
  </funcs>
   
</erlref>