ssh_sftp - SFTP client.

sftp_option() =
           {timeout, timeout()} |
           {sftp_vsn, integer() >= 1} |
           {window_size, integer() >= 1} |
           {packet_size, integer() >= 1}

   Errorcausereason() = atom() | string() | tuple()

              A description of the reason why an operation failed.

              The atom() value is formed from the sftp error codes in the protocol-level responses as defined in
              draft-ietf-secsh-filexfer-13 section 9.1. The codes are named as SSH_FX_*  which  are  transformed
              into  lowercase  of the star-part. E.g. the error code SSH_FX_NO_SUCH_FILE will cause the reason()
              to be no_such_file.

              The string() reason is the error information from the server in case of an  exit-signal.  If  that
              information is empty, the reason is the exit signal name.

              The tuple() reason are other errors like for example {exit_status,1}.

   Cryptooperationsforopen_tartar_crypto_spec() = encrypt_spec() | decrypt_spec()

       encrypt_spec() = {init_fun(), crypto_fun(), final_fun()}

       decrypt_spec() = {init_fun(), crypto_fun()}

              Specifies the encryption or decryption applied to tar files when using open_tar/3 or open_tar/4.

              The  encryption  or  decryption  is  applied to the generated stream of bytes prior to sending the
              resulting stream to the SFTP server.

              For code examples see Section Example with encryption in the ssh Users Guide.

       init_fun() =
           fun(() -> {ok, crypto_state()}) |
           fun(() -> {ok, crypto_state(), chunk_size()})

       chunk_size() = undefined | integer() >= 1

       crypto_state() = any()

              The init_fun() in the tar_crypto_spec is applied once prior to any  other  crypto  operation.  The
              intention  is  that  this  function  initiates the encryption or decryption for example by calling
              crypto:crypto_init/4 or similar. The crypto_state() is the state such a function may return.

              If the selected cipher needs to have the input data partioned into blocks of a certain  size,  the
              init_fun()  should  return  the second form of return value with the chunk_size() set to the block
              size. If the chunk_size() is undefined, the size of the PlainBins varies, because this is intended
              for stream crypto, whereas a fixed chunk_size() is intended for block crypto. A  chunk_size()  can
              be changed in the return from the crypto_fun(). The value can be changed between pos_integer() and
              undefined.

       crypto_fun() =
           fun((TextIn :: binary(), crypto_state()) -> crypto_result())

       crypto_result() =
           {ok, TextOut :: binary(), crypto_state()} |
           {ok, TextOut :: binary(), crypto_state(), chunk_size()}

              The  initial  crypto_state()  returned from the init_fun() is folded into repeated applications of
              the crypto_fun() in the tar_crypto_spec. The binary returned from that fun is sent to  the  remote
              SFTP server and the new crypto_state() is used in the next call of the crypto_fun().

              If the crypto_fun() reurns a chunk_size(), that value is as block size for further blocks in calls
              to crypto_fun().

       final_fun() =
           fun((FinalTextIn :: binary(), crypto_state()) ->
                   {ok, FinalTextOut :: binary()})

              If  doing encryption, the final_fun() in the tar_crypto_spec is applied to the last piece of data.
              The final_fun() is responsible for padding (if needed) and encryption of that last piece.

       This  module  implements  an  SSH  FTP  (SFTP)  client. SFTP is a secure, encrypted file transfer service
       available for SSH.

apread(ChannelPid,Handle,Position,Len)->{async,N}|Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Position = Len = integer()
                 Error = {error, reason()}
                 N = term()

              The apread/4 function reads from a  specified  position,  combining  the  position/3  and  aread/3
              functions.

       apwrite(ChannelPid,Handle,Position,Data)->{async,N}|Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Position = integer()
                 Data = binary()
                 Error = {error, reason()}
                 N = term()

              The  apwrite/4  function  writes  to  a  specified position, combining the position/3 and awrite/3
              functions.

       aread(ChannelPid,Handle,Len)->{async,N}|Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Len = integer()
                 Error = {error, reason()}
                 N = term()

              Reads from an open file, without waiting for the result. If the  handle  is  valid,  the  function
              returns  {async,N}, where N is a term guaranteed to be unique between calls of aread. The actual
              data is sent as a message to the calling process. This  message  has  the  form  {async_reply,N,Result}, where Result is the result from the read, either {ok,Data}, eof, or {error,reason()}.

       awrite(ChannelPid,Handle,Data)->{async,N}|Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Data = binary()
                 Error = {error, reason()}
                 N = term()

              Writes  to  an  open  file,  without  waiting for the result. If the handle is valid, the function
              returns {async,N}, where N is a term guaranteed to be unique between calls of awrite. The  result
              of  the  write  operation  is  sent as a message to the calling process. This message has the form
              {async_reply,N,Result}, where Result is the  result  from  the  write,  either  ok,  or  {error,reason()}.

       close(ChannelPid,Handle)->ok|Errorclose(ChannelPid,Handle,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Timeout = timeout()
                 Error = {error, reason()}

              Closes a handle to an open file or directory on the server.

       delete(ChannelPid,Name)->ok|Errordelete(ChannelPid,Name,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 Name = string()
                 Timeout = timeout()
                 Error = {error, reason()}

              Deletes the file specified by Name.

       del_dir(ChannelPid,Name)->ok|Errordel_dir(ChannelPid,Name,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 Name = string()
                 Timeout = timeout()
                 Error = {error, reason()}

              Deletes  a  directory specified by Name. The directory must be empty before it can be successfully
              deleted.

       list_dir(ChannelPid,Path)->{ok,FileNames}|Errorlist_dir(ChannelPid,Path,Timeout)->{ok,FileNames}|Error

              Types:

                 ChannelPid = pid()
                 Path = string()
                 Timeout = timeout()
                 FileNames = [FileName]
                 FileName = string()
                 Error = {error, reason()}

              Lists the given directory on the server, returning the filenames as a list of strings.

       make_dir(ChannelPid,Name)->ok|Errormake_dir(ChannelPid,Name,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 Name = string()
                 Timeout = timeout()
                 Error = {error, reason()}

              Creates a directory specified by Name. Name must be a full path to a new directory. The  directory
              can only be created in an existing directory.

       make_symlink(ChannelPid,Name,Target)->ok|Errormake_symlink(ChannelPid,Name,Target,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 Name = Target = string()
                 Timeout = timeout()
                 Error = {error, reason()}

              Creates a symbolic link pointing to Target with the name Name.

       open(ChannelPid,Name,Mode)->{ok,Handle}|Erroropen(ChannelPid,Name,Mode,Timeout)->{ok,Handle}|Error

              Types:

                 ChannelPid = pid()
                 Name = string()
                 Mode = [read | write | append | binary | raw]
                 Timeout = timeout()
                 Handle = term()
                 Error = {error, reason()}

              Opens a file on the server and returns a handle, which can be used for reading or writing.

       opendir(ChannelPid,Path)->{ok,Handle}|Erroropendir(ChannelPid,Path,Timeout)->{ok,Handle}|Error

              Types:

                 ChannelPid = pid()
                 Path = string()
                 Timeout = timeout()
                 Handle = term()
                 Error = {error, reason()}

              Opens  a  handle  to  a  directory  on  the  server.  The handle can be used for reading directory
              contents.

       open_tar(ChannelPid,Path,Mode)->{ok,Handle}|Erroropen_tar(ChannelPid,Path,Mode,Timeout)->{ok,Handle}|Error

              Types:

                 ChannelPid = pid()
                 Path = string()
                 Mode = [read | write | {crypto, tar_crypto_spec()}]
                 Timeout = timeout()
                 Handle = term()
                 Error = {error, reason()}

              Opens a handle to a tar file on the server, associated with ChannelPid. The handle can be used for
              remote tar creation and extraction. The actual writing  and  reading  is  performed  by  calls  to
              erl_tar:add/3,4  and  erl_tar:extract/2.  Note:  The erl_tar:init/3 function should not be called,
              that one is called by this open_tar function.

              For code examples see Section SFTP Client with TAR Compression in the ssh Users Guide.

              The crypto mode option is explained in the data types section above,  see  Crypto  operations  for
              open_tar.  Encryption  is  assumed if the Mode contains write, and decryption if the Mode contains
              read.

       position(ChannelPid,Handle,Location)->
                   {ok, NewPosition} | Error

       position(ChannelPid,Handle,Location,Timeout)->
                   {ok, NewPosition} | Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Location =
                     Offset |
                     {bof, Offset} |
                     {cur, Offset} |
                     {eof, Offset} |
                     bof | cur | eof
                 Timeout = timeout()
                 Offset = NewPosition = integer()
                 Error = {error, reason()}

              Sets the file position of the file referenced by Handle. Returns {ok,NewPosition} (as an absolute
              offset) if successful, otherwise {error,reason()}. Location is one of the following:

                Offset:
                  The same as {bof,Offset}.

                {bof,Offset}:
                  Absolute offset.

                {cur,Offset}:
                  Offset from the current position.

                {eof,Offset}:
                  Offset from the end of file.

                bof|cur|eof:
                  The same as eariler with Offset 0, that is, {bof,0}|{cur,0}|{eof,0}.

       pread(ChannelPid,Handle,Position,Len)->
                {ok, Data} | eof | Error

       pread(ChannelPid,Handle,Position,Len,Timeout)->
                {ok, Data} | eof | Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Position = Len = integer()
                 Timeout = timeout()
                 Data = string() | binary()
                 Error = {error, reason()}

              The pread/3,4 function reads from a specified position,  combining  the  position/3  and  read/3,4
              functions.

       pwrite(ChannelPid,Handle,Position,Data)->ok|Errorpwrite(ChannelPid,Handle,Position,Data,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Position = integer()
                 Data = iolist()
                 Timeout = timeout()
                 Error = {error, reason()}

              The  pwrite/3,4  function  writes  to a specified position, combining the position/3 and write/3,4
              functions.

       read(ChannelPid,Handle,Len)->{ok,Data}|eof|Errorread(ChannelPid,Handle,Len,Timeout)->{ok,Data}|eof|Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Len = integer()
                 Timeout = timeout()
                 Data = string() | binary()
                 Error = {error, reason()}

              Reads Len bytes from the file referenced by Handle. Returns {ok,Data}, eof, or {error,reason()}.
              If the file is opened with binary, Data is a binary, otherwise it is a string.

              If the file is read past eof, only the remaining bytes are read and  returned.  If  no  bytes  are
              read, eof is returned.

       read_file(ChannelPid,File)->{ok,Data}|Errorread_file(ChannelPid,File,Timeout)->{ok,Data}|Error

              Types:

                 ChannelPid = pid()
                 File = string()
                 Data = binary()
                 Timeout = timeout()
                 Error = {error, reason()}

              Reads a file from the server, and returns the data in a binary.

       read_file_info(ChannelPid,Name)->{ok,FileInfo}|Errorread_file_info(ChannelPid,Name,Timeout)->
                         {ok, FileInfo} | Error

              Types:

                 ChannelPid = pid()
                 Name = string()
                 Timeout = timeout()
                 FileInfo = file:file_info()
                 Error = {error, reason()}

              Returns  a  file_info  record  from  the  file  system  object  specified  by  Name or Handle. See
              file:read_file_info/2 for information about the record.

              Depending on the underlying OS:es links might be followed and info on the  final  file,  directory
              etc is returned. See read_link_info/2 on how to get information on links instead.

       read_link(ChannelPid,Name)->{ok,Target}|Errorread_link(ChannelPid,Name,Timeout)->{ok,Target}|Error

              Types:

                 ChannelPid = pid()
                 Name = Target = string()
                 Timeout = timeout()
                 Error = {error, reason()}

              Reads the link target from the symbolic link specified by name.

       read_link_info(ChannelPid,Name)->{ok,FileInfo}|Errorread_link_info(ChannelPid,Name,Timeout)->
                         {ok, FileInfo} | Error

              Types:

                 ChannelPid = pid()
                 Name = string()
                 FileInfo = file:file_info()
                 Timeout = timeout()
                 Error = {error, reason()}

              Returns   a   file_info   record  from  the  symbolic  link  specified  by  Name  or  Handle.  See
              file:read_link_info/2 for information about the record.

       rename(ChannelPid,OldName,NewName)->ok|Errorrename(ChannelPid,OldName,NewName,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 OldName = NewName = string()
                 Timeout = timeout()
                 Error = {error, reason()}

              Renames a file named OldName and gives it the name NewName.

       start_channel(ConnectionRef)->start_channel(ConnectionRef,SftpOptions)->{ok,ChannelPid}|Errorstart_channel(Host)->start_channel(Host,Options)->start_channel(Host,Port,Options)->start_channel(TcpSocket)->start_channel(TcpSocket,Options)->{ok,ChannelPid,ConnectionRef}|Error

              Types:

                 Host = ssh:host()
                 Port = inet:port_number()
                 TcpSocket = ssh:open_socket()
                 Options = [ sftp_option() | ssh:client_option() ]
                 SftpOptions = [ sftp_option() ]
                 ChannelPid = pid()
                 ConnectionRef = ssh:connection_ref()
                 Error = {error, reason()}

              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 is to be used as input to all other API functions in this module.

              Options:

                {timeout,timeout()}:
                  There are two ways to set a timeout for the underlying ssh connection:

                  * If the connection timeout option connect_timeout is set, that value is  used  also  for  the
                    negotiation timeout and this option (timeout) is ignored.

                  * Otherwise,  this  option  (timeout)  is used as the negotiation timeout only and there is no
                    connection timeout set

                  The value defaults to infinity.

                {sftp_vsn,integer()}:
                  Desired SFTP protocol version. The actual version is the minimum of the  desired  version  and
                  the maximum supported versions by the SFTP server.

              All  other  options  are  directly  passed  to ssh:connect/3 or ignored if a connection is already
              provided.

       stop_channel(ChannelPid)->ok

              Types:

                 ChannelPid = pid()

              Stops an SFTP channel. Does not close the SSH connection. Use ssh:close/1 to close it.

       write(ChannelPid,Handle,Data)->ok|Errorwrite(ChannelPid,Handle,Data,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 Handle = term()
                 Data = iodata()
                 Timeout = timeout()
                 Error = {error, reason()}

              Writes data to the file referenced by Handle. The file is to be opened with write or append  flag.
              Returns ok if successful or {error,reason()} otherwise.

       write_file(ChannelPid,File,Data)->ok|Errorwrite_file(ChannelPid,File,Data,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 File = string()
                 Data = iodata()
                 Timeout = timeout()
                 Error = {error, reason()}

              Writes  a  file  to  the  server.  The  file is created if it does not exist but overwritten if it
              exists.

       write_file_info(ChannelPid,Name,FileInfo)->ok|Errorwrite_file_info(ChannelPid,Name,FileInfo,Timeout)->ok|Error

              Types:

                 ChannelPid = pid()
                 Name = string()
                 FileInfo = file:file_info()
                 Timeout = timeout()
                 Error = {error, reason()}

              Writes  file  information  from  a  file_info  record  to  the  file  specified   by   Name.   See
              file:write_file_info/[2,3] for information about the record.

Ericsson AB                                         ssh 4.13                                      ssh_sftp(3erl)

       ssh_sftp - SFTP client.