SFTP¶
- class paramiko.sftp.int64¶
- class paramiko.sftp_client.SFTP(sock)¶
An alias for
SFTPClient
for backwards compatibility.
- class paramiko.sftp_client.SFTPClient(sock)¶
SFTP client object.
Used to open an SFTP session across an open SSH
Transport
and perform remote file operations.Instances of this class may be used as context managers.
- __init__(sock)¶
Create an SFTP client from an existing
Channel
. The channel should already have requested the"sftp"
subsystem.An alternate way to create an SFTP client context is by using
from_transport
.- Parameters
- Raises
SSHException
– if there’s an exception while negotiating sftp
- chdir(path=None)¶
Change the “current directory” of this SFTP session. Since SFTP doesn’t really have the concept of a current working directory, this is emulated by Paramiko. Once you use this method to set a working directory, all operations on this
SFTPClient
object will be relative to that path. You can pass inNone
to stop using a current working directory.- Parameters
path (str) – new current working directory
- Raises
IOError
– if the requested path doesn’t exist on the server
New in version 1.4.
- chmod(path, mode)¶
Change the mode (permissions) of a file. The permissions are unix-style and identical to those used by Python’s
os.chmod
function.
- chown(path, uid, gid)¶
Change the owner (
uid
) and group (gid
) of a file. As with Python’sos.chown
function, you must pass both arguments, so if you only want to change one, usestat
first to retrieve the current owner and group.
- close()¶
Close the SFTP session and its underlying channel.
New in version 1.4.
- file(filename, mode='r', bufsize=- 1)¶
Open a file on the remote server. The arguments are the same as for Python’s built-in
python:file
(akaopen
). A file-like object is returned, which closely mimics the behavior of a normal Python file object, including the ability to be used as a context manager.The mode indicates how the file is to be opened:
'r'
for reading,'w'
for writing (truncating an existing file),'a'
for appending,'r+'
for reading/writing,'w+'
for reading/writing (truncating an existing file),'a+'
for reading/appending. The Python'b'
flag is ignored, since SSH treats all files as binary. The'U'
flag is supported in a compatible way.Since 1.5.2, an
'x'
flag indicates that the operation should only succeed if the file was created and did not previously exist. This has no direct mapping to Python’s file flags, but is commonly known as theO_EXCL
flag in posix.The file will be buffered in standard Python style by default, but can be altered with the
bufsize
parameter.<=0
turns off buffering,1
uses line buffering, and any number greater than 1 (>1
) uses that specific buffer size.
- classmethod from_transport(t, window_size=None, max_packet_size=None)¶
Create an SFTP client channel from an open
Transport
.Setting the window and packet sizes might affect the transfer speed. The default settings in the
Transport
class are the same as in OpenSSH and should work adequately for both files transfers and interactive sessions.- Parameters
t (Transport) – an open
Transport
which is already authenticatedwindow_size (int) – optional window size for the
SFTPClient
session.max_packet_size (int) – optional max packet size for the
SFTPClient
session..
- Returns
a new
SFTPClient
object, referring to an sftp session (channel) across the transport
Changed in version 1.15: Added the
window_size
andmax_packet_size
arguments.
- get(remotepath, localpath, callback=None, prefetch=True, max_concurrent_prefetch_requests=None)¶
Copy a remote file (
remotepath
) from the SFTP server to the local host aslocalpath
. Any exception raised by operations will be passed through. This method is primarily provided as a convenience.- Parameters
remotepath (str) – the remote file to copy
localpath (str) – the destination path on the local host
callback (callable) – optional callback function (form:
func(int, int)
) that accepts the bytes transferred so far and the total bytes to be transferredprefetch (bool) – controls whether prefetching is performed (default: True)
max_concurrent_prefetch_requests (int) – The maximum number of concurrent read requests to prefetch. When this is
None
(the default), do not limit the number of concurrent prefetch requests. Note: OpenSSH’s sftp internally imposes a limit of 64 concurrent requests, while Paramiko imposes no limit by default; consider setting a limit if a file can be successfully received with sftp but hangs with Paramiko.
New in version 1.4.
Changed in version 1.7.4: Added the
callback
paramChanged in version 2.8: Added the
prefetch
keyword argument.Changed in version 3.3: Added
max_concurrent_prefetch_requests
.
- get_channel()¶
Return the underlying
Channel
object for this SFTP session. This might be useful for doing things like setting a timeout on the channel.New in version 1.7.1.
- getcwd()¶
Return the “current working directory” for this SFTP session, as emulated by Paramiko. If no directory has been set with
chdir
, this method will returnNone
.New in version 1.4.
- getfo(remotepath, fl, callback=None, prefetch=True, max_concurrent_prefetch_requests=None)¶
Copy a remote file (
remotepath
) from the SFTP server and write to an open file or file-like object,fl
. Any exception raised by operations will be passed through. This method is primarily provided as a convenience.- Parameters
remotepath (object) – opened file or file-like object to copy to
fl (str) – the destination path on the local host or open file object
callback (callable) – optional callback function (form:
func(int, int)
) that accepts the bytes transferred so far and the total bytes to be transferredprefetch (bool) – controls whether prefetching is performed (default: True)
max_concurrent_prefetch_requests (int) – The maximum number of concurrent read requests to prefetch. See
SFTPClient.get
(itsmax_concurrent_prefetch_requests
param) for details.
- Returns
the
number
of bytes written to the opened file object
New in version 1.10.
Changed in version 2.8: Added the
prefetch
keyword argument.Changed in version 3.3: Added
max_concurrent_prefetch_requests
.
- listdir(path='.')¶
Return a list containing the names of the entries in the given
path
.The list is in arbitrary order. It does not include the special entries
'.'
and'..'
even if they are present in the folder. This method is meant to mirroros.listdir
as closely as possible. For a list of fullSFTPAttributes
objects, seelistdir_attr
.- Parameters
path (str) – path to list (defaults to
'.'
)
- listdir_attr(path='.')¶
Return a list containing
SFTPAttributes
objects corresponding to files in the givenpath
. The list is in arbitrary order. It does not include the special entries'.'
and'..'
even if they are present in the folder.The returned
SFTPAttributes
objects will each have an additional field:longname
, which may contain a formatted string of the file’s attributes, in unix format. The content of this string will probably depend on the SFTP server implementation.- Parameters
path (str) – path to list (defaults to
'.'
)- Returns
list of
SFTPAttributes
objects
New in version 1.2.
- listdir_iter(path='.', read_aheads=50)¶
Generator version of
listdir_attr
.See the API docs for
listdir_attr
for overall details.This function adds one more kwarg on top of
listdir_attr
:read_aheads
, an integer controlling how manySSH_FXP_READDIR
requests are made to the server. The default of 50 should suffice for most file listings as each request/response cycle may contain multiple files (dependent on server implementation.)New in version 1.15.
- lstat(path)¶
Retrieve information about a file on the remote system, without following symbolic links (shortcuts). This otherwise behaves exactly the same as
stat
.- Parameters
path (str) – the filename to stat
- Returns
an
SFTPAttributes
object containing attributes about the given file
- mkdir(path, mode=511)¶
Create a folder (directory) named
path
with numeric modemode
. The default mode is 0777 (octal). On some systems, mode is ignored. Where it is used, the current umask value is first masked out.
- normalize(path)¶
Return the normalized path (on the server) of a given path. This can be used to quickly resolve symbolic links or determine what the server is considering to be the “current folder” (by passing
'.'
aspath
).
- open(filename, mode='r', bufsize=- 1)¶
Open a file on the remote server. The arguments are the same as for Python’s built-in
python:file
(akaopen
). A file-like object is returned, which closely mimics the behavior of a normal Python file object, including the ability to be used as a context manager.The mode indicates how the file is to be opened:
'r'
for reading,'w'
for writing (truncating an existing file),'a'
for appending,'r+'
for reading/writing,'w+'
for reading/writing (truncating an existing file),'a+'
for reading/appending. The Python'b'
flag is ignored, since SSH treats all files as binary. The'U'
flag is supported in a compatible way.Since 1.5.2, an
'x'
flag indicates that the operation should only succeed if the file was created and did not previously exist. This has no direct mapping to Python’s file flags, but is commonly known as theO_EXCL
flag in posix.The file will be buffered in standard Python style by default, but can be altered with the
bufsize
parameter.<=0
turns off buffering,1
uses line buffering, and any number greater than 1 (>1
) uses that specific buffer size.
- posix_rename(oldpath, newpath)¶
Rename a file or folder from
oldpath
tonewpath
, following posix conventions.
- put(localpath, remotepath, callback=None, confirm=True)¶
Copy a local file (
localpath
) to the SFTP server asremotepath
. Any exception raised by operations will be passed through. This method is primarily provided as a convenience.The SFTP operations use pipelining for speed.
- Parameters
localpath (str) – the local file to copy
remotepath (str) – the destination path on the SFTP server. Note that the filename should be included. Only specifying a directory may result in an error.
callback (callable) – optional callback function (form:
func(int, int)
) that accepts the bytes transferred so far and the total bytes to be transferredconfirm (bool) – whether to do a stat() on the file afterwards to confirm the file size
- Returns
an
SFTPAttributes
object containing attributes about the given file
New in version 1.4.
Changed in version 1.7.4:
callback
and rich attribute return value added.Changed in version 1.7.7:
confirm
param added.
- putfo(fl, remotepath, file_size=0, callback=None, confirm=True)¶
Copy the contents of an open file object (
fl
) to the SFTP server asremotepath
. Any exception raised by operations will be passed through.The SFTP operations use pipelining for speed.
- Parameters
fl – opened file or file-like object to copy
remotepath (str) – the destination path on the SFTP server
file_size (int) – optional size parameter passed to callback. If none is specified, size defaults to 0
callback (callable) – optional callback function (form:
func(int, int)
) that accepts the bytes transferred so far and the total bytes to be transferred (since 1.7.4)confirm (bool) – whether to do a stat() on the file afterwards to confirm the file size (since 1.7.7)
- Returns
an
SFTPAttributes
object containing attributes about the given file.
New in version 1.10.
- readlink(path)¶
Return the target of a symbolic link (shortcut). You can use
symlink
to create these. The result may be either an absolute or relative pathname.
- remove(path)¶
Remove the file at the given path. This only works on files; for removing folders (directories), use
rmdir
.- Parameters
path (str) – path (absolute or relative) of the file to remove
- Raises
IOError
– if the path refers to a folder (directory)
- rename(oldpath, newpath)¶
Rename a file or folder from
oldpath
tonewpath
.Note
This method implements ‘standard’ SFTP
RENAME
behavior; those seeking the OpenSSH “POSIX rename” extension behavior should useposix_rename
.
- stat(path)¶
Retrieve information about a file on the remote system. The return value is an object whose attributes correspond to the attributes of Python’s
stat
structure as returned byos.stat
, except that it contains fewer fields. An SFTP server may return as much or as little info as it wants, so the results may vary from server to server.Unlike a Python
stat
object, the result may not be accessed as a tuple. This is mostly due to the author’s slack factor.The fields supported are:
st_mode
,st_size
,st_uid
,st_gid
,st_atime
, andst_mtime
.- Parameters
path (str) – the filename to stat
- Returns
an
SFTPAttributes
object containing attributes about the given file
- symlink(source, dest)¶
Create a symbolic link to the
source
path atdestination
.
- truncate(path, size)¶
Change the size of the file specified by
path
. This usually extends or shrinks the size of the file, just like thetruncate
method on Python file objects.
- unlink(path)¶
Remove the file at the given path. This only works on files; for removing folders (directories), use
rmdir
.- Parameters
path (str) – path (absolute or relative) of the file to remove
- Raises
IOError
– if the path refers to a folder (directory)
- utime(path, times)¶
Set the access and modified times of the file specified by
path
. Iftimes
isNone
, then the file’s access and modified times are set to the current time. Otherwise,times
must be a 2-tuple of numbers, of the form(atime, mtime)
, which is used to set the access and modified times, respectively. This bizarre API is mimicked from Python for the sake of consistency – I apologize.
Server-mode SFTP support.
- class paramiko.sftp_server.SFTPServer(channel, name, server, sftp_si=<class 'paramiko.sftp_si.SFTPServerInterface'>, *args, **kwargs)¶
Server-side SFTP subsystem support. Since this is a
SubsystemHandler
, it can be (and is meant to be) set as the handler for"sftp"
requests. UseTransport.set_subsystem_handler
to activate this class.- __init__(channel, name, server, sftp_si=<class 'paramiko.sftp_si.SFTPServerInterface'>, *args, **kwargs)¶
The constructor for SFTPServer is meant to be called from within the
Transport
as a subsystem handler.server
and any additional parameters or keyword parameters are passed from the original call toTransport.set_subsystem_handler
.- Parameters
name (str) – name of the requested subsystem.
server (ServerInterface) – the server object associated with this channel and subsystem
sftp_si – a subclass of
SFTPServerInterface
to use for handling individual requests.
- static convert_errno(e)¶
Convert an errno value (as from an
OSError
orIOError
) into a standard SFTP result code. This is a convenience function for trapping exceptions in server code and returning an appropriate result.
- finish_subsystem()¶
Perform any cleanup at the end of a subsystem. The default implementation just closes the channel.
New in version 1.1.
- static set_file_attr(filename, attr)¶
Change a file’s attributes on the local filesystem. The contents of
attr
are used to change the permissions, owner, group ownership, and/or modification & access time of the file, depending on which attributes are present inattr
.This is meant to be a handy helper function for translating SFTP file requests into local file operations.
- Parameters
filename (str) – name of the file to alter (should usually be an absolute path).
attr (SFTPAttributes) – attributes to change.
- start_subsystem(name, transport, channel)¶
Process an ssh subsystem in server mode. This method is called on a new object (and in a new thread) for each subsystem request. It is assumed that all subsystem logic will take place here, and when the subsystem is finished, this method will return. After this method returns, the channel is closed.
The combination of
transport
andchannel
are unique; this handler corresponds to exactly oneChannel
on oneTransport
.Note
It is the responsibility of this method to exit if the underlying
Transport
is closed. This can be done by checkingTransport.is_active
or noticing an EOF on theChannel
. If this method loops forever without checking for this case, your Python interpreter may refuse to exit because this thread will still be running.
- class paramiko.sftp_attr.SFTPAttributes¶
Representation of the attributes of a file (or proxied file) for SFTP in client or server mode. It attempts to mirror the object returned by
os.stat
as closely as possible, so it may have the following fields, with the same meanings as those returned by anos.stat
object:st_size
st_uid
st_gid
st_mode
st_atime
st_mtime
Because SFTP allows flags to have other arbitrary named attributes, these are stored in a dict named
attr
. Occasionally, the filename is also stored, infilename
.- __init__()¶
Create a new (empty) SFTPAttributes object. All fields will be empty.
- __repr__()¶
Return repr(self).
- __str__()¶
create a unix-style long description of the file (like ls -l)
- __weakref__¶
list of weak references to the object (if defined)
- classmethod from_stat(obj, filename=None)¶
Create an
SFTPAttributes
object from an existingstat
object (an object returned byos.stat
).- Parameters
- Returns
new
SFTPAttributes
object with the same attribute fields.
SFTP file object
- class paramiko.sftp_file.SFTPFile(sftp, handle, mode='r', bufsize=- 1)¶
Bases:
paramiko.file.BufferedFile
Proxy object for a file on the remote server, in client mode SFTP.
Instances of this class may be used as context managers in the same way that built-in Python file objects are.
- check(hash_algorithm, offset=0, length=0, block_size=0)¶
Ask the server for a hash of a section of this file. This can be used to verify a successful upload or download, or for various rsync-like operations.
The file is hashed from
offset
, forlength
bytes. Iflength
is 0, the remainder of the file is hashed. Thus, if bothoffset
andlength
are zero, the entire file is hashed.Normally,
block_size
will be 0 (the default), and this method will return a byte string representing the requested hash (for example, a string of length 16 for MD5, or 20 for SHA-1). If a non-zeroblock_size
is given, each chunk of the file (fromoffset
tooffset + length
) ofblock_size
bytes is computed as a separate hash. The hash results are all concatenated and returned as a single string.For example,
check('sha1', 0, 1024, 512)
will return a string of length 40. The first 20 bytes will be the SHA-1 of the first 512 bytes of the file, and the last 20 bytes will be the SHA-1 of the next 512 bytes.- Parameters
hash_algorithm (str) – the name of the hash algorithm to use (normally
"sha1"
or"md5"
)offset – offset into the file to begin hashing (0 means to start from the beginning)
length – number of bytes to hash (0 means continue to the end of the file)
block_size (int) – number of bytes to hash per result (must not be less than 256; 0 means to compute only one hash of the entire segment)
- Returns
str
of bytes representing the hash of each block, concatenated together- Raises
IOError
– if the server doesn’t support the “check-file” extension, or possibly doesn’t support the hash algorithm requested
Note
Many (most?) servers don’t support this extension yet.
New in version 1.4.
- chmod(mode)¶
Change the mode (permissions) of this file. The permissions are unix-style and identical to those used by Python’s
os.chmod
function.- Parameters
mode (int) – new permissions
- chown(uid, gid)¶
Change the owner (
uid
) and group (gid
) of this file. As with Python’sos.chown
function, you must pass both arguments, so if you only want to change one, usestat
first to retrieve the current owner and group.
- close()¶
Close the file.
- flush()¶
Write out any data in the write buffer. This may do nothing if write buffering is not turned on.
- gettimeout()¶
Returns the timeout in seconds (as a
float
) associated with the socket or sshChannel
used for this file.See also
- prefetch(file_size=None, max_concurrent_requests=None)¶
Pre-fetch the remaining contents of this file in anticipation of future
read
calls. If reading the entire file, pre-fetching can dramatically improve the download speed by avoiding roundtrip latency. The file’s contents are incrementally buffered in a background thread.The prefetched data is stored in a buffer until read via the
read
method. Once data has been read, it’s removed from the buffer. The data may be read in a random order (usingseek
); chunks of the buffer that haven’t been read will continue to be buffered.- Parameters
file_size (int) – When this is
None
(the default), this method callsstat
to determine the remote file size. In some situations, doing so can cause exceptions or hangs (see #562); as a workaround, one may callstat
explicitly and pass its value in via this parameter.max_concurrent_requests (int) – The maximum number of concurrent read requests to prefetch. See
SFTPClient.get
(itsmax_concurrent_prefetch_requests
param) for details.
New in version 1.5.1.
Changed in version 1.16.0: The
file_size
parameter was added (with no default value).Changed in version 1.16.1: The
file_size
parameter was made optional for backwards compatibility.Changed in version 3.3: Added
max_concurrent_requests
.
- read(size=None)¶
Read at most
size
bytes from the file (less if we hit the end of the file first). If thesize
argument is negative or omitted, read all the remaining data in the file.Note
'b'
mode flag is ignored (self.FLAG_BINARY
inself._flags
), because SSH treats all files as binary, since we have no idea what encoding the file is in, or even if the file is text data.- Parameters
size (int) – maximum number of bytes to read
- Returns
data read from the file (as bytes), or an empty string if EOF was encountered immediately
- readable()¶
Check if the file can be read from.
- readinto(buff)¶
Read up to
len(buff)
bytes intobytearray
buff and return the number of bytes read.- Returns
The number of bytes read.
- readline(size=None)¶
Read one entire line from the file. A trailing newline character is kept in the string (but may be absent when a file ends with an incomplete line). If the size argument is present and non-negative, it is a maximum byte count (including the trailing newline) and an incomplete line may be returned. An empty string is returned only when EOF is encountered immediately.
Note
Unlike stdio’s
fgets
, the returned string contains null characters ('\0'
) if they occurred in the input.- Parameters
size (int) – maximum length of returned string.
- Returns
next line of the file, or an empty string if the end of the file has been reached.
If the file was opened in binary (
'b'
) mode: bytes are returned Else: the encoding of the file is assumed to be UTF-8 and character strings (str
) are returned
- readlines(sizehint=None)¶
Read all remaining lines using
readline
and return them as a list. If the optionalsizehint
argument is present, instead of reading up to EOF, whole lines totalling approximately sizehint bytes (possibly after rounding up to an internal buffer size) are read.- Parameters
sizehint (int) – desired maximum number of bytes to read.
- Returns
list of lines read from the file.
- readv(chunks, max_concurrent_prefetch_requests=None)¶
Read a set of blocks from the file by (offset, length). This is more efficient than doing a series of
seek
andread
calls, since the prefetch machinery is used to retrieve all the requested blocks at once.- Parameters
chunks – a list of
(offset, length)
tuples indicating which sections of the file to readmax_concurrent_prefetch_requests (int) – The maximum number of concurrent read requests to prefetch. See
SFTPClient.get
(itsmax_concurrent_prefetch_requests
param) for details.
- Returns
a list of blocks read, in the same order as in
chunks
New in version 1.5.4.
Changed in version 3.3: Added
max_concurrent_prefetch_requests
.
- seek(offset, whence=0)¶
Set the file’s current position.
See
file.seek
for details.
- seekable()¶
Check if the file supports random access.
- set_pipelined(pipelined=True)¶
Turn on/off the pipelining of write operations to this file. When pipelining is on, paramiko won’t wait for the server response after each write operation. Instead, they’re collected as they come in. At the first non-write operation (including
close
), all remaining server responses are collected. This means that if there was an error with one of your later writes, an exception might be thrown from withinclose
instead ofwrite
.By default, files are not pipelined.
- Parameters
pipelined (bool) –
True
if pipelining should be turned on for this file;False
otherwise
New in version 1.5.
- setblocking(blocking)¶
Set blocking or non-blocking mode on the underiying socket or ssh
Channel
.- Parameters
blocking (int) – 0 to set non-blocking mode; non-0 to set blocking mode.
See also
- settimeout(timeout)¶
Set a timeout on read/write operations on the underlying socket or ssh
Channel
.- Parameters
timeout (float) – seconds to wait for a pending read/write operation before raising
socket.timeout
, orNone
for no timeout
See also
- stat()¶
Retrieve information about this file from the remote system. This is exactly like
SFTPClient.stat
, except that it operates on an already-open file.- Returns
an
SFTPAttributes
object containing attributes about this file.
- tell()¶
Return the file’s current position. This may not be accurate or useful if the underlying file doesn’t support random access, or was opened in append mode.
- Returns
file position (
number
of bytes).
- truncate(size)¶
Change the size of this file. This usually extends or shrinks the size of the file, just like the
truncate()
method on Python file objects.- Parameters
size – the new size of the file
- utime(times)¶
Set the access and modified times of this file. If
times
isNone
, then the file’s access and modified times are set to the current time. Otherwise,times
must be a 2-tuple of numbers, of the form(atime, mtime)
, which is used to set the access and modified times, respectively. This bizarre API is mimicked from Python for the sake of consistency – I apologize.- Parameters
times (tuple) –
None
or a tuple of (access time, modified time) in standard internet epoch time (seconds since 01 January 1970 GMT)
- writable()¶
Check if the file can be written to.
- write(data)¶
Write data to the file. If write buffering is on (
bufsize
was specified and non-zero), some or all of the data may not actually be written yet. (Useflush
orclose
to force buffered data to be written out.)- Parameters
data –
str
/bytes
data to write
- writelines(sequence)¶
Write a sequence of strings to the file. The sequence can be any iterable object producing strings, typically a list of strings. (The name is intended to match
readlines
;writelines
does not add line separators.)- Parameters
sequence – an iterable sequence of strings.
- xreadlines()¶
Identical to
iter(f)
. This is a deprecated file interface that predates Python iterator support.
Abstraction of an SFTP file handle (for server mode).
- class paramiko.sftp_handle.SFTPHandle(flags=0)¶
Abstract object representing a handle to an open file (or folder) in an SFTP server implementation. Each handle has a string representation used by the client to refer to the underlying file.
Server implementations can (and should) subclass SFTPHandle to implement features of a file handle, like
stat
orchattr
.Instances of this class may be used as context managers.
- __init__(flags=0)¶
Create a new file handle representing a local file being served over SFTP. If
flags
is passed in, it’s used to determine if the file is open in append mode.- Parameters
flags (int) – optional flags as passed to
SFTPServerInterface.open
- chattr(attr)¶
Change the attributes of this file. The
attr
object will contain only those fields provided by the client in its request, so you should check for the presence of fields before using them.- Parameters
attr (SFTPAttributes) – the attributes to change on this file.
- Returns
an
int
error code likeSFTP_OK
.
- close()¶
When a client closes a file, this method is called on the handle. Normally you would use this method to close the underlying OS level file object(s).
The default implementation checks for attributes on
self
namedreadfile
and/orwritefile
, and if either or both are present, theirclose()
methods are called. This means that if you are using the default implementations ofread
andwrite
, this method’s default implementation should be fine also.
- read(offset, length)¶
Read up to
length
bytes from this file, starting at positionoffset
. The offset may be a Python long, since SFTP allows it to be 64 bits.If the end of the file has been reached, this method may return an empty string to signify EOF, or it may also return
SFTP_EOF
.The default implementation checks for an attribute on
self
namedreadfile
, and if present, performs the read operation on the Python file-like object found there. (This is meant as a time saver for the common case where you are wrapping a Python file object.)
- stat()¶
Return an
SFTPAttributes
object referring to this open file, or an error code. This is equivalent toSFTPServerInterface.stat
, except it’s called on an open file instead of a path.- Returns
an attributes object for the given file, or an SFTP error code (like
SFTP_PERMISSION_DENIED
).- Return type
SFTPAttributes
or error code
- write(offset, data)¶
Write
data
into this file at positionoffset
. Extending the file past its original end is expected. Unlike Python’s normalwrite()
methods, this method cannot do a partial write: it must write all ofdata
or else return an error.The default implementation checks for an attribute on
self
namedwritefile
, and if present, performs the write operation on the Python file-like object found there. The attribute is named differently fromreadfile
to make it easy to implement read-only (or write-only) files, but if both attributes are present, they should refer to the same file.- Parameters
offset – position in the file to start reading from.
data (bytes) – data to write into the file.
- Returns
an SFTP error code like
SFTP_OK
.
An interface to override for SFTP server support.
- class paramiko.sftp_si.SFTPServerInterface(server, *args, **kwargs)¶
This class defines an interface for controlling the behavior of paramiko when using the
SFTPServer
subsystem to provide an SFTP server.Methods on this class are called from the SFTP session’s thread, so you can block as long as necessary without affecting other sessions (even other SFTP sessions). However, raising an exception will usually cause the SFTP session to abruptly end, so you will usually want to catch exceptions and return an appropriate error code.
All paths are in string form instead of unicode because not all SFTP clients & servers obey the requirement that paths be encoded in UTF-8.
- __init__(server, *args, **kwargs)¶
Create a new SFTPServerInterface object. This method does nothing by default and is meant to be overridden by subclasses.
- Parameters
server (ServerInterface) – the server object associated with this channel and SFTP subsystem
- __weakref__¶
list of weak references to the object (if defined)
- canonicalize(path)¶
Return the canonical form of a path on the server. For example, if the server’s home folder is
/home/foo
, the path"../betty"
would be canonicalized to"/home/betty"
. Note the obvious security issues: if you’re serving files only from a specific folder, you probably don’t want this method to reveal path names outside that folder.You may find the Python methods in
os.path
useful, especiallyos.path.normpath
andos.path.realpath
.The default implementation returns
os.path.normpath('/' + path)
.
- chattr(path, attr)¶
Change the attributes of a file. The
attr
object will contain only those fields provided by the client in its request, so you should check for the presence of fields before using them.- Parameters
path (str) – requested path (relative or absolute) of the file to change.
attr – requested attributes to change on the file (an
SFTPAttributes
object)
- Returns
an error code
int
likeSFTP_OK
.
- list_folder(path)¶
Return a list of files within a given folder. The
path
will use posix notation ("/"
separates folder names) and may be an absolute or relative path.The list of files is expected to be a list of
SFTPAttributes
objects, which are similar in structure to the objects returned byos.stat
. In addition, each object should have itsfilename
field filled in, since this is important to a directory listing and not normally present inos.stat
results. The methodSFTPAttributes.from_stat
will usually do what you want.In case of an error, you should return one of the
SFTP_*
error codes, such asSFTP_PERMISSION_DENIED
.- Parameters
path (str) – the requested path (relative or absolute) to be listed.
- Returns
a list of the files in the given folder, using
SFTPAttributes
objects.
Note
You should normalize the given
path
first (see theos.path
module) and check appropriate permissions before returning the list of files. Be careful of malicious clients attempting to use relative paths to escape restricted folders, if you’re doing a direct translation from the SFTP server path to your local filesystem.
- lstat(path)¶
Return an
SFTPAttributes
object for a path on the server, or an error code. If your server supports symbolic links (also known as “aliases”), you should not follow them – instead, you should return data on the symlink or alias itself. (stat
is the corresponding call that follows symlinks/aliases.)- Parameters
path (str) – the requested path (relative or absolute) to fetch file statistics for.
- Returns
an
SFTPAttributes
object for the given file, or an SFTP error code (likeSFTP_PERMISSION_DENIED
).
- mkdir(path, attr)¶
Create a new directory with the given attributes. The
attr
object may be considered a “hint” and ignored.The
attr
object will contain only those fields provided by the client in its request, so you should usehasattr
to check for the presence of fields before using them. In some cases, theattr
object may be completely empty.- Parameters
path (str) – requested path (relative or absolute) of the new folder.
attr (SFTPAttributes) – requested attributes of the new folder.
- Returns
an SFTP error code
int
likeSFTP_OK
.
- open(path, flags, attr)¶
Open a file on the server and create a handle for future operations on that file. On success, a new object subclassed from
SFTPHandle
should be returned. This handle will be used for future operations on the file (read, write, etc). On failure, an error code such asSFTP_PERMISSION_DENIED
should be returned.flags
contains the requested mode for opening (read-only, write-append, etc) as a bitset of flags from theos
module:os.O_RDONLY
os.O_WRONLY
os.O_RDWR
os.O_APPEND
os.O_CREAT
os.O_TRUNC
os.O_EXCL
(One of
os.O_RDONLY
,os.O_WRONLY
, oros.O_RDWR
will always be set.)The
attr
object contains requested attributes of the file if it has to be created. Some or all attribute fields may be missing if the client didn’t specify them.Note
The SFTP protocol defines all files to be in “binary” mode. There is no equivalent to Python’s “text” mode.
- Parameters
path (str) – the requested path (relative or absolute) of the file to be opened.
flags (int) – flags or’d together from the
os
module indicating the requested mode for opening the file.attr (SFTPAttributes) – requested attributes of the file if it is newly created.
- Returns
a new
SFTPHandle
or error code.
- posix_rename(oldpath, newpath)¶
Rename (or move) a file, following posix conventions. If newpath already exists, it will be overwritten.
- readlink(path)¶
Return the target of a symbolic link (or shortcut) on the server. If the specified path doesn’t refer to a symbolic link, an error should be returned.
- remove(path)¶
Delete a file, if possible.
- rename(oldpath, newpath)¶
Rename (or move) a file. The SFTP specification implies that this method can be used to move an existing file into a different folder, and since there’s no other (easy) way to move files via SFTP, it’s probably a good idea to implement “move” in this method too, even for files that cross disk partition boundaries, if at all possible.
Note
You should return an error if a file with the same name as
newpath
already exists. (The rename operation should be non-desctructive.)Note
This method implements ‘standard’ SFTP
RENAME
behavior; those seeking the OpenSSH “POSIX rename” extension behavior should useposix_rename
.
- rmdir(path)¶
Remove a directory if it exists. The
path
should refer to an existing, empty folder – otherwise this method should return an error.
- session_ended()¶
The SFTP server session has just ended, either cleanly or via an exception. This method is meant to be overridden to perform any necessary cleanup before this
SFTPServerInterface
object is destroyed.
- session_started()¶
The SFTP server session has just started. This method is meant to be overridden to perform any necessary setup before handling callbacks from SFTP operations.
- stat(path)¶
Return an
SFTPAttributes
object for a path on the server, or an error code. If your server supports symbolic links (also known as “aliases”), you should follow them. (lstat
is the corresponding call that doesn’t follow symlinks/aliases.)- Parameters
path (str) – the requested path (relative or absolute) to fetch file statistics for.
- Returns
an
SFTPAttributes
object for the given file, or an SFTP error code (likeSFTP_PERMISSION_DENIED
).
- symlink(target_path, path)¶
Create a symbolic link on the server, as new pathname
path
, withtarget_path
as the target of the link.