Package paramiko :: Class SFTPServerInterface |
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# Class SFTPServerInterface

source code

    object --+
             |
            SFTPServerInterface

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.

Instance Methods
__init__(self, server, *largs, **kwargs) Create a new SFTPServerInterface object. | source code
canonicalize(self, path) Return the canonical form of a path on the server. | source code
int |
chattr(self, path, attr) Change the attributes of a file. | source code
list of SFTPAttributes or error code |
list_folder(self, path) Return a list of files within a given folder. | source code
SFTPAttributes or error code |
lstat(self, path) Return an SFTPAttributes object for a path on the server, or an error code. | source code
int |
mkdir(self, path, attr) Create a new directory with the given attributes. | source code
open(self, path, flags, attr) Open a file on the server and create a handle for future operations on that file. | source code
str or error code |
readlink(self, path) Return the target of a symbolic link (or shortcut) on the server. | source code
int |
remove(self, path) Delete a file, if possible. | source code
int |
rename(self, oldpath, newpath) Rename (or move) a file. | source code
int |
rmdir(self, path) Remove a directory if it exists. | source code
session_ended(self) The SFTP server session has just ended, either cleanly or via an exception. | source code
session_started(self) The SFTP server session has just started. | source code
SFTPAttributes or error code |
stat(self, path) Return an SFTPAttributes object for a path on the server, or an error code. | source code
int |
symlink(self, target_path, path) Create a symbolic link on the server, as new pathname `path`, with `target_path` as the target of the link. | source code
Inherited from `object`: `__delattr__`, `__getattribute__`, `__hash__`, `__new__`, `__reduce__`, `__reduce_ex__`, `__repr__`, `__setattr__`, `__str__`

Properties
Inherited from `object`: `__class__`

Method Details

### __init__(self, server, *largs, **kwargs) (Constructor) | source code
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 Overrides: object.__init__

### canonicalize(self, path) | source code
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, especially `os.path.normpath` and `os.path.realpath`. The default implementation returns `os.path.normpath('/' + path)`.

### chattr(self, path, attr) | source code
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` (SFTPAttributes) - requested attributes to change on the file. Returns: int an error code like SFTP_OK.

### list_folder(self, path) | source code
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 by `os.stat`. In addition, each object should have its `filename` field filled in, since this is important to a directory listing and not normally present in `os.stat` results. The method SFTPAttributes.from_stat will usually do what you want. In case of an error, you should return one of the `SFTP_*` error codes, such as SFTP_PERMISSION_DENIED. Parameters: `path` (str) - the requested path (relative or absolute) to be listed. Returns: list of SFTPAttributes or error code a list of the files in the given folder, using SFTPAttributes objects. Note: You should normalize the given `path` first (see the `os.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(self, path) | source code
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: SFTPAttributes or error code an attributes object for the given file, or an SFTP error code (like SFTP_PERMISSION_DENIED).

### mkdir(self, path, attr) | source code
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 use `hasattr` to check for the presense of fields before using them. In some cases, the `attr` 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: int an SFTP error code like SFTP_OK.

### open(self, path, flags, attr) | source code
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 as SFTP_PERMISSION_DENIED should be returned. `flags` contains the requested mode for opening (read-only, write-append, etc) as a bitset of flags from the `os` 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`, or `os.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. 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. @rtype SFTPHandle Note: The SFTP protocol defines all files to be in "binary" mode. There is no equivalent to python's "text" mode.

### readlink(self, path) | source code
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. Parameters: `path` (str) - path (relative or absolute) of the symbolic link. Returns: str or error code the target path of the symbolic link, or an error code like SFTP_NO_SUCH_FILE.

### remove(self, path) | source code
Delete a file, if possible. Parameters: `path` (str) - the requested path (relative or absolute) of the file to delete. Returns: int an SFTP error code like SFTP_OK.

### rename(self, oldpath, newpath) | source code
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. Parameters: `oldpath` (str) - the requested path (relative or absolute) of the existing file. `newpath` (str) - the requested new path of the file. Returns: int an SFTP error code like SFTP_OK. Note: You should return an error if a file with the same name as `newpath` already exists. (The rename operation should be non-desctructive.)

### rmdir(self, path) | source code
Remove a directory if it exists. The `path` should refer to an existing, empty folder -- otherwise this method should return an error. Parameters: `path` (str) - requested path (relative or absolute) of the folder to remove. Returns: int an SFTP error code like SFTP_OK.

### session_ended(self) | source code
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(self) | source code
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(self, path) | source code
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: SFTPAttributes or error code an attributes object for the given file, or an SFTP error code (like SFTP_PERMISSION_DENIED).

### symlink(self, target_path, path) | source code
Create a symbolic link on the server, as new pathname `path`, with `target_path` as the target of the link. Parameters: `target_path` (str) - path (relative or absolute) of the target for this new symbolic link. `path` (str) - path (relative or absolute) of the symbolic link to create. Returns: int an error code like `SFTP_OK`.