github.com/pkg/sftp@v1.13.6/request-readme.md (about)

     1  # Request Based SFTP API
     2  
     3  The request based API allows for custom backends in a way similar to the http
     4  package. In order to create a backend you need to implement 4 handler
     5  interfaces; one for reading, one for writing, one for misc commands and one for
     6  listing files. Each has 1 required method and in each case those methods take
     7  the Request as the only parameter and they each return something different.
     8  These 4 interfaces are enough to handle all the SFTP traffic in a simplified
     9  manner.
    10  
    11  The Request structure has 5 public fields which you will deal with.
    12  
    13  - Method (string) - string name of incoming call
    14  - Filepath (string) - POSIX path of file to act on
    15  - Flags (uint32) - 32bit bitmask value of file open/create flags
    16  - Attrs ([]byte) - byte string of file attribute data
    17  - Target (string) - target path for renames and sym-links
    18  
    19  Below are the methods and a brief description of what they need to do.
    20  
    21  ### Fileread(*Request) (io.Reader, error)
    22  
    23  Handler for "Get" method and returns an io.Reader for the file which the server
    24  then sends to the client.
    25  
    26  ### Filewrite(*Request) (io.Writer, error)
    27  
    28  Handler for "Put" method and returns an io.Writer for the file which the server
    29  then writes the uploaded file to. The file opening "pflags" are currently
    30  preserved in the Request.Flags field as a 32bit bitmask value. See the [SFTP
    31  spec](https://filezilla-project.org/specs/draft-ietf-secsh-filexfer-02.txt#section-6.3) for
    32  details.
    33  
    34  ###    Filecmd(*Request) error
    35  
    36  Handles "SetStat", "Rename", "Rmdir", "Mkdir"  and "Symlink" methods. Makes the
    37  appropriate changes and returns nil for success or an filesystem like error
    38  (eg. os.ErrNotExist). The attributes are currently propagated in their raw form
    39  ([]byte) and will need to be unmarshalled to be useful. See the respond method
    40  on sshFxpSetstatPacket for example of you might want to do this.
    41  
    42  ### Fileinfo(*Request) ([]os.FileInfo, error)
    43  
    44  Handles "List", "Stat", "Readlink" methods. Gathers/creates FileInfo structs
    45  with the data on the files and returns in a list (list of 1 for Stat and
    46  Readlink).
    47  
    48  
    49  ## TODO
    50  
    51  - Add support for API users to see trace/debugging info of what is going on
    52  inside SFTP server.
    53  - Unmarshal the file attributes into a structure on the Request object.