Lua

Initialize the SFTP Subsystem

Demonstrates the Chilkat SFtp.InitializeSftp method, which opens the SFTP subsystem and negotiates the SFTP protocol version. It takes no arguments and must be called after connecting and authenticating, before any file or directory operation.

Background: SFTP is not a standalone protocol but a subsystem requested over an authenticated SSH session, which is why this separate step exists. It is also where the SFTP protocol version is negotiated — that version determines which capabilities (such as certain timestamp and path-composition features) are available for the session. Skipping this call, or calling it before authentication, leaves every file operation failing.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the SFtp.InitializeSftp method, which opens the SFTP subsystem and negotiates the
-- SFTP protocol version.  It takes no arguments and must be called after connecting and
-- authenticating, before any file or directory operations.

local sftp = chilkat.SFtp.new()

-- Step 1: Connect the SSH transport.  Port 22 is the usual port.
local port = 22
local success = sftp:connect("sftp.example.com", port)
if not success then
    print(sftp.last_error_text)
    return
end

-- Normally you would not hard-code the password in source.  You should instead obtain it
-- from an interactive prompt, environment variable, or a secrets vault.
local password = "mySshPassword"

success = sftp:authenticate_pw("mySshLogin", password)
if not success then
    print(sftp.last_error_text)
    return
end

-- Step 3: Open the SFTP subsystem.  This must be done after authentication and before any
-- file or directory operations.
success = sftp:initialize_sftp()
if not success then
    print(sftp.last_error_text)
    return
end

print("The SFTP subsystem is ready.")

sftp:disconnect()