Lua

Get a Remote File's Last-Modified Time

Demonstrates the Chilkat SFtp.GetFileLastModifiedStr method, which returns a remote file's last-modified date and time. The arguments are the remote path (or handle), whether symbolic links are followed, and whether the first argument is a handle.

Background: The last-modified time is the workhorse timestamp — it updates whenever a file's contents change and is what incremental-sync logic compares to decide whether a file needs re-transferring. It is the most reliably supported of the three across servers and filesystems, which is why timestamp-based sync keys off it.

Chilkat Lua Downloads

Download Chilkat for Lua

Lua

local chilkat = require("chilkat")

-- Demonstrates the SFtp.GetFileLastModifiedStr method, which returns a remote file's last-modified
-- date and time.  The 1st argument is the remote path (or handle), the 2nd selects whether
-- symbolic links are followed, and the 3rd indicates whether the 1st argument is a handle.

local sftp = chilkat.SFtp.new()

-- Connect, authenticate, and initialize the SFTP subsystem.
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

success = sftp:initialize_sftp()
if not success then
    print(sftp.last_error_text)
    return
end

-- The 2nd argument (bFollowLinks) selects whether a symbolic link is followed to its target.
-- The 3rd argument (bIsHandle) is false here because the 1st argument is a path, not an
-- open handle.
local bFollowLinks = true
local bIsHandle = false

local lastModified = sftp:get_file_last_modified_str("subdir/report.pdf", bFollowLinks, bIsHandle)
if not sftp.last_method_success then
    print(sftp.last_error_text)
    return
end

print("Last modified: " .. lastModified)

sftp:disconnect()