Lua

Download an FTP File to a Stream

Demonstrates the Chilkat Ftp2.GetFileToStream method, which downloads a remote file and writes its bytes to a Stream. The first argument is the remote file path and the second is the Stream, which must have a destination sink configured beforehand.

Note: The local paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: Streaming to a Stream object decouples the download from where the bytes ultimately go — a file (as here, via SinkFile), or a pipe feeding another component such as a decompressor or a hashing routine — and processes the data as it arrives rather than buffering the whole file. That keeps memory flat for large downloads and lets you chain the transfer into a processing pipeline.

Chilkat Lua Downloads

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Lua

local chilkat = require("chilkat")

-- Demonstrates the Ftp2.GetFileToStream method, which downloads a remote file and writes its
-- bytes to a Stream.  The 1st argument is the remote file path and the 2nd is the Stream.

local ftp = chilkat.Ftp2.new()

ftp.hostname = "ftp.example.com"
ftp.username = "myFtpLogin"

-- 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.
ftp.password = "myPassword"

local success = ftp:connect()
if not success then
    print(ftp.last_error_text)
    return
end

-- Configure the stream's destination sink before downloading.  Here the stream writes to a
-- local file.
local fileStream = chilkat.Stream.new()
fileStream.sink_file = "qa_output/report.pdf"

success = ftp:get_file_to_stream("public_html/report.pdf", fileStream)
if not success then
    print(ftp.last_error_text)
    return
end

print("Downloaded to stream.")

success = ftp:disconnect()
if not success then
    print(ftp.last_error_text)
    return
end