Lua

Monitor FTP Transfer Progress

Demonstrates the progress properties CurBytesReceived, CurBytesReceivedStr, CurBytesSent, CurBytesSentStr, ProgressMonSize, PercentDoneScale, and AutoGetSizeForProgress.

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: Percentage progress needs a known total, but FTP does not always report a file's size up front — so AutoGetSizeForProgress issues a SIZE command before a download, and ProgressMonSize supplies an expected size when even that is unavailable (a one-shot value consumed by the next transfer). PercentDoneScale sets the resolution of progress callbacks. The current byte counts are exposed both as 32-bit integers and as strings, the string forms avoiding integer-width limits for very large transfers.

Chilkat Lua Downloads

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Lua

local chilkat = require("chilkat")

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

-- AutoGetSizeForProgress sends a SIZE command before a download so percentage-based progress can
-- be computed.
ftp.auto_get_size_for_progress = true

-- PercentDoneScale sets the value representing one hundred percent in PercentDone callbacks.
-- 1000 gives tenth-of-a-percent resolution.
ftp.percent_done_scale = 1000

-- ProgressMonSize is a one-shot expected size for the next download when the size is not
-- otherwise known.  It is consumed by the next download and reset to 0.
ftp.progress_mon_size = 20485760

success = ftp:get_file("public_html/bigfile.zip", "qa_output/bigfile.zip")
if not success then
    print(ftp.last_error_text)
    return
end

-- After a transfer, the current byte counts are available as 32-bit numbers or as strings (the
-- string forms avoid integer-size limits).
print("Bytes received: " .. ftp.cur_bytes_received)
print("Bytes received (str): " .. ftp.cur_bytes_received_str)
print("Bytes sent: " .. ftp.cur_bytes_sent)
print("Bytes sent (str): " .. ftp.cur_bytes_sent_str)

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