LUA FTP Client

--[[
URLs MUST conform to RFC 1738, that is, an URL is a string in the form:
[ftp://][<user>[:<password>]@]<host>[:<port>][/<path>][type=a|i]
--]]

local ftp = require("socket.ftp")
local ltn12 = require("ltn12")
local url = require("socket.url")
local socket = require("socket")
local pretty = require("pl.pretty")

print(socket._VERSION)
print(url._VERSION)

-- List files in a remote directory
local function list(u)
    local t = {}
    local p = url.parse(u)
    p.command = "nlst"
    p.argument = string.gsub(p.path, "^/", "")
    if p.argument == "" then p.argument = nil end
    p.sink = ltn12.sink.table(t)
    local r, e = ftp.get(p)
    pretty.dump(t)
    return r and table.concat(t), e
end

-- Delete a remote file
local function delete(u)
    local p = url.parse(u)
    p.command = "dele"
    p.argument = string.gsub(p.path, "^/", "")
    if p.argument == "" then p.argument = nil end
    p.check = 250
    return ftp.command(p)
end

-- Upload a file
function upload(remotePath, localFile)
    local p = url.parse(remotePath)
    p.command = "appe"
    p.argument = string.gsub(p.path, "^/", "")
    if p.argument == "" then p.argument = nil end
    p.check = 250
    p.source = ltn12.source.file(io.open(localFile, "r"))
    return ftp.command(p)
end

-- Retrieve a remote file
function download(u)
    local t = {}
    local p = url.parse(u)
    return ftp.get(p)
end

Using libraries from http://w3.impa.br/~diego/software/luasocket/old/luasocket-2.0-beta/ftp.html