FTP Client ComputerCraft

local args = { ... }

if #args < 2 then
    error("Usage: ftp <side> <id>")
end

local side = args[1]
local id = tonumber(args[2])
local username
local password = ""
local dir = ""

local function split(s, del)
    local ret = {}
    local del = del or " "
    local pattern = string.format("([^%s]+)", del)
    s:gsub(pattern, function(c) ret[#ret+1] = c end)
    return ret
end

local function receive()
    while true do
        local src,mes,dst = rednet.receive(1)
        if tonumber(src) == id then
            return mes
        elseif src == nil or mes == nil then
            return ""
        end
    end
end

local function getCode(s)
    local splt = split(s, " ")
    return tonumber(splt[1])
end

local function connect()
    while true do
        print("Connecting to " .. id .. ", please enter username:")
        username = read()
        rednet.send(id, username)
        local code = getCode(receive())
        if code == 230 then -- Login successful
            print("Login successful.")
            return
        elseif code == 331 then -- Password required
            print("Password required for " .. username .. ":")
            password = read()
            rednet.send(id, password)
            code = getCode(receive())
            if code == 230 then
                print("Login successful.")
                return
            else
                print("Wrong password.")
            end
        elseif code == 500 then
            print("Already logged in.")
            return
        else
            print("Wrong username.")
        end
    end
end

--Init
rednet.open(side)

term.clear()
term.setCursorPos(1,1)

connect()

-- Mainloop

while true do
    local command = read()
    local cmdargs = split(command, " ")
    if #cmdargs ~= 0 and cmdargs[1] ~= "" then
        local cmd = cmdargs[1]:lower()
        if cmd == "lcd" then
            if #cmdargs < 2 then
                print("Not enough parameters.")
            else
                dir = fs.combine(dir, cmdargs[2])
            end
        elseif cmd == "ls" then
            rednet.send(id, command)
            local ls = split(receive(), " ")
            local rec = receive()
            local code = getCode(rec)
            if code == 200 then
                textutils.pagedTabulate(ls)
            else
                print(rec)
            end
        elseif cmd == "lls" then
            local directory
            if #cmdargs < 2 then
                directory = dir
            else
                directory = fs.combine(dir, cmdargs[2])
            end
            if not fs.exists(directory) then
                print("File or directory not found.")
            else
                local list = fs.list(directory)
                textutils.pagedTabulate(list)
            end
        elseif cmd == "get" then
            if #cmdargs < 2 then
                print("Not enough parameters.")
            else
                local locfile
                if #cmdargs >= 3 then
                    locfile = fs.combine(dir, cmdargs[3])
                else
                    locfile = fs.combine(dir, fs.getName(cmdargs[2]))
                end

                rednet.send(id, "GET " .. cmdargs[2])
                local content = receive()
                local rec = receive()
                local code = getCode(rec)

                if code == 200 then
                    local file = io.open(locfile, "w")
                    if file then
                        file:write(content)
                        file:close()
                        print("File " .. fs.getName(locfile) .. " saved successfully.")
                    else
                        print("Could not open file for writing.")
                    end
                else
                    print(rec)
                end
            end
        elseif cmd == "put" then
            if #cmdargs < 1 then
                print("Not enough parameters.")
            else
                local remfile
                rednet.send(id, "pwd")
                local pwd = receive()
                if getCode(receive()) == 200 then
                    if #cmdargs >= 3 then
                        remfile = fs.combine(pwd, cmdargs[3])
                    else
                        remfile = fs.combine(pwd, fs.getName(cmdargs[2]))
                    end

                    rednet.send(id, "PUT " .. remfile)
                    local rec = receive()
                    if getCode(rec) == 150 then
                        local file = io.open(fs.combine(dir, cmdargs[2]), "r")
                        if file then
                            local content = file:read("*a")
                            file:close()
                            rednet.send(id, content)

                            local rec = receive()
                            if getCode(rec) == 200 then
                                print("File " .. fs.getName(remfile) .. " uploaded successfully.")
                            else
                                print(rec)
                            end
                        else
                            print("Could not open file for reading.")
                            print("Debug: " .. fs.combine(dir, cmdargs[2]))
                        end
                    else
                        print(rec)
                    end
                end
            end
        elseif cmd == "help" then
            print("Commands:")
            textutils.pagedTabulate({"bye", "quit", "cd", "rm", "get", "help", "lcd", "ls", "lls", "mkdir", "put", "pwd"})
        elseif cmd == "pwd" then
            rednet.send(id, command)
            local pwd = receive()
            local rec = receive()
            local code = getCode(rec)
            if code == 200 then
                print(pwd)
            else
                print(rec)
            end
        else
            rednet.send(id, command)
            local rec = receive()
            print(rec)
            if getCode(rec) == 221 then
                break
            end
        end
    end
end