serverside

local side = "top"

function split(str, pattern)
  local t = { }
  local fpat = "(.-)" .. pattern
  local last_end = 1
  local s, e, cap = str:find(fpat, 1)
  while s do
    if s ~= 1 or cap ~= "" then
      table.insert(t,cap)
    end
    last_end = e+1
    s, e, cap = str:find(fpat, last_end)
  end
  if last_end <= #str then
    cap = str:sub(last_end)
    table.insert(t, cap)
  end
  return t
end
rednet.open(side)
print("fileserv made by Egor305")
while true do
    local sender,msg=rednet.receive()
    data = split(msg,"~!SP!~")
    if data[1] == "$send" and data[2] and data[3] then
        if not fs.exists("/data/~"..sender) or not fs.isDir("/data/~"..sender) then
            fs.makeDir("/data/~"..sender)
        end
        fh=fs.open("/data/~"..sender.."/"..data[2],"w")
        if fh then
            fh.write(data[3])
            fh.close()
            rednet.send(sender,"All, ok!")
            print(sender..": "..data[1].." "..data[2].." "..data[3])
        end
    end
    if data[1] == "$get" and data[2] and data[3] then
        if not fs.exists("/data/~"..data[2].."/"..data[3]) or (data[3]:sub(1,1) == "!" and data[2]~=tostring(sender)) then
            rednet.send(sender,"")
        else
            fh = fs.open("/data/~"..data[2].."/"..data[3],"r")
            if fh then
                rednet.send(sender,fh.readAll())
                fh.close()
                print(sender..": "..data[1].." "..data[2].." "..data[3])
            end
        end
    end
    if data[1] == "$dir" then
        if not fs.exists("/data/~"..sender) or not fs.isDir("/data/~"..sender) then
            fs.makeDir("/data/~"..sender)
        end
        rednet.send(sender,textutils.serialize(fs.list("/data/~"..sender)))
        print(sender..": "..data[1])
    end
    if data[1] == "$del" then
        if fs.exists("/data/~"..sender.."/"..data[2]) then
            fs.delete("/data/~"..sender.."/"..data[2])
            rednet.send(sender,"All, ok!")
            print(sender..": "..data[1].." "..data[2])
        end
    end
end