Computercraft File Sharing Server

side = "back"

if fs.exists("bin/crazyapi")==false then
 print("This program requires Crazyapi")
 print("Installing crazyapi with cc-get...")
 shell.run("cc-get", "install", "crazyapi")
end

shell.run("crazyapi")
networkOpen(side)

print("Server started")
while true do
 id, m = networkIDReceive()
 cmd = string.sub(m, 1, 5)
 arg = string.sub(m, 6)
 print(id.." did "..cmd)
 if cmd == "!!get" then
  file = io.open(arg, "r")
  data = file:read("*a")
  file:close()
  networkSendToID(id, data)
 elseif cmd == "sendd" then
  name = networkReceive()
  if fs.exists(name) then fs.delete(name) end
  if name == "startup" then networkSendToID(id, "Error: Name Not Allowed")
  else
   file = io.open(name, "w")
   file:write(arg)
   file:close()
   networkSendToID(id, "Success")
  end
 elseif cmd == "!list" then
  tFiles = fs.list("")
  tFiles2 = {}
  for i,v in pairs(tFiles) do
   if fs.isDir(v)==false and v~="server" then
    table.insert(tFiles2, v.."\n")
   end
  end
  data = table.concat(tFiles2)
--  print(data)
  networkSendToID(id, data)
 end
end