file protector

local ending = "_f"

local orfa = {} --original fake mapping
local faor = {}

local used = false

for i,j in pairs(fs.list("/")) do
local k = string.match(j,"(.*)"..ending.."$")
while k do
orfa[k..ending] = k
faor[k] = k..ending
used = true
k=string.match(k,"(.*)"..ending.."$")
end
end

local args = {...}

if #args % 2 == 1  or (not used and #args == 0) then
print(shell.getRunningProgram().." <actualFile> <displayName> [<actualFile>] <displayName> ...")
return
end

for i=1,#args,2 do
faor[args[i+1]] = args[i]
orfa[args[i]] = args[i+1]
end

local ofs = {combine=true,getDrive=true,getDir=true,getName=true}
local nfs = {}
for i,j in pairs(fs) do
if not ofs[i] then
nfs[i] = j
end
end
for i in pairs(nfs) do
fs[i] = nil
end

local mt ={__index = function(t,k)
if not nfs[k] then
return
end
return function(...)
local pars = {...}
for i,file in ipairs(pars) do
if orfa[file] then
faor[file] = file..ending
orfa[file..ending] = file
end
if faor[file] then
pars[i] = faor[file]
end
end
local r = nfs[k](unpack(pars))
if k == "list" or k == "find" then
local n = {}
for i,file in ipairs(r) do
if orfa[file] then
table.insert(n,orfa[file])
elseif not faor[file] then
table.insert(n,file)
end
end
r=n
end
return r
end
end,__metatable="nil"}

setmetatable(fs,mt)