File/IO helper with Lua

file.lua

local fileMt = {}
fileMt.__index = fileMt

function fileMt:exists()
  local f = io.open(self.path,"r")

  if f then
    f:close()
  end

  return (f ~= nil)
end

function fileMt:read(concat)
  if not self:exists() then
    return error("file does not exist",2)
  end

  local f = io.open(self.path,"r")

  local lines = {}
  for line in f:lines() do
    table.insert(lines,line)
  end

  f:close()

  return (concat and table.concat(lines,"\n") or lines)
end

function fileMt:write(content)
  if not content then
    return error("content not provided",2)
  end

  content = tostring(content)

  local f = io.open(self.path,"a+")

  if not f then
    return error("error writing to file",1)
  end

  f:write(content)
  f:close()
end

function fileMt:overwrite(content)
  if not content then
    return error("content not provided",2)
  end

  content = tostring(content)

  local f = io.open(self.path,"w+")

  if not f then
    return error("error writing to file",1)
  end

  f:write(content)
  f:close()
end

file = {}

setmetatable(file,{
  __call = function(self,path)
    if type(path) ~= "string" then
      return error("path not provided",2)
    end

    return setmetatable({path = path},fileMt)
  end
})