OC-KittenOS/code/libs/sys-filewrap.lua

75 lines
1.5 KiB
Lua

-- This is released into the public domain.
-- No warranty is provided, implied or otherwise.
local function ensureMode(mode)
local n = "rb"
if type(mode) == "boolean" then
if mode then
n = "wb"
end
elseif type(mode) == "string" then
if mode == "append" then
n = "ab"
else
error("Invalid fmode " .. mode)
end
else
error("Invalid fmode")
end
return n
end
local function create(dev, file, mode)
local n = ensureMode(mode)
local handle, r = dev.open(file, n)
if not handle then return nil, r end
local open = true
local function closer()
if not open then return end
open = false
pcall(function()
dev.close(handle)
end)
end
local function reader(len)
if not open then return end
if len == "*a" then
local ch = ""
local c = dev.read(handle, neo.readBufSize)
while c do
ch = ch .. c
c = dev.read(handle, neo.readBufSize)
end
return ch
end
if type(len) ~= "number" then error("Length of read must be number or '*a'") end
return dev.read(handle, len)
end
local function writer(txt)
if not open then return end
neo.ensureType(txt, "string")
return dev.write(handle, txt)
end
local function seeker(whence, point)
if not open then return end
return dev.seek(handle, whence, point)
end
if mode == "rb" then
return {
close = closer,
seek = seeker,
read = reader
}, closer
else
return {
close = closer,
seek = seeker,
read = reader,
write = writer
}, closer
end
end
return {
createMode = createMode,
create = create
}