msgpack

The msgpack library (lua-cmsgpack) packs Lua values into a compact binary MessagePack string and back. On error the functions return nil and an error text.

Packing rules are the same as for database: nesting up to 16; functions, userdata and cdata become nil.

msgpack.pack(...)#

Packs all arguments one after another into one string.

Returns: string.

local s = msgpack.pack({ 7, 8 }, "x", true)
print(#s, " bytes")

msgpack.unpack(s: string)#

Unpacks all values from a string.

Returns: all unpacked values.

local s = msgpack.pack({ 7, 8 }, "x")
local t, x = msgpack.unpack(s)
print(t[2], " ", x)   --> 8 x

msgpack.unpack_one(s: string, offset?: number)#

Unpacks one value starting at an offset.

Returns: number, any — the offset of the next value (-1 if the data is over) and the value itself.

local s = msgpack.pack(1, 2, 3)
local off, v = 0, nil
while off ~= -1 do
    off, v = msgpack.unpack_one(s, off)
    print(v)
end

msgpack.unpack_limit(s: string, limit: number, offset?: number)#

Unpacks at most limit values.

Returns: number, ... — the offset of the next value (-1 if the data is over) and the unpacked values.

local s = msgpack.pack("a", "b", "c", "d")
local off, x, y = msgpack.unpack_limit(s, 2)
print(x, y, " next at ", off)   --> ab next at 4