luaL_argcheck[-0, +0, v] void luaL_argcheck (lua_State *L, int cond,

lua_len[-0, +1, e] void lua_len (lua_State *L, int index); Returns the length of the value at

os.tmpname () Returns a string with a file name that can be used for a temporary file. The file must be explicitly opened before its use and explicitly removed when no longer

lua_absindex[-0, +0, –] int lua_absindex (lua_State *L, int idx); Converts the acceptable index idx

lua_isnumber[-0, +0, –] int lua_isnumber (lua_State *L, int index); Returns 1 if the value at the given

math.tan (x) Returns the tangent of x (assumed to be in radians).

lua_yieldk[-?, +?, e] int lua_yieldk (lua_State *L, int nresults, lua_KContext

luaL_ref[-1, +0, m] int luaL_ref (lua_State *L, int t); Creates and returns a reference

luaL_setmetatable[-0, +0, –] void luaL_setmetatable (lua_State *L, const char *tname); Sets the metatable

file:lines (···) Returns an iterator function that, each time it is called, reads the file according to the given formats. When no format is given, uses "l" as a