luaL_optlstring[-0, +0, v] const char *luaL_optlstring (lua_State *L, int arg

lua_getuservalue[-0, +1, –] int lua_getuservalue (lua_State *L, int index); Pushes onto the stack the Lua

math.log (x [, base]) Returns the logarithm of x in the given base. The default for base is e (so that the function returns the natural logarithm

os.execute ([command]) This function is equivalent to the ISO C function system. It passes command to be executed by an operating system shell. Its first

luaL_opt[-0, +0, e] T luaL_opt (L, func, arg, dflt); This macro is defined as follows:

collectgarbage ([opt [, arg]]) This function is a generic interface to the garbage collector. It performs different functions according to its first argument, opt:

debug.setuservalue (udata, value) Sets the given value as the Lua value associated to the given udata. udata must be a full userdata.

io.close ([file]) Equivalent to file:close(). Without a file, closes the default output file.

math.acos (x) Returns the arc cosine of x (in radians).

luaL_tolstring[-0, +1, e] const char *luaL_tolstring (lua_State *L, int idx, size_t *len); Converts