KLUA_MOD_REGISTER(9)

KLUA_MOD_REGISTER(9) | Kernel Developer's Manual | KLUA_MOD_REGISTER(9)

# NAME

`klua_mod_register`, `klua_mod_unregister` —
Lua kernel bindings

# SYNOPSIS

`#include <sys/lua.h>`

void
`klua_mod_register`(const char *name, lua_CFunction open);

void
`klua_mod_unregister`(const char *name);

# DESCRIPTION

The Lua kernel bindings are designed to provide functionality to Lua scripts normally not available in the language itself, e.g. to access core kernel functionality. This is achieved by utilizing the lua_modules functionality.

The lua_module structure is declared as follows:

    struct lua_module {
            char                    mod_name[LUA_MAX_MODNAME];
            lua_CFunction           open;
            int                     refcount;
            LIST_ENTRY(lua_module)  mod_next;
    };

The mod_name defines the unique name of a module. A C function must use the standard Lua protocol in order to communicate with Lua, this part is maintained with the open element in the standard Lua way. refcount protects the module from being unloaded whilst still in use. The last parameter, mod_next, is used for the standard container LIST(3).

The `klua_mod_register`() function registers a new function which is made available to the lua(9) device and Lua code using the `require` directive. The `require` directive can be called from luactl(8) and the kernel Lua version. The name parameter is a unique identifier of the kernel Lua module. open points to a function used in the C to Lua binding, defined with the appropriate standard Lua API.

Once registered, a C function can be unregistered with the `klua_mod_unregister`() function. This function takes as its parameter the unique literal identifier of the extending module.

# EXAMPLES

A set of example modules is available in the src/sys/modules/examples directory hierarchy.

# SEE ALSO

lua(1), luac(1), intro(3lua), lua(4), klua_close(9), klua_lock(9), klua_newstate(9), klua_unlock(9), kluaL_newstate(9), intro(9lua)

# AUTHORS

Kamil Rytarowski <kamil@NetBSD.org>.

April 15, 2017 | NetBSD 9.3