lua: expose subprocess_detached

DOCS/man/lua.rst

@@ -635,6 +635,19 @@ strictly part of the guaranteed API.
 
     In all cases, ``mp.resume_all()`` is implicitly called.
 
+``utils.subprocess_detached(t)``
+    Runs an external process and detaches it from mpv's control.
+
+    The parameter ``t`` is a table. The function reads the following entries:
+
+        ``args``
+            Array of strings of the same semantics as the ``args`` used in the
+            ``subprocess`` function.
+
+    The function returns ``nil``.
+
+    In all cases, ``mp.resume_all()`` is implicitly called.
+
 ``utils.parse_json(str [, trail])``
     Parses the given string argument as JSON, and returns it as a Lua table. On
     error, returns ``nil, error``. (Currently, ``error`` is just a string

player/lua.c

@@ -1185,6 +1185,37 @@ static int script_subprocess(lua_State *L)
     return 1;
 }
 
+static int script_subprocess_detached(lua_State *L)
+{
+    struct script_ctx *ctx = get_ctx(L);
+    luaL_checktype(L, 1, LUA_TTABLE);
+    void *tmp = mp_lua_PITA(L);
+
+    mp_resume_all(ctx->client);
+
+    lua_getfield(L, 1, "args"); // args
+    int num_args = mp_lua_len(L, -1);
+    char *args[256];
+    if (num_args > MP_ARRAY_SIZE(args) - 1) // last needs to be NULL
+        luaL_error(L, "too many arguments");
+    if (num_args < 1)
+        luaL_error(L, "program name missing");
+    for (int n = 0; n < num_args; n++) {
+        lua_pushinteger(L, n + 1); // args n
+        lua_gettable(L, -2); // args arg
+        args[n] = talloc_strdup(tmp, lua_tostring(L, -1));
+        if (!args[n])
+            luaL_error(L, "program arguments must be strings");
+        lua_pop(L, 1); // args
+    }
+    args[num_args] = NULL;
+    lua_pop(L, 1); // -
+
+    mp_subprocess_detached(ctx->log, args);
+    lua_pushnil(L);
+    return 1;
+}
+
 static int script_parse_json(lua_State *L)
 {
     mp_lua_optarg(L, 2);
@@ -1269,6 +1300,7 @@ static const struct fn_entry utils_fns[] = {
     FN_ENTRY(split_path),
     FN_ENTRY(join_path),
     FN_ENTRY(subprocess),
+    FN_ENTRY(subprocess_detached),
     FN_ENTRY(parse_json),
     FN_ENTRY(format_json),
     {0}