Expose uv_os_get_group

src/c/luv_c_function_descriptions.ml

@@ -1803,6 +1803,14 @@ struct
     let free_passwd =
       foreign "uv_os_free_passwd"
         (ptr t @-> returning void)
+
+    let get_group =
+      foreign "uv_os_get_group"
+        (ptr Types.Passwd.group @-> ulong @-> returning error_code)
+
+    let free_group =
+      foreign "uv_os_free_group"
+        (ptr Types.Passwd.group @-> returning void)
   end
 
   module Env =

src/c/luv_c_type_descriptions.ml

@@ -957,6 +957,13 @@ struct
     let shell = field t "shell" string_opt
     let homedir = field t "homedir" string
     let () = seal t
+
+    let group : ([ `Group ] structure) typ =
+      typedef (structure "`Group") "uv_group_t"
+    let groupname = field group "groupname" string
+    let group_gid = field group "gid" ulong
+    let members = field group "members" (ptr (ptr char))
+    let () = seal group
   end
 
   module Time =

src/c/shims.h

@@ -700,4 +700,18 @@
     {
         return ENOSYS;
     }
+
+    typedef struct {
+        char *groupname;
+        unsigned long gid;
+        char **members;
+    } uv_group_t;
+
+    static int uv_os_get_group(uv_group_t *group, unsigned long gid)
+    {
+        return ENOSYS;
+    }
+    static void uv_os_free_group(uv_passwd_t *group)
+    {
+    }
 #endif

src/feature/detect_features.ml

@@ -263,6 +263,7 @@ let () =
   needs 23 "open_osfhandle" "See {!Luv.File.open_osfhandle}.";
   needs 31 "os_environ" "See {!Luv.Env.environ}.";
   needs  6 "os_homedir" "See {!Luv.Path.homedir}.";
+  needs 45 "os_get_group" "See {!Luv.Passwd.get_group}.";
   needs  9 "os_get_passwd" "See {!Luv.Passwd.get_passwd}.";
   needs 45 "os_get_passwd_uid" "See {!Luv.Passwd.get_passwd}.";
   needs 12 "os_getenv" "See {!Luv.Env.getenv}.";

src/passwd.ml

@@ -3,14 +3,16 @@
 
 
 
-type t = {
+type user = {
   username : string;
   uid : Unsigned.ulong;
   gid : Unsigned.ulong;
   shell : string option;
   homedir : string;
 }
 
+type t = user
+
 let get_passwd ?uid () =
   let c_passwd = Ctypes.make C.Types.Passwd.t in
   let pointer = Ctypes.addr c_passwd in
@@ -31,3 +33,45 @@ let get_passwd ?uid () =
     C.Functions.Passwd.free_passwd pointer;
     passwd
   end
+
+type group = {
+  groupname : string;
+  gid : Unsigned.ulong;
+  members : string list;
+}
+
+let strlen c_string =
+  let rec loop i =
+    if Ctypes.(!@ (c_string +@ i)) = '\x00' then
+      i
+    else
+      loop (i + 1)
+  in
+  loop 0
+
+let string_list_from_c c_strings =
+  let rec loop i acc =
+    let c_string = Ctypes.(!@ (c_strings +@ i)) in
+    if Ctypes.is_null c_string then
+      List.rev acc
+    else
+      let length = strlen c_string in
+      let s = Ctypes.string_from_ptr c_string ~length in
+      loop (i + 1) (s::acc)
+  in
+  loop 0 []
+
+let get_group gid =
+  let c_group = Ctypes.make C.Types.Passwd.group in
+  C.Functions.Passwd.get_group (Ctypes.addr c_group) gid
+  |> Error.to_result_lazy begin fun () ->
+    let module G = C.Types.Passwd in
+    let group = {
+      groupname = Ctypes.getf c_group G.groupname;
+      gid = Ctypes.getf c_group G.group_gid;
+      members = Ctypes.getf c_group G.members |> string_list_from_c;
+    }
+    in
+    C.Functions.Passwd.free_group (Ctypes.addr c_group);
+    group
+  end

src/passwd.mli

@@ -3,7 +3,7 @@
 
 
 
-type t = {
+type user = {
   username : string;
   uid : Unsigned.ulong;
   gid : Unsigned.ulong;
@@ -13,7 +13,11 @@ type t = {
 (** Binds {{:http://docs.libuv.org/en/v1.x/misc.html#c.uv_passwd_t}
     [uv_passwd_t]}. *)
 
-val get_passwd : ?uid:Unsigned.ulong -> unit -> (t, Error.t) result
+(**/**)
+type t = user
+(**/**)
+
+val get_passwd : ?uid:Unsigned.ulong -> unit -> (user, Error.t) result
 (** Gets passwd entry for the current user or the user with the given uid.
 
     Binds {{:http://docs.libuv.org/en/v1.x/misc.html#c.uv_os_get_passwd}
@@ -28,3 +32,19 @@ val get_passwd : ?uid:Unsigned.ulong -> unit -> (t, Error.t) result
     The [?uid] argument requires Luv 0.5.13 and libuv 1.45.0.
 
     {{!Luv.Require} Feature check}: [Luv.Require.(has os_get_passwd_uid)] *)
+
+type group = {
+  groupname : string;
+  gid : Unsigned.ulong;
+  members : string list;
+}
+(** Binds [uv_group_t]. *)
+
+val get_group : Unsigned.ulong -> (group, Error.t) result
+(** Gets the entry for the group with the given gid.
+
+    Binds [uv_os_get_group].
+
+    Requires Luv 0.5.13 and libuv 1.45.0.
+
+    {{!Luv.Require} Feature check}: [Luv.Require.(has os_get_group)] *)

src/process.ml

@@ -80,7 +80,7 @@ let null_callback =
 let c_string_array strings =
   (* The array-of-pointers doesn't hold a reference to the individual string
      pointers, so we need to allocate and return them so the consumer can ensure
-     they stayed referenced to avoid the GC cleaning them up early. *)
+     they stay referenced to avoid the GC cleaning them up early. *)
   let c_string_ptrs = strings @ [""]
     |> List.map Ctypes.(CArray.of_string)
     |> List.map Ctypes.CArray.start