From 775f9763a4ff5422fca837c2fb213273adb772c9 Mon Sep 17 00:00:00 2001
From: Pino Toscano <ptoscano@redhat.com>
Date: Wed, 29 May 2019 11:48:44 +0200
Subject: [PATCH] Add Augeas.label

Simple binding for aug_label.
---
 augeas-c.c | 27 +++++++++++++++++++++++++++
 augeas.ml  |  2 ++
 augeas.mli |  6 ++++++
 3 files changed, 35 insertions(+)

diff --git a/augeas-c.c b/augeas-c.c
index 5dbaa83..ae22dff 100644
--- a/augeas-c.c
+++ b/augeas-c.c
@@ -44,6 +44,7 @@ extern CAMLprim value ocaml_augeas_defvar (value tv, value namev, value exprv);
 extern CAMLprim value ocaml_augeas_get (value tv, value pathv);
 extern CAMLprim value ocaml_augeas_exists (value tv, value pathv);
 extern CAMLprim value ocaml_augeas_insert (value tv, value beforev, value pathv, value labelv);
+extern CAMLprim value ocaml_augeas_label (value tv, value pathv);
 extern CAMLprim value ocaml_augeas_mv (value tv, value srcv, value destv);
 extern CAMLprim value ocaml_augeas_rm (value tv, value pathv);
 extern CAMLprim value ocaml_augeas_match (value tv, value pathv);
@@ -363,6 +364,32 @@ ocaml_augeas_insert (value tv, value beforev, value pathv, value labelv)
   CAMLreturn (Val_unit);
 }
 
+/* val label : t -> path -> string option */
+CAMLprim value
+ocaml_augeas_label (value tv, value pathv)
+{
+  CAMLparam2 (tv, pathv);
+  CAMLlocal2 (optv, v);
+  augeas_t t = Augeas_t_val (tv);
+  const char *path = String_val (pathv);
+  const char *val;
+  int r;
+
+  r = aug_label (t, path, &val);
+  if (r == 1 && val) {		/* Return Some val */
+    v = caml_copy_string (val);
+    optv = caml_alloc (1, 0);
+    Field (optv, 0) = v;
+  } else if (r == 0 || !val)	/* Return None */
+    optv = Val_int (0);
+  else if (r == -1)		/* Error or multiple matches */
+    raise_error (t, "Augeas.label");
+  else
+    caml_failwith ("Augeas.label: bad return value");
+
+  CAMLreturn (optv);
+}
+
 /* val mv : t -> path -> path -> unit */
 CAMLprim value
 ocaml_augeas_mv (value tv, value srcv, value destv)
diff --git a/augeas.ml b/augeas.ml
index 63379a2..006b76b 100644
--- a/augeas.ml
+++ b/augeas.ml
@@ -72,6 +72,8 @@ external exists : t -> path -> bool
   = "ocaml_augeas_exists"
 external insert : t -> ?before:bool -> path -> string -> unit
   = "ocaml_augeas_insert"
+external label : t -> path -> string option
+  = "ocaml_augeas_label"
 external rm : t -> path -> int
   = "ocaml_augeas_rm"
 external matches : t -> path -> path list
diff --git a/augeas.mli b/augeas.mli
index c1862f1..dc98c62 100644
--- a/augeas.mli
+++ b/augeas.mli
@@ -115,6 +115,12 @@ val insert : t -> ?before:bool -> path -> string -> unit
       of [path].  By default it is inserted after [path], unless
       [~before:true] is specified. *)
 
+val label : t -> path -> string option
+  (** [label t path] gets the label of [path].
+
+      Returns [Some value] when [path] matches only one node, and
+      that has an associated label. *)
+
 val rm : t -> path -> int
   (** [rm t path] removes all nodes matching [path].
 
-- 
1.8.3.1