From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Date: Mon, 18 Nov 2019 04:22:44 +0000 (+0900)
Subject: ctl: add global method to get devnode string of control device for sound card
X-Git-Tag: v0.1.0~425
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=af34dd2a5266b2d50a3d4e1724915221d9f97f9a;p=alsa-gobject.git

ctl: add global method to get devnode string of control device for sound card
---

diff --git a/src/ctl/alsactl.map b/src/ctl/alsactl.map
index d88b1e7..45d84d3 100644
--- a/src/ctl/alsactl.map
+++ b/src/ctl/alsactl.map
@@ -9,6 +9,7 @@ ALSA_GOBJECT_0_0_0 {
     "alsactl_get_card_id_list";
     "alsactl_get_card_sysname";
     "alsactl_get_control_sysname";
+    "alsactl_get_control_devnode";
   local:
     *;
 };
diff --git a/src/ctl/query.c b/src/ctl/query.c
index 1a8118d..47499a9 100644
--- a/src/ctl/query.c
+++ b/src/ctl/query.c
@@ -276,3 +276,51 @@ void alsactl_get_control_sysname(guint card_id, char **sysname, GError **error)
 
     *sysname = name;
 }
+
+/**
+ * alsactl_get_control_devnode:
+ * @card_id: The numerical ID of sound card.
+ * @devnode: (out): The string for devnode of control device for the sound card.
+ * @error: A #GError.
+ *
+ * Allocate string of devnode for control device of the sound card and return it
+ * if exists.
+ */
+void alsactl_get_control_devnode(guint card_id, char **devnode, GError **error)
+{
+    char *sysname;
+    struct udev *ctx;
+    struct udev_device *dev;
+    const char *node;
+
+    g_return_if_fail(devnode != NULL);
+
+    allocate_sysname(&sysname, CONTROL_SYSNAME_TEMPLATE, card_id, error);
+    if (*error != NULL)
+        return;
+
+    ctx = udev_new();
+    if (ctx == NULL) {
+        generate_error(error, errno);
+        g_free(sysname);
+        return;
+    }
+
+    dev = udev_device_new_from_subsystem_sysname(ctx, "sound", sysname);
+    if (dev == NULL) {
+        generate_error(error, ENODEV);
+        g_free(sysname);
+        udev_unref(ctx);
+        return;
+    }
+    g_free(sysname);
+
+    node = udev_device_get_devnode(dev);
+    if (node != NULL)
+        *devnode = strdup(node);
+    else
+        generate_error(error, ENODEV);
+
+    udev_device_unref(dev);
+    udev_unref(ctx);
+}
diff --git a/src/ctl/query.h b/src/ctl/query.h
index ef135d4..d9d3c72 100644
--- a/src/ctl/query.h
+++ b/src/ctl/query.h
@@ -14,6 +14,8 @@ void alsactl_get_card_sysname(guint card_id, char **sysname, GError **error);
 
 void alsactl_get_control_sysname(guint card_id, char **sysname, GError **error);
 
+void alsactl_get_control_devnode(guint card_id, char **devnode, GError **error);
+
 G_END_DECLS
 
 #endif