udevadm: split out find_device helper

[elogind.git] / src / udev / udevadm-util.c

diff --git a/src/udev/udevadm-util.c b/src/udev/udevadm-util.c
new file mode 100644 (file)
index 0000000..37e80c3
--- /dev/null
+++ b/src/udev/udevadm-util.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2008-2009 Kay Sievers <kay@vrfy.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "udevadm-util.h"
+
+struct udev_device *find_device(struct udev *udev,
+                                const char *id,
+                                const char *prefix) {
+
+        assert(udev);
+        assert(id);
+
+        if (prefix && !startswith(id, prefix))
+                id = strappenda(prefix, id);
+
+        if (startswith(id, "/dev/")) {
+                struct stat statbuf;
+                char type;
+
+                if (stat(id, &statbuf) < 0)
+                        return NULL;
+
+                if (S_ISBLK(statbuf.st_mode))
+                        type = 'b';
+                else if (S_ISCHR(statbuf.st_mode))
+                        type = 'c';
+                else
+                        return NULL;
+
+                return udev_device_new_from_devnum(udev, type, statbuf.st_rdev);
+        } else if (startswith(id, "/sys/"))
+                return udev_device_new_from_syspath(udev, id);
+        else
+                return NULL;
+}