1 files changed, 126 insertions, 0 deletions
diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c
new file mode 100644
index 0000000000..3378907f91
--- /dev/null
+++ b/src/backlight/backlight.c
@@ -0,0 +1,126 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <libudev.h>
+
+#include "util.h"
+#include "mkdir.h"
+#include "fileio.h"
+
+int main(int argc, char *argv[]) {
+        struct udev *udev = NULL;
+        struct udev_device *device = NULL;
+        _cleanup_free_ char *saved = NULL;
+        int r;
+
+        if (argc != 3) {
+                log_error("This program requires two arguments.");
+                return EXIT_FAILURE;
+        }
+
+        log_set_target(LOG_TARGET_AUTO);
+        log_parse_environment();
+        log_open();
+
+        umask(0022);
+
+        r = mkdir_p("/var/lib/backlight", 0755);
+        if (r < 0) {
+                log_error("Failed to create backlight directory: %s", strerror(-r));
+                goto finish;
+        }
+
+        udev = udev_new();
+        if (!udev) {
+                r = log_oom();
+                goto finish;
+        }
+
+        device = udev_device_new_from_syspath(udev, argv[2]);
+        if (!device) {
+                r = log_oom();
+                goto finish;
+        }
+
+        if (!streq_ptr(udev_device_get_subsystem(device), "backlight")) {
+                log_error("Not a backlight device: %s", argv[2]);
+                r = -ENODEV;
+                goto finish;
+        }
+
+        saved = strappend("/var/lib/backlight/", udev_device_get_sysname(device));
+        if (!saved) {
+                r = log_oom();
+                goto finish;
+        }
+
+        if (streq(argv[1], "load")) {
+                _cleanup_free_ char *value = NULL;
+
+                r = read_one_line_file(saved, &value);
+                if (r < 0) {
+
+                        if (r == -ENOENT) {
+                                r = 0;
+                                goto finish;
+                        }
+
+                        log_error("Failed to read %s: %s", saved, strerror(-r));
+                        goto finish;
+                }
+
+                r = udev_device_set_sysattr_value(device, "brightness", value);
+                if (r < 0) {
+                        log_error("Failed to write system attribute: %s", strerror(-r));
+                        goto finish;
+                }
+
+        } else if (streq(argv[1], "save")) {
+                const char *value;
+
+                value = udev_device_get_sysattr_value(device, "brightness");
+                if (!value) {
+                        log_error("Failed to read system attribute: %s", strerror(-r));
+                        goto finish;
+                }
+
+                r = write_string_file(saved, value);
+                if (r < 0) {
+                        log_error("Failed to write %s: %s", saved, strerror(-r));
+                        goto finish;
+                }
+
+        } else {
+                log_error("Unknown verb %s.", argv[1]);
+                r = -EINVAL;
+                goto finish;
+        }
+
+finish:
+        if (device)
+                udev_device_unref(device);
+
+        if (udev)
+                udev_unref(udev);
+
+        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+
+}