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-rw-r--r--src/backlight/backlight.c126
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;
+
+}