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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
*
* Copyright (C) 2010-2011 Richard Hughes <richard@hughsie.com>
*
* Licensed under the GNU General Public License Version 2
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <unistd.h>
#include <glib-object.h>
#include <locale.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <gudev/gudev.h>
#define GSD_BACKLIGHT_HELPER_EXIT_CODE_SUCCESS 0
#define GSD_BACKLIGHT_HELPER_EXIT_CODE_FAILED 1
#define GSD_BACKLIGHT_HELPER_EXIT_CODE_ARGUMENTS_INVALID 3
#define GSD_BACKLIGHT_HELPER_EXIT_CODE_INVALID_USER 4
#define GSD_BACKLIGHT_HELPER_EXIT_CODE_NO_DEVICES 5
static gchar *
gsd_backlight_helper_get_type (GList *devices, const gchar *type)
{
const gchar *type_tmp;
GList *d;
for (d = devices; d != NULL; d = d->next) {
type_tmp = g_udev_device_get_sysfs_attr (d->data, "type");
if (g_strcmp0 (type_tmp, type) == 0)
return g_strdup (g_udev_device_get_sysfs_path (d->data));
}
return NULL;
}
static gchar *
gsd_backlight_helper_get_best_backlight ()
{
gchar *path = NULL;
GList *devices;
GUdevClient *client;
client = g_udev_client_new (NULL);
devices = g_udev_client_query_by_subsystem (client, "backlight");
if (devices == NULL)
goto out;
/* search the backlight devices and prefer the types:
* firmware -> platform -> raw */
path = gsd_backlight_helper_get_type (devices, "firmware");
if (path != NULL)
goto out;
path = gsd_backlight_helper_get_type (devices, "platform");
if (path != NULL)
goto out;
path = gsd_backlight_helper_get_type (devices, "raw");
if (path != NULL)
goto out;
out:
g_object_unref (client);
g_list_foreach (devices, (GFunc) g_object_unref, NULL);
g_list_free (devices);
return path;
}
static gboolean
gsd_backlight_helper_write (const gchar *filename, gint value, GError **error)
{
gchar *text = NULL;
gint retval;
gint length;
gint fd = -1;
gboolean ret = TRUE;
fd = open (filename, O_WRONLY);
if (fd < 0) {
ret = FALSE;
g_set_error (error, 1, 0, "failed to open filename: %s", filename);
goto out;
}
/* convert to text */
text = g_strdup_printf ("%i", value);
length = strlen (text);
/* write to device file */
retval = write (fd, text, length);
if (retval != length) {
ret = FALSE;
g_set_error (error, 1, 0, "writing '%s' to %s failed", text, filename);
goto out;
}
out:
if (fd >= 0)
close (fd);
g_free (text);
return ret;
}
int
main (int argc, char *argv[])
{
GOptionContext *context;
gint uid;
gint euid;
guint retval = 0;
GError *error = NULL;
gboolean ret = FALSE;
gint set_brightness = -1;
gboolean get_brightness = FALSE;
gboolean get_max_brightness = FALSE;
gchar *filename = NULL;
gchar *filename_file = NULL;
gchar *contents = NULL;
const GOptionEntry options[] = {
{ "set-brightness", '\0', 0, G_OPTION_ARG_INT, &set_brightness,
/* command line argument */
"Set the current brightness", NULL },
{ "get-brightness", '\0', 0, G_OPTION_ARG_NONE, &get_brightness,
/* command line argument */
"Get the current brightness", NULL },
{ "get-max-brightness", '\0', 0, G_OPTION_ARG_NONE, &get_max_brightness,
/* command line argument */
"Get the number of brightness levels supported", NULL },
{ NULL}
};
/* setup type system */
g_type_init ();
context = g_option_context_new (NULL);
g_option_context_set_summary (context, "GNOME Settings Daemon Backlight Helper");
g_option_context_add_main_entries (context, options, NULL);
g_option_context_parse (context, &argc, &argv, NULL);
g_option_context_free (context);
#ifndef __linux__
/* the g-s-d plugin should only call this helper on linux */
g_critical ("Attempting to call gsb-backlight-helper on non-Linux");
g_assert_not_reached ();
#endif
/* no input */
if (set_brightness == -1 && !get_brightness && !get_max_brightness) {
g_print ("%s\n", "No valid option was specified");
retval = GSD_BACKLIGHT_HELPER_EXIT_CODE_ARGUMENTS_INVALID;
goto out;
}
/* find device */
filename = gsd_backlight_helper_get_best_backlight ();
if (filename == NULL) {
retval = GSD_BACKLIGHT_HELPER_EXIT_CODE_NO_DEVICES;
g_print ("%s: %s\n",
"Could not get or set the value of the backlight",
"No backlight devices present");
goto out;
}
/* GetBrightness */
if (get_brightness) {
filename_file = g_build_filename (filename, "brightness", NULL);
ret = g_file_get_contents (filename_file, &contents, NULL, &error);
if (!ret) {
g_print ("%s: %s\n",
"Could not get the value of the backlight",
error->message);
g_error_free (error);
retval = GSD_BACKLIGHT_HELPER_EXIT_CODE_ARGUMENTS_INVALID;
goto out;
}
/* just print the contents to stdout */
g_print ("%s", contents);
retval = GSD_BACKLIGHT_HELPER_EXIT_CODE_SUCCESS;
goto out;
}
/* GetSteps */
if (get_max_brightness) {
filename_file = g_build_filename (filename, "max_brightness", NULL);
ret = g_file_get_contents (filename_file, &contents, NULL, &error);
if (!ret) {
g_print ("%s: %s\n",
"Could not get the maximum value of the backlight",
error->message);
g_error_free (error);
retval = GSD_BACKLIGHT_HELPER_EXIT_CODE_ARGUMENTS_INVALID;
goto out;
}
/* just print the contents to stdout */
g_print ("%s", contents);
retval = GSD_BACKLIGHT_HELPER_EXIT_CODE_SUCCESS;
goto out;
}
/* check calling UID */
uid = getuid ();
euid = geteuid ();
if (uid != 0 || euid != 0) {
g_print ("%s\n",
"This program can only be used by the root user");
retval = GSD_BACKLIGHT_HELPER_EXIT_CODE_ARGUMENTS_INVALID;
goto out;
}
/* SetBrightness */
if (set_brightness != -1) {
filename_file = g_build_filename (filename, "brightness", NULL);
ret = gsd_backlight_helper_write (filename_file, set_brightness, &error);
if (!ret) {
g_print ("%s: %s\n",
"Could not set the value of the backlight",
error->message);
g_error_free (error);
retval = GSD_BACKLIGHT_HELPER_EXIT_CODE_ARGUMENTS_INVALID;
goto out;
}
}
/* success */
retval = GSD_BACKLIGHT_HELPER_EXIT_CODE_SUCCESS;
out:
g_free (filename);
g_free (filename_file);
g_free (contents);
return retval;
}
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