Exemple #1
0
int
main(int argc, char *argv[])
{
	int r;

#ifdef ENABLE_NLS
	/* Init locale */
	setlocale(LC_CTYPE, "");
	setlocale(LC_MESSAGES, "");

	/* Internationalisation */
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);
#endif

	/* Initialize settings to NULL values. */
	char *config_filepath = NULL;

	int temp_set = -1;
	int temp_day = -1;
	int temp_night = -1;
	float gamma[3] = { NAN, NAN, NAN };
	float brightness_day = NAN;
	float brightness_night = NAN;

	const gamma_method_t *method = NULL;
	char *method_args = NULL;

	const location_provider_t *provider = NULL;
	char *provider_args = NULL;

	int transition = -1;
	program_mode_t mode = PROGRAM_MODE_CONTINUAL;
	int verbose = 0;
	char *s;

	/* Flush messages consistently even if redirected to a pipe or
	   file.  Change the flush behaviour to line-buffered, without
	   changing the actual buffers being used. */
	setvbuf(stdout, NULL, _IOLBF, 0);
	setvbuf(stderr, NULL, _IOLBF, 0);

	/* Parse command line arguments. */
	int opt;
	while ((opt = getopt(argc, argv, "b:c:g:hl:m:oO:prt:vVx")) != -1) {
		switch (opt) {
		case 'b':
			parse_brightness_string(optarg, &brightness_day, &brightness_night);
			break;
		case 'c':
			if (config_filepath != NULL) free(config_filepath);
			config_filepath = strdup(optarg);
			break;
		case 'g':
			r = parse_gamma_string(optarg, gamma);
			if (r < 0) {
				fputs(_("Malformed gamma argument.\n"),
				      stderr);
				fputs(_("Try `-h' for more"
					" information.\n"), stderr);
				exit(EXIT_FAILURE);
			}
			break;
		case 'h':
			print_help(argv[0]);
			exit(EXIT_SUCCESS);
			break;
		case 'l':
			/* Print list of providers if argument is `list' */
			if (strcasecmp(optarg, "list") == 0) {
				print_provider_list();
				exit(EXIT_SUCCESS);
			}

			char *provider_name = NULL;

			/* Don't save the result of strtof(); we simply want
			   to know if optarg can be parsed as a float. */
			errno = 0;
			char *end;
			strtof(optarg, &end);
			if (errno == 0 && *end == ':') {
				/* Use instead as arguments to `manual'. */
				provider_name = "manual";
				provider_args = optarg;
			} else {
				/* Split off provider arguments. */
				s = strchr(optarg, ':');
				if (s != NULL) {
					*(s++) = '\0';
					provider_args = s;
				}

				provider_name = optarg;
			}

			/* Lookup provider from name. */
			provider = find_location_provider(provider_name);
			if (provider == NULL) {
				fprintf(stderr, _("Unknown location provider"
						  " `%s'.\n"), provider_name);
				exit(EXIT_FAILURE);
			}

			/* Print provider help if arg is `help'. */
			if (provider_args != NULL &&
			    strcasecmp(provider_args, "help") == 0) {
				provider->print_help(stdout);
				exit(EXIT_SUCCESS);
			}
			break;
		case 'm':
			/* Print list of methods if argument is `list' */
			if (strcasecmp(optarg, "list") == 0) {
				print_method_list();
				exit(EXIT_SUCCESS);
			}

			/* Split off method arguments. */
			s = strchr(optarg, ':');
			if (s != NULL) {
				*(s++) = '\0';
				method_args = s;
			}

			/* Find adjustment method by name. */
			method = find_gamma_method(optarg);
			if (method == NULL) {
				/* TRANSLATORS: This refers to the method
				   used to adjust colors e.g VidMode */
				fprintf(stderr, _("Unknown adjustment method"
						  " `%s'.\n"), optarg);
				exit(EXIT_FAILURE);
			}

			/* Print method help if arg is `help'. */
			if (method_args != NULL &&
			    strcasecmp(method_args, "help") == 0) {
				method->print_help(stdout);
				exit(EXIT_SUCCESS);
			}
			break;
		case 'o':
			mode = PROGRAM_MODE_ONE_SHOT;
			break;
		case 'O':
			mode = PROGRAM_MODE_MANUAL;
			temp_set = atoi(optarg);
			break;
		case 'p':
			mode = PROGRAM_MODE_PRINT;
			break;
		case 'r':
			transition = 0;
			break;
		case 't':
			s = strchr(optarg, ':');
			if (s == NULL) {
				fputs(_("Malformed temperature argument.\n"),
				      stderr);
				fputs(_("Try `-h' for more information.\n"),
				      stderr);
				exit(EXIT_FAILURE);
			}
			*(s++) = '\0';
			temp_day = atoi(optarg);
			temp_night = atoi(s);
			break;
		case 'v':
			verbose = 1;
			break;
                case 'V':
                        printf("%s\n", PACKAGE_STRING);
                        exit(EXIT_SUCCESS);
                        break;
		case 'x':
			mode = PROGRAM_MODE_RESET;
			break;
		case '?':
			fputs(_("Try `-h' for more information.\n"), stderr);
			exit(EXIT_FAILURE);
			break;
		}
	}

	/* Load settings from config file. */
	config_ini_state_t config_state;
	r = config_ini_init(&config_state, config_filepath);
	if (r < 0) {
		fputs("Unable to load config file.\n", stderr);
		exit(EXIT_FAILURE);
	}

	if (config_filepath != NULL) free(config_filepath);

	/* Read global config settings. */
	config_ini_section_t *section = config_ini_get_section(&config_state,
							       "redshift");
	if (section != NULL) {
		config_ini_setting_t *setting = section->settings;
		while (setting != NULL) {
			if (strcasecmp(setting->name, "temp-day") == 0) {
				if (temp_day < 0) {
					temp_day = atoi(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "temp-night") == 0) {
				if (temp_night < 0) {
					temp_night = atoi(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "transition") == 0) {
				if (transition < 0) {
					transition = !!atoi(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "brightness") == 0) {
				if (isnan(brightness_day)) {
					brightness_day = atof(setting->value);
				}
				if (isnan(brightness_night)) {
					brightness_night = atof(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "brightness-day") == 0) {
				if (isnan(brightness_day)) {
					brightness_day = atof(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "brightness-night") == 0) {
				if (isnan(brightness_night)) {
					brightness_night = atof(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "elevation-high") == 0) {
				transition_high = atof(setting->value);
			} else if (strcasecmp(setting->name,
					      "elevation-low") == 0) {
				transition_low = atof(setting->value);
			} else if (strcasecmp(setting->name, "gamma") == 0) {
				if (isnan(gamma[0])) {
					r = parse_gamma_string(setting->value,
							       gamma);
					if (r < 0) {
						fputs(_("Malformed gamma"
							" setting.\n"),
						      stderr);
						exit(EXIT_FAILURE);
					}
				}
			} else if (strcasecmp(setting->name,
					      "adjustment-method") == 0) {
				if (method == NULL) {
					method = find_gamma_method(
						setting->value);
					if (method == NULL) {
						fprintf(stderr, _("Unknown"
								  " adjustment"
								  " method"
								  " `%s'.\n"),
							setting->value);
						exit(EXIT_FAILURE);
					}
				}
			} else if (strcasecmp(setting->name,
					      "location-provider") == 0) {
				if (provider == NULL) {
					provider = find_location_provider(
						setting->value);
					if (provider == NULL) {
						fprintf(stderr, _("Unknown"
								  " location"
								  " provider"
								  " `%s'.\n"),
							setting->value);
						exit(EXIT_FAILURE);
					}
				}
			} else {
				fprintf(stderr, _("Unknown configuration"
						  " setting `%s'.\n"),
					setting->name);
			}
			setting = setting->next;
		}
	}

	/* Use default values for settings that were neither defined in
	   the config file nor on the command line. */
	if (temp_day < 0) temp_day = DEFAULT_DAY_TEMP;
	if (temp_night < 0) temp_night = DEFAULT_NIGHT_TEMP;
	if (isnan(brightness_day)) brightness_day = DEFAULT_BRIGHTNESS;
	if (isnan(brightness_night)) brightness_night = DEFAULT_BRIGHTNESS;
	if (isnan(gamma[0])) gamma[0] = gamma[1] = gamma[2] = DEFAULT_GAMMA;
	if (transition < 0) transition = 1;

	float lat = NAN;
	float lon = NAN;

	/* Initialize location provider. If provider is NULL
	   try all providers until one that works is found. */
	location_state_t location_state;

	/* Location is not needed for reset mode and manual mode. */
	if (mode != PROGRAM_MODE_RESET &&
	    mode != PROGRAM_MODE_MANUAL) {
		if (provider != NULL) {
			/* Use provider specified on command line. */
			r = provider_try_start(provider, &location_state,
					       &config_state, provider_args);
			if (r < 0) exit(EXIT_FAILURE);
		} else {
			/* Try all providers, use the first that works. */
			for (int i = 0;
			     location_providers[i].name != NULL; i++) {
				const location_provider_t *p =
					&location_providers[i];
				fprintf(stderr,
					_("Trying location provider `%s'...\n"),
					p->name);
				r = provider_try_start(p, &location_state,
						       &config_state, NULL);
				if (r < 0) {
					fputs(_("Trying next provider...\n"),
					      stderr);
					continue;
				}

				/* Found provider that works. */
				printf(_("Using provider `%s'.\n"), p->name);
				provider = p;
				break;
			}

			/* Failure if no providers were successful at this
			   point. */
			if (provider == NULL) {
				fputs(_("No more location providers"
					" to try.\n"), stderr);
				exit(EXIT_FAILURE);
			}
		}

		/* Get current location. */
		r = provider->get_location(&location_state, &lat, &lon);
		if (r < 0) {
		        fputs(_("Unable to get location from provider.\n"),
		              stderr);
		        exit(EXIT_FAILURE);
		}
	
		provider->free(&location_state);
	
		if (verbose) {
		        /* TRANSLATORS: Append degree symbols if possible. */
		        printf(_("Location: %f, %f\n"), lat, lon);
			printf(_("Temperatures: %dK at day, %dK at night\n"),
			       temp_day, temp_night);
		        /* TRANSLATORS: Append degree symbols if possible. */
			printf(_("Solar elevations: day above %.1f, night below %.1f\n"),
			       transition_high, transition_low);
		}

		/* Latitude */
		if (lat < MIN_LAT || lat > MAX_LAT) {
		        /* TRANSLATORS: Append degree symbols if possible. */
		        fprintf(stderr,
		                _("Latitude must be between %.1f and %.1f.\n"),
		                MIN_LAT, MAX_LAT);
		        exit(EXIT_FAILURE);
		}
	
		/* Longitude */
		if (lon < MIN_LON || lon > MAX_LON) {
		        /* TRANSLATORS: Append degree symbols if possible. */
		        fprintf(stderr,
		                _("Longitude must be between"
		                  " %.1f and %.1f.\n"), MIN_LON, MAX_LON);
		        exit(EXIT_FAILURE);
		}

		/* Color temperature at daytime */
		if (temp_day < MIN_TEMP || temp_day > MAX_TEMP) {
			fprintf(stderr,
				_("Temperature must be between %uK and %uK.\n"),
				MIN_TEMP, MAX_TEMP);
			exit(EXIT_FAILURE);
		}
	
		/* Color temperature at night */
		if (temp_night < MIN_TEMP || temp_night > MAX_TEMP) {
			fprintf(stderr,
				_("Temperature must be between %uK and %uK.\n"),
				MIN_TEMP, MAX_TEMP);
			exit(EXIT_FAILURE);
		}

		/* Solar elevations */
		if (transition_high < transition_low) {
		        fprintf(stderr,
		                _("High transition elevation cannot be lower than"
				  " the low transition elevation.\n"));
		        exit(EXIT_FAILURE);
		}
	}

	if (mode == PROGRAM_MODE_MANUAL) {
		/* Check color temperature to be set */
		if (temp_set < MIN_TEMP || temp_set > MAX_TEMP) {
			fprintf(stderr,
				_("Temperature must be between %uK and %uK.\n"),
				MIN_TEMP, MAX_TEMP);
			exit(EXIT_FAILURE);
		}
	}

	/* Brightness */
	if (brightness_day < MIN_BRIGHTNESS ||
	    brightness_day > MAX_BRIGHTNESS ||
	    brightness_night < MIN_BRIGHTNESS ||
	    brightness_night > MAX_BRIGHTNESS) {
		fprintf(stderr,
			_("Brightness values must be between %.1f and %.1f.\n"),
			MIN_BRIGHTNESS, MAX_BRIGHTNESS);
		exit(EXIT_FAILURE);
	}

	if (verbose) {
		printf(_("Brightness: %.2f:%.2f\n"), brightness_day, brightness_night);
	}

	/* Gamma */
	if (gamma[0] < MIN_GAMMA || gamma[0] > MAX_GAMMA ||
	    gamma[1] < MIN_GAMMA || gamma[1] > MAX_GAMMA ||
	    gamma[2] < MIN_GAMMA || gamma[2] > MAX_GAMMA) {
		fprintf(stderr,
			_("Gamma value must be between %.1f and %.1f.\n"),
			MIN_GAMMA, MAX_GAMMA);
		exit(EXIT_FAILURE);
	}

	if (verbose) {
		printf(_("Gamma: %.3f, %.3f, %.3f\n"),
		       gamma[0], gamma[1], gamma[2]);
	}

	/* Initialize gamma adjustment method. If method is NULL
	   try all methods until one that works is found. */
	gamma_state_t state;

	/* Gamma adjustment not needed for print mode */
	if (mode != PROGRAM_MODE_PRINT) {
		if (method != NULL) {
			/* Use method specified on command line. */
			r = method_try_start(method, &state, &config_state,
					     method_args);
			if (r < 0) exit(EXIT_FAILURE);
		} else {
			/* Try all methods, use the first that works. */
			for (int i = 0; gamma_methods[i].name != NULL; i++) {
				const gamma_method_t *m = &gamma_methods[i];
				if (!m->autostart) continue;

				r = method_try_start(m, &state, &config_state, NULL);
				if (r < 0) {
					fputs(_("Trying next method...\n"), stderr);
					continue;
				}

				/* Found method that works. */
				printf(_("Using method `%s'.\n"), m->name);
				method = m;
				break;
			}

			/* Failure if no methods were successful at this point. */
			if (method == NULL) {
				fputs(_("No more methods to try.\n"), stderr);
				exit(EXIT_FAILURE);
			}
		}
	}

	config_ini_free(&config_state);

	switch (mode) {
	case PROGRAM_MODE_ONE_SHOT:
	case PROGRAM_MODE_PRINT:
	{
		/* Current angular elevation of the sun */
		double now;
		r = systemtime_get_time(&now);
		if (r < 0) {
			fputs(_("Unable to read system time.\n"), stderr);
			method->free(&state);
			exit(EXIT_FAILURE);
		}

		double elevation = solar_elevation(now, lat, lon);

		if (verbose) {
			/* TRANSLATORS: Append degree symbol if possible. */
			printf(_("Solar elevation: %f\n"), elevation);
		}

		/* Use elevation of sun to set color temperature */
		int temp = (int)calculate_interpolated_value(elevation,
							     temp_day, temp_night);
		float brightness = calculate_interpolated_value(elevation,
								brightness_day, brightness_night);

		if (verbose || mode == PROGRAM_MODE_PRINT) {
			print_period(elevation);
			printf(_("Color temperature: %uK\n"), temp);
			printf(_("Brightness: %.2f\n"), brightness);
		}

		if (mode == PROGRAM_MODE_PRINT) {
			exit(EXIT_SUCCESS);
		}

		/* Adjust temperature */
		r = method->set_temperature(&state, temp, brightness, gamma);
		if (r < 0) {
			fputs(_("Temperature adjustment failed.\n"), stderr);
			method->free(&state);
			exit(EXIT_FAILURE);
		}
	}
	break;
	case PROGRAM_MODE_MANUAL:
	{
		if (verbose) printf(_("Color temperature: %uK\n"), temp_set);

		/* Adjust temperature */
		r = method->set_temperature(&state, temp_set, brightness_day, gamma);
		if (r < 0) {
			fputs(_("Temperature adjustment failed.\n"), stderr);
			method->free(&state);
			exit(EXIT_FAILURE);
		}

	}
	break;
	case PROGRAM_MODE_RESET:
	{
		/* Reset screen */
		r = method->set_temperature(&state, NEUTRAL_TEMP, 1.0, gamma);
		if (r < 0) {
			fputs(_("Temperature adjustment failed.\n"), stderr);
			method->free(&state);
			exit(EXIT_FAILURE);
		}
	}
	break;
	case PROGRAM_MODE_CONTINUAL:
	{
		/* Make an initial transition from 6500K */
		int short_trans_delta = -1;
		int short_trans_len = 10;

		/* Amount of adjustment to apply. At zero the color
		   temperature will be exactly as calculated, and at one it
		   will be exactly 6500K. */
		double adjustment_alpha = 1.0;

#if defined(HAVE_SIGNAL_H) && !defined(__WIN32__)
		struct sigaction sigact;
		sigset_t sigset;
		sigemptyset(&sigset);

		/* Install signal handler for INT and TERM signals */
		sigact.sa_handler = sigexit;
		sigact.sa_mask = sigset;
		sigact.sa_flags = 0;
		sigaction(SIGINT, &sigact, NULL);
		sigaction(SIGTERM, &sigact, NULL);

		/* Install signal handler for USR1 singal */
		sigact.sa_handler = sigdisable;
		sigact.sa_mask = sigset;
		sigact.sa_flags = 0;
		sigaction(SIGUSR1, &sigact, NULL);
#endif /* HAVE_SIGNAL_H && ! __WIN32__ */

		if (verbose) {
			printf("Status: %s\n", "Enabled");
		}

		/* Continuously adjust color temperature */
		int done = 0;
		int disabled = 0;
		while (1) {
			/* Check to see if disable signal was caught */
			if (disable) {
				short_trans_len = 2;
				if (!disabled) {
					/* Transition to disabled state */
					short_trans_delta = 1;
				} else {
					/* Transition back to enabled */
					short_trans_delta = -1;
				}
				disabled = !disabled;
				disable = 0;

				if (verbose) {
					printf("Status: %s\n", disabled ?
					       "Disabled" : "Enabled");
				}
			}

			/* Check to see if exit signal was caught */
			if (exiting) {
				if (done) {
					/* On second signal stop the
					   ongoing transition */
					short_trans_delta = 0;
					adjustment_alpha = 0.0;
				} else {
					if (!disabled) {
						/* Make a short transition
						   back to 6500K */
						short_trans_delta = 1;
						short_trans_len = 2;
					}

					done = 1;
				}
				exiting = 0;
			}

			/* Read timestamp */
			double now;
			r = systemtime_get_time(&now);
			if (r < 0) {
				fputs(_("Unable to read system time.\n"),
				      stderr);
				method->free(&state);
				exit(EXIT_FAILURE);
			}

			/* Skip over transition if transitions are disabled */
			int set_adjustments = 0;
			if (!transition) {
				if (short_trans_delta) {
					adjustment_alpha = short_trans_delta < 0 ? 0.0 : 1.0;
					short_trans_delta = 0;
					set_adjustments = 1;
				}
			}

			/* Current angular elevation of the sun */
			double elevation = solar_elevation(now, lat, lon);

			/* Use elevation of sun to set color temperature */
			int temp = (int)calculate_interpolated_value(elevation,
								temp_day, temp_night);
			float brightness = calculate_interpolated_value(elevation,
								brightness_day, brightness_night);

			if (verbose) print_period(elevation);

			/* Ongoing short transition */
			if (short_trans_delta) {
				/* Calculate alpha */
				adjustment_alpha += short_trans_delta * 0.1 /
					(float)short_trans_len;

				/* Stop transition when done */
				if (adjustment_alpha <= 0.0 ||
				    adjustment_alpha >= 1.0) {
					short_trans_delta = 0;
				}

				/* Clamp alpha value */
				adjustment_alpha =
					MAX(0.0, MIN(adjustment_alpha, 1.0));
			}

			/* Interpolate between 6500K and calculated
			   temperature */
			temp = adjustment_alpha*6500 +
				(1.0-adjustment_alpha)*temp;

			brightness = adjustment_alpha*1.0 +
				(1.0-adjustment_alpha)*brightness;

			/* Quit loop when done */
			if (done && !short_trans_delta) break;

			if (verbose) {
				printf(_("Color temperature: %uK\n"), temp);
				printf(_("Brightness: %.2f\n"), brightness);
			}

			/* Adjust temperature */
			if (!disabled || short_trans_delta || set_adjustments) {
				r = method->set_temperature(&state,
							    temp, brightness,
							    gamma);
				if (r < 0) {
					fputs(_("Temperature adjustment"
						" failed.\n"), stderr);
					method->free(&state);
					exit(EXIT_FAILURE);
				}
			}

			/* Sleep for 5 seconds or 0.1 second. */
#ifndef _WIN32
			if (short_trans_delta) usleep(100000);
			else usleep(5000000);
#else /* ! _WIN32 */
			if (short_trans_delta) Sleep(100);
			else Sleep(5000);
#endif /* ! _WIN32 */
		}

		/* Restore saved gamma ramps */
		method->restore(&state);
	}
	break;
	}

	/* Clean up gamma adjustment state */
	method->free(&state);

	return EXIT_SUCCESS;
}
Exemple #2
0
int
main(int argc, char *argv[])
{
	int r;

#ifdef ENABLE_NLS
	/* Init locale */
	setlocale(LC_CTYPE, "");
	setlocale(LC_MESSAGES, "");

	/* Internationalisation */
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);
#endif

	/* Initialize settings to NULL values. */
	char *config_filepath = NULL;

	/* Settings for day, night and transition.
	   Initialized to indicate that the values are not set yet. */
	transition_scheme_t scheme =
		{ TRANSITION_HIGH, TRANSITION_LOW };

	scheme.day.temperature = -1;
	scheme.day.gamma[0] = NAN;
	scheme.day.brightness = NAN;

	scheme.night.temperature = -1;
	scheme.night.gamma[0] = NAN;
	scheme.night.brightness = NAN;

	/* Temperature for manual mode */
	int temp_set = -1;

	const gamma_method_t *method = NULL;
	char *method_args = NULL;

	const location_provider_t *provider = NULL;
	char *provider_args = NULL;

	int transition = -1;
	program_mode_t mode = PROGRAM_MODE_CONTINUAL;
	int verbose = 0;
	char *s;

	/* Flush messages consistently even if redirected to a pipe or
	   file.  Change the flush behaviour to line-buffered, without
	   changing the actual buffers being used. */
	setvbuf(stdout, NULL, _IOLBF, 0);
	setvbuf(stderr, NULL, _IOLBF, 0);

	/* Parse command line arguments. */
	int opt;
	while ((opt = getopt(argc, argv, "b:c:g:hl:m:oO:prt:vVx")) != -1) {
		switch (opt) {
		case 'b':
			parse_brightness_string(optarg,
						&scheme.day.brightness,
						&scheme.night.brightness);
			break;
		case 'c':
			free(config_filepath);
			config_filepath = strdup(optarg);
			break;
		case 'g':
			r = parse_gamma_string(optarg, scheme.day.gamma);
			if (r < 0) {
				fputs(_("Malformed gamma argument.\n"),
				      stderr);
				fputs(_("Try `-h' for more"
					" information.\n"), stderr);
				exit(EXIT_FAILURE);
			}

			/* Set night gamma to the same value as day gamma.
			   To set these to distinct values use the config
			   file. */
			memcpy(scheme.night.gamma, scheme.day.gamma,
			       sizeof(scheme.night.gamma));
			break;
		case 'h':
			print_help(argv[0]);
			exit(EXIT_SUCCESS);
			break;
		case 'l':
			/* Print list of providers if argument is `list' */
			if (strcasecmp(optarg, "list") == 0) {
				print_provider_list();
				exit(EXIT_SUCCESS);
			}

			char *provider_name = NULL;

			/* Don't save the result of strtof(); we simply want
			   to know if optarg can be parsed as a float. */
			errno = 0;
			char *end;
			strtof(optarg, &end);
			if (errno == 0 && *end == ':') {
				/* Use instead as arguments to `manual'. */
				provider_name = "manual";
				provider_args = optarg;
			} else {
				/* Split off provider arguments. */
				s = strchr(optarg, ':');
				if (s != NULL) {
					*(s++) = '\0';
					provider_args = s;
				}

				provider_name = optarg;
			}

			/* Lookup provider from name. */
			provider = find_location_provider(provider_name);
			if (provider == NULL) {
				fprintf(stderr, _("Unknown location provider"
						  " `%s'.\n"), provider_name);
				exit(EXIT_FAILURE);
			}

			/* Print provider help if arg is `help'. */
			if (provider_args != NULL &&
			    strcasecmp(provider_args, "help") == 0) {
				provider->print_help(stdout);
				exit(EXIT_SUCCESS);
			}
			break;
		case 'm':
			/* Print list of methods if argument is `list' */
			if (strcasecmp(optarg, "list") == 0) {
				print_method_list();
				exit(EXIT_SUCCESS);
			}

			/* Split off method arguments. */
			s = strchr(optarg, ':');
			if (s != NULL) {
				*(s++) = '\0';
				method_args = s;
			}

			/* Find adjustment method by name. */
			method = find_gamma_method(optarg);
			if (method == NULL) {
				/* TRANSLATORS: This refers to the method
				   used to adjust colors e.g VidMode */
				fprintf(stderr, _("Unknown adjustment method"
						  " `%s'.\n"), optarg);
				exit(EXIT_FAILURE);
			}

			/* Print method help if arg is `help'. */
			if (method_args != NULL &&
			    strcasecmp(method_args, "help") == 0) {
				method->print_help(stdout);
				exit(EXIT_SUCCESS);
			}
			break;
		case 'o':
			mode = PROGRAM_MODE_ONE_SHOT;
			break;
		case 'O':
			mode = PROGRAM_MODE_MANUAL;
			temp_set = atoi(optarg);
			break;
		case 'p':
			mode = PROGRAM_MODE_PRINT;
			break;
		case 'r':
			transition = 0;
			break;
		case 't':
			s = strchr(optarg, ':');
			if (s == NULL) {
				fputs(_("Malformed temperature argument.\n"),
				      stderr);
				fputs(_("Try `-h' for more information.\n"),
				      stderr);
				exit(EXIT_FAILURE);
			}
			*(s++) = '\0';
			scheme.day.temperature = atoi(optarg);
			scheme.night.temperature = atoi(s);
			break;
		case 'v':
			verbose = 1;
			break;
                case 'V':
                        printf("%s\n", PACKAGE_STRING);
                        exit(EXIT_SUCCESS);
                        break;
		case 'x':
			mode = PROGRAM_MODE_RESET;
			break;
		case '?':
			fputs(_("Try `-h' for more information.\n"), stderr);
			exit(EXIT_FAILURE);
			break;
		}
	}

	/* Load settings from config file. */
	config_ini_state_t config_state;
	r = config_ini_init(&config_state, config_filepath);
	if (r < 0) {
		fputs("Unable to load config file.\n", stderr);
		exit(EXIT_FAILURE);
	}

	free(config_filepath);

	/* Read global config settings. */
	config_ini_section_t *section = config_ini_get_section(&config_state,
							       "redshift");
	if (section != NULL) {
		config_ini_setting_t *setting = section->settings;
		while (setting != NULL) {
			if (strcasecmp(setting->name, "temp-day") == 0) {
				if (scheme.day.temperature < 0) {
					scheme.day.temperature =
						atoi(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "temp-night") == 0) {
				if (scheme.night.temperature < 0) {
					scheme.night.temperature =
						atoi(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "transition") == 0) {
				if (transition < 0) {
					transition = !!atoi(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "brightness") == 0) {
				if (isnan(scheme.day.brightness)) {
					scheme.day.brightness =
						atof(setting->value);
				}
				if (isnan(scheme.night.brightness)) {
					scheme.night.brightness =
						atof(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "brightness-day") == 0) {
				if (isnan(scheme.day.brightness)) {
					scheme.day.brightness =
						atof(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "brightness-night") == 0) {
				if (isnan(scheme.night.brightness)) {
					scheme.night.brightness =
						atof(setting->value);
				}
			} else if (strcasecmp(setting->name,
					      "elevation-high") == 0) {
				scheme.high = atof(setting->value);
			} else if (strcasecmp(setting->name,
					      "elevation-low") == 0) {
				scheme.low = atof(setting->value);
			} else if (strcasecmp(setting->name, "gamma") == 0) {
				if (isnan(scheme.day.gamma[0])) {
					r = parse_gamma_string(setting->value,
							       scheme.day.gamma);
					if (r < 0) {
						fputs(_("Malformed gamma"
							" setting.\n"),
						      stderr);
						exit(EXIT_FAILURE);
					}
					memcpy(scheme.night.gamma, scheme.day.gamma,
					       sizeof(scheme.night.gamma));
				}
			} else if (strcasecmp(setting->name, "gamma-day") == 0) {
				if (isnan(scheme.day.gamma[0])) {
					r = parse_gamma_string(setting->value,
							       scheme.day.gamma);
					if (r < 0) {
						fputs(_("Malformed gamma"
							" setting.\n"),
						      stderr);
						exit(EXIT_FAILURE);
					}
				}
			} else if (strcasecmp(setting->name, "gamma-night") == 0) {
				if (isnan(scheme.night.gamma[0])) {
					r = parse_gamma_string(setting->value,
							       scheme.night.gamma);
					if (r < 0) {
						fputs(_("Malformed gamma"
							" setting.\n"),
						      stderr);
						exit(EXIT_FAILURE);
					}
				}
			} else if (strcasecmp(setting->name,
					      "adjustment-method") == 0) {
				if (method == NULL) {
					method = find_gamma_method(
						setting->value);
					if (method == NULL) {
						fprintf(stderr, _("Unknown"
								  " adjustment"
								  " method"
								  " `%s'.\n"),
							setting->value);
						exit(EXIT_FAILURE);
					}
				}
			} else if (strcasecmp(setting->name,
					      "location-provider") == 0) {
				if (provider == NULL) {
					provider = find_location_provider(
						setting->value);
					if (provider == NULL) {
						fprintf(stderr, _("Unknown"
								  " location"
								  " provider"
								  " `%s'.\n"),
							setting->value);
						exit(EXIT_FAILURE);
					}
				}
			} else {
				fprintf(stderr, _("Unknown configuration"
						  " setting `%s'.\n"),
					setting->name);
			}
			setting = setting->next;
		}
	}

	/* Use default values for settings that were neither defined in
	   the config file nor on the command line. */
	if (scheme.day.temperature < 0) {
		scheme.day.temperature = DEFAULT_DAY_TEMP;
	}
	if (scheme.night.temperature < 0) {
		scheme.night.temperature = DEFAULT_NIGHT_TEMP;
	}

	if (isnan(scheme.day.brightness)) {
		scheme.day.brightness = DEFAULT_BRIGHTNESS;
	}
	if (isnan(scheme.night.brightness)) {
		scheme.night.brightness = DEFAULT_BRIGHTNESS;
	}

	if (isnan(scheme.day.gamma[0])) {
		scheme.day.gamma[0] = DEFAULT_GAMMA;
		scheme.day.gamma[1] = DEFAULT_GAMMA;
		scheme.day.gamma[2] = DEFAULT_GAMMA;
	}
	if (isnan(scheme.night.gamma[0])) {
		scheme.night.gamma[0] = DEFAULT_GAMMA;
		scheme.night.gamma[1] = DEFAULT_GAMMA;
		scheme.night.gamma[2] = DEFAULT_GAMMA;
	}

	if (transition < 0) transition = 1;

	location_t loc = { NAN, NAN };

	/* Initialize location provider. If provider is NULL
	   try all providers until one that works is found. */
	location_state_t location_state;

	/* Location is not needed for reset mode and manual mode. */
	if (mode != PROGRAM_MODE_RESET &&
	    mode != PROGRAM_MODE_MANUAL) {
		if (provider != NULL) {
			/* Use provider specified on command line. */
			r = provider_try_start(provider, &location_state,
					       &config_state, provider_args);
			if (r < 0) exit(EXIT_FAILURE);
		} else {
			/* Try all providers, use the first that works. */
			for (int i = 0;
			     location_providers[i].name != NULL; i++) {
				const location_provider_t *p =
					&location_providers[i];
				fprintf(stderr,
					_("Trying location provider `%s'...\n"),
					p->name);
				r = provider_try_start(p, &location_state,
						       &config_state, NULL);
				if (r < 0) {
					fputs(_("Trying next provider...\n"),
					      stderr);
					continue;
				}

				/* Found provider that works. */
				printf(_("Using provider `%s'.\n"), p->name);
				provider = p;
				break;
			}

			/* Failure if no providers were successful at this
			   point. */
			if (provider == NULL) {
				fputs(_("No more location providers"
					" to try.\n"), stderr);
				exit(EXIT_FAILURE);
			}
		}

		/* Get current location. */
		r = provider->get_location(&location_state, &loc);
		if (r < 0) {
		        fputs(_("Unable to get location from provider.\n"),
		              stderr);
		        exit(EXIT_FAILURE);
		}
	
		provider->free(&location_state);
	
		if (verbose) {
			print_location(&loc);

			printf(_("Temperatures: %dK at day, %dK at night\n"),
			       scheme.day.temperature,
			       scheme.night.temperature);

		        /* TRANSLATORS: Append degree symbols if possible. */
			printf(_("Solar elevations: day above %.1f, night below %.1f\n"),
			       scheme.high, scheme.low);
		}

		/* Latitude */
		if (loc.lat < MIN_LAT || loc.lat > MAX_LAT) {
		        /* TRANSLATORS: Append degree symbols if possible. */
		        fprintf(stderr,
		                _("Latitude must be between %.1f and %.1f.\n"),
		                MIN_LAT, MAX_LAT);
		        exit(EXIT_FAILURE);
		}
	
		/* Longitude */
		if (loc.lon < MIN_LON || loc.lon > MAX_LON) {
		        /* TRANSLATORS: Append degree symbols if possible. */
		        fprintf(stderr,
		                _("Longitude must be between"
		                  " %.1f and %.1f.\n"), MIN_LON, MAX_LON);
		        exit(EXIT_FAILURE);
		}

		/* Color temperature */
		if (scheme.day.temperature < MIN_TEMP ||
		    scheme.day.temperature > MAX_TEMP ||
		    scheme.night.temperature < MIN_TEMP ||
		    scheme.night.temperature > MAX_TEMP) {
			fprintf(stderr,
				_("Temperature must be between %uK and %uK.\n"),
				MIN_TEMP, MAX_TEMP);
			exit(EXIT_FAILURE);
		}

		/* Solar elevations */
		if (scheme.high < scheme.low) {
		        fprintf(stderr,
		                _("High transition elevation cannot be lower than"
				  " the low transition elevation.\n"));
		        exit(EXIT_FAILURE);
		}
	}

	if (mode == PROGRAM_MODE_MANUAL) {
		/* Check color temperature to be set */
		if (temp_set < MIN_TEMP || temp_set > MAX_TEMP) {
			fprintf(stderr,
				_("Temperature must be between %uK and %uK.\n"),
				MIN_TEMP, MAX_TEMP);
			exit(EXIT_FAILURE);
		}
	}

	/* Brightness */
	if (scheme.day.brightness < MIN_BRIGHTNESS ||
	    scheme.day.brightness > MAX_BRIGHTNESS ||
	    scheme.night.brightness < MIN_BRIGHTNESS ||
	    scheme.night.brightness > MAX_BRIGHTNESS) {
		fprintf(stderr,
			_("Brightness values must be between %.1f and %.1f.\n"),
			MIN_BRIGHTNESS, MAX_BRIGHTNESS);
		exit(EXIT_FAILURE);
	}

	if (verbose) {
		printf(_("Brightness: %.2f:%.2f\n"),
		       scheme.day.brightness, scheme.night.brightness);
	}

	/* Gamma */
	if (!gamma_is_valid(scheme.day.gamma) ||
	    !gamma_is_valid(scheme.night.gamma)) {
		fprintf(stderr,
			_("Gamma value must be between %.1f and %.1f.\n"),
			MIN_GAMMA, MAX_GAMMA);
		exit(EXIT_FAILURE);
	}

	if (verbose) {
		/* TRANSLATORS: The string in parenthesis is either
		   Daytime or Night (translated). */
		printf(_("Gamma (%s): %.3f, %.3f, %.3f\n"),
		       _("Daytime"), scheme.day.gamma[0],
		       scheme.day.gamma[1], scheme.day.gamma[2]);
		printf(_("Gamma (%s): %.3f, %.3f, %.3f\n"),
		       _("Night"), scheme.night.gamma[0],
		       scheme.night.gamma[1], scheme.night.gamma[2]);
	}

	/* Initialize gamma adjustment method. If method is NULL
	   try all methods until one that works is found. */
	gamma_state_t state;

	/* Gamma adjustment not needed for print mode */
	if (mode != PROGRAM_MODE_PRINT) {
		if (method != NULL) {
			/* Use method specified on command line. */
			r = method_try_start(method, &state, &config_state,
					     method_args);
			if (r < 0) exit(EXIT_FAILURE);
		} else {
			/* Try all methods, use the first that works. */
			for (int i = 0; gamma_methods[i].name != NULL; i++) {
				const gamma_method_t *m = &gamma_methods[i];
				if (!m->autostart) continue;

				r = method_try_start(m, &state, &config_state, NULL);
				if (r < 0) {
					fputs(_("Trying next method...\n"), stderr);
					continue;
				}

				/* Found method that works. */
				printf(_("Using method `%s'.\n"), m->name);
				method = m;
				break;
			}

			/* Failure if no methods were successful at this point. */
			if (method == NULL) {
				fputs(_("No more methods to try.\n"), stderr);
				exit(EXIT_FAILURE);
			}
		}
	}

	config_ini_free(&config_state);

	switch (mode) {
	case PROGRAM_MODE_ONE_SHOT:
	case PROGRAM_MODE_PRINT:
	{
		/* Current angular elevation of the sun */
		double now;
		r = systemtime_get_time(&now);
		if (r < 0) {
			fputs(_("Unable to read system time.\n"), stderr);
			method->free(&state);
			exit(EXIT_FAILURE);
		}

		double elevation = solar_elevation(now, loc.lat, loc.lon);

		if (verbose) {
			/* TRANSLATORS: Append degree symbol if possible. */
			printf(_("Solar elevation: %f\n"), elevation);
		}

		/* Use elevation of sun to set color temperature */
		color_setting_t interp;
		interpolate_color_settings(&scheme, elevation, &interp);

		if (verbose || mode == PROGRAM_MODE_PRINT) {
			period_t period = get_period(&scheme,
						     elevation);
			double transition =
				get_transition_progress(&scheme,
							elevation);
			print_period(period, transition);
			printf(_("Color temperature: %uK\n"),
			       interp.temperature);
			printf(_("Brightness: %.2f\n"),
			       interp.brightness);
		}

		if (mode == PROGRAM_MODE_PRINT) {
			exit(EXIT_SUCCESS);
		}

		/* Adjust temperature */
		r = method->set_temperature(&state, &interp);
		if (r < 0) {
			fputs(_("Temperature adjustment failed.\n"), stderr);
			method->free(&state);
			exit(EXIT_FAILURE);
		}

		/* In Quartz (OSX) the gamma adjustments will automatically
		   revert when the process exits. Therefore, we have to loop
		   until CTRL-C is received. */
		if (strcmp(method->name, "quartz") == 0) {
			fputs(_("Press ctrl-c to stop...\n"), stderr);
			pause();
		}
	}
	break;
	case PROGRAM_MODE_MANUAL:
	{
		if (verbose) printf(_("Color temperature: %uK\n"), temp_set);

		/* Adjust temperature */
		color_setting_t manual;
		memcpy(&manual, &scheme.day, sizeof(color_setting_t));
		manual.temperature = temp_set;
		r = method->set_temperature(&state, &manual);
		if (r < 0) {
			fputs(_("Temperature adjustment failed.\n"), stderr);
			method->free(&state);
			exit(EXIT_FAILURE);
		}

		/* In Quartz (OSX) the gamma adjustments will automatically
		   revert when the process exits. Therefore, we have to loop
		   until CTRL-C is received. */
		if (strcmp(method->name, "quartz") == 0) {
			fputs(_("Press ctrl-c to stop...\n"), stderr);
			pause();
		}
	}
	break;
	case PROGRAM_MODE_RESET:
	{
		/* Reset screen */
		color_setting_t reset = { NEUTRAL_TEMP, { 1.0, 1.0, 1.0 }, 1.0 };
		r = method->set_temperature(&state, &reset);
		if (r < 0) {
			fputs(_("Temperature adjustment failed.\n"), stderr);
			method->free(&state);
			exit(EXIT_FAILURE);
		}

		/* In Quartz (OSX) the gamma adjustments will automatically
		   revert when the process exits. Therefore, we have to loop
		   until CTRL-C is received. */
		if (strcmp(method->name, "quartz") == 0) {
			fputs(_("Press ctrl-c to stop...\n"), stderr);
			pause();
		}
	}
	break;
	case PROGRAM_MODE_CONTINUAL:
	{
		r = run_continual_mode(&loc, &scheme,
				       method, &state,
				       transition, verbose);
		if (r < 0) exit(EXIT_FAILURE);
	}
	break;
	}

	/* Clean up gamma adjustment state */
	method->free(&state);

	return EXIT_SUCCESS;
}