Use getopt() to parse arguments.

1 files changed, 87 insertions, 31 deletions

diff --git a/redshift.c b/redshift.c
index ef71609..cba23b8 100644
--- a/redshift.c
+++ b/redshift.c
@@ -3,7 +3,10 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
 #include <time.h>
+#include <math.h>
 #include <locale.h>
 
 #include "solar.h"
@@ -16,100 +19,153 @@
 #define MIN_TEMP   1000
 #define MAX_TEMP  10000
 
+#define DEFAULT_DAY_TEMP    5500
+#define DEFAULT_NIGHT_TEMP  3700
 
 #define USAGE  \
-	"Usage: %s LAT LON DAY-TEMP NIGHT-TEMP [GAMMA]\n"
+	"Usage: %s -l LAT:LON -t DAY:NIGHT [OPTIONS...]\n"
+#define HELP \
+	USAGE \
+	" Set color temperature of display according to time of day.\n" \
+	"  -g GAMMA\tAdditional gamma correction to apply\n" \
+	"  -h\t\tDisplay this help message\n" \
+	"  -l LAT:LON\tYour current location\n" \
+	"  -t DAY:NIGHT\tColor temperature to set at night/day\n" \
+	"  -v\t\tVerbose output\n"
 
 #define DEG_CHAR  0xb0
 
 
-static void
-printtime(time_t time)
-{
-	char s[64];
-	strftime(s, 64, "%a, %d %b %Y %H:%M:%S %z", localtime(&time));
-	printf("%s\n", s);
-}
-
 int
 main(int argc, char *argv[])
 {
 	/* Check extensions needed for color temperature adjustment. */
 	int r = colortemp_check_extension();
 	if (r < 0) {
-		fprintf(stderr, "Unable to set color temperature.\n");
+		fprintf(stderr, "Unable to set color temperature:"
+			" Needed extension is missing.\n");
 		exit(EXIT_FAILURE);
 	}
 
-	/* Init locale for special symbols */
-	char *loc = setlocale(LC_CTYPE, "");
+	/* Init locale for special (degree) symbol */
+	char *loc = setlocale(LC_ALL, "");
 	if (loc == NULL) {
 		fprintf(stderr, "Unable to set locale.\n");
 		exit(EXIT_FAILURE);
 	}
 
-	/* Load arguments */
-	if (argc < 5) {
-		printf(USAGE, argv[0]);
+	float lat = NAN;
+	float lon = NAN;
+	int temp_day = DEFAULT_DAY_TEMP;
+	int temp_night = DEFAULT_NIGHT_TEMP;
+	float gamma = 1.0;
+	int verbose = 0;
+	char *s;
+	
+	int opt;
+	while ((opt = getopt(argc, argv, "g:hl:t:v")) != -1) {
+		switch (opt) {
+		case 'g':
+			gamma = atof(optarg);
+			break;
+		case 'h':
+			printf(HELP, argv[0]);
+			exit(EXIT_SUCCESS);
+			break;
+		case 'l':
+			s = strchr(optarg, ':');
+			if (s == NULL) {
+				fprintf(stderr, USAGE, argv[0]);
+				exit(EXIT_FAILURE);
+			}
+			*(s++) = '\0';
+			lat = atof(optarg);
+			lon = atof(s);
+			break;
+		case 't':
+			s = strchr(optarg, ':');
+			if (s == NULL) {
+				fprintf(stderr, USAGE, argv[0]);
+				exit(EXIT_FAILURE);
+			}
+			*(s++) = '\0';
+			temp_day = atoi(optarg);
+			temp_night = atoi(s);
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		default:
+			fprintf(stderr, USAGE, argv[0]);
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	/* Latitude and longitude must be set */
+	if (isnan(lat) || isnan(lon)) {
+		fprintf(stderr, USAGE, argv[0]);
+		fprintf(stderr, "Latitude and longitude must be set.\n");
 		exit(EXIT_FAILURE);
 	}
 
+	if (verbose) {
+		printf("Location: %f%lc, %f%lc\n",
+		       lat, DEG_CHAR, lon, DEG_CHAR);
+	}
+
 	/* Latitude */
-	float lat = atof(argv[1]);
 	if (lat < MIN_LAT || lat > MAX_LAT) {
 		fprintf(stderr,
-			"Latitude must be between %.1f%lc and %.1f%lc\n",
+			"Latitude must be between %.1f%lc and %.1f%lc.\n",
 			MIN_LAT, DEG_CHAR, MAX_LAT, DEG_CHAR);
 		exit(EXIT_FAILURE);
 	}
 
 	/* Longitude */
-	float lon = atof(argv[2]);
 	if (lon < MIN_LON || lon > MAX_LON) {
 		fprintf(stderr,
-			"Longitude must be between %.1f%lc and %.1f%lc\n",
+			"Longitude must be between %.1f%lc and %.1f%lc.\n",
 			MIN_LON, DEG_CHAR, MAX_LON, DEG_CHAR);
 		exit(EXIT_FAILURE);
 	}
 
 	/* Color temperature at daytime */
-	int temp_day = atoi(argv[3]);
 	if (temp_day < MIN_TEMP || temp_day >= MAX_TEMP) {
-		fprintf(stderr, "Temperature must be between %uK and %uK\n",
+		fprintf(stderr, "Temperature must be between %uK and %uK.\n",
 			MIN_TEMP, MAX_TEMP);
 		exit(EXIT_FAILURE);
 	}
 
 	/* Color temperature at night */
-	int temp_night = atoi(argv[4]);
 	if (temp_night < MIN_TEMP || temp_night >= MAX_TEMP) {
-		fprintf(stderr, "Temperature must be between %uK and %uK\n",
+		fprintf(stderr, "Temperature must be between %uK and %uK.\n",
 			MIN_TEMP, MAX_TEMP);
 		exit(EXIT_FAILURE);
 	}
 
-	/* Gamma value */
-	float gamma = 1.0;
-	if (argc > 5) gamma = atof(argv[5]);
-
 	/* Current angular elevation of the sun */
 	time_t now = time(NULL);
 	double elevation = solar_elevation(now, lat, lon);
-	printf("Solar elevation is %f\n", elevation);
+
+	if (verbose) {
+		printf("Solar elevation is %f%lc.\n", elevation, DEG_CHAR);
+	}
 
 	/* Use elevation of sun to set color temperature */
 	int temp = 0;
 	if (elevation < SOLAR_CIVIL_TWILIGHT_ELEV) {
 		temp = temp_night;
-		printf("Set color temperature to %uK\n", temp_night);
 	} else if (elevation < SOLAR_DAYTIME_ELEV) {
+		/* Interpolate */
 		float a = (SOLAR_DAYTIME_ELEV - elevation) /
 			(SOLAR_DAYTIME_ELEV - SOLAR_CIVIL_TWILIGHT_ELEV);
 		temp = (1.0-a)*temp_day + a*temp_night;
-		printf("Interpolated (%f) temperature is %uK\n", a, temp);
 	} else {
 		temp = temp_day;
-		printf("Set color temperature to %uK\n", temp_day);
+	}
+
+	if (verbose) {
+		printf("Set color temperature to %uK.\n", temp_day);
 	}
 
 	/* Set color temperature */