spark fix: r, n args add

miscutils/spark.c

@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <unistd.h>
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
@@ -14,37 +15,65 @@ long parse_long(const char *str) {
 	return val;
 }
 
+void print(long diff, long val, long min) {
+	putchar('\xe2');
+	putchar('\x96');
+	putchar('\x82' + round(val - min - 1) / diff * 7);
+}
+
 int main(int argc, char **argv) {
-	long min = 0;
-	long max = 0;
+	unsigned int r_flag = 0;
+	char ret = '\n';
 
-	if (argc > 1) {
-		for (int i = 1; i < argc; i++) {
-			long val = parse_long(argv[i]);
-			if (val > max)
-				max = val;
+	int opt;
+	while ((opt = getopt(argc, argv, "nr")) != -1) {
+		switch (opt) {
+			case 'r':
+				r_flag = 1;
+				break;
 
-			else if (val < min)
-				min = val;
+			case 'n':
+				ret = '\r';
+				break;
+
+			default:
+				printf("spark [val1 val2...]\n\t[-n Use \\r] [-r Reverse args]\n");
+				return 0;
 		}
 	}
 
-	else {
-		printf("spark [val1 val2...]\n");
-		return 0;
+	argv += optind;
+	argc -= optind;
+
+	if (argc == 0) {
+		fprintf(stderr, "spark: missing operands\n");
+		return 1;
 	}
 
+	long min = 0;
+	long max = 0;
+
+	for (int i = 1; i < argc; i++) {
+		long val = parse_long(argv[i]);
+		if (val > max)
+			max = val;
+
+		else if (val < min)
+			min = val;
+	}
 
 	long diff = max - min - 1;
 	if (diff < 1)
 		diff = 1;
 
-	for (int i = 1; i < argc; i++) {
-		putchar('\xe2');
-		putchar('\x96');
-		putchar('\x82' + round(parse_long(argv[i]) - min - 1) / diff * 7);
-	}
+	if (r_flag)
+		for (int i = argc - 1; i >= 0; i--)
+			print(diff, parse_long(argv[i]), min);
 
-	putchar('\n');
+	else
+		for (int i = 0; i < argc; i++)
+			print(diff, parse_long(argv[i]), min);
+
+	putchar(ret);
 	return 0;
 }