Add camera selection in getframe

util/getframe.c

@@ -6,9 +6,10 @@
 #include <sys/ioctl.h>
 #include <stdlib.h>
 #include <sys/types.h>
-#include <unistd.h>
 #include <errno.h>
 #include <sys/mman.h>
+#include <getopt.h>
+#include <ctype.h>
 
 struct buffer {
 		void *start;
@@ -27,8 +28,38 @@ xioctl(int fd, int request, void *arg)
 }
 
 int
-main()
+main(int argc, char *argv[])
 {
+	int c;
+	int camera_id = 0;
+	long res;
+	char *end;
+
+	while ((c = getopt(argc, argv, "c:")) != -1) {
+		switch (c) {
+			case 'c':
+				res = strtol(optarg, &end, 10);
+				if (end == optarg || end == NULL || *end != '\0') {
+					fprintf(stderr, "Invalid number for -c\n");
+					return 1;
+				}
+				camera_id = (int) res;
+				break;
+			case '?':
+				if (optopt == 'd' || optopt == 'l') {
+					fprintf(stderr, "Option -%c requires an argument.\n", optopt);
+				} else if (isprint(optopt)) {
+					fprintf(stderr, "Unknown option '-%c'\n", optopt);
+				} else {
+					fprintf(stderr, "Unknown option character x%x\n", optopt);
+				}
+				return 1;
+			default:
+				return 1;
+		}
+	}
+
+
 	char configpath[PATH_MAX];
 	int ret = libmegapixels_find_config(configpath);
 	libmegapixels_devconfig *config = {0};
@@ -45,7 +76,11 @@ main()
 		return 1;
 	}
 
-	libmegapixels_camera *camera = config->cameras[0];
+	if (camera_id > config->count) {
+		fprintf(stderr, "Camera id %d does not exist\n", camera_id);
+	}
+
+	libmegapixels_camera *camera = config->cameras[camera_id];
 	if (libmegapixels_open(camera) != 0) {
 		fprintf(stderr, "Could not open default camera\n");
 		return 1;