Merge 1d0cdb9f00 into b56fc99c2c

Allow user to specify the scan interval for searching for devices.
Scanning places every interface on the machine in promiscuous mode
and currently runs once a second.  This behaviour may have undesirable
side-effects and also pollutes the kernel log.

The new parameter --scan-interval-ms <interval> will allow the user
to specify the rate at which scanning occurs.  If equal to 0, then
only a single scan is performed.

src/main.cpp

@@ -407,8 +407,20 @@ int main(int argc, char** argv) {
 			serialFilter = argv[++i];
 			transform(serialFilter.begin(), serialFilter.end(), serialFilter.begin(), ::toupper);
 		} else if(arg == "--scan-interval-ms" && i + 1 <= argc) {
-                       scanIntervalMs = std::atoi(argv[i + 1]);
-                       i++;
+			try {
+				scanIntervalMs = std::stoi(argv[++i]);
+			} catch (const std::invalid_argument& e) {
+				std::cerr << "Invalid input for scan-interval-ms\n";
+				return EX_USAGE;
+			} catch (const std::out_of_range& e) {
+				std::cerr << "Out of range input for scan-interval-ms\n";
+				return EX_USAGE;
+			}
+
+			if(scanIntervalMs < 0) {
+				std::cerr << "Invalid input for scan-interval-ms\n";
+				return EX_USAGE;
+			}
 		} else {
 			usage(argv[0]);
 			return EX_USAGE;