Added command line arguments

src/main.c

@@ -2,12 +2,16 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
+#include <limits.h>
+#include <string.h>
 #include <xcb/xcb.h>
 
+const long MS_SLEEP_MAX = (UINT_MAX + 1L) * 1000 - 1;
+
 xcb_connection_t *conn = NULL;
 char running;
-char grabk = 1;
-char grabp = 1;
+char grabk = 0;
+char grabp = 0;
 
 void sig_handler(int sig)
 {
@@ -111,8 +115,178 @@ void check_pointer(xcb_screen_t* screen)
 			);
 }
 
+void sleep_ms(long ms)
+{
+	sleep((unsigned int)(ms / 1000));
+	usleep((unsigned int)((ms % 1000) * 1000));
+}
+
+char try_parse_long(char * str, long * result)
+{
+	char * endptr = NULL;
+	*result = strtol(str, &endptr, 10);
+	if (*endptr != '\0')
+		return 1;
+	return 0;
+}
+
+int set_max_iters(char * str, long * max_iters_ptr)
+{
+	long int val = 0;
+	if (try_parse_long(str, &val) != 0)
+	{
+		fprintf(stderr, "Invalid number: \"%s\"\n", str);
+		return 4;
+	}
+	if (val < -1)
+	{
+		fprintf(stderr, "Iterations number out of range: %s\n", str);
+		return 5;
+	}
+	*max_iters_ptr = val;
+	return 0;
+}
+
+int set_delay_ms(char * str, long * delay_ms_ptr)
+{
+	long int val = 0;
+	if (try_parse_long(str, &val) != 0)
+	{
+		fprintf(stderr, "Invalid number: \"%s\"\n", str);
+		return 4;
+	}
+	if (val < 1 || val > MS_SLEEP_MAX)
+	{
+		fprintf(stderr, "Delay duration out of range: %s\n", str);
+		return 5;
+	}
+	*delay_ms_ptr = val;
+	return 0;
+}
+
 int main(int argc, char ** argv)
 {
+	long max_iters = -1;
+	long delay_ms = 150;
+
+	char show_usage = 0;
+
+	int argi;
+	for (argi = 1; argi < argc; argi++)
+	{
+		char * arg = argv[argi];
+		if (arg[0] == '-')
+		{
+			if (arg[1] == '-')
+			{
+				arg += 2;
+				if (!strcmp(arg, "pointer"))
+				{
+					grabp = 1;
+				}
+				else if (!strcmp(arg, "keyboard"))
+				{
+					grabk = 1;
+				}
+				else if (!strcmp(arg, "number"))
+				{
+					if (++argi >= argc)
+					{
+						fprintf(stderr, "Argument expected after: \"%s\"\n", arg - 2);
+						return 3;
+					}
+					int status = set_max_iters(argv[argi], &max_iters);
+					if (status)
+						return status;
+				}
+				else if (!strcmp(arg, "delay"))
+				{
+					if (++argi >= argc)
+					{
+						fprintf(stderr, "Argument expected after: \"%s\"\n", arg - 2);
+						return 3;
+					}
+					int status = set_delay_ms(argv[argi], &delay_ms);
+					if (status)
+						return status;
+				}
+				else if (!strcmp(arg, "help"))
+				{
+					show_usage = 1;
+				}
+				else
+				{
+					fprintf(stderr, "Unknown option: \"%s\"\n", arg - 2);
+					return 2;
+				}
+			}
+			else
+			{
+				while (arg[1] != 0)
+				{
+					++arg;
+					switch(*arg)
+					{
+						case 'p': grabp = 1; break;
+						case 'k': grabk = 1; break;
+						case 'n': 
+							if (++argi >= argc)
+							{
+								fprintf(stderr, "Argument expected after: \"%s\"\n", arg - 2);
+								return 3;
+							}
+							int status = set_max_iters(argv[argi], &max_iters);
+							if (status)
+								return status;
+							break;
+						case 'd': 
+							if (++argi >= argc)
+							{
+								fprintf(stderr, "Argument expected after: \"%s\"\n", arg - 2);
+								return 3;
+							}
+							status = set_delay_ms(argv[argi], &delay_ms);
+							if (status)
+								return status;
+							break;
+						case 'h': show_usage = 1; break;
+						default:
+							fprintf(stderr, "Unknown option: \"-%c\"\n", *arg);
+							return 2;
+					}
+				}
+			}
+		}
+		else
+		{
+			fprintf(stderr, "Option expected: \"%s\"\n", arg);
+			return 2;
+		}
+	}
+
+	if (show_usage)
+	{
+		printf("Usage: %s <OPTIONS...>\n"\
+				"Options:\n"\
+				"  -p, --pointer           Detect pointer grabbing\n"\
+				"  -k, --keyboard          Detect keyboard grabbing\n"\
+				"  -n <N>, --number <N>    Iterations number, -1 for infinity\n"\
+				"  -d <N>, --delay  <N>    Delay duration (ms)\n"\
+				"  -h, --help              Show this message\n"\
+				"Limits:\n"\
+				"  -1 <= iterations number <= %li\n"\
+				"   1 <= delay duration <= %li\n"\
+				, argv[0], LONG_MAX, MS_SLEEP_MAX);
+		return 0;
+	}
+
+	if (!grabk && !grabp)
+	{
+		fprintf(stderr, "--keyboard and/or --pointer should be passed\n"\
+				"Pass --help for usage\n");
+		return 6;
+	}
+
 	conn = xcb_connect(NULL, NULL);
 	if (xcb_connection_has_error(conn))
 	{
@@ -133,14 +307,18 @@ int main(int argc, char ** argv)
 	signal(SIGUSR2, sig_handler);
 
 	running = 1;
+	unsigned long i = 0;
 	while (running)
 	{
+		if (max_iters != -1 && i++ >= max_iters)
+			break;
 		if (grabk)
 			check_keyboard(screen);
 		if (grabp)
 			check_pointer(screen);
 		xcb_flush(conn);
-		usleep(150000);
+		if (running)
+			sleep_ms(delay_ms);
 	}
 	return 0;
 }