Command line options with getopt_long

src/nyancat.c

@@ -59,6 +59,7 @@
 #include <time.h>
 #include <setjmp.h>
 #include <sys/ioctl.h>
+#include <getopt.h>
 
 #ifndef TIOCGWINSZ
 #include <termios.h>
@@ -236,6 +237,17 @@ void send_command(int cmd, int opt) {
 	}
 }
 
+void usage(char * argv[]) {
+	printf(
+			"Terminal Nyancat\n"
+			"\n"
+			"usage: %s [-h] [-t] [-i] \n"
+			"\n"
+			" -i --intro     \033[3mShow the introduction / about informaiton at startup.\033[0m\n"
+			" -t --telnet    \033[3mTelnet mode.\033[0m\n",
+			" -h --help      \033[3mShow this help message.\033[0m\n",
+			argv[0]);
+}
 
 int main(int argc, char ** argv) {
 
@@ -249,10 +261,45 @@ int main(int argc, char ** argv) {
 	char sb[1024] = {0};
 	char sb_len   = 0;
 
-	if (argc > 1) {
-		if (!strcmp(argv[1], "-t")) {
-			/* Yes, I know, lame way to get arguments, whatever, we only want one of them. */
+	char show_intro = 0;
+
+	/* Long option names */
+	static struct option long_opts[] = {
+		{"help",   no_argument,    0, 'h'},
+		{"telnet", no_argument,    0, 't'},
+		{"intro",  no_argument,    0, 'i'},
+		{0,0,0,0}
+	};
+
+	/* Process arguments */
+	int index, c;
+	while ((c = getopt_long(argc, argv, "hit", long_opts, &index)) != -1) {
+		if (!c) {
+			if (long_opts[index].flag == 0) {
+				c = long_opts[index].val;
+			}
+		}
+		switch (c) {
+			case 'i': /* Show introduction */
+				show_intro = 1;
+				break;
+			case 't': /* Expect telnet bits */
 				telnet = 1;
+				break;
+			case 'h': /* Show help and exit */
+				usage(argv);
+				exit(0);
+				break;
+			default:
+				break;
+		}
+	}
+
+	if (telnet) {
+		/* Telnet mode */
+
+		/* Intro is implied by telnet mode, so override whatever was asked for. */
+		show_intro = 1;
 
 		/* Set the default options */
 		set_options();
@@ -372,7 +419,6 @@ int main(int argc, char ** argv) {
 				}
 			}
 		}
-		}
 	} else {
 		/* We are running standalone, retrieve the
 		 * terminal type from the environment. */
@@ -548,6 +594,7 @@ int main(int argc, char ** argv) {
 	/* Clear the screen */
 	printf("\033[H\033[2J\033[?25l");
 
+	if (show_intro) {
 		/* Display the MOTD */
 		int countdown_clock = 5;
 		for (k = 0; k < countdown_clock; ++k) {
@@ -581,6 +628,7 @@ int main(int argc, char ** argv) {
 
 		/* Clear the screen again */
 		printf("\033[H\033[2J\033[?25l");
+	}
 
 	/* Store the start time */
 	time_t start, current;