enforce mode selection, fix indentation, add usage

main.cc

@@ -37,8 +37,8 @@ int serverSocketDescriptor; // a global variable for storing the server socket
 int clientSocketDescriptor;
 
 // This has not been used:
-//vector<int> clientSocketDescriptors; // a global vector for storing client
-				     // socket descriptors
+// vector<int> clientSocketDescriptors; // a global vector for storing client
+// socket descriptors
 
 // keep track of the session time using global variables
 struct timeval start1, end1;
@@ -60,15 +60,32 @@ struct waitClientArgs {
 		    // struct to keep track of
 };
 
+void usage(char *progname);
+
 int
 main(int argc, char *argv[])
 {
-	if (argc > 1 && (!strncmp(argv[1], "client", 6))) {
-		logFileName = "client.txt";
-		mode = CLIENT_MODE;
+	/*
+	 * userInput: character buffer for the user's next message
+	 * exit: set to true when infinite loop is to end
+	 * modeless: check whether a modeless exit was accidental
+	 */
+	char *userInput = new char[1024];
+	bool exit = false;
+	bool modeless = false;
+
+	if (argc > 1) {
+		if (!strncmp(argv[1], "client", 6)) {
+			logFileName = "client.txt";
+			mode = CLIENT_MODE;
+		} else if (!strncmp(argv[1], "server", 6)) {
+			logFileName = "server.txt";
+			mode = SERVER_MODE;
+		}
 	} else {
-		logFileName = "server.txt";
-		mode = SERVER_MODE;
+		usage(argv[0]);
+		modeless = true;
+		goto leave;
 	}
 
 	// putting this lower down to circumvent the terminal brick when the
@@ -85,9 +102,6 @@ main(int argc, char *argv[])
 	// there was already content in the log file
 	linePos = linesInFile(logFileName) - LOG_LENGTH + 1;
 
-	char *userInput = new char[1024];
-	bool exit = false;
-
 	switch (mode) {
 	case CLIENT_MODE:
 		writeToFile(logFileName, "CLIENT MODE");
@@ -107,21 +121,21 @@ main(int argc, char *argv[])
 	while (!exit) {
 		clear();
 
-		//Draw outer chat border
+		// Draw outer chat border
 		box(stdscr, 0, 0);
 
 		// Get screen size
 		int height, width;
-        getmaxyx(stdscr, height, width);
+		getmaxyx(stdscr, height, width);
 
 		// Draw separator line above input
-        mvhline(height - 3, 1, 0, width - 2);
+		mvhline(height - 3, 1, 0, width - 2);
 
-        // Labels
-        mvprintw(0, 2, " Chat ");
-        mvprintw(height - 3, 2, " Input ");
+		// Labels
+		mvprintw(0, 2, " Chat ");
+		mvprintw(height - 3, 2, " Input ");
 
-		//Display Chat Log
+		// Display Chat Log
 		displayFile(logFileName, linePos, LOG_LENGTH);
 
 		// scroll along the screen if and when required so that it stays
@@ -130,10 +144,10 @@ main(int argc, char *argv[])
 			linePos++;
 
 		// Input area
-        move(height - 2, 2);
-        clrtoeol();
-        printw("You: ");
-        move(height - 2, 7);
+		move(height - 2, 2);
+		clrtoeol();
+		printw("You: ");
+		move(height - 2, 7);
 
 		refresh();
 
@@ -161,11 +175,22 @@ leave:
 		closeServer();
 		break;
 	default:
-		puts("Warn: program appears to have successfully finished without ever setting "
-		     "mode.");
-		return 1;
+		if (!modeless) {
+			puts("Warn: program appears to have successfully finished without ever "
+			     "setting mode.");
+			return 1;
+		}
 		break;
 	}
 
 	return 0;
 }
+
+void
+usage(char *progname)
+{
+	printf("\x1b[1mUsage:\x1b[0m\n"
+	       "\t%s client\t\x1b[3m# run as client\x1b[0m\n"
+	       "\t%s server\t\x1b[3m# run as server\x1b[0m\n",
+	       progname, progname);
+}