Introduce read only sessions (-r option)

Based on a patch from Lars Kellogg-Stedman.

abduco.1

@@ -12,6 +12,7 @@ abduco
 .RI [ args \ ... "" ]
 .br
 .B abduco
+.RB [ \-r ]
 .RB [ \-e 
 .IR detachkey ]
 .RB \-n 
@@ -28,6 +29,7 @@ abduco
 .RI [ args \ ... "" ]
 .br
 .B abduco
+.RB [ \-r ]
 .RB [ \-e 
 .IR detachkey ]
 .RB \-a
@@ -74,6 +76,9 @@ indicate that at least one client is connected.
 .B \-v
 Print version information to standard output and exit.
 .TP
+.B \-r
+Readonly session, i.e. no user input is ignored.
+.TP
 .BI \-e \ detachkey
 Set the key to detach which by default is set to CTRL+\\ i.e. ^\\ to detachkey.
 .TP

abduco.c

@@ -74,6 +74,7 @@ typedef struct {
 		char msg[BUFSIZ];
 		struct winsize ws;
 		int i;
+		bool b;
 	} u;
 } Packet;
 
@@ -87,6 +88,7 @@ struct Client {
 		STATE_DISCONNECTED,
 	} state;
 	bool need_resize;
+	bool readonly;
 	Client *next;
 };
 
@@ -104,6 +106,7 @@ typedef struct {
 } Server;
 
 static Server server = { .running = true, .exit_status = -1 };
+static Client client;
 static struct termios orig_term, cur_term;
 bool has_term;
 
@@ -202,7 +205,7 @@ static void die(const char *s) {
 }
 
 static void usage() {
-	fprintf(stderr, "usage: abduco [-a|-A|-c|-n] [-e detachkey] name command\n");
+	fprintf(stderr, "usage: abduco [-a|-A|-c|-n] [-r] [-e detachkey] name command\n");
 	exit(EXIT_FAILURE);
 }
 
@@ -432,6 +435,9 @@ int main(int argc, char *argv[]) {
 				*esc = CTRL(esc[1]);
 			KEY_DETACH = *esc;
 			break;
+		case 'r':
+			client.readonly = true;
+			break;
 		case 'v':
 			puts("abduco-"VERSION" © 2013-2014 Marc André Tanner");
 			exit(EXIT_SUCCESS);
@@ -446,7 +452,7 @@ int main(int argc, char *argv[]) {
 			cmd[0] = "dvtm";
 	}
 
-	if (!action || !server.session_name)
+	if (!action || !server.session_name || ((action == 'c' || action == 'A') && client.readonly))
 		usage();
 
 	if (tcgetattr(STDIN_FILENO, &orig_term) != -1) {

client.c

@@ -1,5 +1,3 @@
-static Client client;
-
 static void client_sigwinch_handler(int sig) {
 	client.need_resize = true;
 }
@@ -36,6 +34,8 @@ static void client_restore_terminal() {
 
 static int client_mainloop() {
 	client.need_resize = true;
+	Packet pkt = { .type = MSG_ATTACH, .u = { .b = client.readonly }, .len = sizeof(pkt.u.b) };
+	client_send_packet(&pkt);
 	while (server.running) {
 		fd_set fds;
 		FD_ZERO(&fds);
@@ -92,7 +92,7 @@ static int client_mainloop() {
 					pkt.len = 0;
 					client_send_packet(&pkt);
 					return -1;
-				} else {
+				} else if (!client.readonly) {
 					client_send_packet(&pkt);
 				}
 			}

server.c

@@ -206,10 +206,12 @@ static void server_mainloop() {
 					server_write_pty(&client_packet);
 					break;
 				case MSG_ATTACH:
+					c->readonly = client_packet.u.b;
+					break;
 				case MSG_RESIZE:
 					c->state = STATE_ATTACHED;
 				case MSG_REDRAW:
-					if (client_packet.type == MSG_REDRAW || c == server.clients) {
+					if (!c->readonly && (client_packet.type == MSG_REDRAW || c == server.clients)) {
 						debug("server-ioct: TIOCSWINSZ\n");
 						ioctl(server.pty, TIOCSWINSZ, &client_packet.u.ws);
 					}