we do need a separate scrollback size and possibly multiple packets

Makefile

@@ -13,9 +13,9 @@ INSTALL ?= install
 PREFIX ?= /usr/local
 SHAREDIR ?= ${PREFIX}/share
 
-SRC = abduco.c
+SRC = splex.c
 
-all: abduco
+all: splex
 
 config.h:
 	cp config.def.h config.h
@@ -23,7 +23,7 @@ config.h:
 config.mk:
 	@touch $@
 
-abduco: config.h config.mk *.c
+splex: config.h config.mk splex.c client.c debug.c forkpty-aix.c forkpty-sunos.c server.c
 	${CC} ${CFLAGS} ${CFLAGS_STD} ${CFLAGS_AUTO} ${CFLAGS_EXTRA} ${SRC} ${LDFLAGS} ${LDFLAGS_STD} ${LDFLAGS_AUTO} -o $@
 
 debug: clean
@@ -31,37 +31,37 @@ debug: clean
 
 clean:
 	@echo cleaning
-	@rm -f abduco abduco-*.tar.gz
+	@rm -f splex splex splex-*.tar.gz
 
 dist: clean
 	@echo creating dist tarball
-	@git archive --prefix=abduco-${VERSION}/ -o abduco-${VERSION}.tar.gz HEAD
+	@git archive --prefix=splex-${VERSION}/ -o splex-${VERSION}.tar.gz HEAD
 
 installdirs:
 	@${INSTALL} -d ${DESTDIR}${PREFIX}/bin \
 		${DESTDIR}${MANPREFIX}/man1
 
-install: abduco installdirs
+install: splex installdirs
 	@echo installing executable file to ${DESTDIR}${PREFIX}/bin
-	@${INSTALL} -m 0755 abduco ${DESTDIR}${PREFIX}/bin
+	@${INSTALL} -m 0755 splex ${DESTDIR}${PREFIX}/bin
 	@echo installing manual page to ${DESTDIR}${MANPREFIX}/man1
 	@mkdir -p ${DESTDIR}${MANPREFIX}/man1
-	@sed "s/VERSION/${VERSION}/g" < abduco.1 > ${DESTDIR}${MANPREFIX}/man1/abduco.1
-	@chmod 644 ${DESTDIR}${MANPREFIX}/man1/abduco.1
+	@sed "s/VERSION/${VERSION}/g" < splex.1 > ${DESTDIR}${MANPREFIX}/man1/splex.1
+	@chmod 644 ${DESTDIR}${MANPREFIX}/man1/splex.1
 
 install-strip: install
-	${STRIP} ${DESTDIR}${PREFIX}/bin/abduco
+	${STRIP} ${DESTDIR}${PREFIX}/bin/splex
 
 install-completion:
 	@echo installing zsh completion file to ${DESTDIR}${SHAREDIR}/zsh/site-functions
-	@install -Dm644 contrib/abduco.zsh ${DESTDIR}${SHAREDIR}/zsh/site-functions/_abduco
+	@install -Dm644 contrib/splex.zsh ${DESTDIR}${SHAREDIR}/zsh/site-functions/_splex
 
 uninstall:
 	@echo removing executable file from ${DESTDIR}${PREFIX}/bin
-	@rm -f ${DESTDIR}${PREFIX}/bin/abduco
+	@rm -f ${DESTDIR}${PREFIX}/bin/splex
 	@echo removing manual page from ${DESTDIR}${MANPREFIX}/man1
-	@rm -f ${DESTDIR}${MANPREFIX}/man1/abduco.1
+	@rm -f ${DESTDIR}${MANPREFIX}/man1/splex.1
 	@echo removing zsh completion file from ${DESTDIR}${SHAREDIR}/zsh/site-functions
-	@rm -f ${DESTDIR}${SHAREDIR}/zsh/site-functions/_abduco
+	@rm -f ${DESTDIR}${SHAREDIR}/zsh/site-functions/_splex
 
 .PHONY: all clean dist install installdirs install-strip install-completion uninstall debug

client.c

@@ -63,12 +63,14 @@ static int client_mainloop(void) {
 	sigprocmask(SIG_BLOCK, &blockset, NULL);
 
 	client.need_resize = true;
+    client.await_command = false;
 	Packet pkt = {
 		.type = MSG_ATTACH,
 		.u.i = client.flags,
 		.len = sizeof(pkt.u.i),
 	};
 	client_send_packet(&pkt);
+    write_all(STDOUT_FILENO,"Welcome\r\n",9);
 
 	while (server.running) {
 		fd_set fds;
@@ -100,8 +102,7 @@ static int client_mainloop(void) {
 			if (client_recv_packet(&pkt)) {
 				switch (pkt.type) {
 				case MSG_CONTENT:
-					if (!passthrough)
-						write_all(STDOUT_FILENO, pkt.u.msg, pkt.len);
+					write_all(STDOUT_FILENO, pkt.u.msg, pkt.len);
 					break;
 				case MSG_RESIZE:
 					client.need_resize = true;
@@ -121,21 +122,48 @@ static int client_mainloop(void) {
 				die("client-stdin");
 			if (len > 0) {
 				debug("client-stdin: %c\n", pkt.u.msg[0]);
+                if (client.await_command) {
+                    client.await_command = false;
+                    bool detach = false;
+                    switch (pkt.u.msg[0]) {
+                        case 'd': 
+                            server.next_session[0] = '\0'; 
+                            detach = true;
+                            break;
+                        case '0':
+                        case '1':
+                        case '2':
+                        case '3':
+                        case '4':
+                        case '5':
+                        case '6':
+                        case '7':
+                        case '8':
+                        case '9':
+                            server.next_session[0] = pkt.u.msg[0];
+                            detach = true;
+                            break;
+                    }
+                    if (detach) {
+                        pkt.type = MSG_DETACH;
+                        pkt.len = 0;
+                        client_send_packet(&pkt);
+                        close(server.socket);
+                        return RV_DETACH;
+                    }
+                }
 				pkt.len = len;
 				if (KEY_REDRAW && pkt.u.msg[0] == KEY_REDRAW) {
 					client.need_resize = true;
-				} else if (pkt.u.msg[0] == KEY_DETACH) {
-					pkt.type = MSG_DETACH;
-					pkt.len = 0;
-					client_send_packet(&pkt);
-					close(server.socket);
-					return -1;
+				} else if (pkt.u.msg[0] == KEY_COMMAND) {
+                    client.await_command = true;
 				} else if (!(client.flags & CLIENT_READONLY)) {
 					client_send_packet(&pkt);
 				}
 			} else if (len == 0) {
 				debug("client-stdin: EOF\n");
-				return -1;
+                server.next_session[0] = '\0';
+				return 0;
 			}
 		}
 	}

config.def.h

@@ -1,7 +1,7 @@
 /* default command to execute if non is given and $ABDUCO_CMD is unset */
-#define ABDUCO_CMD "dvtm"
+#define ABDUCO_CMD "bash"
 /* default detach key, can be overriden at run time using -e option */
-static char KEY_DETACH = CTRL('\\');
+static char KEY_COMMAND = CTRL('\\');
 /* redraw key to send a SIGWINCH signal to underlying process
  * (set to 0 to disable the redraw key) */
 static char KEY_REDRAW = 0;

server.c

@@ -98,6 +98,43 @@ static bool server_write_pty(Packet *pkt) {
 	return false;
 }
 
+static bool server_write_scrollback(Packet *pkt) {
+	print_packet("server-write-scrollback:", pkt);
+	size_t size = pkt->len;
+    uint32_t ii;
+    for (ii=0;ii<size;ii++) {
+        scrollback.buffer[scrollback.position++] = pkt->u.msg[ii];
+        if (scrollback.position>SCROLLBACK_SIZE) {
+            scrollback.position = 0;
+            scrollback.wrap = true;
+        }
+    }
+	return true;
+}
+
+static bool server_send_scrollback(Packet *pkt) {
+	print_packet("server-send-scrollback:", pkt);
+    ssize_t len, sblen;
+    uint32_t ii;
+    if (scrollback.wrap)
+        sblen = SCROLLBACK_SIZE;
+    else
+        sblen = scrollback.position-1;
+	pkt->type = MSG_CONTENT;
+    // Multiple packets need to be set possibly: need a double loop
+    for (ii=0;ii<len;ii++) {
+        pkt->u.msg[ii] = 1;
+    }
+	/* if (len > 0) */
+	/* 	pkt->len = len; */
+	/* else if (len == 0) */
+	/* 	server.running = false; */
+	/* else if (len == -1 && errno != EAGAIN && errno != EINTR && errno != EWOULDBLOCK) */
+	/* 	server.running = false; */
+    // double loop to message size
+    return true;
+}
+
 static bool server_recv_packet(Client *c, Packet *pkt) {
 	if (recv_packet(c->socket, pkt)) {
 		print_packet("server-recv:", pkt);
@@ -216,6 +253,9 @@ static void server_mainloop(void) {
 		if (FD_ISSET(server.pty, &readfds))
 			pty_data = server_read_pty(&server_packet);
 
+        if (pty_data)
+            server_write_scrollback(&server_packet);
+
 		for (Client **prev_next = &server.clients, *c = server.clients; c;) {
 			if (FD_ISSET(c->socket, &readfds) && server_recv_packet(c, &client_packet)) {
 				switch (client_packet.type) {

splex.c

@@ -62,6 +62,13 @@
 
 #define countof(arr) (sizeof(arr) / sizeof((arr)[0]))
 
+#define RV_DETACH -1
+#define PACKET_MSG_SIZE 4096-2*sizeof(uint32_t)
+#define SCROLLBACK_SIZE 1024
+
+char* splex_session_names = "0123456789";
+char* shell_cmd[2] = { "/bin/bash", NULL };
+
 enum PacketType {
 	MSG_CONTENT = 0,
 	MSG_ATTACH  = 1,
@@ -75,7 +82,7 @@ typedef struct {
 	uint32_t type;
 	uint32_t len;
 	union {
-		char msg[4096 - 2*sizeof(uint32_t)];
+		char msg[PACKET_MSG_SIZE];
 		struct {
 			uint16_t rows;
 			uint16_t cols;
@@ -100,6 +107,7 @@ struct Client {
 		CLIENT_LOWPRIORITY = 1 << 1,
 	} flags;
 	Client *next;
+    bool await_command;
 };
 
 typedef struct {
@@ -116,12 +124,20 @@ typedef struct {
 	const char *session_name;
 	char host[255];
 	bool read_pty;
+    char next_session[2];
 } Server;
 
-static Server server = { .running = true, .exit_status = -1, .host = "@localhost" };
+typedef struct {
+    char buffer[SCROLLBACK_SIZE];
+    uint32_t position;
+    bool wrap;
+} Scrollback;
+
+static Server server = { .running = true, .exit_status = -1, .host = "@localhost" , .next_session = { '\0', '\0' } };
 static Client client;
+static Scrollback scrollback = { .buffer = {}, .position = 0, .wrap = false };
 static struct termios orig_term, cur_term;
-static bool has_term, alternate_buffer, quiet, passthrough;
+static bool has_term, alternate_buffer, quiet;
 
 static struct sockaddr_un sockaddr = {
 	.sun_family = AF_UNIX,
@@ -224,7 +240,6 @@ static void die(const char *s) {
 
 static void usage(void) {
 	fprintf(stderr, "usage: abduco [-a|-A|-c|-n] [-p] [-r] [-q] [-l] [-f] [-e detachkey] name command\n");
-	exit(EXIT_FAILURE);
 }
 
 static bool xsnprintf(char *buf, size_t size, const char *fmt, ...) {
@@ -532,8 +547,8 @@ static bool attach_session(const char *name, const bool terminate) {
 	client_setup_terminal();
 	int status = client_mainloop();
 	client_restore_terminal();
-	if (status == -1) {
-		info("detached");
+	if (status == RV_DETACH) {
+		info("detached with return value %d", status);
 	} else if (status == -EIO) {
 		info("exited due to I/O errors");
 	} else {
@@ -545,6 +560,80 @@ static bool attach_session(const char *name, const bool terminate) {
 	return terminate;
 }
 
+static bool set_next_session() {
+    char* siter = splex_session_names;
+    info("siter %x\n",siter);
+    char sname[] = "\0";
+    while (*siter != '\0') {
+        sname[0] = *siter;
+        if (session_alive(sname))
+            break;
+        siter++;
+    }
+    info("*siter %c\n",*siter);
+    if (*siter == '\0')
+        return false;
+    server.next_session[0] = *siter;
+    return true;
+}
+
+static bool session_loop() {
+    // Set initial session, or create a new one
+    if (!set_next_session()) {
+        server.next_session[0] = '0';
+    }
+    // printf("%s\n",server.session_name);
+    while (true) {
+        server.session_name = server.next_session;
+        info("Iteration with session %s\n",server.next_session);
+	    if (!session_alive(server.session_name)) {
+            info("Session not alive: %s",server.session_name);
+            if (!create_session(server.session_name, shell_cmd))
+		        die("create-session");
+        } else {
+            info("Session alive: %s",server.session_name);
+        }
+        server.session_name = server.next_session;
+        info("server.socket > 0\n");
+        if (server.socket > 0)
+            close(server.socket);
+        info("session_connect successful?\n");
+        if ((server.socket = session_connect(server.session_name)) == -1)
+            return false;
+        info("session_set_socket_non_blocking successful?\n");
+        if (server_set_socket_non_blocking(server.socket) == -1)
+            return false;
+        info("Passed all initial checks.\n");
+
+        struct sigaction sa;
+        sa.sa_flags = 0;
+        sigemptyset(&sa.sa_mask);
+        sa.sa_handler = client_sigwinch_handler;
+        sigaction(SIGWINCH, &sa, NULL);
+        sa.sa_handler = SIG_IGN;
+        sigaction(SIGPIPE, &sa, NULL);
+
+        client_setup_terminal();
+        int status = client_mainloop();
+        client_restore_terminal();
+
+        if (status == -EIO) {
+            info("exited due to I/O errors");
+            exit(-EIO);
+        } else if (status == RV_DETACH) {
+            info("detached with return value %d and next session %s", status, server.next_session);
+            if (server.next_session[0] == '\0') {
+                exit(EXIT_SUCCESS);
+            }
+        } else {
+            info("session terminated with exit status %d", status);
+            if (!set_next_session()){
+                exit(EXIT_SUCCESS);
+            }
+        }
+    }
+}
+
 static int session_filter(const struct dirent *d) {
 	return strstr(d->d_name, server.host) != NULL;
 }
@@ -594,53 +683,52 @@ static int list_session(void) {
 
 int main(int argc, char *argv[]) {
 	int opt;
-	bool force = false;
+	bool force = false; // to be removed
 	char **cmd = NULL, action = '\0';
 
-	char *default_cmd[4] = { "/bin/sh", "-c", getenv("ABDUCO_CMD"), NULL };
-	if (!default_cmd[2]) {
-		default_cmd[0] = ABDUCO_CMD;
-		default_cmd[1] = NULL;
-	}
+	char *default_cmd[2] = { "/bin/bash", NULL };
 
 	server.name = basename(argv[0]);
 	gethostname(server.host+1, sizeof(server.host) - 1);
-
-	while ((opt = getopt(argc, argv, "aAclne:fpqrv")) != -1) {
+	while ((opt = getopt(argc, argv, "aAchlne:qrtvz")) != -1) {
 		switch (opt) {
 		case 'a':
 		case 'A':
 		case 'c':
 		case 'n':
+        case 't':
 			action = opt;
 			break;
 		case 'e':
-			if (!optarg)
+			if (!optarg) {
 				usage();
+	            exit(EXIT_FAILURE);
+            }
 			if (optarg[0] == '^' && optarg[1])
 				optarg[0] = CTRL(optarg[1]);
-			KEY_DETACH = optarg[0];
-			break;
-		case 'f':
-			force = true;
-			break;
-		case 'p':
-			passthrough = true;
+			KEY_COMMAND = optarg[0];
 			break;
+        case 'h':
+            usage();
+            exit(EXIT_SUCCESS);
+        case 'l':
+            list_session();
+            exit(EXIT_SUCCESS);
 		case 'q':
 			quiet = true;
 			break;
 		case 'r':
 			client.flags |= CLIENT_READONLY;
 			break;
-		case 'l':
+		case 'v':
+			puts("splex-0.1, based on abduco-"VERSION" by Marc André Tanner");
+			exit(EXIT_SUCCESS);
+		case 'z':
 			client.flags |= CLIENT_LOWPRIORITY;
 			break;
-		case 'v':
-			puts("abduco-"VERSION" © 2013-2018 Marc André Tanner");
-			exit(EXIT_SUCCESS);
 		default:
 			usage();
+	        exit(EXIT_FAILURE);
 		}
 	}
 
@@ -654,22 +742,17 @@ int main(int argc, char *argv[]) {
 	else
 		cmd = default_cmd;
 
-	if (server.session_name && !isatty(STDIN_FILENO))
-		passthrough = true;
-
-	if (passthrough) {
-		if (!action)
-			action = 'a';
-		quiet = true;
-		client.flags |= CLIENT_LOWPRIORITY;
-	}
+	if (!isatty(STDIN_FILENO))
+        die("STDIN is not a tty");
 
 	if (!action && !server.session_name)
 		exit(list_session());
-	if (!action || !server.session_name)
+	if (!action || !server.session_name) {
 		usage();
+	    exit(EXIT_FAILURE);
+    }
 
-	if (!passthrough && tcgetattr(STDIN_FILENO, &orig_term) != -1) {
+	if (tcgetattr(STDIN_FILENO, &orig_term) != -1) {
 		server.term = orig_term;
 		has_term = true;
 	}
@@ -712,6 +795,15 @@ int main(int argc, char *argv[]) {
 			goto redo;
 		}
 		break;
+    case 't':
+        session_loop();
+		/* if (!session_alive(server.session_name)) { */
+		/*           if (!create_session(server.session_name, cmd)) */
+		/* 	    die("create-session"); */
+		/*       } */
+		/*       if (!attach_session(server.session_name, true)) */
+		/* 	die("attach-session"); */
+        break;
 	}
 
 	return 0;