New session selection rules:

- find by name if given
	- otherwise try current index from $TMUX
	- otherwise if only one session, use it
	- otherwise error

client.c

@@ -1,4 +1,4 @@
-/* $Id: client.c,v 1.5 2007-09-26 19:09:30 nicm Exp $ */
+/* $Id: client.c,v 1.6 2007-09-27 09:52:03 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -196,6 +196,36 @@ local_dead:
 	fatalx("local socket dead");
 }
 
+void
+client_fill_sessid(struct sessid *sid, char name[MAXNAMELEN])
+{
+	char		*env, *ptr, buf[256];
+	const char	*errstr;
+	long long	 ll;
+
+	strlcpy(sid->name, name, sizeof sid->name);
+
+	sid->pid = -1;
+	if ((env = getenv("TMUX")) == NULL)
+		return;
+	if ((ptr = strchr(env, ',')) == NULL)
+		return;
+	if ((size_t) (ptr - env) > sizeof buf)
+		return;
+	memcpy(buf, env, ptr - env);
+	buf[ptr - env] = '\0';
+
+	ll = strtonum(ptr + 1, 0, UINT_MAX, &errstr);
+	if (errstr != NULL)
+		return;
+	sid->idx = ll;
+
+	ll = strtonum(buf, 0, LLONG_MAX, &errstr);
+	if (errstr != NULL)
+		return;
+	sid->pid = ll;
+}
+
 void
 client_write_server(
     struct client_ctx *cctx, enum hdrtype type, void *buf, size_t len)

op-list.c

@@ -1,4 +1,4 @@
-/* $Id: op-list.c,v 1.3 2007-09-26 19:38:42 nicm Exp $ */
+/* $Id: op-list.c,v 1.4 2007-09-27 09:52:03 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -63,7 +63,7 @@ op_list(char *path, int argc, char **argv)
 	if (*name == '\0')
 		client_write_server(&cctx, MSG_SESSIONS, &sdata, sizeof sdata);
 	else {
-		strlcpy(wdata.name, name, sizeof wdata.name);
+		client_fill_sessid(&wdata.sid, name);
 		client_write_server(&cctx, MSG_WINDOWS, &wdata, sizeof wdata);
 	}
 

op.c

@@ -1,4 +1,4 @@
-/* $Id: op.c,v 1.5 2007-09-26 19:38:42 nicm Exp $ */
+/* $Id: op.c,v 1.6 2007-09-27 09:52:03 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -93,7 +93,7 @@ op_attach(char *path, int argc, char **argv)
 	if (client_init(path, &cctx, 1) != 0)
 		return (1);
 
-	strlcpy(data.name, name, sizeof data.name);
+	client_fill_sessid(&data.sid, name);
 	data.sx = cctx.ws.ws_col;
 	data.sy = cctx.ws.ws_row;
 	client_write_server(&cctx, MSG_ATTACH, &data, sizeof data);

server-fn.c

@@ -1,4 +1,4 @@
-/* $Id: server-fn.c,v 1.3 2007-09-27 09:15:58 nicm Exp $ */
+/* $Id: server-fn.c,v 1.4 2007-09-27 09:52:03 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -19,9 +19,60 @@
 #include <sys/types.h>
 
 #include <string.h>
+#include <unistd.h>
 
 #include "tmux.h"
 
+/* Find session from sessid. */
+struct session *
+server_find_sessid(struct sessid *sid, char **cause)
+{
+	struct session *s;
+	u_int		i, n;
+
+	if (*sid->name != '\0') {
+		if ((s = session_find(sid->name)) == NULL) {
+			xasprintf(cause, "session not found: %s", sid->name);
+			return (NULL);
+		}
+		return (s);
+	}
+
+	if (sid->pid != -1) {
+		if (sid->pid != getpid()) {
+			xasprintf(cause, "wrong server: %lld", sid->pid);
+			return (NULL);
+		}
+		if (sid->idx > ARRAY_LENGTH(&sessions)) {
+			xasprintf(cause, "index out of range: %u", sid->idx);
+			return (NULL);
+		}
+		if ((s = ARRAY_ITEM(&sessions, sid->idx) = NULL)) {
+			xasprintf(cause, "session doesn't exist: %u", sid->idx);
+			return (NULL);
+		}
+		return (s);
+	}
+
+	s = NULL;
+	n = 0;
+	for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
+		if (ARRAY_ITEM(&sessions, i) != NULL) {
+			s = ARRAY_ITEM(&sessions, i);
+			n++;
+		}
+	}
+	if (s == NULL) {
+		xasprintf(cause, "no sessions");
+		return (NULL);
+	}
+	if (n != 1) {
+		xasprintf(cause, "multiple sessions and session not specified");
+		return (NULL);
+	}
+	return (s);		
+}
+
 /* Write command to a client. */
 void
 server_write_client(struct client *c, enum hdrtype type, void *buf, size_t len)

server-msg.c

@@ -1,4 +1,4 @@
-/* $Id: server-msg.c,v 1.4 2007-09-26 18:50:49 nicm Exp $ */
+/* $Id: server-msg.c,v 1.5 2007-09-27 09:52:03 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -138,9 +138,7 @@ int
 server_msg_fn_attach(struct hdr *hdr, struct client *c)
 {
 	struct attach_data	 data;
-	char			*msg;
+	char			*cause;
-	struct session		*s;
-	u_int			 i;
 	
 	if (c->session != NULL)
 		return (0);
@@ -155,23 +153,9 @@ server_msg_fn_attach(struct hdr *hdr, struct client *c)
 	if (c->sy == 0)
 		c->sy = 25;
 
-	if (*data.name != '\0') {
+	if ((c->session = server_find_sessid(&data.sid, &cause)) == NULL) {
-		if ((c->session = session_find(data.name)) == NULL)
+		server_write_client(c, MSG_ERROR, cause, strlen(cause));
-			xasprintf(&msg, "session not found: %s", data.name);
+		xfree(cause);
-	} else {
-		/* Find the oldest session. */
-		for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
-			if ((s = ARRAY_ITEM(&sessions, i)) == NULL)
-				continue;
-			if (c->session == NULL || s->tim < c->session->tim)
-				c->session = s;
-		}
-		if (c->session == NULL)
-			xasprintf(&msg, "no sessions found");
-	}
-	if (c->session == NULL) {
-		server_write_client(c, MSG_ERROR, msg, strlen(msg));
-		xfree(msg);
 		return (0);
 	}
 
@@ -361,15 +345,15 @@ server_msg_fn_windows(struct hdr *hdr, struct client *c)
 	struct session		*s;
 	struct window		*w;
 	u_int			 i;
+	char		 	*cause;
 
 	if (hdr->size != sizeof data)
 		fatalx("bad MSG_WINDOWS size");
 	buffer_read(c->in, &data, hdr->size);
 
-	s = session_find(data.name);
+	if ((s = server_find_sessid(&data.sid, &cause)) == NULL) {
-	if (s == NULL) {
+		server_write_client(c, MSG_ERROR, cause, strlen(cause));
-		data.windows = 0;
+		xfree(cause);
-		server_write_client(c, MSG_WINDOWS, &data, sizeof data);
 		return (0);
 	}
 

session.c

@@ -1,4 +1,4 @@
-/* $Id: session.c,v 1.16 2007-09-27 09:15:58 nicm Exp $ */
+/* $Id: session.c,v 1.17 2007-09-27 09:52:03 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -112,13 +112,13 @@ session_new(struct session *s, const char *cmd, u_int sx, u_int sy)
 {
 	struct window	*w;
 	const char	*environ[] = { NULL, "TERM=screen", NULL };
-	char		 blk[256];
+	char		 buf[256];
 	u_int		 i;
 
 	if (session_index(s, &i) != 0)
 		fatalx("session not found");
-	xsnprintf(blk, sizeof blk, "TMUX=%ld,%u", (long) getpid(), i);
+	xsnprintf(buf, sizeof buf, "TMUX=%ld,%u", (long) getpid(), i);
-	environ[0] = blk;
+	environ[0] = buf;
 	
 	if ((w = window_create(cmd, environ, sx, sy)) == NULL)
 		return (-1);

tmux.h

@@ -1,4 +1,4 @@
-/* $Id: tmux.h,v 1.16 2007-09-27 09:15:58 nicm Exp $ */
+/* $Id: tmux.h,v 1.17 2007-09-27 09:52:03 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -285,53 +285,60 @@ struct hdr {
 	size_t		size;
 };
 
+/* Session identification. */
+struct sessid {
+	long long	pid;			/* pid from $TMUX or -1 */
+	u_int		idx;			/* index from $TMUX */
+	char		name[MAXNAMELEN];	/* empty for current */
+};
+
 struct new_data {
-	char	name[MAXNAMELEN];
+	char		name[MAXNAMELEN];
-	u_int	sx;
+	u_int		sx;
-	u_int	sy;
+	u_int		sy;
 };
 
 struct attach_data {
-	char	name[MAXNAMELEN];
+	struct sessid	sid;
-	u_int	sx;
+	u_int		sx;
-	u_int	sy;
+	u_int		sy;
 };
 
 struct sessions_data {
-	u_int	sessions;
+	u_int		sessions;
 };
 
 struct sessions_entry {
-	char	name[MAXNAMELEN];
+	char		name[MAXNAMELEN];
-	time_t	tim;
+	time_t		tim;
-	u_int	windows;
+	u_int		windows;
 };
 
 struct windows_data {
-	char	name[MAXNAMELEN];
+	struct sessid	sid;
-	u_int	windows;
+	u_int		windows;
 };
 
 struct windows_entry {
-	u_int	idx;
+	u_int		idx;
-	char	tty[TTY_NAME_MAX];
+	char		tty[TTY_NAME_MAX];
 
-	char	name[MAXNAMELEN];
+	char		name[MAXNAMELEN];
-	char	title[MAXTITLELEN];
+	char		title[MAXTITLELEN];
 };
 
 struct size_data {
-	u_int	sx;
+	u_int		sx;
-	u_int	sy;
+	u_int		sy;
 };
 
 struct select_data {
-	u_int	idx;
+	u_int		idx;
 };
 
 struct refresh_data {
-	u_int	py_upper;
+	u_int		py_upper;
-	u_int	py_lower;
+	u_int		py_lower;
 };
 
 /* Attributes. */
@@ -449,6 +456,7 @@ int	 op_list(char *, int, char **);
 int	 client_init(char *, struct client_ctx *, int);
 int	 client_main(struct client_ctx *);
 void	 client_write_server(struct client_ctx *, enum hdrtype, void *, size_t);
+void	 client_fill_sessid(struct sessid *, char [MAXNAMELEN]);
 
 /* client-msg.c */
 int	 client_msg_dispatch(struct client_ctx *, char **);
@@ -465,6 +473,7 @@ int	 server_start(char *);
 int	 server_msg_dispatch(struct client *);
 
 /* server-fn.c */
+struct session *server_find_sessid(struct sessid *, char **);
 void	 server_write_message(struct client *, const char *, ...);
 void	 server_write_client(struct client *, enum hdrtype, void *, size_t);
 void	 server_write_client2(