Alter how tmux handles the working directory to internally use file descriptors

rather than strings.

- Each session still has a current working directory.

- New sessions still get their working directory from the client that created
  them or its attached session if any.

- New windows are created by default in the session working directory.

- The -c flag to new, neww, splitw allows the working directory to be
  overridden.

- The -c flag to attach let's the session working directory be changed.

- The default-path option has been removed.

To get the equivalent to default-path '.', do:

        bind c neww -c $PWD

To get the equivalent of default-path '', do:

        bind c neww -c '#{pane_current_path}'

The equivalent of default-path '~' is left as an exercise for the reader.

This also changes the client identify protocol to be a set of messages rather
than one as well as some other changes that should make it easier to make
backwards-compatible protocol changes in future.

17 files changed, 363 insertions, 308 deletions

diff --git a/client.c b/client.c
index 0a1c8da5..61791876 100644
--- a/client.c
+++ b/client.c
@@ -53,7 +53,6 @@ int		client_attached;
 int		client_get_lock(char *);
 int		client_connect(char *, int);
 void		client_send_identify(int);
-void		client_send_environ(void);
 int		client_write_one(enum msgtype, int, const void *, size_t);
 int		client_write_server(enum msgtype, const void *, size_t);
 void		client_update_event(void);
@@ -261,8 +260,7 @@ client_main(int argc, char **argv, int flags)
 	/* Establish signal handlers. */
 	set_signals(client_signal);
 
-	/* Send initial environment. */
-	client_send_environ();
+	/* Send identify messages. */
 	client_send_identify(flags);
 
 	/* Send first command. */
@@ -320,48 +318,38 @@ client_main(int argc, char **argv, int flags)
 	return (client_exitval);
 }
 
-/* Send identify message to server with the file descriptors. */
+/* Send identify messages to server. */
 void
 client_send_identify(int flags)
 {
-	struct msg_identify_data	data;
-	char			       *term;
-	int				fd;
+	const char	*s;
+	char		**ss;
+	int		 fd;
 
-	data.flags = flags;
+	client_write_one(MSG_IDENTIFY_FLAGS, -1, &flags, sizeof flags);
 
-	if (getcwd(data.cwd, sizeof data.cwd) == NULL)
-		*data.cwd = '\0';
+	if ((s = getenv("TERM")) == NULL)
+		s = "";
+	client_write_one(MSG_IDENTIFY_TERM, -1, s, strlen(s) + 1);
 
-	term = getenv("TERM");
-	if (term == NULL ||
-	    strlcpy(data.term, term, sizeof data.term) >= sizeof data.term)
-		*data.term = '\0';
+	if ((s = ttyname(STDIN_FILENO)) == NULL)
+		s = "";
+	client_write_one(MSG_IDENTIFY_TTYNAME, -1, s, strlen(s) + 1);
+
+	if ((fd = open(".", O_RDONLY)) == -1)
+		fd = open("/", O_RDONLY);
+	client_write_one(MSG_IDENTIFY_CWD, fd, NULL, 0);
 
-#ifdef __CYGWIN__
-	snprintf(&data.ttyname, sizeof data.ttyname, "%s",
-	    ttyname(STDIN_FILENO));
-#else
 	if ((fd = dup(STDIN_FILENO)) == -1)
 		fatal("dup failed");
-#endif
-	imsg_compose(&client_ibuf,
-	    MSG_IDENTIFY, PROTOCOL_VERSION, -1, fd, &data, sizeof data);
-	client_update_event();
-}
+	client_write_one(MSG_IDENTIFY_STDIN, fd, NULL, 0);
 
-/* Forward entire environment to server. */
-void
-client_send_environ(void)
-{
-	struct msg_environ_data	data;
-	char		      **var;
+	for (ss = environ; *ss != NULL; ss++)
+		client_write_one(MSG_IDENTIFY_ENVIRON, -1, *ss, strlen(*ss) + 1);
 
-	for (var = environ; *var != NULL; var++) {
-		if (strlcpy(data.var, *var, sizeof data.var) >= sizeof data.var)
-			continue;
-		client_write_server(MSG_ENVIRON, &data, sizeof data);
-	}
+	client_write_one(MSG_IDENTIFY_DONE, -1, NULL, 0);
+
+	client_update_event();
 }
 
 /* Helper to send one message. */
@@ -604,8 +592,6 @@ client_dispatch_wait(void *data0)
 		case MSG_EXITED:
 			imsg_free(&imsg);
 			return (-1);
-		default:
-			fatalx("unexpected message");
 		}
 
 		imsg_free(&imsg);
@@ -684,8 +670,6 @@ client_dispatch_attached(void)
 			system(data);
 			client_write_server(MSG_UNLOCK, NULL, 0);
 			break;
-		default:
-			fatalx("unexpected message");
 		}
 
 		imsg_free(&imsg);
diff --git a/cmd-attach-session.c b/cmd-attach-session.c
index 7a952e59..f78a89fd 100644
--- a/cmd-attach-session.c
+++ b/cmd-attach-session.c
@@ -18,7 +18,11 @@
 
 #include <sys/types.h>
 
+#include <errno.h>
+#include <fcntl.h>
 #include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
 #include "tmux.h"
 
@@ -30,21 +34,25 @@ enum cmd_retval	cmd_attach_session_exec(struct cmd *, struct cmd_q *);
 
 const struct cmd_entry cmd_attach_session_entry = {
 	"attach-session", "attach",
-	"drt:", 0, 0,
-	"[-dr] " CMD_TARGET_SESSION_USAGE,
+	"c:drt:", 0, 0,
+	"[-dr] [-c working-directory] " CMD_TARGET_SESSION_USAGE,
 	CMD_CANTNEST|CMD_STARTSERVER,
 	NULL,
 	cmd_attach_session_exec
 };
 
 enum cmd_retval
-cmd_attach_session(struct cmd_q *cmdq, const char* tflag, int dflag, int rflag)
+cmd_attach_session(struct cmd_q *cmdq, const char *tflag, int dflag, int rflag,
+    const char *cflag)
 {
-	struct session	*s;
-	struct client	*c;
-	const char	*update;
-	char		*cause;
-	u_int		 i;
+	struct session		*s;
+	struct client		*c;
+	const char		*update;
+	char			*cause;
+	u_int			 i;
+	int			 fd;
+	struct format_tree	*ft;
+	char			*cp;
 
 	if (RB_EMPTY(&sessions)) {
 		cmdq_error(cmdq, "no sessions");
@@ -73,6 +81,27 @@ cmd_attach_session(struct cmd_q *cmdq, const char* tflag, int dflag, int rflag)
 			}
 		}
 
+		if (cflag != NULL) {
+			ft = format_create();
+			if ((c = cmd_find_client(cmdq, NULL, 1)) != NULL)
+				format_client(ft, c);
+			format_session(ft, s);
+			format_winlink(ft, s, s->curw);
+			format_window_pane(ft, s->curw->window->active);
+			cp = format_expand(ft, cflag);
+			format_free(ft);
+
+			fd = open(cp, O_RDONLY|O_DIRECTORY);
+			free(cp);
+			if (fd == -1) {
+				cmdq_error(cmdq, "bad working directory: %s",
+				    strerror(errno));
+				return (CMD_RETURN_ERROR);
+			}
+			close(s->cwd);
+			s->cwd = fd;
+		}
+
 		cmdq->client->session = s;
 		notify_attached_session_changed(cmdq->client);
 		session_update_activity(s);
@@ -85,6 +114,27 @@ cmd_attach_session(struct cmd_q *cmdq, const char* tflag, int dflag, int rflag)
 			return (CMD_RETURN_ERROR);
 		}
 
+		if (cflag != NULL) {
+			ft = format_create();
+			if ((c = cmd_find_client(cmdq, NULL, 1)) != NULL)
+				format_client(ft, c);
+			format_session(ft, s);
+			format_winlink(ft, s, s->curw);
+			format_window_pane(ft, s->curw->window->active);
+			cp = format_expand(ft, cflag);
+			format_free(ft);
+
+			fd = open(cp, O_RDONLY|O_DIRECTORY);
+			free(cp);
+			if (fd == -1) {
+				cmdq_error(cmdq, "bad working directory: %s",
+				    strerror(errno));
+				return (CMD_RETURN_ERROR);
+			}
+			close(s->cwd);
+			s->cwd = fd;
+		}
+
 		if (rflag)
 			cmdq->client->flags |= CLIENT_READONLY;
 
@@ -115,5 +165,5 @@ cmd_attach_session_exec(struct cmd *self, struct cmd_q *cmdq)
 	struct args	*args = self->args;
 
 	return (cmd_attach_session(cmdq, args_get(args, 't'),
-	    args_has(args, 'd'), args_has(args, 'r')));
+	    args_has(args, 'd'), args_has(args, 'r'), args_get(args, 'c')));
 }
diff --git a/cmd-load-buffer.c b/cmd-load-buffer.c
index 82b8f574..4acbab5e 100644
--- a/cmd-load-buffer.c
+++ b/cmd-load-buffer.c
@@ -19,6 +19,7 @@
 #include <sys/types.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -49,11 +50,11 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 	struct client	*c = cmdq->client;
 	struct session  *s;
 	FILE		*f;
-	const char	*path, *newpath, *wd;
+	const char	*path;
 	char		*pdata, *new_pdata, *cause;
 	size_t		 psize;
 	u_int		 limit;
-	int		 ch, error, buffer, *buffer_ptr;
+	int		 ch, error, buffer, *buffer_ptr, cwd, fd;
 
 	if (!args_has(args, 'b'))
 		buffer = -1;
@@ -81,20 +82,17 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 		return (CMD_RETURN_WAIT);
 	}
 
-	if (c != NULL)
-		wd = c->cwd;
-	else if ((s = cmd_current_session(cmdq, 0)) != NULL) {
-		wd = options_get_string(&s->options, "default-path");
-		if (*wd == '\0')
-			wd = s->cwd;
-	} else
-		wd = NULL;
-	if (wd != NULL && *wd != '\0') {
-		newpath = get_full_path(wd, path);
-		if (newpath != NULL)
-			path = newpath;
-	}
-	if ((f = fopen(path, "rb")) == NULL) {
+	if (c != NULL && c->session == NULL)
+		cwd = c->cwd;
+	else if ((s = cmd_current_session(cmdq, 0)) != NULL)
+		cwd = s->cwd;
+	else
+		cwd = AT_FDCWD;
+
+	if ((fd = openat(cwd, path, O_RDONLY)) == -1 ||
+	    (f = fdopen(fd, "rb")) == NULL) {
+		if (fd != -1)
+			close(fd);
 		cmdq_error(cmdq, "%s: %s", path, strerror(errno));
 		return (CMD_RETURN_ERROR);
 	}
diff --git a/cmd-new-session.c b/cmd-new-session.c
index 38c79a6d..3ce24397 100644
--- a/cmd-new-session.c
+++ b/cmd-new-session.c
@@ -18,6 +18,8 @@
 
 #include <sys/types.h>
 
+#include <errno.h>
+#include <fcntl.h>
 #include <pwd.h>
 #include <stdlib.h>
 #include <string.h>
@@ -47,18 +49,15 @@ enum cmd_retval
 cmd_new_session_exec(struct cmd *self, struct cmd_q *cmdq)
 {
 	struct args		*args = self->args;
-	struct client		*c = cmdq->client;
+	struct client		*c = cmdq->client, *c0;
 	struct session		*s, *groupwith;
 	struct window		*w;
 	struct environ		 env;
 	struct termios		 tio, *tiop;
-	struct passwd		*pw;
-	const char		*newname, *target, *update, *base, *cwd;
-	const char		*errstr, *template;
+	const char		*newname, *target, *update, *errstr, *template;
 	char			*cmd, *cause, *cp;
-	int			 detached, idx;
+	int			 detached, already_attached, idx, cwd, fd = -1;
 	u_int			 sx, sy;
-	int			 already_attached;
 	struct format_tree	*ft;
 
 	if (args_has(args, 't') && (args->argc != 0 || args_has(args, 'n'))) {
@@ -75,7 +74,7 @@ cmd_new_session_exec(struct cmd *self, struct cmd_q *cmdq)
 		if (session_find(newname) != NULL) {
 			if (args_has(args, 'A')) {
 				return (cmd_attach_session(cmdq, newname,
-				    args_has(args, 'D'), 0));
+				    args_has(args, 'D'), 0, NULL));
 			}
 			cmdq_error(cmdq, "duplicate session: %s", newname);
 			return (CMD_RETURN_ERROR);
@@ -100,6 +99,31 @@ cmd_new_session_exec(struct cmd *self, struct cmd_q *cmdq)
 	if (c != NULL && c->session != NULL)
 		already_attached = 1;
 
+	/* Get the new session working directory. */
+	if (args_has(args, 'c')) {
+		ft = format_create();
+		if ((c0 = cmd_find_client(cmdq, NULL, 1)) != NULL)
+			format_client(ft, c0);
+		cp = format_expand(ft, args_get(args, 'c'));
+		format_free(ft);
+
+		fd = open(cp, O_RDONLY|O_DIRECTORY);
+		free(cp);
+		if (fd == -1) {
+			cmdq_error(cmdq, "bad working directory: %s",
+			    strerror(errno));
+			return (CMD_RETURN_ERROR);
+		}
+		cwd = fd;
+	} else if (c->session == NULL)
+		cwd = c->cwd;
+	else if ((c0 = cmd_current_client(cmdq)) != NULL)
+		cwd = c0->session->cwd;
+	else {
+		fd = open(".", O_RDONLY);
+		cwd = fd;
+	}
+
 	/*
 	 * Save the termios settings, part of which is used for new windows in
 	 * this session.
@@ -121,26 +145,10 @@ cmd_new_session_exec(struct cmd *self, struct cmd_q *cmdq)
 		if (server_client_open(c, NULL, &cause) != 0) {
 			cmdq_error(cmdq, "open terminal failed: %s", cause);
 			free(cause);
-			return (CMD_RETURN_ERROR);
+			goto error;
 		}
 	}
 
-	/* Get the new session working directory. */
-	if (c != NULL && c->cwd != NULL)
-		base = c->cwd;
-	else {
-		pw = getpwuid(getuid());
-		if (pw->pw_dir != NULL && *pw->pw_dir != '\0')
-			base = pw->pw_dir;
-		else
-			base = "/";
-	}
-	if (args_has(args, 'c'))
-		cwd = args_get(args, 'c');
-	else
-		cwd = options_get_string(&global_s_options, "default-path");
-	cwd = cmd_default_path(base, base, cwd);
-
 	/* Find new session size. */
 	if (c != NULL) {
 		sx = c->tty.sx;
@@ -153,14 +161,14 @@ cmd_new_session_exec(struct cmd *self, struct cmd_q *cmdq)
 		sx = strtonum(args_get(args, 'x'), 1, USHRT_MAX, &errstr);
 		if (errstr != NULL) {
 			cmdq_error(cmdq, "width %s", errstr);
-			return (CMD_RETURN_ERROR);
+			goto error;
 		}
 	}
 	if (detached && args_has(args, 'y')) {
 		sy = strtonum(args_get(args, 'y'), 1, USHRT_MAX, &errstr);
 		if (errstr != NULL) {
 			cmdq_error(cmdq, "height %s", errstr);
-			return (CMD_RETURN_ERROR);
+			goto error;
 		}
 	}
 	if (sy > 0 && options_get_number(&global_s_options, "status"))
@@ -190,7 +198,7 @@ cmd_new_session_exec(struct cmd *self, struct cmd_q *cmdq)
 	if (s == NULL) {
 		cmdq_error(cmdq, "create session failed: %s", cause);
 		free(cause);
-		return (CMD_RETURN_ERROR);
+		goto error;
 	}
 	environ_free(&env);
 
@@ -241,8 +249,8 @@ cmd_new_session_exec(struct cmd *self, struct cmd_q *cmdq)
 			template = NEW_SESSION_TEMPLATE;
 
 		ft = format_create();
-		if ((c = cmd_find_client(cmdq, NULL, 1)) != NULL)
-			format_client(ft, c);
+		if ((c0 = cmd_find_client(cmdq, NULL, 1)) != NULL)
+			format_client(ft, c0);
 		format_session(ft, s);
 
 		cp = format_expand(ft, template);
@@ -254,5 +262,13 @@ cmd_new_session_exec(struct cmd *self, struct cmd_q *cmdq)
 
 	if (!detached)
 		cmdq->client_exit = 0;
+
+	if (fd != -1)
+		close(fd);
 	return (CMD_RETURN_NORMAL);
+
+error:
+	if (fd != -1)
+		close(fd);
+	return (CMD_RETURN_ERROR);
 }
diff --git a/cmd-new-window.c b/cmd-new-window.c
index e5658b37..f6a925b1 100644
--- a/cmd-new-window.c
+++ b/cmd-new-window.c
@@ -18,7 +18,11 @@
 
 #include <sys/types.h>
 
+#include <errno.h>
+#include <fcntl.h>
 #include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
 #include "tmux.h"
 
@@ -45,9 +49,9 @@ cmd_new_window_exec(struct cmd *self, struct cmd_q *cmdq)
 	struct session		*s;
 	struct winlink		*wl;
 	struct client		*c;
-	const char		*cmd, *cwd, *template;
+	const char		*cmd, *template;
 	char			*cause, *cp;
-	int			 idx, last, detached;
+	int			 idx, last, detached, cwd, fd = -1;
 	struct format_tree	*ft;
 
 	if (args_has(args, 'a')) {
@@ -102,7 +106,29 @@ cmd_new_window_exec(struct cmd *self, struct cmd_q *cmdq)
 		cmd = options_get_string(&s->options, "default-command");
 	else
 		cmd = args->argv[0];
-	cwd = cmdq_default_path(cmdq, args_get(args, 'c'));
+
+	if (args_has(args, 'c')) {
+		ft = format_create();
+		if ((c = cmd_find_client(cmdq, NULL, 1)) != NULL)
+			format_client(ft, c);
+		format_session(ft, s);
+		format_winlink(ft, s, s->curw);
+		format_window_pane(ft, s->curw->window->active);
+		cp = format_expand(ft, args_get(args, 'c'));
+		format_free(ft);
+
+		fd = open(cp, O_RDONLY|O_DIRECTORY);
+		free(cp);
+		if (fd == -1) {
+			cmdq_error(cmdq, "bad working directory: %s",
+			    strerror(errno));
+			return (CMD_RETURN_ERROR);
+		}
+		cwd = fd;
+	} else if (cmdq->client->session == NULL)
+		cwd = cmdq->client->cwd;
+	else
+		cwd = s->cwd;
 
 	if (idx == -1)
 		idx = -1 - options_get_number(&s->options, "base-index");
@@ -110,7 +136,7 @@ cmd_new_window_exec(struct cmd *self, struct cmd_q *cmdq)
 	if (wl == NULL) {
 		cmdq_error(cmdq, "create window failed: %s", cause);
 		free(cause);
-		return (CMD_RETURN_ERROR);
+		goto error;
 	}
 	if (!detached) {
 		session_select(s, wl->idx);
@@ -136,5 +162,12 @@ cmd_new_window_exec(struct cmd *self, struct cmd_q *cmdq)
 		format_free(ft);
 	}
 
+	if (fd != -1)
+		close(fd);
 	return (CMD_RETURN_NORMAL);
+
+error:
+	if (fd != -1)
+		close(fd);
+	return (CMD_RETURN_ERROR);
 }
diff --git a/cmd-queue.c b/cmd-queue.c
index 7feb25ef..c5905bdb 100644
--- a/cmd-queue.c
+++ b/cmd-queue.c
@@ -283,27 +283,3 @@ cmdq_flush(struct cmd_q *cmdq)
 	}
 	cmdq->item = NULL;
 }
-
-/* Get default path using command queue. */
-const char *
-cmdq_default_path(struct cmd_q *cmdq, const char *cwd)
-{
-	struct client	*c = cmdq->client;
-	struct session	*s;
-	const char	*current;
-
-	if ((s = cmd_current_session(cmdq, 0)) == NULL)
-		return (NULL);
-
-	if (cwd == NULL)
-		cwd = options_get_string(&s->options, "default-path");
-
-	if (c != NULL && c->session == NULL && c->cwd != NULL)
-		current = c->cwd;
-	else if (s->curw != NULL)
-		current = osdep_get_cwd(s->curw->window->active->fd);
-	else
-		current = NULL;
-
-	return (cmd_default_path(s->cwd, current, cwd));
-}
diff --git a/cmd-save-buffer.c b/cmd-save-buffer.c
index c6c54019..3788fc22 100644
--- a/cmd-save-buffer.c
+++ b/cmd-save-buffer.c
@@ -20,8 +20,10 @@
 #include <sys/stat.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 #include "tmux.h"
 
@@ -53,17 +55,14 @@ enum cmd_retval
 cmd_save_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 {
 	struct args		*args = self->args;
-	struct client		*c;
+	struct client		*c = cmdq->client;
 	struct session          *s;
 	struct paste_buffer	*pb;
-	const char		*path, *newpath, *wd;
-	char			*cause, *start, *end;
-	size_t			 size, used;
-	int			 buffer;
-	mode_t			 mask;
+	const char		*path;
+	char			*cause, *start, *end, *msg;
+	size_t			 size, used, msglen;
+	int			 cwd, fd, buffer;
 	FILE			*f;
-	char			*msg;
-	size_t			 msglen;
 
 	if (!args_has(args, 'b')) {
 		if ((pb = paste_get_top(&global_buffers)) == NULL) {
@@ -90,7 +89,6 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 	else
 		path = args->argv[0];
 	if (strcmp(path, "-") == 0) {
-		c = cmdq->client;
 		if (c == NULL) {
 			cmdq_error(cmdq, "can't write to stdout");
 			return (CMD_RETURN_ERROR);
@@ -100,28 +98,26 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 		goto do_print;
 	}
 
-	c = cmdq->client;
-	if (c != NULL)
-		wd = c->cwd;
-	else if ((s = cmd_current_session(cmdq, 0)) != NULL) {
-		wd = options_get_string(&s->options, "default-path");
-		if (*wd == '\0')
-			wd = s->cwd;
-	} else
-		wd = NULL;
-	if (wd != NULL && *wd != '\0') {
-		newpath = get_full_path(wd, path);
-		if (newpath != NULL)
-			path = newpath;
-	}
-
-	mask = umask(S_IRWXG | S_IRWXO);
-	if (args_has(self->args, 'a'))
-		f = fopen(path, "ab");
+	if (c != NULL && c->session == NULL)
+		cwd = c->cwd;
+	else if ((s = cmd_current_session(cmdq, 0)) != NULL)
+		cwd = s->cwd;
 	else
-		f = fopen(path, "wb");
-	umask(mask);
+		cwd = AT_FDCWD;
+
+	f = NULL;
+	if (args_has(self->args, 'a')) {
+		fd = openat(cwd, path, O_CREAT|O_RDWR|O_APPEND, 0600);
+		if (fd != -1)
+			f = fdopen(fd, "ab");
+	} else {
+		fd = openat(cwd, path, O_CREAT|O_RDWR, 0600);
+		if (fd != -1)
+			f = fdopen(fd, "wb");
+	}
 	if (f == NULL) {
+		if (fd != -1)
+			close(fd);
 		cmdq_error(cmdq, "%s: %s", path, strerror(errno));
 		return (CMD_RETURN_ERROR);
 	}
diff --git a/cmd-split-window.c b/cmd-split-window.c
index a2403253..ef1d3cbc 100644
--- a/cmd-split-window.c
+++ b/cmd-split-window.c
@@ -18,7 +18,10 @@
 
 #include <sys/types.h>
 
+#include <errno.h>
+#include <fcntl.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 #include "tmux.h"
@@ -57,16 +60,14 @@ cmd_split_window_exec(struct cmd *self, struct cmd_q *cmdq)
 	struct window		*w;
 	struct window_pane	*wp, *new_wp = NULL;
 	struct environ		 env;
-	const char		*cmd, *cwd, *shell;
-	char			*cause, *new_cause;
+	const char		*cmd, *shell, *template;
+	char			*cause, *new_cause, *cp;
 	u_int			 hlimit;
-	int			 size, percentage;
+	int			 size, percentage, cwd, fd = -1;
 	enum layout_type	 type;
 	struct layout_cell	*lc;
-	const char		*template;
 	struct client		*c;
 	struct format_tree	*ft;
-	char			*cp;
 
 	if ((wl = cmd_find_pane(cmdq, args_get(args, 't'), &s, &wp)) == NULL)
 		return (CMD_RETURN_ERROR);
@@ -82,7 +83,29 @@ cmd_split_window_exec(struct cmd *self, struct cmd_q *cmdq)
 		cmd = options_get_string(&s->options, "default-command");
 	else
 		cmd = args->argv[0];
-	cwd = cmdq_default_path(cmdq, args_get(args, 'c'));
+
+	if (args_has(args, 'c')) {
+		ft = format_create();
+		if ((c = cmd_find_client(cmdq, NULL, 1)) != NULL)
+			format_client(ft, c);
+		format_session(ft, s);
+		format_winlink(ft, s, s->curw);
+		format_window_pane(ft, s->curw->window->active);
+		cp = format_expand(ft, args_get(args, 'c'));
+		format_free(ft);
+
+		fd = open(cp, O_RDONLY|O_DIRECTORY);
+		free(cp);
+		if (fd == -1) {
+			cmdq_error(cmdq, "bad working directory: %s",
+			    strerror(errno));
+			return (CMD_RETURN_ERROR);
+		}
+		cwd = fd;
+	} else if (cmdq->client->session == NULL)
+		cwd = cmdq->client->cwd;
+	else
+		cwd = s->cwd;
 
 	type = LAYOUT_TOPBOTTOM;
 	if (args_has(args, 'h'))
@@ -155,6 +178,9 @@ cmd_split_window_exec(struct cmd *self, struct cmd_q *cmdq)
 		format_free(ft);
 	}
 	notify_window_layout_changed(w);
+
+	if (fd != -1)
+		close(fd);
 	return (CMD_RETURN_NORMAL);
 
 error:
@@ -163,5 +189,7 @@ error:
 		window_remove_pane(w, new_wp);
 	cmdq_error(cmdq, "create pane failed: %s", cause);
 	free(cause);
+	if (fd != -1)
+		close(fd);
 	return (CMD_RETURN_ERROR);
 }
diff --git a/format.c b/format.c
index ba4b95b2..a7f1fdee 100644
--- a/format.c
+++ b/format.c
@@ -403,7 +403,6 @@ format_client(struct format_tree *ft, struct client *c)
 	time_t		 t;
 	struct session	*s;
 
-	format_add(ft, "client_cwd", "%s", c->cwd);
 	format_add(ft, "client_height", "%u", c->tty.sy);
 	format_add(ft, "client_width", "%u", c->tty.sx);
 	if (c->tty.path != NULL)
@@ -552,8 +551,6 @@ format_window_pane(struct format_tree *ft, struct window_pane *wp)
 	format_add(ft, "pane_pid", "%ld", (long) wp->pid);
 	if (wp->cmd != NULL)
 		format_add(ft, "pane_start_command", "%s", wp->cmd);
-	if (wp->cwd != NULL)
-		format_add(ft, "pane_start_path", "%s", wp->cwd);
 	if ((cwd = osdep_get_cwd(wp->fd)) != NULL)
 		format_add(ft, "pane_current_path", "%s", cwd);
 	if ((cmd = format_get_command(wp)) != NULL) {
diff --git a/options-table.c b/options-table.c
index f6a15472..5da095b1 100644
--- a/options-table.c
+++ b/options-table.c
@@ -125,11 +125,6 @@ const struct options_table_entry session_options_table[] = {
 	  .default_str = ""
 	},
 
-	{ .name = "default-path",
-	  .type = OPTIONS_TABLE_STRING,
-	  .default_str = ""
-	},
-
 	{ .name = "default-shell",
 	  .type = OPTIONS_TABLE_STRING,
 	  .default_str = _PATH_BSHELL
diff --git a/server-client.c b/server-client.c
index 11f19376..8a99367c 100644
--- a/server-client.c
+++ b/server-client.c
@@ -41,8 +41,7 @@ int	server_client_assume_paste(struct session *);
 
 int	server_client_msg_dispatch(struct client *);
 void	server_client_msg_command(struct client *, struct imsg *);
-void	server_client_msg_identify(
-	    struct client *, struct msg_identify_data *, int);
+void	server_client_msg_identify(struct client *, struct imsg *);
 void	server_client_msg_shell(struct client *);
 
 /* Create a new client. */
@@ -151,6 +150,8 @@ server_client_lost(struct client *c)
 	 */
 	if (c->flags & CLIENT_TERMINAL)
 		tty_free(&c->tty);
+	free(c->ttyname);
+	free(c->term);
 
 	evbuffer_free (c->stdin_data);
 	evbuffer_free (c->stdout_data);
@@ -162,6 +163,7 @@ server_client_lost(struct client *c)
 	screen_free(&c->status);
 
 	free(c->title);
+	close(c->cwd);
 
 	evtimer_del(&c->repeat_timer);
 
@@ -179,7 +181,6 @@ server_client_lost(struct client *c)
 
 	free(c->prompt_string);
 	free(c->prompt_buffer);
-	free(c->cwd);
 
 	c->cmdq->dead = 1;
 	cmdq_free(c->cmdq);
@@ -786,8 +787,6 @@ int
 server_client_msg_dispatch(struct client *c)
 {
 	struct imsg		 imsg;
-	struct msg_identify_data identifydata;
-	struct msg_environ_data	 environdata;
 	struct msg_stdin_data	 stdindata;
 	const char		*data;
 	ssize_t			 n, datalen;
@@ -813,14 +812,14 @@ server_client_msg_dispatch(struct client *c)
 
 		log_debug("got %d from client %d", imsg.hdr.type, c->ibuf.fd);
 		switch (imsg.hdr.type) {
-		case MSG_IDENTIFY:
-			if (datalen != sizeof identifydata)
-				fatalx("bad MSG_IDENTIFY size");
-			memcpy(&identifydata, imsg.data, sizeof identifydata);
-#ifdef __CYGWIN__
-			imsg.fd = open(identifydata.ttyname, O_RDWR|O_NOCTTY);
-#endif
-			server_client_msg_identify(c, &identifydata, imsg.fd);
+		case MSG_IDENTIFY_FLAGS:
+		case MSG_IDENTIFY_TERM:
+		case MSG_IDENTIFY_TTYNAME:
+		case MSG_IDENTIFY_CWD:
+		case MSG_IDENTIFY_STDIN:
+		case MSG_IDENTIFY_ENVIRON:
+		case MSG_IDENTIFY_DONE:
+			server_client_msg_identify(c, &imsg);
 			break;
 		case MSG_COMMAND:
 			server_client_msg_command(c, &imsg);
@@ -878,23 +877,12 @@ server_client_msg_dispatch(struct client *c)
 			server_redraw_client(c);
 			recalculate_sizes();
 			break;
-		case MSG_ENVIRON:
-			if (datalen != sizeof environdata)
-				fatalx("bad MSG_ENVIRON size");
-			memcpy(&environdata, imsg.data, sizeof environdata);
-
-			environdata.var[(sizeof environdata.var) - 1] = '\0';
-			if (strchr(environdata.var, '=') != NULL)
-				environ_put(&c->environ, environdata.var);
-			break;
 		case MSG_SHELL:
 			if (datalen != 0)
 				fatalx("bad MSG_SHELL size");
 
 			server_client_msg_shell(c);
 			break;
-		default:
-			fatalx("unexpected message");
 		}
 
 		imsg_free(&imsg);
@@ -953,46 +941,99 @@ error:
 
 /* Handle identify message. */
 void
-server_client_msg_identify(
-    struct client *c, struct msg_identify_data *data, int fd)
+server_client_msg_identify(struct client *c, struct imsg *imsg)
 {
-	c->cwd = NULL;
-	data->cwd[(sizeof data->cwd) - 1] = '\0';
-	if (*data->cwd != '\0')
-		c->cwd = xstrdup(data->cwd);
+	const char	*data;
+	size_t	 	 datalen;
+	int		 flags;
+
+	if (c->flags & CLIENT_IDENTIFIED)
+		fatalx("out-of-order identify message");
+
+	data = imsg->data;
+	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
+
+	switch (imsg->hdr.type)	{
+	case MSG_IDENTIFY_FLAGS:
+		if (datalen != sizeof flags)
+			fatalx("bad MSG_IDENTIFY_FLAGS size");
+		memcpy(&flags, data, sizeof flags);
+		c->flags |= flags;
+		break;
+	case MSG_IDENTIFY_TERM:
+		if (data[datalen - 1] != '\0')
+			fatalx("bad MSG_IDENTIFY_TERM string");
+		c->term = xstrdup(data);
+		break;
+	case MSG_IDENTIFY_TTYNAME:
+		if (data[datalen - 1] != '\0')
+			fatalx("bad MSG_IDENTIFY_TTYNAME string");
+		c->ttyname = xstrdup(data);
+		break;
+	case MSG_IDENTIFY_CWD:
+		if (datalen != 0)
+			fatalx("bad MSG_IDENTIFY_CWD size");
+		c->cwd = imsg->fd;
+		break;
+	case MSG_IDENTIFY_STDIN:
+		if (datalen != 0)
+			fatalx("bad MSG_IDENTIFY_STDIN size");
+		c->fd = imsg->fd;
+		break;
+	case MSG_IDENTIFY_ENVIRON:
+		if (data[datalen - 1] != '\0')
+			fatalx("bad MSG_IDENTIFY_ENVIRON string");
+		if (strchr(data, '=') != NULL)
+			environ_put(&c->environ, data);
+		break;
+	default:
+		break;
+	}
+
+	if (imsg->hdr.type != MSG_IDENTIFY_DONE)
+		return;
+	c->flags |= CLIENT_IDENTIFIED;
 
-	if (data->flags & CLIENT_CONTROL) {
+#ifdef __CYGWIN__
+	c->fd = open(c->ttyname, O_RDWR|O_NOCTTY);
+	c->cwd = open(".", O_RDONLY);
+#endif
+
+	if (c->flags & CLIENT_CONTROL) {
 		c->stdin_callback = control_callback;
+
 		evbuffer_free(c->stderr_data);
 		c->stderr_data = c->stdout_data;
-		c->flags |= CLIENT_CONTROL;
-		if (data->flags & CLIENT_CONTROLCONTROL)
+
+		if (c->flags & CLIENT_CONTROLCONTROL)
 			evbuffer_add_printf(c->stdout_data, "\033P1000p");
 		server_write_client(c, MSG_STDIN, NULL, 0);
 
 		c->tty.fd = -1;
 		c->tty.log_fd = -1;
 
-		close(fd);
+		close(c->fd);
+		c->fd = -1;
+
 		return;
 	}
 
-	if (fd == -1)
+	if (c->fd == -1)
 		return;
-	if (!isatty(fd)) {
-		close(fd);
+	if (!isatty(c->fd)) {
+		close(c->fd);
+		c->fd = -1;
 		return;
 	}
-	data->term[(sizeof data->term) - 1] = '\0';
-	tty_init(&c->tty, c, fd, data->term);
-	if (data->flags & CLIENT_UTF8)
+	tty_init(&c->tty, c, c->fd, c->term);
+	if (c->flags & CLIENT_UTF8)
 		c->tty.flags |= TTY_UTF8;
-	if (data->flags & CLIENT_256COLOURS)
+	if (c->flags & CLIENT_256COLOURS)
 		c->tty.term_flags |= TERM_256COLOURS;
 
 	tty_resize(&c->tty);
 
-	if (!(data->flags & CLIENT_CONTROL))
+	if (!(c->flags & CLIENT_CONTROL))
 		c->flags |= CLIENT_TERMINAL;
 }
 
diff --git a/server-fn.c b/server-fn.c
index 1b49985f..4fc4eb5c 100644
--- a/server-fn.c
+++ b/server-fn.c
@@ -56,8 +56,8 @@ server_write_ready(struct client *c)
 }
 
 int
-server_write_client(
-    struct client *c, enum msgtype type, const void *buf, size_t len)
+server_write_client(struct client *c, enum msgtype type, const void *buf,
+    size_t len)
 {
 	struct imsgbuf	*ibuf = &c->ibuf;
 	int              error;
@@ -73,8 +73,8 @@ server_write_client(
 }
 
 void
-server_write_session(
-    struct session *s, enum msgtype type, const void *buf, size_t len)
+server_write_session(struct session *s, enum msgtype type, const void *buf,
+    size_t len)
 {
 	struct client	*c;
 	u_int		 i;
diff --git a/session.c b/session.c
index bb742d8f..66a52bc6 100644
--- a/session.c
+++ b/session.c
@@ -84,9 +84,8 @@ session_find_by_id(u_int id)
 
 /* Create a new session. */
 struct session *
-session_create(const char *name, const char *cmd, const char *cwd,
-    struct environ *env, struct termios *tio, int idx, u_int sx, u_int sy,
-    char **cause)
+session_create(const char *name, const char *cmd, int cwd, struct environ *env,
+    struct termios *tio, int idx, u_int sx, u_int sy, char **cause)
 {
 	struct session	*s;
 
@@ -98,7 +97,7 @@ session_create(const char *name, const char *cmd, const char *cwd,
 		fatal("gettimeofday failed");
 	session_update_activity(s);
 
-	s->cwd = xstrdup(cwd);
+	s->cwd = dup(cwd);
 
 	s->curw = NULL;
 	TAILQ_INIT(&s->lastw);
@@ -170,7 +169,7 @@ session_destroy(struct session *s)
 		winlink_remove(&s->windows, wl);
 	}
 
-	free(s->cwd);
+	close(s->cwd);
 
 	RB_INSERT(sessions, &dead_sessions, s);
 }
@@ -226,8 +225,8 @@ session_previous_session(struct session *s)
 
 /* Create a new window on a session. */
 struct winlink *
-session_new(struct session *s,
-    const char *name, const char *cmd, const char *cwd, int idx, char **cause)
+session_new(struct session *s, const char *name, const char *cmd, int cwd,
+    int idx, char **cause)
 {
 	struct window	*w;
 	struct winlink	*wl;
@@ -250,8 +249,8 @@ session_new(struct session *s,
 		shell = _PATH_BSHELL;
 
 	hlimit = options_get_number(&s->options, "history-limit");
-	w = window_create(
-	    name, cmd, shell, cwd, &env, s->tio, s->sx, s->sy, hlimit, cause);
+	w = window_create(name, cmd, shell, cwd, &env, s->tio, s->sx, s->sy,
+	    hlimit, cause);
 	if (w == NULL) {
 		winlink_remove(&s->windows, wl);
 		environ_free(&env);
diff --git a/tmux.1 b/tmux.1
index ba5fe187..07eb93fb 100644
--- a/tmux.1
+++ b/tmux.1
@@ -568,6 +568,7 @@ The following commands are available to manage clients and sessions:
 .Bl -tag -width Ds
 .It Xo Ic attach-session
 .Op Fl dr
+.Op Fl c Ar working-directory
 .Op Fl t Ar target-session
 .Xc
 .D1 (alias: Ic attach )
@@ -601,6 +602,10 @@ needs to select the most recently used session, it will prefer the most
 recently used
 .Em unattached
 session.
+.Pp
+.Fl c
+will set the session working directory (used for new windows) to
+.Ar working-directory .
 .It Xo Ic detach-client
 .Op Fl P
 .Op Fl a
@@ -1513,13 +1518,6 @@ is not specified, the value of the
 option is used.
 .Fl c
 specifies the working directory in which the new window is created.
-It may have an absolute path or one of the following values (or a subdirectory):
-.Bl -column "XXXXXXXXXXXX" "XXXXXXXXXXXXXXXXXXXXXXXX" -offset indent
-.It Li "Empty string" Ta "Current pane's directory"
-.It Li "~" Ta "User's home directory"
-.It Li "-" Ta "Where session was started"
-.It Li "." Ta "Where server was started"
-.El
 .Pp
 When the shell command completes, the window closes.
 See the
@@ -2179,15 +2177,6 @@ The default is an empty string, which instructs
 to create a login shell using the value of the
 .Ic default-shell
 option.
-.It Ic default-path Ar path
-Set the default working directory for new panes.
-If empty (the default), the working directory is determined from the process
-running in the active pane, from the command line environment or from the
-working directory where the session was created.
-Otherwise the same options are available as for the
-.Fl c
-flag to
-.Ic new-window .
 .It Ic default-shell Ar path
 Specify the default shell.
 This is used as the login shell for new windows when the
@@ -3056,7 +3045,6 @@ The following variables are available, where appropriate:
 .It Li "client_activity_string" Ta "" Ta "String time client last had activity"
 .It Li "client_created" Ta "" Ta "Integer time client created"
 .It Li "client_created_string" Ta "" Ta "String time client created"
-.It Li "client_cwd" Ta "" Ta "Working directory of client"
 .It Li "client_height" Ta "" Ta "Height of client"
 .It Li "client_last_session" Ta "" Ta "Name of the client's last session"
 .It Li "client_prefix" Ta "" Ta "1 if prefix key has been pressed"
diff --git a/tmux.c b/tmux.c
index 76b09cf4..a0359969 100644
--- a/tmux.c
+++ b/tmux.c
@@ -127,30 +127,6 @@ areshell(const char *shell)
 	return (0);
 }
 
-const char *
-get_full_path(const char *wd, const char *path)
-{
-	int		 fd;
-	static char	 newpath[MAXPATHLEN];
-	const char	*retval;
-
-	fd = open(".", O_RDONLY);
-	if (fd == -1)
-		return (NULL);
-
-	retval = NULL;
-	if (chdir(wd) == 0) {
-		if (realpath(path, newpath) == 0)
-			retval = newpath;
-	}
-
-	if (fchdir(fd) != 0)
-		chdir("/");
-	close(fd);
-
-	return (retval);
-}
-
 void
 parseenvironment(void)
 {
@@ -249,7 +225,7 @@ int
 main(int argc, char **argv)
 {
 	struct passwd	*pw;
-	char		*s, *path, *label, *home, **var;
+	char		*s, *path, *label, *home, **var, tmp[MAXPATHLEN];
 	int	 	 opt, flags, quiet, keys;
 
 #if defined(DEBUG) && defined(__OpenBSD__)
@@ -333,6 +309,8 @@ main(int argc, char **argv)
 	environ_init(&global_environ);
 	for (var = environ; *var != NULL; var++)
 		environ_put(&global_environ, *var);
+	if (getcwd(tmp, sizeof tmp) != NULL)
+		environ_set(&global_environ, "PWD", tmp);
 
 	options_init(&global_options, NULL);
 	options_table_populate_tree(server_options_table, &global_options);
diff --git a/tmux.h b/tmux.h
index 5e6de257..a76d1024 100644
--- a/tmux.h
+++ b/tmux.h
@@ -52,13 +52,6 @@ extern char   **environ;
 #define NAME_INTERVAL 500
 
 /*
- * Maximum sizes of strings in message data. Don't forget to bump
- * PROTOCOL_VERSION if any of these change!
- */
-#define TERMINAL_LENGTH 128	/* length of TERM environment variable */
-#define ENVIRON_LENGTH 1024	/* environment variable length */
-
-/*
  * UTF-8 data size. This must be big enough to hold combined characters as well
  * as single.
  */
@@ -456,9 +449,6 @@ enum msgtype {
 	MSG_SUSPEND,
 	MSG_UNLOCK,
 	MSG_WAKEUP,
-
-	MSG_IDENTIFY = 300,
-	MSG_ENVIRON
 };
 
 /*
@@ -473,21 +463,6 @@ struct msg_command_data {
 	int	argc;
 }; /* followed by packed argv */
 
-struct msg_identify_data {
-	char		cwd[MAXPATHLEN];
-	char		term[TERMINAL_LENGTH];
-
-#ifdef __CYGWIN__
-	char		ttyname[TTY_NAME_MAX];
-#endif
-
-	int		flags;
-};
-
-struct msg_environ_data {
-	char		var[ENVIRON_LENGTH];
-};
-
 struct msg_stdin_data {
 	ssize_t	size;
 	char	data[BUFSIZ];
@@ -934,7 +909,7 @@ struct window_pane {
 
 	char		*cmd;
 	char		*shell;
-	char		*cwd;
+	int		 cwd;
 
 	pid_t		 pid;
 	char		 tty[TTY_NAME_MAX];
@@ -1081,7 +1056,7 @@ struct session {
 	u_int		 id;
 
 	char		*name;
-	char		*cwd;
+	int		 cwd;
 
 	struct timeval	 creation_time;
 	struct timeval	 activity_time;
@@ -1281,6 +1256,7 @@ RB_HEAD(status_out_tree, status_out);
 struct client {
 	struct imsgbuf	 ibuf;
 
+	int		 fd;
 	struct event	 event;
 	int		 retval;
 
@@ -1290,8 +1266,10 @@ struct client {
 	struct environ	 environ;
 
 	char		*title;
-	char		*cwd;
+	int		 cwd;
 
+	char		*term;
+	char		*ttyname;
 	struct tty	 tty;
 
 	void		(*stdin_callback)(struct client *, int, void *);
@@ -1524,7 +1502,6 @@ void		 logfile(const char *);
 const char	*getshell(void);
 int		 checkshell(const char *);
 int		 areshell(const char *);
-const char*	 get_full_path(const char *, const char *);
 void		 setblocking(int, int);
 __dead void	 shell_exec(const char *, const char *);
 
@@ -1760,7 +1737,6 @@ int		 cmd_find_index(struct cmd_q *, const char *,
 struct winlink	*cmd_find_pane(struct cmd_q *, const char *, struct session **,
 		     struct window_pane **);
 char		*cmd_template_replace(const char *, const char *, int);
-const char     	*cmd_default_path(const char *, const char *, const char *);
 extern const struct cmd_entry *cmd_table[];
 extern const struct cmd_entry cmd_attach_session_entry;
 extern const struct cmd_entry cmd_bind_key_entry;
@@ -1851,7 +1827,8 @@ extern const struct cmd_entry cmd_up_pane_entry;
 extern const struct cmd_entry cmd_wait_for_entry;
 
 /* cmd-attach-session.c */
-enum cmd_retval	 cmd_attach_session(struct cmd_q *, const char*, int, int);
+enum cmd_retval	 cmd_attach_session(struct cmd_q *, const char *, int, int,
+		     const char *);
 
 /* cmd-list.c */
 struct cmd_list	*cmd_list_parse(int, char **, const char *, u_int, char **);
@@ -1869,7 +1846,6 @@ void		 cmdq_run(struct cmd_q *, struct cmd_list *);
 void		 cmdq_append(struct cmd_q *, struct cmd_list *);
 int		 cmdq_continue(struct cmd_q *);
 void		 cmdq_flush(struct cmd_q *);
-const char     	*cmdq_default_path(struct cmd_q *, const char *);
 
 /* cmd-string.c */
 int	cmd_string_parse(const char *, struct cmd_list **, const char *,
@@ -2141,9 +2117,9 @@ void		 winlink_stack_remove(struct winlink_stack *, struct winlink *);
 int		 window_index(struct window *, u_int *);
 struct window	*window_find_by_id(u_int);
 struct window	*window_create1(u_int, u_int);
-struct window	*window_create(const char *, const char *, const char *,
-		     const char *, struct environ *, struct termios *,
-		     u_int, u_int, u_int, char **);
+struct window	*window_create(const char *, const char *, const char *, int,
+		     struct environ *, struct termios *, u_int, u_int, u_int,
+		     char **);
 void		 window_destroy(struct window *);
 struct window_pane *window_get_active_at(struct window *, u_int, u_int);
 void		 window_set_active_at(struct window *, u_int, u_int);
@@ -2167,8 +2143,8 @@ struct window_pane *window_pane_create(struct window *, u_int, u_int, u_int);
 void		 window_pane_destroy(struct window_pane *);
 void		 window_pane_timer_start(struct window_pane *);
 int		 window_pane_spawn(struct window_pane *, const char *,
-		     const char *, const char *, struct environ *,
-		     struct termios *, char **);
+		     const char *, int, struct environ *, struct termios *,
+		     char **);
 void		 window_pane_resize(struct window_pane *, u_int, u_int);
 void		 window_pane_alternate_on(struct window_pane *,
 		     struct grid_cell *, int);
@@ -2304,7 +2280,7 @@ RB_PROTOTYPE(sessions, session, entry, session_cmp);
 int		 session_alive(struct session *);
 struct session	*session_find(const char *);
 struct session	*session_find_by_id(u_int);
-struct session	*session_create(const char *, const char *, const char *,
+struct session	*session_create(const char *, const char *, int,
 		     struct environ *, struct termios *, int, u_int, u_int,
 		     char **);
 void		 session_destroy(struct session *);
@@ -2312,8 +2288,8 @@ int		 session_check_name(const char *);
 void		 session_update_activity(struct session *);
 struct session	*session_next_session(struct session *);
 struct session	*session_previous_session(struct session *);
-struct winlink	*session_new(struct session *,
-		     const char *, const char *, const char *, int, char **);
+struct winlink	*session_new(struct session *, const char *, const char *, int,
+		     int, char **);
 struct winlink	*session_attach(
 		     struct session *, struct window *, int, char **);
 int		 session_detach(struct session *, struct winlink *);
diff --git a/window.c b/window.c
index 7912bd37..9f47f444 100644
--- a/window.c
+++ b/window.c
@@ -306,7 +306,7 @@ window_create1(u_int sx, u_int sy)
 
 struct window *
 window_create(const char *name, const char *cmd, const char *shell,
-    const char *cwd, struct environ *env, struct termios *tio,
+    int cwd, struct environ *env, struct termios *tio,
     u_int sx, u_int sy, u_int hlimit, char **cause)
 {
 	struct window		*w;
@@ -672,7 +672,7 @@ window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
 
 	wp->cmd = NULL;
 	wp->shell = NULL;
-	wp->cwd = NULL;
+	wp->cwd = -1;
 
 	wp->fd = -1;
 	wp->event = NULL;
@@ -727,7 +727,7 @@ window_pane_destroy(struct window_pane *wp)
 
 	RB_REMOVE(window_pane_tree, &all_window_panes, wp);
 
-	free(wp->cwd);
+	close(wp->cwd);
 	free(wp->shell);
 	free(wp->cmd);
 	free(wp);
@@ -735,7 +735,7 @@ window_pane_destroy(struct window_pane *wp)
 
 int
 window_pane_spawn(struct window_pane *wp, const char *cmd, const char *shell,
-    const char *cwd, struct environ *env, struct termios *tio, char **cause)
+    int cwd, struct environ *env, struct termios *tio, char **cause)
 {
 	struct winsize	 ws;
 	char		*argv0, paneid[16];
@@ -754,9 +754,9 @@ window_pane_spawn(struct window_pane *wp, const char *cmd, const char *shell,
 		free(wp->shell);
 		wp->shell = xstrdup(shell);
 	}
-	if (cwd != NULL) {
-		free(wp->cwd);
-		wp->cwd = xstrdup(cwd);
+	if (cwd != -1) {
+		close(wp->cwd);
+		wp->cwd = dup(cwd);
 	}
 
 	log_debug("spawn: %s -- %s", wp->shell, wp->cmd);
@@ -771,7 +771,7 @@ window_pane_spawn(struct window_pane *wp, const char *cmd, const char *shell,
 		xasprintf(cause, "%s: %s", cmd, strerror(errno));
 		return (-1);
 	case 0:
-		if (chdir(wp->cwd) != 0)
+		if (fchdir(wp->cwd) != 0)
 			chdir("/");
 
 		if (tcgetattr(STDIN_FILENO, &tio2) != 0)