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 ~

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.

1 files changed, 59 insertions, 9 deletions

diff --git a/cmd-attach-session.c b/cmd-attach-session.c
index 70fea988..8dcc5997 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')));
 }