Add pane_dead_status for exit status of dead panes.

format.c

@@ -17,6 +17,7 @@
  */
 
 #include <sys/types.h>
+#include <sys/wait.h>
 
 #include <ctype.h>
 #include <errno.h>
@@ -581,6 +582,7 @@ format_window_pane(struct format_tree *ft, struct window_pane *wp)
 	unsigned long long	 size;
 	u_int			 i, idx;
 	char			*cmd;
+	int			 status;
 
 	if (ft->w == NULL)
 		ft->w = wp->window;
@@ -604,9 +606,13 @@ format_window_pane(struct format_tree *ft, struct window_pane *wp)
 	format_add(ft, "pane_title", "%s", wp->base.title);
 	format_add(ft, "pane_id", "%%%u", wp->id);
 	format_add(ft, "pane_active", "%d", wp == wp->window->active);
-	format_add(ft, "pane_dead", "%d", wp->fd == -1);
 	format_add(ft, "pane_input_off", "%d", !!(wp->flags & PANE_INPUTOFF));
 
+	status = wp->status;
+	if (wp->fd == -1 && WIFEXITED(status))
+		format_add(ft, "pane_dead_status", "%d", WEXITSTATUS(status));
+	format_add(ft, "pane_dead", "%d", wp->fd == -1);
+
 	if (window_pane_visible(wp)) {
 		format_add(ft, "pane_left", "%u", wp->xoff);
 		format_add(ft, "pane_top", "%u", wp->yoff);

server.c

@@ -441,6 +441,7 @@ server_child_exited(pid_t pid, int status)
 			continue;
 		TAILQ_FOREACH(wp, &w->panes, entry) {
 			if (wp->pid == pid) {
+				wp->status = status;
 				server_destroy_pane(wp);
 				break;
 			}

tmux.1

@@ -3117,6 +3117,7 @@ The following variables are available, where appropriate:
 .It Li "pane_bottom" Ta "" Ta "Bottom of pane"
 .It Li "pane_current_command" Ta "" Ta "Current command if available"
 .It Li "pane_dead" Ta "" Ta "1 if pane is dead"
+.It Li "pane_dead_status" Ta "" Ta "Exit status of process in dead pane"
 .It Li "pane_height" Ta "" Ta "Height of pane"
 .It Li "pane_id" Ta "#D" Ta "Unique pane ID"
 .It Li "pane_in_mode" Ta "" Ta "If pane is in a mode"

tmux.h

@@ -890,6 +890,7 @@ struct window_pane {
 
 	pid_t		 pid;
 	char		 tty[TTY_NAME_MAX];
+	int		 status;
 
 	u_int		 changes;
 	struct event	 changes_timer;