text: /* $OpenBSD$ */
  
  /*
   * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
   *
   * Permission to use, copy, modify, and distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
   * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
   * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  #include <sys/types.h>
  #include <sys/ioctl.h>
  #include <sys/uio.h>
  
  #include <errno.h>
  #include <event.h>
  #include <fcntl.h>
  #include <stdlib.h>
  #include <string.h>
  #include <time.h>
  #include <unistd.h>
  
  #include "tmux.h"
  
  static void	server_client_free(int, short, void *);
  static void	server_client_check_pane_focus(struct window_pane *);
  static void	server_client_check_pane_resize(struct window_pane *);
  static void	server_client_check_pane_buffer(struct window_pane *);
  static void	server_client_check_window_resize(struct window *);
  static key_code	server_client_check_mouse(struct client *, struct key_event *);
  static void	server_client_repeat_timer(int, short, void *);
  static void	server_client_click_timer(int, short, void *);
  static void	server_client_check_exit(struct client *);
  static void	server_client_check_redraw(struct client *);
  static void	server_client_set_title(struct client *);
  static void	server_client_reset_state(struct client *);
  static int	server_client_assume_paste(struct session *);
  
  static void	server_client_dispatch(struct imsg *, void *);
  static void	server_client_dispatch_command(struct client *, struct imsg *);
  static void	server_client_dispatch_identify(struct client *, struct imsg *);
  static void	server_client_dispatch_shell(struct client *);
  static void	server_client_dispatch_write_ready(struct client *,
  		    struct imsg *);
  static void	server_client_dispatch_read_data(struct client *,
  		    struct imsg *);
  static void	server_client_dispatch_read_done(struct client *,
  		    struct imsg *);
  
  /* Compare client windows. */
  static int
  server_client_window_cmp(struct client_window *cw1,
      struct client_window *cw2)
  {
  	if (cw1->window < cw2->window)
  		return (-1);
  	if (cw1->window > cw2->window)
  		return (1);
  	return (0);
  }
  RB_GENERATE(client_windows, client_window, entry, server_client_window_cmp);
  
  /* Number of attached clients. */
  u_int
  server_client_how_many(void)
  {
  	struct client  	*c;
  	u_int		 n;
  
  	n = 0;
  	TAILQ_FOREACH(c, &clients, entry) {
  		if (c->session != NULL && (~c->flags & CLIENT_UNATTACHEDFLAGS))
  			n++;
  	}
  	return (n);
  }
  
  /* Overlay timer callback. */
  static void
  server_client_overlay_timer(__unused int fd, __unused short events, void *data)
  {
  	server_client_clear_overlay(data);
  }
  
  /* Set an overlay on client. */
  void
  server_client_set_overlay(struct client *c, u_int delay,
      overlay_check_cb checkcb, overlay_mode_cb modecb,
      overlay_draw_cb drawcb, overlay_key_cb keycb, overlay_free_cb freecb,
      void *data)
  {
  	struct timeval	tv;
  
  	if (c->overlay_draw != NULL)
  		server_client_clear_overlay(c);
  
  	tv.tv_sec = delay / 1000;
  	tv.tv_usec = (delay % 1000) * 1000L;
  
  	if (event_initialized(&c->overlay_timer))
  		evtimer_del(&c->overlay_timer);
  	evtimer_set(&c->overlay_timer, server_client_overlay_timer, c);
  	if (delay != 0)
  		evtimer_add(&c->overlay_timer, &tv);
  
  	c->overlay_check = checkcb;
  	c->overlay_mode = modecb;
  	c->overlay_draw = drawcb;
  	c->overlay_key = keycb;
  	c->overlay_free = freecb;
  	c->overlay_data = data;
  
  	c->tty.flags |= TTY_FREEZE;
  	if (c->overlay_mode == NULL)
  		c->tty.flags |= TTY_NOCURSOR;
  	server_redraw_client(c);
  }
  
  /* Clear overlay mode on client. */
  void
  server_client_clear_overlay(struct client *c)
  {
  	if (c->overlay_draw == NULL)
  		return;
  
  	if (event_initialized(&c->overlay_timer))
  		evtimer_del(&c->overlay_timer);
  
  	if (c->overlay_free != NULL)
  		c->overlay_free(c);
  
  	c->overlay_check = NULL;
  	c->overlay_mode = NULL;
  	c->overlay_draw = NULL;
  	c->overlay_key = NULL;
  	c->overlay_free = NULL;
  	c->overlay_data = NULL;
  
  	c->tty.flags &= ~(TTY_FREEZE|TTY_NOCURSOR);
  	server_redraw_client(c);
  }
  
  /* Check if this client is inside this server. */
  int
  server_client_check_nested(struct client *c)
  {
  	struct environ_entry	*envent;
  	struct window_pane	*wp;
  
  	envent = environ_find(c->environ, "TMUX");
  	if (envent == NULL || *envent->value == '\0')
  		return (0);
  
  	RB_FOREACH(wp, window_pane_tree, &all_window_panes) {
  		if (strcmp(wp->tty, c->ttyname) == 0)
  			return (1);
  	}
  	return (0);
  }
  
  /* Set client key table. */
  void
  server_client_set_key_table(struct client *c, const char *name)
  {
  	if (name == NULL)
  		name = server_client_get_key_table(c);
  
  	key_bindings_unref_table(c->keytable);
  	c->keytable = key_bindings_get_table(name, 1);
  	c->keytable->references++;
  }
  
  /* Get default key table. */
  const char *
  server_client_get_key_table(struct client *c)
  {
  	struct session	*s = c->session;
  	const char	*name;
  
  	if (s == NULL)
  		return ("root");
  
  	name = options_get_string(s->options, "key-table");
  	if (*name == '\0')
  		return ("root");
  	return (name);
  }
  
  /* Is this table the default key table? */
  static int
  server_client_is_default_key_table(struct client *c, struct key_table *table)
  {
  	return (strcmp(table->name, server_client_get_key_table(c)) == 0);
  }
  
  /* Create a new client. */
  struct client *
  server_client_create(int fd)
  {
  	struct client	*c;
  
  	setblocking(fd, 0);
  
  	c = xcalloc(1, sizeof *c);
  	c->references = 1;
  	c->peer = proc_add_peer(server_proc, fd, server_client_dispatch, c);
  
  	if (gettimeofday(&c->creation_time, NULL) != 0)
  		fatal("gettimeofday failed");
  	memcpy(&c->activity_time, &c->creation_time, sizeof c->activity_time);
  
  	c->environ = environ_create();
  
  	c->fd = -1;
  	c->out_fd = -1;
  
  	c->queue = cmdq_new();
  	RB_INIT(&c->windows);
  	RB_INIT(&c->files);
  
  	c->tty.sx = 80;
  	c->tty.sy = 24;
  
  	status_init(c);
  	c->flags |= CLIENT_FOCUSED;
  
  	c->keytable = key_bindings_get_table("root", 1);
  	c->keytable->references++;
  
  	evtimer_set(&c->repeat_timer, server_client_repeat_timer, c);
  	evtimer_set(&c->click_timer, server_client_click_timer, c);
  
  	TAILQ_INSERT_TAIL(&clients, c, entry);
  	log_debug("new client %p", c);
  	return (c);
  }
  
  /* Open client terminal if needed. */
  int
  server_client_open(struct client *c, char **cause)
  {
  	const char	*ttynam = _PATH_TTY;
  
  	if (c->flags & CLIENT_CONTROL)
  		return (0);
  
  	if (strcmp(c->ttyname, ttynam) == 0||
  	    ((isatty(STDIN_FILENO) &&
  	    (ttynam = ttyname(STDIN_FILENO)) != NULL &&
  	    strcmp(c->ttyname, ttynam) == 0) ||
  	    (isatty(STDOUT_FILENO) &&
  	    (ttynam = ttyname(STDOUT_FILENO)) != NULL &&
  	    strcmp(c->ttyname, ttynam) == 0) ||
  	    (isatty(STDERR_FILENO) &&
  	    (ttynam = ttyname(STDERR_FILENO)) != NULL &&
  	    strcmp(c->ttyname, ttynam) == 0))) {
  		xasprintf(cause, "can't use %s", c->ttyname);
  		return (-1);
  	}
  
  	if (!(c->flags & CLIENT_TERMINAL)) {
  		*cause = xstrdup("not a terminal");
  		return (-1);
  	}
  
  	if (tty_open(&c->tty, cause) != 0)
  		return (-1);
  
  	return (0);
  }
  
  /* Lost a client. */
  void
  server_client_lost(struct client *c)
  {
  	struct client_file	*cf, *cf1;
  	struct client_window	*cw, *cw1;
  
  	c->flags |= CLIENT_DEAD;
  
  	server_client_clear_overlay(c);
  	status_prompt_clear(c);
  	status_message_clear(c);
  
  	RB_FOREACH_SAFE(cf, client_files, &c->files, cf1) {
  		cf->error = EINTR;
  		file_fire_done(cf);
  	}
  	RB_FOREACH_SAFE(cw, client_windows, &c->windows, cw1) {
  		RB_REMOVE(client_windows, &c->windows, cw);
  		free(cw);
  	}
  
  	TAILQ_REMOVE(&clients, c, entry);
  	log_debug("lost client %p", c);
  
  	if (c->flags & CLIENT_CONTROL)
  		control_stop(c);
  	if (c->flags & CLIENT_TERMINAL)
  		tty_free(&c->tty);
  	free(c->ttyname);
  
  	free(c->term_name);
  	free(c->term_type);
  
  	status_free(c);
  
  	free(c->title);
  	free((void *)c->cwd);
  
  	evtimer_del(&c->repeat_timer);
  	evtimer_del(&c->click_timer);
  
  	key_bindings_unref_table(c->keytable);
  
  	free(c->message_string);
  	if (event_initialized(&c->message_timer))
  		evtimer_del(&c->message_timer);
  
  	free(c->prompt_saved);
  	free(c->prompt_string);
  	free(c->prompt_buffer);
  
  	format_lost_client(c);
  	environ_free(c->environ);
  
  	proc_remove_peer(c->peer);
  	c->peer = NULL;
  
  	if (c->out_fd != -1)
  		close(c->out_fd);
  	if (c->fd != -1) {
  		close(c->fd);
  		c->fd = -1;
  	}
  	server_client_unref(c);
  
  	server_add_accept(0); /* may be more file descriptors now */
  
  	recalculate_sizes();
  	server_check_unattached();
  	server_update_socket();
  }
  
  /* Remove reference from a client. */
  void
  server_client_unref(struct client *c)
  {
  	log_debug("unref client %p (%d references)", c, c->references);
  
  	c->references--;
  	if (c->references == 0)
  		event_once(-1, EV_TIMEOUT, server_client_free, c, NULL);
  }
  
  /* Free dead client. */
  static void
  server_client_free(__unused int fd, __unused short events, void *arg)
  {
  	struct client	*c = arg;
  
  	log_debug("free client %p (%d references)", c, c->references);
  
  	cmdq_free(c->queue);
  
  	if (c->references == 0) {
  		free((void *)c->name);
  		free(c);
  	}
  }
  
  /* Suspend a client. */
  void
  server_client_suspend(struct client *c)
  {
  	struct session	*s = c->session;
  
  	if (s == NULL || (c->flags & CLIENT_UNATTACHEDFLAGS))
  		return;
  
  	tty_stop_tty(&c->tty);
  	c->flags |= CLIENT_SUSPENDED;
  	proc_send(c->peer, MSG_SUSPEND, -1, NULL, 0);
  }
  
  /* Detach a client. */
  void
  server_client_detach(struct client *c, enum msgtype msgtype)
  {
  	struct session	*s = c->session;
  
  	if (s == NULL || (c->flags & CLIENT_UNATTACHEDFLAGS))
  		return;
  
  	c->flags |= CLIENT_EXIT;
  
  	c->exit_type = CLIENT_EXIT_DETACH;
  	c->exit_msgtype = msgtype;
  	c->exit_session = xstrdup(s->name);
  }
  
  /* Execute command to replace a client. */
  void
  server_client_exec(struct client *c, const char *cmd)
  {
  	struct session	*s = c->session;
  	char		*msg;
  	const char	*shell;
  	size_t		 cmdsize, shellsize;
  
  	if (*cmd == '\0')
  		return;
  	cmdsize = strlen(cmd) + 1;
  
  	if (s != NULL)
  		shell = options_get_string(s->options, "default-shell");
  	else
  		shell = options_get_string(global_s_options, "default-shell");
  	if (!checkshell(shell))
  		shell = _PATH_BSHELL;
  	shellsize = strlen(shell) + 1;
  
  	msg = xmalloc(cmdsize + shellsize);
  	memcpy(msg, cmd, cmdsize);
  	memcpy(msg + cmdsize, shell, shellsize);
  
  	proc_send(c->peer, MSG_EXEC, -1, msg, cmdsize + shellsize);
  	free(msg);
  }
  
  /* Check for mouse keys. */
  static key_code
  server_client_check_mouse(struct client *c, struct key_event *event)
  {
  	struct mouse_event	*m = &event->m;
  	struct session		*s = c->session;
  	struct winlink		*wl;
  	struct window_pane	*wp;
  	u_int			 x, y, b, sx, sy, px, py;
  	int			 ignore = 0;
  	key_code		 key;
  	struct timeval		 tv;
  	struct style_range	*sr;
  	enum { NOTYPE,
  	       MOVE,
  	       DOWN,
  	       UP,
  	       DRAG,
  	       WHEEL,
  	       SECOND,
  	       DOUBLE,
  	       TRIPLE } type = NOTYPE;
  	enum { NOWHERE,
  	       PANE,
  	       STATUS,
  	       STATUS_LEFT,
  	       STATUS_RIGHT,
  	       STATUS_DEFAULT,
  	       BORDER } where = NOWHERE;
  
  	log_debug("%s mouse %02x at %u,%u (last %u,%u) (%d)", c->name, m->b,
  	    m->x, m->y, m->lx, m->ly, c->tty.mouse_drag_flag);
  
  	/* What type of event is this? */
  	if (event->key == KEYC_DOUBLECLICK) {
  		type = DOUBLE;
  		x = m->x, y = m->y, b = m->b;
  		ignore = 1;
  		log_debug("double-click at %u,%u", x, y);
  	} else if ((m->sgr_type != ' ' &&
  	    MOUSE_DRAG(m->sgr_b) &&
  	    MOUSE_BUTTONS(m->sgr_b) == 3) ||
  	    (m->sgr_type == ' ' &&
  	    MOUSE_DRAG(m->b) &&
  	    MOUSE_BUTTONS(m->b) == 3 &&
  	    MOUSE_BUTTONS(m->lb) == 3)) {
  		type = MOVE;
  		x = m->x, y = m->y, b = 0;
  		log_debug("move at %u,%u", x, y);
  	} else if (MOUSE_DRAG(m->b)) {
  		type = DRAG;
  		if (c->tty.mouse_drag_flag) {
  			x = m->x, y = m->y, b = m->b;
  			if (x == m->lx && y == m->ly)
  				return (KEYC_UNKNOWN);
  			log_debug("drag update at %u,%u", x, y);
  		} else {
  			x = m->lx, y = m->ly, b = m->lb;
  			log_debug("drag start at %u,%u", x, y);
  		}
  	} else if (MOUSE_WHEEL(m->b)) {
  		type = WHEEL;
  		x = m->x, y = m->y, b = m->b;
  		log_debug("wheel at %u,%u", x, y);
  	} else if (MOUSE_RELEASE(m->b)) {
  		type = UP;
  		x = m->x, y = m->y, b = m->lb;
  		log_debug("up at %u,%u", x, y);
  	} else {
  		if (c->flags & CLIENT_DOUBLECLICK) {
  			evtimer_del(&c->click_timer);
  			c->flags &= ~CLIENT_DOUBLECLICK;
  			if (m->b == c->click_button) {
  				type = SECOND;
  				x = m->x, y = m->y, b = m->b;
  				log_debug("second-click at %u,%u", x, y);
  				c->flags |= CLIENT_TRIPLECLICK;
  			}
  		} else if (c->flags & CLIENT_TRIPLECLICK) {
  			evtimer_del(&c->click_timer);
  			c->flags &= ~CLIENT_TRIPLECLICK;
  			if (m->b == c->click_button) {
  				type = TRIPLE;
  				x = m->x, y = m->y, b = m->b;
  				log_debug("triple-click at %u,%u", x, y);
  				goto have_event;
  			}
  		} else {
  			type = DOWN;
  			x = m->x, y = m->y, b = m->b;
  			log_debug("down at %u,%u", x, y);
  			c->flags |= CLIENT_DOUBLECLICK;
  		}
  
  		if (KEYC_CLICK_TIMEOUT != 0) {
  			memcpy(&c->click_event, m, sizeof c->click_event);
  			c->click_button = m->b;
  
  			log_debug("click timer started");
  			tv.tv_sec = KEYC_CLICK_TIMEOUT / 1000;
  			tv.tv_usec = (KEYC_CLICK_TIMEOUT % 1000) * 1000L;
  			evtimer_del(&c->click_timer);
  			evtimer_add(&c->click_timer, &tv);
  		}
  	}
  
  have_event:
  	if (type == NOTYPE)
  		return (KEYC_UNKNOWN);
  
  	/* Save the session. */
  	m->s = s->id;
  	m->w = -1;
  	m->ignore = ignore;
  
  	/* Is this on the status line? */
  	m->statusat = status_at_line(c);
  	m->statuslines = status_line_size(c);
  	if (m->statusat != -1 &&
  	    y >= (u_int)m->statusat &&
  	    y < m->statusat + m->statuslines) {
  		sr = status_get_range(c, x, y - m->statusat);
  		if (sr == NULL) {
  			where = STATUS_DEFAULT;
  		} else {
  			switch (sr->type) {
  			case STYLE_RANGE_NONE:
  				return (KEYC_UNKNOWN);
  			case STYLE_RANGE_LEFT:
  				where = STATUS_LEFT;
  				break;
  			case STYLE_RANGE_RIGHT:
  				where = STATUS_RIGHT;
  				break;
  			case STYLE_RANGE_WINDOW:
  				wl = winlink_find_by_index(&s->windows,
  				    sr->argument);
  				if (wl == NULL)
  					return (KEYC_UNKNOWN);
  				m->w = wl->window->id;
  
  				where = STATUS;
  				break;
  			}
  		}
  	}
  
  	/* Not on status line. Adjust position and check for border or pane. */
  	if (where == NOWHERE) {
  		px = x;
  		if (m->statusat == 0 && y >= m->statuslines)
  			py = y - m->statuslines;
  		else if (m->statusat > 0 && y >= (u_int)m->statusat)
  			py = m->statusat - 1;
  		else
  			py = y;
  
  		tty_window_offset(&c->tty, &m->ox, &m->oy, &sx, &sy);
  		log_debug("mouse window @%u at %u,%u (%ux%u)",
  		    s->curw->window->id, m->ox, m->oy, sx, sy);
  		if (px > sx || py > sy)
  			return (KEYC_UNKNOWN);
  		px = px + m->ox;
  		py = py + m->oy;
  
  		/* Try the pane borders if not zoomed. */
  		if (~s->curw->window->flags & WINDOW_ZOOMED) {
  			TAILQ_FOREACH(wp, &s->curw->window->panes, entry) {
  				if ((wp->xoff + wp->sx == px &&
  				    wp->yoff <= 1 + py &&
  				    wp->yoff + wp->sy >= py) ||
  				    (wp->yoff + wp->sy == py &&
  				    wp->xoff <= 1 + px &&
  				    wp->xoff + wp->sx >= px))
  					break;
  			}
  			if (wp != NULL)
  				where = BORDER;
  		}
  
  		/* Otherwise try inside the pane. */
  		if (where == NOWHERE) {
  			wp = window_get_active_at(s->curw->window, px, py);
  			if (wp != NULL)
  				where = PANE;
  			else
  				return (KEYC_UNKNOWN);
  		}
  		if (where == PANE)
  			log_debug("mouse %u,%u on pane %%%u", x, y, wp->id);
  		else if (where == BORDER)
  			log_debug("mouse on pane %%%u border", wp->id);
  		m->wp = wp->id;
  		m->w = wp->window->id;
  	} else
  		m->wp = -1;
  
  	/* Stop dragging if needed. */
  	if (type != DRAG && type != WHEEL && c->tty.mouse_drag_flag) {
  		if (c->tty.mouse_drag_release != NULL)
  			c->tty.mouse_drag_release(c, m);
  
  		c->tty.mouse_drag_update = NULL;
  		c->tty.mouse_drag_release = NULL;
  
  		/*
  		 * End a mouse drag by passing a MouseDragEnd key corresponding
  		 * to the button that started the drag.
  		 */
  		switch (c->tty.mouse_drag_flag) {
  		case 1:
  			if (where == PANE)
  				key = KEYC_MOUSEDRAGEND1_PANE;
  			if (where == STATUS)
  				key = KEYC_MOUSEDRAGEND1_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_MOUSEDRAGEND1_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_MOUSEDRAGEND1_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_MOUSEDRAGEND1_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_MOUSEDRAGEND1_BORDER;
  			break;
  		case 2:
  			if (where == PANE)
  				key = KEYC_MOUSEDRAGEND2_PANE;
  			if (where == STATUS)
  				key = KEYC_MOUSEDRAGEND2_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_MOUSEDRAGEND2_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_MOUSEDRAGEND2_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_MOUSEDRAGEND2_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_MOUSEDRAGEND2_BORDER;
  			break;
  		case 3:
  			if (where == PANE)
  				key = KEYC_MOUSEDRAGEND3_PANE;
  			if (where == STATUS)
  				key = KEYC_MOUSEDRAGEND3_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_MOUSEDRAGEND3_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_MOUSEDRAGEND3_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_MOUSEDRAGEND3_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_MOUSEDRAGEND3_BORDER;
  			break;
  		default:
  			key = KEYC_MOUSE;
  			break;
  		}
  		c->tty.mouse_drag_flag = 0;
  		goto out;
  	}
  
  	/* Convert to a key binding. */
  	key = KEYC_UNKNOWN;
  	switch (type) {
  	case NOTYPE:
  		break;
  	case MOVE:
  		if (where == PANE)
  			key = KEYC_MOUSEMOVE_PANE;
  		if (where == STATUS)
  			key = KEYC_MOUSEMOVE_STATUS;
  		if (where == STATUS_LEFT)
  			key = KEYC_MOUSEMOVE_STATUS_LEFT;
  		if (where == STATUS_RIGHT)
  			key = KEYC_MOUSEMOVE_STATUS_RIGHT;
  		if (where == STATUS_DEFAULT)
  			key = KEYC_MOUSEMOVE_STATUS_DEFAULT;
  		if (where == BORDER)
  			key = KEYC_MOUSEMOVE_BORDER;
  		break;
  	case DRAG:
  		if (c->tty.mouse_drag_update != NULL)
  			key = KEYC_DRAGGING;
  		else {
  			switch (MOUSE_BUTTONS(b)) {
  			case 0:
  				if (where == PANE)
  					key = KEYC_MOUSEDRAG1_PANE;
  				if (where == STATUS)
  					key = KEYC_MOUSEDRAG1_STATUS;
  				if (where == STATUS_LEFT)
  					key = KEYC_MOUSEDRAG1_STATUS_LEFT;
  				if (where == STATUS_RIGHT)
  					key = KEYC_MOUSEDRAG1_STATUS_RIGHT;
  				if (where == STATUS_DEFAULT)
  					key = KEYC_MOUSEDRAG1_STATUS_DEFAULT;
  				if (where == BORDER)
  					key = KEYC_MOUSEDRAG1_BORDER;
  				break;
  			case 1:
  				if (where == PANE)
  					key = KEYC_MOUSEDRAG2_PANE;
  				if (where == STATUS)
  					key = KEYC_MOUSEDRAG2_STATUS;
  				if (where == STATUS_LEFT)
  					key = KEYC_MOUSEDRAG2_STATUS_LEFT;
  				if (where == STATUS_RIGHT)
  					key = KEYC_MOUSEDRAG2_STATUS_RIGHT;
  				if (where == STATUS_DEFAULT)
  					key = KEYC_MOUSEDRAG2_STATUS_DEFAULT;
  				if (where == BORDER)
  					key = KEYC_MOUSEDRAG2_BORDER;
  				break;
  			case 2:
  				if (where == PANE)
  					key = KEYC_MOUSEDRAG3_PANE;
  				if (where == STATUS)
  					key = KEYC_MOUSEDRAG3_STATUS;
  				if (where == STATUS_LEFT)
  					key = KEYC_MOUSEDRAG3_STATUS_LEFT;
  				if (where == STATUS_RIGHT)
  					key = KEYC_MOUSEDRAG3_STATUS_RIGHT;
  				if (where == STATUS_DEFAULT)
  					key = KEYC_MOUSEDRAG3_STATUS_DEFAULT;
  				if (where == BORDER)
  					key = KEYC_MOUSEDRAG3_BORDER;
  				break;
  			}
  		}
  
  		/*
  		 * Begin a drag by setting the flag to a non-zero value that
  		 * corresponds to the mouse button in use.
  		 */
  		c->tty.mouse_drag_flag = MOUSE_BUTTONS(b) + 1;
  		break;
  	case WHEEL:
  		if (MOUSE_BUTTONS(b) == MOUSE_WHEEL_UP) {
  			if (where == PANE)
  				key = KEYC_WHEELUP_PANE;
  			if (where == STATUS)
  				key = KEYC_WHEELUP_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_WHEELUP_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_WHEELUP_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_WHEELUP_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_WHEELUP_BORDER;
  		} else {
  			if (where == PANE)
  				key = KEYC_WHEELDOWN_PANE;
  			if (where == STATUS)
  				key = KEYC_WHEELDOWN_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_WHEELDOWN_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_WHEELDOWN_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_WHEELDOWN_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_WHEELDOWN_BORDER;
  		}
  		break;
  	case UP:
  		switch (MOUSE_BUTTONS(b)) {
  		case 0:
  			if (where == PANE)
  				key = KEYC_MOUSEUP1_PANE;
  			if (where == STATUS)
  				key = KEYC_MOUSEUP1_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_MOUSEUP1_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_MOUSEUP1_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_MOUSEUP1_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_MOUSEUP1_BORDER;
  			break;
  		case 1:
  			if (where == PANE)
  				key = KEYC_MOUSEUP2_PANE;
  			if (where == STATUS)
  				key = KEYC_MOUSEUP2_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_MOUSEUP2_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_MOUSEUP2_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_MOUSEUP2_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_MOUSEUP2_BORDER;
  			break;
  		case 2:
  			if (where == PANE)
  				key = KEYC_MOUSEUP3_PANE;
  			if (where == STATUS)
  				key = KEYC_MOUSEUP3_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_MOUSEUP3_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_MOUSEUP3_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_MOUSEUP3_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_MOUSEUP3_BORDER;
  			break;
  		}
  		break;
  	case DOWN:
  		switch (MOUSE_BUTTONS(b)) {
  		case 0:
  			if (where == PANE)
  				key = KEYC_MOUSEDOWN1_PANE;
  			if (where == STATUS)
  				key = KEYC_MOUSEDOWN1_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_MOUSEDOWN1_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_MOUSEDOWN1_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_MOUSEDOWN1_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_MOUSEDOWN1_BORDER;
  			break;
  		case 1:
  			if (where == PANE)
  				key = KEYC_MOUSEDOWN2_PANE;
  			if (where == STATUS)
  				key = KEYC_MOUSEDOWN2_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_MOUSEDOWN2_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_MOUSEDOWN2_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_MOUSEDOWN2_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_MOUSEDOWN2_BORDER;
  			break;
  		case 2:
  			if (where == PANE)
  				key = KEYC_MOUSEDOWN3_PANE;
  			if (where == STATUS)
  				key = KEYC_MOUSEDOWN3_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_MOUSEDOWN3_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_MOUSEDOWN3_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_MOUSEDOWN3_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_MOUSEDOWN3_BORDER;
  			break;
  		}
  		break;
  	case SECOND:
  		switch (MOUSE_BUTTONS(b)) {
  		case 0:
  			if (where == PANE)
  				key = KEYC_SECONDCLICK1_PANE;
  			if (where == STATUS)
  				key = KEYC_SECONDCLICK1_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_SECONDCLICK1_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_SECONDCLICK1_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_SECONDCLICK1_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_SECONDCLICK1_BORDER;
  			break;
  		case 1:
  			if (where == PANE)
  				key = KEYC_SECONDCLICK2_PANE;
  			if (where == STATUS)
  				key = KEYC_SECONDCLICK2_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_SECONDCLICK2_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_SECONDCLICK2_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_SECONDCLICK2_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_SECONDCLICK2_BORDER;
  			break;
  		case 2:
  			if (where == PANE)
  				key = KEYC_SECONDCLICK3_PANE;
  			if (where == STATUS)
  				key = KEYC_SECONDCLICK3_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_SECONDCLICK3_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_SECONDCLICK3_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_SECONDCLICK3_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_SECONDCLICK3_BORDER;
  			break;
  		}
  		break;
  	case DOUBLE:
  		switch (MOUSE_BUTTONS(b)) {
  		case 0:
  			if (where == PANE)
  				key = KEYC_DOUBLECLICK1_PANE;
  			if (where == STATUS)
  				key = KEYC_DOUBLECLICK1_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_DOUBLECLICK1_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_DOUBLECLICK1_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_DOUBLECLICK1_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_DOUBLECLICK1_BORDER;
  			break;
  		case 1:
  			if (where == PANE)
  				key = KEYC_DOUBLECLICK2_PANE;
  			if (where == STATUS)
  				key = KEYC_DOUBLECLICK2_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_DOUBLECLICK2_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_DOUBLECLICK2_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_DOUBLECLICK2_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_DOUBLECLICK2_BORDER;
  			break;
  		case 2:
  			if (where == PANE)
  				key = KEYC_DOUBLECLICK3_PANE;
  			if (where == STATUS)
  				key = KEYC_DOUBLECLICK3_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_DOUBLECLICK3_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_DOUBLECLICK3_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_DOUBLECLICK3_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_DOUBLECLICK3_BORDER;
  			break;
  		}
  		break;
  	case TRIPLE:
  		switch (MOUSE_BUTTONS(b)) {
  		case 0:
  			if (where == PANE)
  				key = KEYC_TRIPLECLICK1_PANE;
  			if (where == STATUS)
  				key = KEYC_TRIPLECLICK1_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_TRIPLECLICK1_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_TRIPLECLICK1_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_TRIPLECLICK1_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_TRIPLECLICK1_BORDER;
  			break;
  		case 1:
  			if (where == PANE)
  				key = KEYC_TRIPLECLICK2_PANE;
  			if (where == STATUS)
  				key = KEYC_TRIPLECLICK2_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_TRIPLECLICK2_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_TRIPLECLICK2_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_TRIPLECLICK2_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_TRIPLECLICK2_BORDER;
  			break;
  		case 2:
  			if (where == PANE)
  				key = KEYC_TRIPLECLICK3_PANE;
  			if (where == STATUS)
  				key = KEYC_TRIPLECLICK3_STATUS;
  			if (where == STATUS_LEFT)
  				key = KEYC_TRIPLECLICK3_STATUS_LEFT;
  			if (where == STATUS_RIGHT)
  				key = KEYC_TRIPLECLICK3_STATUS_RIGHT;
  			if (where == STATUS_DEFAULT)
  				key = KEYC_TRIPLECLICK3_STATUS_DEFAULT;
  			if (where == BORDER)
  				key = KEYC_TRIPLECLICK3_BORDER;
  			break;
  		}
  		break;
  	}
  	if (key == KEYC_UNKNOWN)
  		return (KEYC_UNKNOWN);
  
  out:
  	/* Apply modifiers if any. */
  	if (b & MOUSE_MASK_META)
  		key |= KEYC_META;
  	if (b & MOUSE_MASK_CTRL)
  		key |= KEYC_CTRL;
  	if (b & MOUSE_MASK_SHIFT)
  		key |= KEYC_SHIFT;
  
  	if (log_get_level() != 0)
  		log_debug("mouse key is %s", key_string_lookup_key (key, 1));
  	return (key);
  }
  
  /* Is this fast enough to probably be a paste? */
  static int
  server_client_assume_paste(struct session *s)
  {
  	struct timeval	tv;
  	int		t;
  
  	if ((t = options_get_number(s->options, "assume-paste-time")) == 0)
  		return (0);
  
  	timersub(&s->activity_time, &s->last_activity_time, &tv);
  	if (tv.tv_sec == 0 && tv.tv_usec < t * 1000) {
  		log_debug("session %s pasting (flag %d)", s->name,
  		    !!(s->flags & SESSION_PASTING));
  		if (s->flags & SESSION_PASTING)
  			return (1);
  		s->flags |= SESSION_PASTING;
  		return (0);
  	}
  	log_debug("session %s not pasting", s->name);
  	s->flags &= ~SESSION_PASTING;
  	return (0);
  }
  
  /* Has the latest client changed? */
  static void
  server_client_update_latest(struct client *c)
  {
  	struct window	*w;
  
  	if (c->session == NULL)
  		return;
  	w = c->session->curw->window;
  
  	if (w->latest == c)
  		return;
  	w->latest = c;
  
  	if (options_get_number(w->options, "window-size") == WINDOW_SIZE_LATEST)
  		recalculate_size(w, 0);
  }
  
  /*
   * Handle data key input from client. This owns and can modify the key event it
   * is given and is responsible for freeing it.
   */
  static enum cmd_retval
  server_client_key_callback(struct cmdq_item *item, void *data)
  {
  	struct client			*c = cmdq_get_client(item);
  	struct key_event		*event = data;
  	key_code			 key = event->key;
  	struct mouse_event		*m = &event->m;
  	struct session			*s = c->session;
  	struct winlink			*wl;
  	struct window_pane		*wp;
  	struct window_mode_entry	*wme;
  	struct timeval			 tv;
  	struct key_table		*table, *first;
  	struct key_binding		*bd;
  	int				 xtimeout, flags;
  	struct cmd_find_state		 fs;
  	key_code			 key0;
  
  	/* Check the client is good to accept input. */
  	if (s == NULL || (c->flags & CLIENT_UNATTACHEDFLAGS))
  		goto out;
  	wl = s->curw;
  
  	/* Update the activity timer. */
  	if (gettimeofday(&c->activity_time, NULL) != 0)
  		fatal("gettimeofday failed");
  	session_update_activity(s, &c->activity_time);
  
  	/* Check for mouse keys. */
  	m->valid = 0;
  	if (key == KEYC_MOUSE || key == KEYC_DOUBLECLICK) {
  		if (c->flags & CLIENT_READONLY)
  			goto out;
  		key = server_client_check_mouse(c, event);
  		if (key == KEYC_UNKNOWN)
  			goto out;
  
  		m->valid = 1;
  		m->key = key;
  
  		/*
  		 * Mouse drag is in progress, so fire the callback (now that
  		 * the mouse event is valid).
  		 */
  		if ((key & KEYC_MASK_KEY) == KEYC_DRAGGING) {
  			c->tty.mouse_drag_update(c, m);
  			goto out;
  		}
  		event->key = key;
  	}
  
  	/* Find affected pane. */
  	if (!KEYC_IS_MOUSE(key) || cmd_find_from_mouse(&fs, m, 0) != 0)
  		cmd_find_from_client(&fs, c, 0);
  	wp = fs.wp;
  
  	/* Forward mouse keys if disabled. */
  	if (KEYC_IS_MOUSE(key) && !options_get_number(s->options, "mouse"))
  		goto forward_key;
  
  	/* Treat everything as a regular key when pasting is detected. */
  	if (!KEYC_IS_MOUSE(key) && server_client_assume_paste(s))
  		goto forward_key;
  
  	/*
  	 * Work out the current key table. If the pane is in a mode, use
  	 * the mode table instead of the default key table.
  	 */
  	if (server_client_is_default_key_table(c, c->keytable) &&
  	    wp != NULL &&
  	    (wme = TAILQ_FIRST(&wp->modes)) != NULL &&
  	    wme->mode->key_table != NULL)
  		table = key_bindings_get_table(wme->mode->key_table(wme), 1);
  	else
  		table = c->keytable;
  	first = table;
  
  table_changed:
  	/*
  	 * The prefix always takes precedence and forces a switch to the prefix
  	 * table, unless we are already there.
  	 */
  	key0 = (key & (KEYC_MASK_KEY|KEYC_MASK_MODIFIERS));
  	if ((key0 == (key_code)options_get_number(s->options, "prefix") ||
  	    key0 == (key_code)options_get_number(s->options, "prefix2")) &&
  	    strcmp(table->name, "prefix") != 0) {
  		server_client_set_key_table(c, "prefix");
  		server_status_client(c);
  		goto out;
  	}
  	flags = c->flags;
  
  try_again:
  	/* Log key table. */
  	if (wp == NULL)
  		log_debug("key table %s (no pane)", table->name);
  	else
  		log_debug("key table %s (pane %%%u)", table->name, wp->id);
  	if (c->flags & CLIENT_REPEAT)
  		log_debug("currently repeating");
  
  	/* Try to see if there is a key binding in the current table. */
  	bd = key_bindings_get(table, key0);
  	if (bd != NULL) {
  		/*
  		 * Key was matched in this table. If currently repeating but a
  		 * non-repeating binding was found, stop repeating and try
  		 * again in the root table.
  		 */
  		if ((c->flags & CLIENT_REPEAT) &&
  		    (~bd->flags & KEY_BINDING_REPEAT)) {
  			log_debug("found in key table %s (not repeating)",
  			    table->name);
  			server_client_set_key_table(c, NULL);
  			first = table = c->keytable;
  			c->flags &= ~CLIENT_REPEAT;
  			server_status_client(c);
  			goto table_changed;
  		}
  		log_debug("found in key table %s", table->name);
  
  		/*
  		 * Take a reference to this table to make sure the key binding
  		 * doesn't disappear.
  		 */
  		table->references++;
  
  		/*
  		 * If this is a repeating key, start the timer. Otherwise reset
  		 * the client back to the root table.
  		 */
  		xtimeout = options_get_number(s->options, "repeat-time");
  		if (xtimeout != 0 && (bd->flags & KEY_BINDING_REPEAT)) {
  			c->flags |= CLIENT_REPEAT;
  
  			tv.tv_sec = xtimeout / 1000;
  			tv.tv_usec = (xtimeout % 1000) * 1000L;
  			evtimer_del(&c->repeat_timer);
  			evtimer_add(&c->repeat_timer, &tv);
  		} else {
  			c->flags &= ~CLIENT_REPEAT;
  			server_client_set_key_table(c, NULL);
  		}
  		server_status_client(c);
  
  		/* Execute the key binding. */
  		key_bindings_dispatch(bd, item, c, event, &fs);
  		key_bindings_unref_table(table);
  		goto out;
  	}
  
  	/*
  	 * No match, try the ANY key.
  	 */
  	if (key0 != KEYC_ANY) {
  		key0 = KEYC_ANY;
  		goto try_again;
  	}
  
  	/*
  	 * No match in this table. If not in the root table or if repeating,
  	 * switch the client back to the root table and try again.
  	 */
  	log_debug("not found in key table %s", table->name);
  	if (!server_client_is_default_key_table(c, table) ||
  	    (c->flags & CLIENT_REPEAT)) {
  		log_debug("trying in root table");
  		server_client_set_key_table(c, NULL);
  		table = c->keytable;
  		if (c->flags & CLIENT_REPEAT)
  			first = table;
  		c->flags &= ~CLIENT_REPEAT;
  		server_status_client(c);
  		goto table_changed;
  	}
  
  	/*
  	 * No match in the root table either. If this wasn't the first table
  	 * tried, don't pass the key to the pane.
  	 */
  	if (first != table && (~flags & CLIENT_REPEAT)) {
  		server_client_set_key_table(c, NULL);
  		server_status_client(c);
  		goto out;
  	}
  
  forward_key:
  	if (c->flags & CLIENT_READONLY)
  		goto out;
  	if (wp != NULL)
  		window_pane_key(wp, c, s, wl, key, m);
  
  out:
  	if (s != NULL && key != KEYC_FOCUS_OUT)
  		server_client_update_latest(c);
  	free(event);
  	return (CMD_RETURN_NORMAL);
  }
  
  /* Handle a key event. */
  int
  server_client_handle_key(struct client *c, struct key_event *event)
  {
  	struct session		*s = c->session;
  	struct cmdq_item	*item;
  
  	/* Check the client is good to accept input. */
  	if (s == NULL || (c->flags & CLIENT_UNATTACHEDFLAGS))
  		return (0);
  
  	/*
  	 * Key presses in overlay mode and the command prompt are a special
  	 * case. The queue might be blocked so they need to be processed
  	 * immediately rather than queued.
  	 */
  	if (~c->flags & CLIENT_READONLY) {
  		status_message_clear(c);
  		if (c->overlay_key != NULL) {
  			switch (c->overlay_key(c, event)) {
  			case 0:
  				return (0);
  			case 1:
  				server_client_clear_overlay(c);
  				return (0);
  			}
  		}
  		server_client_clear_overlay(c);
  		if (c->prompt_string != NULL) {
  			if (status_prompt_key(c, event->key) == 0)
  				return (0);
  		}
  	}
  
  	/*
  	 * Add the key to the queue so it happens after any commands queued by
  	 * previous keys.
  	 */
  	item = cmdq_get_callback(server_client_key_callback, event);
  	cmdq_append(c, item);
  	return (1);
  }
  
  /* Client functions that need to happen every loop. */
  void
  server_client_loop(void)
  {
  	struct client		*c;
  	struct window		*w;
  	struct window_pane	*wp;
  	int			 focus;
  
  	/* Check for window resize. This is done before redrawing. */
  	RB_FOREACH(w, windows, &windows)
  		server_client_check_window_resize(w);
  
  	/* Check clients. */
  	TAILQ_FOREACH(c, &clients, entry) {
  		server_client_check_exit(c);
  		if (c->session != NULL) {
  			server_client_check_redraw(c);
  			server_client_reset_state(c);
  		}
  	}
  
  	/*
  	 * Any windows will have been redrawn as part of clients, so clear
  	 * their flags now. Also check pane focus and resize.
  	 */
  	focus = options_get_number(global_options, "focus-events");
  	RB_FOREACH(w, windows, &windows) {
  		TAILQ_FOREACH(wp, &w->panes, entry) {
  			if (wp->fd != -1) {
  				if (focus)
  					server_client_check_pane_focus(wp);
  				server_client_check_pane_resize(wp);
  				server_client_check_pane_buffer(wp);
  			}
  			wp->flags &= ~PANE_REDRAW;
  		}
  		check_window_name(w);
  	}
  }
  
  /* Check if window needs to be resized. */
  static void
  server_client_check_window_resize(struct window *w)
  {
  	struct winlink	*wl;
  
  	if (~w->flags & WINDOW_RESIZE)
  		return;
  
  	TAILQ_FOREACH(wl, &w->winlinks, wentry) {
  		if (wl->session->attached != 0 && wl->session->curw == wl)
  			break;
  	}
  	if (wl == NULL)
  		return;
  
  	log_debug("%s: resizing window @%u", __func__, w->id);
  	resize_window(w, w->new_sx, w->new_sy, w->new_xpixel, w->new_ypixel);
  }
  
  /* Resize timer event. */
  static void
  server_client_resize_timer(__unused int fd, __unused short events, void *data)
  {
  	struct window_pane	*wp = data;
  
  	log_debug("%s: %%%u resize timer expired", __func__, wp->id);
  	evtimer_del(&wp->resize_timer);
  }
  
  /* Start the resize timer. */
  static void
  server_client_start_resize_timer(struct window_pane *wp)
  {
  	struct timeval	tv = { .tv_usec = 250000 };
  
  	log_debug("%s: %%%u resize timer started", __func__, wp->id);
  	evtimer_add(&wp->resize_timer, &tv);
  }
  
  /* Force timer event. */
  static void
  server_client_force_timer(__unused int fd, __unused short events, void *data)
  {
  	struct window_pane	*wp = data;
  
  	log_debug("%s: %%%u force timer expired", __func__, wp->id);
  	evtimer_del(&wp->force_timer);
  	wp->flags |= PANE_RESIZENOW;
  }
  
  /* Start the force timer. */
  static void
  server_client_start_force_timer(struct window_pane *wp)
  {
  	struct timeval	tv = { .tv_usec = 10000 };
  
  	log_debug("%s: %%%u force timer started", __func__, wp->id);
  	evtimer_add(&wp->force_timer, &tv);
  }
  
  /* Check if pane should be resized. */
  static void
  server_client_check_pane_resize(struct window_pane *wp)
  {
  	if (!event_initialized(&wp->resize_timer))
  		evtimer_set(&wp->resize_timer, server_client_resize_timer, wp);
  	if (!event_initialized(&wp->force_timer))
  		evtimer_set(&wp->force_timer, server_client_force_timer, wp);
  
  	if (~wp->flags & PANE_RESIZE)
  		return;
  	log_debug("%s: %%%u needs to be resized", __func__, wp->id);
  
  	if (evtimer_pending(&wp->resize_timer, NULL)) {
  		log_debug("%s: %%%u resize timer is running", __func__, wp->id);
  		return;
  	}
  	server_client_start_resize_timer(wp);
  
  	if (~wp->flags & PANE_RESIZEFORCE) {
  		/*
  		 * The timer is not running and we don't need to force a
  		 * resize, so just resize immediately.
  		 */
  		log_debug("%s: resizing %%%u now", __func__, wp->id);
  		window_pane_send_resize(wp, 0);
  		wp->flags &= ~PANE_RESIZE;
  	} else {
  		/*
  		 * The timer is not running, but we need to force a resize. If
  		 * the force timer has expired, resize to the real size now.
  		 * Otherwise resize to the force size and start the timer.
  		 */
  		if (wp->flags & PANE_RESIZENOW) {
  			log_debug("%s: resizing %%%u after forced resize",
  			    __func__, wp->id);
  			window_pane_send_resize(wp, 0);
  			wp->flags &= ~(PANE_RESIZE|PANE_RESIZEFORCE|PANE_RESIZENOW);
  		} else if (!evtimer_pending(&wp->force_timer, NULL)) {
  			log_debug("%s: forcing resize of %%%u", __func__,
  			    wp->id);
  			window_pane_send_resize(wp, 1);
  			server_client_start_force_timer(wp);
  		}
  	}
  }
  
  /* Check pane buffer size. */
  static void
  server_client_check_pane_buffer(struct window_pane *wp)
  {
  	struct evbuffer			*evb = wp->event->input;
  	size_t				 minimum;
  	struct client			*c;
  	struct window_pane_offset	*wpo;
  	int				 off = 1, flag;
  	u_int				 attached_clients = 0;
  	size_t				 new_size;
  
  	/*
  	 * Work out the minimum used size. This is the most that can be removed
  	 * from the buffer.
  	 */
  	minimum = wp->offset.used;
  	if (wp->pipe_fd != -1 && wp->pipe_offset.used < minimum)
  		minimum = wp->pipe_offset.used;
  	TAILQ_FOREACH(c, &clients, entry) {
  		if (c->session == NULL)
  			continue;
  		attached_clients++;
  
  		if (~c->flags & CLIENT_CONTROL) {
  			off = 0;
  			continue;
  		}
  		wpo = control_pane_offset(c, wp, &flag);
  		if (wpo == NULL) {
  			off = 0;
  			continue;
  		}
  		if (!flag)
  			off = 0;
  
  		window_pane_get_new_data(wp, wpo, &new_size);
  		log_debug("%s: %s has %zu bytes used and %zu left for %%%u",
  		    __func__, c->name, wpo->used - wp->base_offset, new_size,
  		    wp->id);
  		if (wpo->used < minimum)
  			minimum = wpo->used;
  	}
  	if (attached_clients == 0)
  		off = 0;
  	minimum -= wp->base_offset;
  	if (minimum == 0)
  		goto out;
  
  	/* Drain the buffer. */
  	log_debug("%s: %%%u has %zu minimum (of %zu) bytes used", __func__,
  	    wp->id, minimum, EVBUFFER_LENGTH(evb));
  	evbuffer_drain(evb, minimum);
  
  	/*
  	 * Adjust the base offset. If it would roll over, all the offsets into
  	 * the buffer need to be adjusted.
  	 */
  	if (wp->base_offset > SIZE_MAX - minimum) {
  		log_debug("%s: %%%u base offset has wrapped", __func__, wp->id);
  		wp->offset.used -= wp->base_offset;
  		if (wp->pipe_fd != -1)
  			wp->pipe_offset.used -= wp->base_offset;
  		TAILQ_FOREACH(c, &clients, entry) {
  			if (c->session == NULL || (~c->flags & CLIENT_CONTROL))
  				continue;
  			wpo = control_pane_offset(c, wp, &flag);
  			if (wpo != NULL && !flag)
  				wpo->used -= wp->base_offset;
  		}
  		wp->base_offset = minimum;
  	} else
  		wp->base_offset += minimum;
  
  out:
  	/*
  	 * If there is data remaining, and there are no clients able to consume
  	 * it, do not read any more. This is true when there are attached
  	 * clients, all of which are control clients which are not able to
  	 * accept any more data.
  	 */
  	log_debug("%s: pane %%%u is %s", __func__, wp->id, off ? "off" : "on");
  	if (off)
  		bufferevent_disable(wp->event, EV_READ);
  	else
  		bufferevent_enable(wp->event, EV_READ);
  }
  
  /* Check whether pane should be focused. */
  static void
  server_client_check_pane_focus(struct window_pane *wp)
  {
  	struct client	*c;
  	int		 push;
  
  	/* Do we need to push the focus state? */
  	push = wp->flags & PANE_FOCUSPUSH;
  	wp->flags &= ~PANE_FOCUSPUSH;
  
  	/* If we're not the active pane in our window, we're not focused. */
  	if (wp->window->active != wp)
  		goto not_focused;
  
  	/*
  	 * If our window is the current window in any focused clients with an
  	 * attached session, we're focused.
  	 */
  	TAILQ_FOREACH(c, &clients, entry) {
  		if (c->session == NULL || !(c->flags & CLIENT_FOCUSED))
  			continue;
  		if (c->session->attached == 0)
  			continue;
  
  		if (c->session->curw->window == wp->window)
  			goto focused;
  	}
  
  not_focused:
  	if (push || (wp->flags & PANE_FOCUSED)) {
  		if (wp->base.mode & MODE_FOCUSON)
  			bufferevent_write(wp->event, "\033[O", 3);
  		notify_pane("pane-focus-out", wp);
  	}
  	wp->flags &= ~PANE_FOCUSED;
  	return;
  
  focused:
  	if (push || !(wp->flags & PANE_FOCUSED)) {
  		if (wp->base.mode & MODE_FOCUSON)
  			bufferevent_write(wp->event, "\033[I", 3);
  		notify_pane("pane-focus-in", wp);
  		session_update_activity(c->session, NULL);
  	}
  	wp->flags |= PANE_FOCUSED;
  }
  
  /*
   * Update cursor position and mode settings. The scroll region and attributes
   * are cleared when idle (waiting for an event) as this is the most likely time
   * a user may interrupt tmux, for example with ~^Z in ssh(1). This is a
   * compromise between excessive resets and likelihood of an interrupt.
   *
   * tty_region/tty_reset/tty_update_mode already take care of not resetting
   * things that are already in their default state.
   */
  static void
  server_client_reset_state(struct client *c)
  {
  	struct tty		*tty = &c->tty;
  	struct window		*w = c->session->curw->window;
  	struct window_pane	*wp = server_client_get_pane(c), *loop;
  	struct screen		*s = NULL;
  	struct options		*oo = c->session->options;
  	int			 mode = 0, cursor, flags;
  	u_int			 cx = 0, cy = 0, ox, oy, sx, sy;
  
  	if (c->flags & (CLIENT_CONTROL|CLIENT_SUSPENDED))
  		return;
  
  	/* Disable the block flag. */
  	flags = (tty->flags & TTY_BLOCK);
  	tty->flags &= ~TTY_BLOCK;
  
  	/* Get mode from overlay if any, else from screen. */
  	if (c->overlay_draw != NULL) {
  		if (c->overlay_mode != NULL)
  			s = c->overlay_mode(c, &cx, &cy);
  	} else
  		s = wp->screen;
  	if (s != NULL)
  		mode = s->mode;
  	log_debug("%s: client %s mode %x", __func__, c->name, mode);
  
  	/* Reset region and margin. */
  	tty_region_off(tty);
  	tty_margin_off(tty);
  
  	/* Move cursor to pane cursor and offset. */
  	if (c->overlay_draw == NULL) {
  		cursor = 0;
  		tty_window_offset(tty, &ox, &oy, &sx, &sy);
  		if (wp->xoff + s->cx >= ox && wp->xoff + s->cx <= ox + sx &&
  		    wp->yoff + s->cy >= oy && wp->yoff + s->cy <= oy + sy) {
  			cursor = 1;
  
  			cx = wp->xoff + s->cx - ox;
  			cy = wp->yoff + s->cy - oy;
  
  			if (status_at_line(c) == 0)
  				cy += status_line_size(c);
  		}
  		if (!cursor)
  			mode &= ~MODE_CURSOR;
  	}
  	log_debug("%s: cursor to %u,%u", __func__, cx, cy);
  	tty_cursor(tty, cx, cy);
  
  	/*
  	 * Set mouse mode if requested. To support dragging, always use button
  	 * mode.
  	 */
  	if (options_get_number(oo, "mouse")) {
  		if (c->overlay_draw == NULL) {
  			mode &= ~ALL_MOUSE_MODES;
  			TAILQ_FOREACH(loop, &w->panes, entry) {
  				if (loop->screen->mode & MODE_MOUSE_ALL)
  					mode |= MODE_MOUSE_ALL;
  			}
  		}
  		if (~mode & MODE_MOUSE_ALL)
  			mode |= MODE_MOUSE_BUTTON;
  	}
  
  	/* Clear bracketed paste mode if at the prompt. */
  	if (c->overlay_draw == NULL && c->prompt_string != NULL)
  		mode &= ~MODE_BRACKETPASTE;
  
  	/* Set the terminal mode and reset attributes. */
  	tty_update_mode(tty, mode, s);
  	tty_reset(tty);
  
  	/* All writing must be done, send a sync end (if it was started). */
  	tty_sync_end(tty);
  	tty->flags |= flags;
  }
  
  /* Repeat time callback. */
  static void
  server_client_repeat_timer(__unused int fd, __unused short events, void *data)
  {
  	struct client	*c = data;
  
  	if (c->flags & CLIENT_REPEAT) {
  		server_client_set_key_table(c, NULL);
  		c->flags &= ~CLIENT_REPEAT;
  		server_status_client(c);
  	}
  }
  
  /* Double-click callback. */
  static void
  server_client_click_timer(__unused int fd, __unused short events, void *data)
  {
  	struct client		*c = data;
  	struct key_event	*event;
  
  	log_debug("click timer expired");
  
  	if (c->flags & CLIENT_TRIPLECLICK) {
  		/*
  		 * Waiting for a third click that hasn't happened, so this must
  		 * have been a double click.
  		 */
  		event = xmalloc(sizeof *event);
  		event->key = KEYC_DOUBLECLICK;
  		memcpy(&event->m, &c->click_event, sizeof event->m);
  		if (!server_client_handle_key(c, event))
  			free(event);
  	}
  	c->flags &= ~(CLIENT_DOUBLECLICK|CLIENT_TRIPLECLICK);
  }
  
  /* Check if client should be exited. */
  static void
  server_client_check_exit(struct client *c)
  {
  	struct client_file	*cf;
  	const char		*name = c->exit_session;
  	char			*data;
  	size_t			 size, msize;
  
  	if (c->flags & (CLIENT_DEAD|CLIENT_EXITED))
  		return;
  	if (~c->flags & CLIENT_EXIT)
  		return;
  
  	if (c->flags & CLIENT_CONTROL) {
  		control_discard(c);
  		if (!control_all_done(c))
  			return;
  	}
  	RB_FOREACH(cf, client_files, &c->files) {
  		if (EVBUFFER_LENGTH(cf->buffer) != 0)
  			return;
  	}
  
  	if (c->flags & CLIENT_ATTACHED)
  		notify_client("client-detached", c);
  	c->flags |= CLIENT_EXITED;
  
  	switch (c->exit_type) {
  	case CLIENT_EXIT_RETURN:
  		if (c->exit_message != NULL) {
  			msize = strlen(c->exit_message) + 1;
  			size = (sizeof c->retval) + msize;
  		} else
  			size = (sizeof c->retval);
  		data = xmalloc(size);
  		memcpy(data, &c->retval, sizeof c->retval);
  		if (c->exit_message != NULL)
  			memcpy(data + sizeof c->retval, c->exit_message, msize);
  		proc_send(c->peer, MSG_EXIT, -1, data, size);
  		free(data);
  		break;
  	case CLIENT_EXIT_SHUTDOWN:
  		proc_send(c->peer, MSG_SHUTDOWN, -1, NULL, 0);
  		break;
  	case CLIENT_EXIT_DETACH:
  		proc_send(c->peer, c->exit_msgtype, -1, name, strlen(name) + 1);
  		break;
  	}
  	free(c->exit_session);
  	free(c->exit_message);
  }
  
  /* Redraw timer callback. */
  static void
  server_client_redraw_timer(__unused int fd, __unused short events,
      __unused void *data)
  {
  	log_debug("redraw timer fired");
  }
  
  /* Check for client redraws. */
  static void
  server_client_check_redraw(struct client *c)
  {
  	struct session		*s = c->session;
  	struct tty		*tty = &c->tty;
  	struct window		*w = c->session->curw->window;
  	struct window_pane	*wp;
  	int			 needed, flags, mode = tty->mode, new_flags = 0;
  	int			 redraw;
  	u_int			 bit = 0;
  	struct timeval		 tv = { .tv_usec = 1000 };
  	static struct event	 ev;
  	size_t			 left;
  
  	if (c->flags & (CLIENT_CONTROL|CLIENT_SUSPENDED))
  		return;
  	if (c->flags & CLIENT_ALLREDRAWFLAGS) {
  		log_debug("%s: redraw%s%s%s%s%s", c->name,
  		    (c->flags & CLIENT_REDRAWWINDOW) ? " window" : "",
  		    (c->flags & CLIENT_REDRAWSTATUS) ? " status" : "",
  		    (c->flags & CLIENT_REDRAWBORDERS) ? " borders" : "",
  		    (c->flags & CLIENT_REDRAWOVERLAY) ? " overlay" : "",
  		    (c->flags & CLIENT_REDRAWPANES) ? " panes" : "");
  	}
  
  	/*
  	 * If there is outstanding data, defer the redraw until it has been
  	 * consumed. We can just add a timer to get out of the event loop and
  	 * end up back here.
  	 */
  	needed = 0;
  	if (c->flags & CLIENT_ALLREDRAWFLAGS)
  		needed = 1;
  	else {
  		TAILQ_FOREACH(wp, &w->panes, entry) {
  			if (wp->flags & PANE_REDRAW) {
  				needed = 1;
  				break;
  			}
  		}
  		if (needed)
  			new_flags |= CLIENT_REDRAWPANES;
  	}
  	if (needed && (left = EVBUFFER_LENGTH(tty->out)) != 0) {
  		log_debug("%s: redraw deferred (%zu left)", c->name, left);
  		if (!evtimer_initialized(&ev))
  			evtimer_set(&ev, server_client_redraw_timer, NULL);
  		if (!evtimer_pending(&ev, NULL)) {
  			log_debug("redraw timer started");
  			evtimer_add(&ev, &tv);
  		}
  
  		if (~c->flags & CLIENT_REDRAWWINDOW) {
  			TAILQ_FOREACH(wp, &w->panes, entry) {
  				if (wp->flags & PANE_REDRAW) {
  					log_debug("%s: pane %%%u needs redraw",
  					    c->name, wp->id);
  					c->redraw_panes |= (1 << bit);
  				}
  				if (++bit == 64) {
  					/*
  					 * If more that 64 panes, give up and
  					 * just redraw the window.
  					 */
  					new_flags &= CLIENT_REDRAWPANES;
  					new_flags |= CLIENT_REDRAWWINDOW;
  					break;
  				}
  			}
  			if (c->redraw_panes != 0)
  				c->flags |= CLIENT_REDRAWPANES;
  		}
  		c->flags |= new_flags;
  		return;
  	} else if (needed)
  		log_debug("%s: redraw needed", c->name);
  
  	flags = tty->flags & (TTY_BLOCK|TTY_FREEZE|TTY_NOCURSOR);
  	tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE))|TTY_NOCURSOR;
  
  	if (~c->flags & CLIENT_REDRAWWINDOW) {
  		/*
  		 * If not redrawing the entire window, check whether each pane
  		 * needs to be redrawn.
  		 */
  		TAILQ_FOREACH(wp, &w->panes, entry) {
  			redraw = 0;
  			if (wp->flags & PANE_REDRAW)
  				redraw = 1;
  			else if (c->flags & CLIENT_REDRAWPANES)
  				redraw = !!(c->redraw_panes & (1 << bit));
  			bit++;
  			if (!redraw)
  				continue;
  			log_debug("%s: redrawing pane %%%u", __func__, wp->id);
  			screen_redraw_pane(c, wp);
  		}
  		c->redraw_panes = 0;
  		c->flags &= ~CLIENT_REDRAWPANES;
  	}
  
  	if (c->flags & CLIENT_ALLREDRAWFLAGS) {
  		if (options_get_number(s->options, "set-titles"))
  			server_client_set_title(c);
  		screen_redraw_screen(c);
  	}
  
  	tty->flags = (tty->flags & ~TTY_NOCURSOR)|(flags & TTY_NOCURSOR);
  	tty_update_mode(tty, mode, NULL);
  	tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE|TTY_NOCURSOR))|flags;
  
  	c->flags &= ~(CLIENT_ALLREDRAWFLAGS|CLIENT_STATUSFORCE);
  
  	if (needed) {
  		/*
  		 * We would have deferred the redraw unless the output buffer
  		 * was empty, so we can record how many bytes the redraw
  		 * generated.
  		 */
  		c->redraw = EVBUFFER_LENGTH(tty->out);
  		log_debug("%s: redraw added %zu bytes", c->name, c->redraw);
  	}
  }
  
  /* Set client title. */
  static void
  server_client_set_title(struct client *c)
  {
  	struct session		*s = c->session;
  	const char		*template;
  	char			*title;
  	struct format_tree	*ft;
  
  	template = options_get_string(s->options, "set-titles-string");
  
  	ft = format_create(c, NULL, FORMAT_NONE, 0);
  	format_defaults(ft, c, NULL, NULL, NULL);
  
  	title = format_expand_time(ft, template);
  	if (c->title == NULL || strcmp(title, c->title) != 0) {
  		free(c->title);
  		c->title = xstrdup(title);
  		tty_set_title(&c->tty, c->title);
  	}
  	free(title);
  
  	format_free(ft);
  }
  
  /* Dispatch message from client. */
  static void
  server_client_dispatch(struct imsg *imsg, void *arg)
  {
  	struct client	*c = arg;
  	ssize_t		 datalen;
  	struct session	*s;
  
  	if (c->flags & CLIENT_DEAD)
  		return;
  
  	if (imsg == NULL) {
  		server_client_lost(c);
  		return;
  	}
  
  	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
  
  	switch (imsg->hdr.type) {
  	case MSG_IDENTIFY_FEATURES:
  	case MSG_IDENTIFY_FLAGS:
  	case MSG_IDENTIFY_LONGFLAGS:
  	case MSG_IDENTIFY_TERM:
  	case MSG_IDENTIFY_TTYNAME:
  	case MSG_IDENTIFY_CWD:
  	case MSG_IDENTIFY_STDIN:
  	case MSG_IDENTIFY_STDOUT:
  	case MSG_IDENTIFY_ENVIRON:
  	case MSG_IDENTIFY_CLIENTPID:
  	case MSG_IDENTIFY_DONE:
  		server_client_dispatch_identify(c, imsg);
  		break;
  	case MSG_COMMAND:
  		server_client_dispatch_command(c, imsg);
  		break;
  	case MSG_RESIZE:
  		if (datalen != 0)
  			fatalx("bad MSG_RESIZE size");
  
  		if (c->flags & CLIENT_CONTROL)
  			break;
  		server_client_update_latest(c);
  		server_client_clear_overlay(c);
  		tty_resize(&c->tty);
  		recalculate_sizes();
  		server_redraw_client(c);
  		if (c->session != NULL)
  			notify_client("client-resized", c);
  		break;
  	case MSG_EXITING:
  		if (datalen != 0)
  			fatalx("bad MSG_EXITING size");
  		c->session = NULL;
  		tty_close(&c->tty);
  		proc_send(c->peer, MSG_EXITED, -1, NULL, 0);
  		break;
  	case MSG_WAKEUP:
  	case MSG_UNLOCK:
  		if (datalen != 0)
  			fatalx("bad MSG_WAKEUP size");
  
  		if (!(c->flags & CLIENT_SUSPENDED))
  			break;
  		c->flags &= ~CLIENT_SUSPENDED;
  
  		if (c->fd == -1 || c->session == NULL) /* exited already */
  			break;
  		s = c->session;
  
  		if (gettimeofday(&c->activity_time, NULL) != 0)
  			fatal("gettimeofday failed");
  
  		tty_start_tty(&c->tty);
  		server_redraw_client(c);
  		recalculate_sizes();
  
  		if (s != NULL)
  			session_update_activity(s, &c->activity_time);
  		break;
  	case MSG_SHELL:
  		if (datalen != 0)
  			fatalx("bad MSG_SHELL size");
  
  		server_client_dispatch_shell(c);
  		break;
  	case MSG_WRITE_READY:
  		server_client_dispatch_write_ready(c, imsg);
  		break;
  	case MSG_READ:
  		server_client_dispatch_read_data(c, imsg);
  		break;
  	case MSG_READ_DONE:
  		server_client_dispatch_read_done(c, imsg);
  		break;
  	}
  }
  
  /* Callback when command is done. */
  static enum cmd_retval
  server_client_command_done(struct cmdq_item *item, __unused void *data)
  {
  	struct client	*c = cmdq_get_client(item);
  
  	if (~c->flags & CLIENT_ATTACHED)
  		c->flags |= CLIENT_EXIT;
  	else if (~c->flags & CLIENT_EXIT)
  		tty_send_requests(&c->tty);
  	return (CMD_RETURN_NORMAL);
  }
  
  /* Handle command message. */
  static void
  server_client_dispatch_command(struct client *c, struct imsg *imsg)
  {
  	struct msg_command	  data;
  	char			 *buf;
  	size_t			  len;
  	int			  argc;
  	char			**argv, *cause;
  	struct cmd_parse_result	 *pr;
  
  	if (c->flags & CLIENT_EXIT)
  		return;
  
  	if (imsg->hdr.len - IMSG_HEADER_SIZE < sizeof data)
  		fatalx("bad MSG_COMMAND size");
  	memcpy(&data, imsg->data, sizeof data);
  
  	buf = (char *)imsg->data + sizeof data;
  	len = imsg->hdr.len  - IMSG_HEADER_SIZE - sizeof data;
  	if (len > 0 && buf[len - 1] != '\0')
  		fatalx("bad MSG_COMMAND string");
  
  	argc = data.argc;
  	if (cmd_unpack_argv(buf, len, argc, &argv) != 0) {
  		cause = xstrdup("command too long");
  		goto error;
  	}
  
  	if (argc == 0) {
  		argc = 1;
  		argv = xcalloc(1, sizeof *argv);
  		*argv = xstrdup("new-session");
  	}
  
  	pr = cmd_parse_from_arguments(argc, argv, NULL);
  	switch (pr->status) {
  	case CMD_PARSE_EMPTY:
  		cause = xstrdup("empty command");
  		goto error;
  	case CMD_PARSE_ERROR:
  		cause = pr->error;
  		goto error;
  	case CMD_PARSE_SUCCESS:
  		break;
  	}
  	cmd_free_argv(argc, argv);
  
  	cmdq_append(c, cmdq_get_command(pr->cmdlist, NULL));
  	cmdq_append(c, cmdq_get_callback(server_client_command_done, NULL));
  
  	cmd_list_free(pr->cmdlist);
  	return;
  
  error:
  	cmd_free_argv(argc, argv);
  
  	cmdq_append(c, cmdq_get_error(cause));
  	free(cause);
  
  	c->flags |= CLIENT_EXIT;
  }
  
  /* Handle identify message. */
  static void
  server_client_dispatch_identify(struct client *c, struct imsg *imsg)
  {
  	const char	*data, *home;
  	size_t		 datalen;
  	int		 flags, feat;
  	uint64_t	 longflags;
  	char		*name;
  
  	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_FEATURES:
  		if (datalen != sizeof feat)
  			fatalx("bad MSG_IDENTIFY_FEATURES size");
  		memcpy(&feat, data, sizeof feat);
  		c->term_features |= feat;
  		log_debug("client %p IDENTIFY_FEATURES %s", c,
  		    tty_get_features(feat));
  		break;
  	case MSG_IDENTIFY_FLAGS:
  		if (datalen != sizeof flags)
  			fatalx("bad MSG_IDENTIFY_FLAGS size");
  		memcpy(&flags, data, sizeof flags);
  		c->flags |= flags;
  		log_debug("client %p IDENTIFY_FLAGS %#x", c, flags);
  		break;
  	case MSG_IDENTIFY_LONGFLAGS:
  		if (datalen != sizeof longflags)
  			fatalx("bad MSG_IDENTIFY_LONGFLAGS size");
  		memcpy(&longflags, data, sizeof longflags);
  		c->flags |= longflags;
  		log_debug("client %p IDENTIFY_LONGFLAGS %#llx", c,
  		    (unsigned long long)longflags);
  		break;
  	case MSG_IDENTIFY_TERM:
  		if (datalen == 0 || data[datalen - 1] != '\0')
  			fatalx("bad MSG_IDENTIFY_TERM string");
  		if (*data == '\0')
  			c->term_name = xstrdup("unknown");
  		else
  			c->term_name = xstrdup(data);
  		log_debug("client %p IDENTIFY_TERM %s", c, data);
  		break;
  	case MSG_IDENTIFY_TTYNAME:
  		if (datalen == 0 || data[datalen - 1] != '\0')
  			fatalx("bad MSG_IDENTIFY_TTYNAME string");
  		c->ttyname = xstrdup(data);
  		log_debug("client %p IDENTIFY_TTYNAME %s", c, data);
  		break;
  	case MSG_IDENTIFY_CWD:
  		if (datalen == 0 || data[datalen - 1] != '\0')
  			fatalx("bad MSG_IDENTIFY_CWD string");
  		if (access(data, X_OK) == 0)
  			c->cwd = xstrdup(data);
  		else if ((home = find_home()) != NULL)
  			c->cwd = xstrdup(home);
  		else
  			c->cwd = xstrdup("/");
  		log_debug("client %p IDENTIFY_CWD %s", c, data);
  		break;
  	case MSG_IDENTIFY_STDIN:
  		if (datalen != 0)
  			fatalx("bad MSG_IDENTIFY_STDIN size");
  		c->fd = imsg->fd;
  		log_debug("client %p IDENTIFY_STDIN %d", c, imsg->fd);
  		break;
  	case MSG_IDENTIFY_STDOUT:
  		if (datalen != 0)
  			fatalx("bad MSG_IDENTIFY_STDOUT size");
  		c->out_fd = imsg->fd;
  		log_debug("client %p IDENTIFY_STDOUT %d", c, imsg->fd);
  		break;
  	case MSG_IDENTIFY_ENVIRON:
  		if (datalen == 0 || data[datalen - 1] != '\0')
  			fatalx("bad MSG_IDENTIFY_ENVIRON string");
  		if (strchr(data, '=') != NULL)
  			environ_put(c->environ, data, 0);
  		log_debug("client %p IDENTIFY_ENVIRON %s", c, data);
  		break;
  	case MSG_IDENTIFY_CLIENTPID:
  		if (datalen != sizeof c->pid)
  			fatalx("bad MSG_IDENTIFY_CLIENTPID size");
  		memcpy(&c->pid, data, sizeof c->pid);
  		log_debug("client %p IDENTIFY_CLIENTPID %ld", c, (long)c->pid);
  		break;
  	default:
  		break;
  	}
  
  	if (imsg->hdr.type != MSG_IDENTIFY_DONE)
  		return;
  	c->flags |= CLIENT_IDENTIFIED;
  
  	if (*c->ttyname != '\0')
  		name = xstrdup(c->ttyname);
  	else
  		xasprintf(&name, "client-%ld", (long)c->pid);
  	c->name = name;
  	log_debug("client %p name is %s", c, c->name);
  
  #ifdef __CYGWIN__
  	c->fd = open(c->ttyname, O_RDWR|O_NOCTTY);
  #endif
  
  	if (c->flags & CLIENT_CONTROL)
  		control_start(c);
  	else if (c->fd != -1) {
  		if (tty_init(&c->tty, c) != 0) {
  			close(c->fd);
  			c->fd = -1;
  		} else {
  			tty_resize(&c->tty);
  			c->flags |= CLIENT_TERMINAL;
  		}
  		close(c->out_fd);
  		c->out_fd = -1;
  	}
  
  	/*
  	 * If this is the first client, load configuration files. Any later
  	 * clients are allowed to continue with their command even if the
  	 * config has not been loaded - they might have been run from inside it
  	 */
  	if ((~c->flags & CLIENT_EXIT) &&
  	     !cfg_finished &&
  	     c == TAILQ_FIRST(&clients))
  		start_cfg();
  }
  
  /* Handle shell message. */
  static void
  server_client_dispatch_shell(struct client *c)
  {
  	const char	*shell;
  
  	shell = options_get_string(global_s_options, "default-shell");
  	if (!checkshell(shell))
  		shell = _PATH_BSHELL;
  	proc_send(c->peer, MSG_SHELL, -1, shell, strlen(shell) + 1);
  
  	proc_kill_peer(c->peer);
  }
  
  /* Handle write ready message. */
  static void
  server_client_dispatch_write_ready(struct client *c, struct imsg *imsg)
  {
  	struct msg_write_ready	*msg = imsg->data;
  	size_t			 msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
  	struct client_file	 find, *cf;
  
  	if (msglen != sizeof *msg)
  		fatalx("bad MSG_WRITE_READY size");
  	find.stream = msg->stream;
  	if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL)
  		return;
  	if (msg->error != 0) {
  		cf->error = msg->error;
  		file_fire_done(cf);
  	} else
  		file_push(cf);
  }
  
  /* Handle read data message. */
  static void
  server_client_dispatch_read_data(struct client *c, struct imsg *imsg)
  {
  	struct msg_read_data	*msg = imsg->data;
  	size_t			 msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
  	struct client_file	 find, *cf;
  	void			*bdata = msg + 1;
  	size_t			 bsize = msglen - sizeof *msg;
  
  	if (msglen < sizeof *msg)
  		fatalx("bad MSG_READ_DATA size");
  	find.stream = msg->stream;
  	if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL)
  		return;
  
  	log_debug("%s: file %d read %zu bytes", c->name, cf->stream, bsize);
  	if (cf->error == 0) {
  		if (evbuffer_add(cf->buffer, bdata, bsize) != 0) {
  			cf->error = ENOMEM;
  			file_fire_done(cf);
  		} else
  			file_fire_read(cf);
  	}
  }
  
  /* Handle read done message. */
  static void
  server_client_dispatch_read_done(struct client *c, struct imsg *imsg)
  {
  	struct msg_read_done	*msg = imsg->data;
  	size_t			 msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
  	struct client_file	 find, *cf;
  
  	if (msglen != sizeof *msg)
  		fatalx("bad MSG_READ_DONE size");
  	find.stream = msg->stream;
  	if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL)
  		return;
  
  	log_debug("%s: file %d read done", c->name, cf->stream);
  	cf->error = msg->error;
  	file_fire_done(cf);
  }
  
  /* Get client working directory. */
  const char *
  server_client_get_cwd(struct client *c, struct session *s)
  {
  	const char	*home;
  
  	if (!cfg_finished && cfg_client != NULL)
  		return (cfg_client->cwd);
  	if (c != NULL && c->session == NULL && c->cwd != NULL)
  		return (c->cwd);
  	if (s != NULL && s->cwd != NULL)
  		return (s->cwd);
  	if (c != NULL && (s = c->session) != NULL && s->cwd != NULL)
  		return (s->cwd);
  	if ((home = find_home()) != NULL)
  		return (home);
  	return ("/");
  }
  
  /* Get control client flags. */
  static uint64_t
  server_client_control_flags(struct client *c, const char *next)
  {
  	if (strcmp(next, "pause-after") == 0) {
  		c->pause_age = 0;
  		return (CLIENT_CONTROL_PAUSEAFTER);
  	}
  	if (sscanf(next, "pause-after=%u", &c->pause_age) == 1) {
  		c->pause_age *= 1000;
  		return (CLIENT_CONTROL_PAUSEAFTER);
  	}
  	if (strcmp(next, "no-output") == 0)
  		return (CLIENT_CONTROL_NOOUTPUT);
  	if (strcmp(next, "wait-exit") == 0)
  		return (CLIENT_CONTROL_WAITEXIT);
  	return (0);
  }
  
  /* Set client flags. */
  void
  server_client_set_flags(struct client *c, const char *flags)
  {
  	char	*s, *copy, *next;
  	uint64_t flag;
  	int	 not;
  
  	s = copy = xstrdup (flags);
  	while ((next = strsep(&s, ",")) != NULL) {
  		not = (*next == '!');
  		if (not)
  			next++;
  
  		if (c->flags & CLIENT_CONTROL)
  			flag = server_client_control_flags(c, next);
  		else
  			flag = 0;
  		if (strcmp(next, "read-only") == 0)
  			flag = CLIENT_READONLY;
  		else if (strcmp(next, "ignore-size") == 0)
  			flag = CLIENT_IGNORESIZE;
  		else if (strcmp(next, "active-pane") == 0)
  			flag = CLIENT_ACTIVEPANE;
  		if (flag == 0)
  			continue;
  
  		log_debug("client %s set flag %s", c->name, next);
  		if (not)
  			c->flags &= ~flag;
  		else
  			c->flags |= flag;
  		if (flag == CLIENT_CONTROL_NOOUTPUT)
  			control_reset_offsets(c);
  	}
  	free(copy);
  	proc_send(c->peer, MSG_FLAGS, -1, &c->flags, sizeof c->flags);
  }
  
  /* Get client flags. This is only flags useful to show to users. */
  const char *
  server_client_get_flags(struct client *c)
  {
  	static char	s[256];
  	char	 	tmp[32];
  
  	*s = '\0';
  	if (c->flags & CLIENT_ATTACHED)
  		strlcat(s, "attached,", sizeof s);
  	if (c->flags & CLIENT_CONTROL)
  		strlcat(s, "control-mode,", sizeof s);
  	if (c->flags & CLIENT_IGNORESIZE)
  		strlcat(s, "ignore-size,", sizeof s);
  	if (c->flags & CLIENT_CONTROL_NOOUTPUT)
  		strlcat(s, "no-output,", sizeof s);
  	if (c->flags & CLIENT_CONTROL_WAITEXIT)
  		strlcat(s, "wait-exit,", sizeof s);
  	if (c->flags & CLIENT_CONTROL_PAUSEAFTER) {
  		xsnprintf(tmp, sizeof tmp, "pause-after=%u,",
  		    c->pause_age / 1000);
  		strlcat(s, tmp, sizeof s);
  	}
  	if (c->flags & CLIENT_READONLY)
  		strlcat(s, "read-only,", sizeof s);
  	if (c->flags & CLIENT_ACTIVEPANE)
  		strlcat(s, "active-pane,", sizeof s);
  	if (c->flags & CLIENT_SUSPENDED)
  		strlcat(s, "suspended,", sizeof s);
  	if (c->flags & CLIENT_UTF8)
  		strlcat(s, "UTF-8,", sizeof s);
  	if (*s != '\0')
  		s[strlen(s) - 1] = '\0';
  	return (s);
  }
  
  /* Get client window. */
  static struct client_window *
  server_client_get_client_window(struct client *c, u_int id)
  {
  	struct client_window	cw = { .window = id };
  
  	return (RB_FIND(client_windows, &c->windows, &cw));
  }
  
  /* Get client active pane. */
  struct window_pane *
  server_client_get_pane(struct client *c)
  {
  	struct session		*s = c->session;
  	struct client_window	*cw;
  
  	if (s == NULL)
  		return (NULL);
  
  	if (~c->flags & CLIENT_ACTIVEPANE)
  		return (s->curw->window->active);
  	cw = server_client_get_client_window(c, s->curw->window->id);
  	if (cw == NULL)
  		return (s->curw->window->active);
  	return (cw->pane);
  }
  
  /* Set client active pane. */
  void
  server_client_set_pane(struct client *c, struct window_pane *wp)
  {
  	struct session		*s = c->session;
  	struct client_window	*cw;
  
  	if (s == NULL)
  		return;
  
  	cw = server_client_get_client_window(c, s->curw->window->id);
  	if (cw == NULL) {
  		cw = xcalloc(1, sizeof *cw);
  		cw->window = s->curw->window->id;
  		RB_INSERT(client_windows, &c->windows, cw);
  	}
  	cw->pane = wp;
  	log_debug("%s pane now %%%u", c->name, wp->id);
  }
  
  /* Remove pane from client lists. */
  void
  server_client_remove_pane(struct window_pane *wp)
  {
  	struct client		*c;
  	struct window		*w = wp->window;
  	struct client_window	*cw;
  
  	TAILQ_FOREACH(c, &clients, entry) {
  		cw = server_client_get_client_window(c, w->id);
  		if (cw != NULL && cw->pane == wp) {
  			RB_REMOVE(client_windows, &c->windows, cw);
  			free(cw);
  		}
  	}
  }
  