xref: /openbsd-src/usr.bin/tmux/window.c (revision 9b9d2a55a62c8e82206c25f94fcc7f4e2765250e)
1 /* $OpenBSD: window.c,v 1.144 2015/08/29 23:55:55 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <fnmatch.h>
24 #include <stdint.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <termios.h>
28 #include <unistd.h>
29 #include <util.h>
30 
31 #include "tmux.h"
32 
33 /*
34  * Each window is attached to a number of panes, each of which is a pty. This
35  * file contains code to handle them.
36  *
37  * A pane has two buffers attached, these are filled and emptied by the main
38  * server poll loop. Output data is received from pty's in screen format,
39  * translated and returned as a series of escape sequences and strings via
40  * input_parse (in input.c). Input data is received as key codes and written
41  * directly via input_key.
42  *
43  * Each pane also has a "virtual" screen (screen.c) which contains the current
44  * state and is redisplayed when the window is reattached to a client.
45  *
46  * Windows are stored directly on a global array and wrapped in any number of
47  * winlink structs to be linked onto local session RB trees. A reference count
48  * is maintained and a window removed from the global list and destroyed when
49  * it reaches zero.
50  */
51 
52 /* Global window list. */
53 struct windows windows;
54 
55 /* Global panes tree. */
56 struct window_pane_tree all_window_panes;
57 u_int	next_window_pane_id;
58 u_int	next_window_id;
59 u_int	next_active_point;
60 
61 void	window_pane_timer_callback(int, short, void *);
62 void	window_pane_read_callback(struct bufferevent *, void *);
63 void	window_pane_error_callback(struct bufferevent *, short, void *);
64 
65 struct window_pane *window_pane_choose_best(struct window_pane **, u_int);
66 
67 RB_GENERATE(windows, window, entry, window_cmp);
68 
69 int
70 window_cmp(struct window *w1, struct window *w2)
71 {
72 	return (w1->id - w2->id);
73 }
74 
75 RB_GENERATE(winlinks, winlink, entry, winlink_cmp);
76 
77 int
78 winlink_cmp(struct winlink *wl1, struct winlink *wl2)
79 {
80 	return (wl1->idx - wl2->idx);
81 }
82 
83 RB_GENERATE(window_pane_tree, window_pane, tree_entry, window_pane_cmp);
84 
85 int
86 window_pane_cmp(struct window_pane *wp1, struct window_pane *wp2)
87 {
88 	return (wp1->id - wp2->id);
89 }
90 
91 struct winlink *
92 winlink_find_by_window(struct winlinks *wwl, struct window *w)
93 {
94 	struct winlink	*wl;
95 
96 	RB_FOREACH(wl, winlinks, wwl) {
97 		if (wl->window == w)
98 			return (wl);
99 	}
100 
101 	return (NULL);
102 }
103 
104 struct winlink *
105 winlink_find_by_index(struct winlinks *wwl, int idx)
106 {
107 	struct winlink	wl;
108 
109 	if (idx < 0)
110 		fatalx("bad index");
111 
112 	wl.idx = idx;
113 	return (RB_FIND(winlinks, wwl, &wl));
114 }
115 
116 struct winlink *
117 winlink_find_by_window_id(struct winlinks *wwl, u_int id)
118 {
119 	struct winlink *wl;
120 
121 	RB_FOREACH(wl, winlinks, wwl) {
122 		if (wl->window->id == id)
123 			return (wl);
124 	}
125 	return (NULL);
126 }
127 
128 int
129 winlink_next_index(struct winlinks *wwl, int idx)
130 {
131 	int	i;
132 
133 	i = idx;
134 	do {
135 		if (winlink_find_by_index(wwl, i) == NULL)
136 			return (i);
137 		if (i == INT_MAX)
138 			i = 0;
139 		else
140 			i++;
141 	} while (i != idx);
142 	return (-1);
143 }
144 
145 u_int
146 winlink_count(struct winlinks *wwl)
147 {
148 	struct winlink	*wl;
149 	u_int		 n;
150 
151 	n = 0;
152 	RB_FOREACH(wl, winlinks, wwl)
153 		n++;
154 
155 	return (n);
156 }
157 
158 struct winlink *
159 winlink_add(struct winlinks *wwl, int idx)
160 {
161 	struct winlink	*wl;
162 
163 	if (idx < 0) {
164 		if ((idx = winlink_next_index(wwl, -idx - 1)) == -1)
165 			return (NULL);
166 	} else if (winlink_find_by_index(wwl, idx) != NULL)
167 		return (NULL);
168 
169 	wl = xcalloc(1, sizeof *wl);
170 	wl->idx = idx;
171 	RB_INSERT(winlinks, wwl, wl);
172 
173 	return (wl);
174 }
175 
176 void
177 winlink_set_window(struct winlink *wl, struct window *w)
178 {
179 	wl->window = w;
180 	w->references++;
181 }
182 
183 void
184 winlink_remove(struct winlinks *wwl, struct winlink *wl)
185 {
186 	struct window	*w = wl->window;
187 
188 	RB_REMOVE(winlinks, wwl, wl);
189 	free(wl->status_text);
190 	free(wl);
191 
192 	if (w != NULL)
193 		window_remove_ref(w);
194 }
195 
196 struct winlink *
197 winlink_next(struct winlink *wl)
198 {
199 	return (RB_NEXT(winlinks, wwl, wl));
200 }
201 
202 struct winlink *
203 winlink_previous(struct winlink *wl)
204 {
205 	return (RB_PREV(winlinks, wwl, wl));
206 }
207 
208 struct winlink *
209 winlink_next_by_number(struct winlink *wl, struct session *s, int n)
210 {
211 	for (; n > 0; n--) {
212 		if ((wl = RB_NEXT(winlinks, wwl, wl)) == NULL)
213 			wl = RB_MIN(winlinks, &s->windows);
214 	}
215 
216 	return (wl);
217 }
218 
219 struct winlink *
220 winlink_previous_by_number(struct winlink *wl, struct session *s, int n)
221 {
222 	for (; n > 0; n--) {
223 		if ((wl = RB_PREV(winlinks, wwl, wl)) == NULL)
224 			wl = RB_MAX(winlinks, &s->windows);
225 	}
226 
227 	return (wl);
228 }
229 
230 void
231 winlink_stack_push(struct winlink_stack *stack, struct winlink *wl)
232 {
233 	if (wl == NULL)
234 		return;
235 
236 	winlink_stack_remove(stack, wl);
237 	TAILQ_INSERT_HEAD(stack, wl, sentry);
238 }
239 
240 void
241 winlink_stack_remove(struct winlink_stack *stack, struct winlink *wl)
242 {
243 	struct winlink	*wl2;
244 
245 	if (wl == NULL)
246 		return;
247 
248 	TAILQ_FOREACH(wl2, stack, sentry) {
249 		if (wl2 == wl) {
250 			TAILQ_REMOVE(stack, wl, sentry);
251 			return;
252 		}
253 	}
254 }
255 
256 struct window *
257 window_find_by_id_str(const char *s)
258 {
259 	const char	*errstr;
260 	u_int		 id;
261 
262 	if (*s != '@')
263 		return (NULL);
264 
265 	id = strtonum(s + 1, 0, UINT_MAX, &errstr);
266 	if (errstr != NULL)
267 		return (NULL);
268 	return (window_find_by_id(id));
269 }
270 
271 struct window *
272 window_find_by_id(u_int id)
273 {
274 	struct window	w;
275 
276 	w.id = id;
277 	return (RB_FIND(windows, &windows, &w));
278 }
279 
280 void
281 window_update_activity(struct window *w)
282 {
283 	gettimeofday(&w->activity_time, NULL);
284 	alerts_queue(w, WINDOW_ACTIVITY);
285 }
286 
287 struct window *
288 window_create1(u_int sx, u_int sy)
289 {
290 	struct window	*w;
291 
292 	w = xcalloc(1, sizeof *w);
293 	w->name = NULL;
294 	w->flags = 0;
295 
296 	TAILQ_INIT(&w->panes);
297 	w->active = NULL;
298 
299 	w->lastlayout = -1;
300 	w->layout_root = NULL;
301 
302 	w->sx = sx;
303 	w->sy = sy;
304 
305 	options_init(&w->options, &global_w_options);
306 
307 	w->references = 0;
308 
309 	w->id = next_window_id++;
310 	RB_INSERT(windows, &windows, w);
311 
312 	window_update_activity(w);
313 
314 	return (w);
315 }
316 
317 struct window *
318 window_create(const char *name, int argc, char **argv, const char *path,
319     const char *shell, int cwd, struct environ *env, struct termios *tio,
320     u_int sx, u_int sy, u_int hlimit, char **cause)
321 {
322 	struct window		*w;
323 	struct window_pane	*wp;
324 
325 	w = window_create1(sx, sy);
326 	wp = window_add_pane(w, hlimit);
327 	layout_init(w, wp);
328 
329 	if (window_pane_spawn(wp, argc, argv, path, shell, cwd, env, tio,
330 	    cause) != 0) {
331 		window_destroy(w);
332 		return (NULL);
333 	}
334 
335 	w->active = TAILQ_FIRST(&w->panes);
336 	if (name != NULL) {
337 		w->name = xstrdup(name);
338 		options_set_number(&w->options, "automatic-rename", 0);
339 	} else
340 		w->name = default_window_name(w);
341 
342 	return (w);
343 }
344 
345 void
346 window_destroy(struct window *w)
347 {
348 	RB_REMOVE(windows, &windows, w);
349 
350 	if (w->layout_root != NULL)
351 		layout_free_cell(w->layout_root);
352 	if (w->saved_layout_root != NULL)
353 		layout_free_cell(w->saved_layout_root);
354 	free(w->old_layout);
355 
356 	if (event_initialized(&w->name_event))
357 		evtimer_del(&w->name_event);
358 
359 	if (event_initialized(&w->alerts_timer))
360 		evtimer_del(&w->alerts_timer);
361 
362 	options_free(&w->options);
363 
364 	window_destroy_panes(w);
365 
366 	free(w->name);
367 	free(w);
368 }
369 
370 void
371 window_remove_ref(struct window *w)
372 {
373 	if (w->references == 0)
374 		fatal("bad reference count");
375 	w->references--;
376 	if (w->references == 0)
377 		window_destroy(w);
378 }
379 
380 void
381 window_set_name(struct window *w, const char *new_name)
382 {
383 	free(w->name);
384 	w->name = xstrdup(new_name);
385 	notify_window_renamed(w);
386 }
387 
388 void
389 window_resize(struct window *w, u_int sx, u_int sy)
390 {
391 	w->sx = sx;
392 	w->sy = sy;
393 }
394 
395 int
396 window_has_pane(struct window *w, struct window_pane *wp)
397 {
398 	struct window_pane	*wp1;
399 
400 	TAILQ_FOREACH(wp1, &w->panes, entry) {
401 		if (wp1 == wp)
402 			return (1);
403 	}
404 	return (0);
405 }
406 
407 int
408 window_set_active_pane(struct window *w, struct window_pane *wp)
409 {
410 	if (wp == w->active)
411 		return (0);
412 	w->last = w->active;
413 	w->active = wp;
414 	while (!window_pane_visible(w->active)) {
415 		w->active = TAILQ_PREV(w->active, window_panes, entry);
416 		if (w->active == NULL)
417 			w->active = TAILQ_LAST(&w->panes, window_panes);
418 		if (w->active == wp)
419 			return (1);
420 	}
421 	w->active->active_point = next_active_point++;
422 	w->active->flags |= PANE_CHANGED;
423 	return (1);
424 }
425 
426 struct window_pane *
427 window_get_active_at(struct window *w, u_int x, u_int y)
428 {
429 	struct window_pane	*wp;
430 
431 	TAILQ_FOREACH(wp, &w->panes, entry) {
432 		if (!window_pane_visible(wp))
433 			continue;
434 		if (x < wp->xoff || x > wp->xoff + wp->sx)
435 			continue;
436 		if (y < wp->yoff || y > wp->yoff + wp->sy)
437 			continue;
438 		return (wp);
439 	}
440 	return (NULL);
441 }
442 
443 struct window_pane *
444 window_find_string(struct window *w, const char *s)
445 {
446 	u_int	x, y;
447 
448 	x = w->sx / 2;
449 	y = w->sy / 2;
450 
451 	if (strcasecmp(s, "top") == 0)
452 		y = 0;
453 	else if (strcasecmp(s, "bottom") == 0)
454 		y = w->sy - 1;
455 	else if (strcasecmp(s, "left") == 0)
456 		x = 0;
457 	else if (strcasecmp(s, "right") == 0)
458 		x = w->sx - 1;
459 	else if (strcasecmp(s, "top-left") == 0) {
460 		x = 0;
461 		y = 0;
462 	} else if (strcasecmp(s, "top-right") == 0) {
463 		x = w->sx - 1;
464 		y = 0;
465 	} else if (strcasecmp(s, "bottom-left") == 0) {
466 		x = 0;
467 		y = w->sy - 1;
468 	} else if (strcasecmp(s, "bottom-right") == 0) {
469 		x = w->sx - 1;
470 		y = w->sy - 1;
471 	} else
472 		return (NULL);
473 
474 	return (window_get_active_at(w, x, y));
475 }
476 
477 int
478 window_zoom(struct window_pane *wp)
479 {
480 	struct window		*w = wp->window;
481 	struct window_pane	*wp1;
482 
483 	if (w->flags & WINDOW_ZOOMED)
484 		return (-1);
485 
486 	if (!window_pane_visible(wp))
487 		return (-1);
488 
489 	if (window_count_panes(w) == 1)
490 		return (-1);
491 
492 	if (w->active != wp)
493 		window_set_active_pane(w, wp);
494 
495 	TAILQ_FOREACH(wp1, &w->panes, entry) {
496 		wp1->saved_layout_cell = wp1->layout_cell;
497 		wp1->layout_cell = NULL;
498 	}
499 
500 	w->saved_layout_root = w->layout_root;
501 	layout_init(w, wp);
502 	w->flags |= WINDOW_ZOOMED;
503 	notify_window_layout_changed(w);
504 
505 	return (0);
506 }
507 
508 int
509 window_unzoom(struct window *w)
510 {
511 	struct window_pane	*wp;
512 
513 	if (!(w->flags & WINDOW_ZOOMED))
514 		return (-1);
515 
516 	w->flags &= ~WINDOW_ZOOMED;
517 	layout_free(w);
518 	w->layout_root = w->saved_layout_root;
519 	w->saved_layout_root = NULL;
520 
521 	TAILQ_FOREACH(wp, &w->panes, entry) {
522 		wp->layout_cell = wp->saved_layout_cell;
523 		wp->saved_layout_cell = NULL;
524 	}
525 	layout_fix_panes(w, w->sx, w->sy);
526 	notify_window_layout_changed(w);
527 
528 	return (0);
529 }
530 
531 struct window_pane *
532 window_add_pane(struct window *w, u_int hlimit)
533 {
534 	struct window_pane	*wp;
535 
536 	wp = window_pane_create(w, w->sx, w->sy, hlimit);
537 	if (TAILQ_EMPTY(&w->panes))
538 		TAILQ_INSERT_HEAD(&w->panes, wp, entry);
539 	else
540 		TAILQ_INSERT_AFTER(&w->panes, w->active, wp, entry);
541 	return (wp);
542 }
543 
544 void
545 window_lost_pane(struct window *w, struct window_pane *wp)
546 {
547 	if (wp == marked_window_pane)
548 		server_clear_marked();
549 
550 	if (wp == w->active) {
551 		w->active = w->last;
552 		w->last = NULL;
553 		if (w->active == NULL) {
554 			w->active = TAILQ_PREV(wp, window_panes, entry);
555 			if (w->active == NULL)
556 				w->active = TAILQ_NEXT(wp, entry);
557 		}
558 	} else if (wp == w->last)
559 		w->last = NULL;
560 }
561 
562 void
563 window_remove_pane(struct window *w, struct window_pane *wp)
564 {
565 	window_lost_pane(w, wp);
566 
567 	TAILQ_REMOVE(&w->panes, wp, entry);
568 	window_pane_destroy(wp);
569 }
570 
571 struct window_pane *
572 window_pane_at_index(struct window *w, u_int idx)
573 {
574 	struct window_pane	*wp;
575 	u_int			 n;
576 
577 	n = options_get_number(&w->options, "pane-base-index");
578 	TAILQ_FOREACH(wp, &w->panes, entry) {
579 		if (n == idx)
580 			return (wp);
581 		n++;
582 	}
583 	return (NULL);
584 }
585 
586 struct window_pane *
587 window_pane_next_by_number(struct window *w, struct window_pane *wp, u_int n)
588 {
589 	for (; n > 0; n--) {
590 		if ((wp = TAILQ_NEXT(wp, entry)) == NULL)
591 			wp = TAILQ_FIRST(&w->panes);
592 	}
593 
594 	return (wp);
595 }
596 
597 struct window_pane *
598 window_pane_previous_by_number(struct window *w, struct window_pane *wp,
599     u_int n)
600 {
601 	for (; n > 0; n--) {
602 		if ((wp = TAILQ_PREV(wp, window_panes, entry)) == NULL)
603 			wp = TAILQ_LAST(&w->panes, window_panes);
604 	}
605 
606 	return (wp);
607 }
608 
609 int
610 window_pane_index(struct window_pane *wp, u_int *i)
611 {
612 	struct window_pane	*wq;
613 	struct window		*w = wp->window;
614 
615 	*i = options_get_number(&w->options, "pane-base-index");
616 	TAILQ_FOREACH(wq, &w->panes, entry) {
617 		if (wp == wq) {
618 			return (0);
619 		}
620 		(*i)++;
621 	}
622 
623 	return (-1);
624 }
625 
626 u_int
627 window_count_panes(struct window *w)
628 {
629 	struct window_pane	*wp;
630 	u_int			 n;
631 
632 	n = 0;
633 	TAILQ_FOREACH(wp, &w->panes, entry)
634 		n++;
635 	return (n);
636 }
637 
638 void
639 window_destroy_panes(struct window *w)
640 {
641 	struct window_pane	*wp;
642 
643 	while (!TAILQ_EMPTY(&w->panes)) {
644 		wp = TAILQ_FIRST(&w->panes);
645 		TAILQ_REMOVE(&w->panes, wp, entry);
646 		window_pane_destroy(wp);
647 	}
648 }
649 
650 /* Retuns the printable flags on a window, empty string if no flags set. */
651 char *
652 window_printable_flags(struct session *s, struct winlink *wl)
653 {
654 	char	flags[32];
655 	int	pos;
656 
657 	pos = 0;
658 	if (wl->flags & WINLINK_ACTIVITY)
659 		flags[pos++] = '#';
660 	if (wl->flags & WINLINK_BELL)
661 		flags[pos++] = '!';
662 	if (wl->flags & WINLINK_SILENCE)
663 		flags[pos++] = '~';
664 	if (wl == s->curw)
665 		flags[pos++] = '*';
666 	if (wl == TAILQ_FIRST(&s->lastw))
667 		flags[pos++] = '-';
668 	if (server_check_marked() && wl == marked_winlink)
669 		flags[pos++] = 'M';
670 	if (wl->window->flags & WINDOW_ZOOMED)
671 		flags[pos++] = 'Z';
672 	flags[pos] = '\0';
673 	return (xstrdup(flags));
674 }
675 
676 struct window_pane *
677 window_pane_find_by_id_str(const char *s)
678 {
679 	const char	*errstr;
680 	u_int		 id;
681 
682 	if (*s != '%')
683 		return (NULL);
684 
685 	id = strtonum(s + 1, 0, UINT_MAX, &errstr);
686 	if (errstr != NULL)
687 		return (NULL);
688 	return (window_pane_find_by_id(id));
689 }
690 
691 struct window_pane *
692 window_pane_find_by_id(u_int id)
693 {
694 	struct window_pane	wp;
695 
696 	wp.id = id;
697 	return (RB_FIND(window_pane_tree, &all_window_panes, &wp));
698 }
699 
700 struct window_pane *
701 window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
702 {
703 	struct window_pane	*wp;
704 	char			 host[HOST_NAME_MAX + 1];
705 
706 	wp = xcalloc(1, sizeof *wp);
707 	wp->window = w;
708 
709 	wp->id = next_window_pane_id++;
710 	RB_INSERT(window_pane_tree, &all_window_panes, wp);
711 
712 	wp->argc = 0;
713 	wp->argv = NULL;
714 	wp->shell = NULL;
715 	wp->cwd = -1;
716 
717 	wp->fd = -1;
718 	wp->event = NULL;
719 
720 	wp->mode = NULL;
721 
722 	wp->layout_cell = NULL;
723 
724 	wp->xoff = 0;
725 	wp->yoff = 0;
726 
727 	wp->sx = sx;
728 	wp->sy = sy;
729 
730 	wp->pipe_fd = -1;
731 	wp->pipe_off = 0;
732 	wp->pipe_event = NULL;
733 
734 	wp->saved_grid = NULL;
735 
736 	memcpy(&wp->colgc, &grid_default_cell, sizeof wp->colgc);
737 
738 	screen_init(&wp->base, sx, sy, hlimit);
739 	wp->screen = &wp->base;
740 
741 	if (gethostname(host, sizeof host) == 0)
742 		screen_set_title(&wp->base, host);
743 
744 	input_init(wp);
745 
746 	return (wp);
747 }
748 
749 void
750 window_pane_destroy(struct window_pane *wp)
751 {
752 	window_pane_reset_mode(wp);
753 
754 	if (event_initialized(&wp->timer))
755 		evtimer_del(&wp->timer);
756 
757 	if (wp->fd != -1) {
758 		bufferevent_free(wp->event);
759 		close(wp->fd);
760 	}
761 
762 	input_free(wp);
763 
764 	screen_free(&wp->base);
765 	if (wp->saved_grid != NULL)
766 		grid_destroy(wp->saved_grid);
767 
768 	if (wp->pipe_fd != -1) {
769 		bufferevent_free(wp->pipe_event);
770 		close(wp->pipe_fd);
771 	}
772 
773 	RB_REMOVE(window_pane_tree, &all_window_panes, wp);
774 
775 	close(wp->cwd);
776 	free(wp->shell);
777 	cmd_free_argv(wp->argc, wp->argv);
778 	free(wp);
779 }
780 
781 int
782 window_pane_spawn(struct window_pane *wp, int argc, char **argv,
783     const char *path, const char *shell, int cwd, struct environ *env,
784     struct termios *tio, char **cause)
785 {
786 	struct winsize	 ws;
787 	char		*argv0, *cmd, **argvp, paneid[16];
788 	const char	*ptr, *first;
789 	struct termios	 tio2;
790 	int		 i;
791 
792 	if (wp->fd != -1) {
793 		bufferevent_free(wp->event);
794 		close(wp->fd);
795 	}
796 	if (argc > 0) {
797 		cmd_free_argv(wp->argc, wp->argv);
798 		wp->argc = argc;
799 		wp->argv = cmd_copy_argv(argc, argv);
800 	}
801 	if (shell != NULL) {
802 		free(wp->shell);
803 		wp->shell = xstrdup(shell);
804 	}
805 	if (cwd != -1) {
806 		close(wp->cwd);
807 		wp->cwd = dup(cwd);
808 	}
809 
810 	cmd = cmd_stringify_argv(wp->argc, wp->argv);
811 	log_debug("spawn: %s -- %s", wp->shell, cmd);
812 	for (i = 0; i < wp->argc; i++)
813 		log_debug("spawn: argv[%d] = %s", i, wp->argv[i]);
814 
815 	memset(&ws, 0, sizeof ws);
816 	ws.ws_col = screen_size_x(&wp->base);
817 	ws.ws_row = screen_size_y(&wp->base);
818 
819 	switch (wp->pid = forkpty(&wp->fd, wp->tty, NULL, &ws)) {
820 	case -1:
821 		wp->fd = -1;
822 		xasprintf(cause, "%s: %s", cmd, strerror(errno));
823 		free(cmd);
824 		return (-1);
825 	case 0:
826 		if (fchdir(wp->cwd) != 0)
827 			chdir("/");
828 
829 		if (tcgetattr(STDIN_FILENO, &tio2) != 0)
830 			fatal("tcgetattr failed");
831 		if (tio != NULL)
832 			memcpy(tio2.c_cc, tio->c_cc, sizeof tio2.c_cc);
833 		tio2.c_cc[VERASE] = '\177';
834 		if (tcsetattr(STDIN_FILENO, TCSANOW, &tio2) != 0)
835 			fatal("tcgetattr failed");
836 
837 		closefrom(STDERR_FILENO + 1);
838 
839 		if (path != NULL)
840 			environ_set(env, "PATH", path);
841 		xsnprintf(paneid, sizeof paneid, "%%%u", wp->id);
842 		environ_set(env, "TMUX_PANE", paneid);
843 		environ_push(env);
844 
845 		clear_signals(1);
846 		log_close();
847 
848 		setenv("SHELL", wp->shell, 1);
849 		ptr = strrchr(wp->shell, '/');
850 
851 		/*
852 		 * If given one argument, assume it should be passed to sh -c;
853 		 * with more than one argument, use execvp(). If there is no
854 		 * arguments, create a login shell.
855 		 */
856 		if (wp->argc > 0) {
857 			if (wp->argc != 1) {
858 				/* Copy to ensure argv ends in NULL. */
859 				argvp = cmd_copy_argv(wp->argc, wp->argv);
860 				execvp(argvp[0], argvp);
861 				fatal("execvp failed");
862 			}
863 			first = wp->argv[0];
864 
865 			if (ptr != NULL && *(ptr + 1) != '\0')
866 				xasprintf(&argv0, "%s", ptr + 1);
867 			else
868 				xasprintf(&argv0, "%s", wp->shell);
869 			execl(wp->shell, argv0, "-c", first, (char *)NULL);
870 			fatal("execl failed");
871 		}
872 		if (ptr != NULL && *(ptr + 1) != '\0')
873 			xasprintf(&argv0, "-%s", ptr + 1);
874 		else
875 			xasprintf(&argv0, "-%s", wp->shell);
876 		execl(wp->shell, argv0, (char *)NULL);
877 		fatal("execl failed");
878 	}
879 
880 	setblocking(wp->fd, 0);
881 
882 	wp->event = bufferevent_new(wp->fd, window_pane_read_callback, NULL,
883 	    window_pane_error_callback, wp);
884 
885 	bufferevent_setwatermark(wp->event, EV_READ, 0, READ_SIZE);
886 	bufferevent_enable(wp->event, EV_READ|EV_WRITE);
887 
888 	free(cmd);
889 	return (0);
890 }
891 
892 void
893 window_pane_timer_callback(unused int fd, unused short events, void *data)
894 {
895 	window_pane_read_callback(NULL, data);
896 }
897 
898 void
899 window_pane_read_callback(unused struct bufferevent *bufev, void *data)
900 {
901 	struct window_pane	*wp = data;
902 	struct evbuffer		*evb = wp->event->input;
903 	char			*new_data;
904 	size_t			 new_size, available;
905 	struct client		*c;
906 	struct timeval		 tv;
907 
908 	if (event_initialized(&wp->timer))
909 		evtimer_del(&wp->timer);
910 
911 	log_debug("%%%u has %zu bytes", wp->id, EVBUFFER_LENGTH(evb));
912 
913 	TAILQ_FOREACH(c, &clients, entry) {
914 		if (!tty_client_ready(c, wp))
915 			continue;
916 
917 		available = EVBUFFER_LENGTH(c->tty.event->output);
918 		if (available > READ_BACKOFF)
919 			goto start_timer;
920 	}
921 
922 	new_size = EVBUFFER_LENGTH(evb) - wp->pipe_off;
923 	if (wp->pipe_fd != -1 && new_size > 0) {
924 		new_data = EVBUFFER_DATA(evb);
925 		bufferevent_write(wp->pipe_event, new_data, new_size);
926 	}
927 
928 	input_parse(wp);
929 
930 	wp->pipe_off = EVBUFFER_LENGTH(evb);
931 	return;
932 
933 start_timer:
934 	log_debug("%%%u backing off (%s %zu > %d)", wp->id, c->ttyname,
935 	    available, READ_BACKOFF);
936 
937 	tv.tv_sec = 0;
938 	tv.tv_usec = READ_TIME;
939 
940 	evtimer_set(&wp->timer, window_pane_timer_callback, wp);
941 	evtimer_add(&wp->timer, &tv);
942 }
943 
944 void
945 window_pane_error_callback(unused struct bufferevent *bufev, unused short what,
946     void *data)
947 {
948 	struct window_pane *wp = data;
949 
950 	server_destroy_pane(wp);
951 }
952 
953 void
954 window_pane_resize(struct window_pane *wp, u_int sx, u_int sy)
955 {
956 	if (sx == wp->sx && sy == wp->sy)
957 		return;
958 	wp->sx = sx;
959 	wp->sy = sy;
960 
961 	screen_resize(&wp->base, sx, sy, wp->saved_grid == NULL);
962 	if (wp->mode != NULL)
963 		wp->mode->resize(wp, sx, sy);
964 
965 	wp->flags |= PANE_RESIZE;
966 }
967 
968 /*
969  * Enter alternative screen mode. A copy of the visible screen is saved and the
970  * history is not updated
971  */
972 void
973 window_pane_alternate_on(struct window_pane *wp, struct grid_cell *gc,
974     int cursor)
975 {
976 	struct screen	*s = &wp->base;
977 	u_int		 sx, sy;
978 
979 	if (wp->saved_grid != NULL)
980 		return;
981 	if (!options_get_number(&wp->window->options, "alternate-screen"))
982 		return;
983 	sx = screen_size_x(s);
984 	sy = screen_size_y(s);
985 
986 	wp->saved_grid = grid_create(sx, sy, 0);
987 	grid_duplicate_lines(wp->saved_grid, 0, s->grid, screen_hsize(s), sy);
988 	if (cursor) {
989 		wp->saved_cx = s->cx;
990 		wp->saved_cy = s->cy;
991 	}
992 	memcpy(&wp->saved_cell, gc, sizeof wp->saved_cell);
993 
994 	grid_view_clear(s->grid, 0, 0, sx, sy);
995 
996 	wp->base.grid->flags &= ~GRID_HISTORY;
997 
998 	wp->flags |= PANE_REDRAW;
999 }
1000 
1001 /* Exit alternate screen mode and restore the copied grid. */
1002 void
1003 window_pane_alternate_off(struct window_pane *wp, struct grid_cell *gc,
1004     int cursor)
1005 {
1006 	struct screen	*s = &wp->base;
1007 	u_int		 sx, sy;
1008 
1009 	if (wp->saved_grid == NULL)
1010 		return;
1011 	if (!options_get_number(&wp->window->options, "alternate-screen"))
1012 		return;
1013 	sx = screen_size_x(s);
1014 	sy = screen_size_y(s);
1015 
1016 	/*
1017 	 * If the current size is bigger, temporarily resize to the old size
1018 	 * before copying back.
1019 	 */
1020 	if (sy > wp->saved_grid->sy)
1021 		screen_resize(s, sx, wp->saved_grid->sy, 1);
1022 
1023 	/* Restore the grid, cursor position and cell. */
1024 	grid_duplicate_lines(s->grid, screen_hsize(s), wp->saved_grid, 0, sy);
1025 	if (cursor)
1026 		s->cx = wp->saved_cx;
1027 	if (s->cx > screen_size_x(s) - 1)
1028 		s->cx = screen_size_x(s) - 1;
1029 	if (cursor)
1030 		s->cy = wp->saved_cy;
1031 	if (s->cy > screen_size_y(s) - 1)
1032 		s->cy = screen_size_y(s) - 1;
1033 	memcpy(gc, &wp->saved_cell, sizeof *gc);
1034 
1035 	/*
1036 	 * Turn history back on (so resize can use it) and then resize back to
1037 	 * the current size.
1038 	 */
1039 	wp->base.grid->flags |= GRID_HISTORY;
1040 	if (sy > wp->saved_grid->sy || sx != wp->saved_grid->sx)
1041 		screen_resize(s, sx, sy, 1);
1042 
1043 	grid_destroy(wp->saved_grid);
1044 	wp->saved_grid = NULL;
1045 
1046 	wp->flags |= PANE_REDRAW;
1047 }
1048 
1049 int
1050 window_pane_set_mode(struct window_pane *wp, const struct window_mode *mode)
1051 {
1052 	struct screen	*s;
1053 
1054 	if (wp->mode != NULL)
1055 		return (1);
1056 	wp->mode = mode;
1057 
1058 	if ((s = wp->mode->init(wp)) != NULL)
1059 		wp->screen = s;
1060 	wp->flags |= (PANE_REDRAW|PANE_CHANGED);
1061 	return (0);
1062 }
1063 
1064 void
1065 window_pane_reset_mode(struct window_pane *wp)
1066 {
1067 	if (wp->mode == NULL)
1068 		return;
1069 
1070 	wp->mode->free(wp);
1071 	wp->mode = NULL;
1072 
1073 	wp->screen = &wp->base;
1074 	wp->flags |= (PANE_REDRAW|PANE_CHANGED);
1075 }
1076 
1077 void
1078 window_pane_key(struct window_pane *wp, struct client *c, struct session *s,
1079     int key, struct mouse_event *m)
1080 {
1081 	struct window_pane	*wp2;
1082 
1083 	if (KEYC_IS_MOUSE(key) && m == NULL)
1084 		return;
1085 
1086 	if (wp->mode != NULL) {
1087 		if (wp->mode->key != NULL)
1088 			wp->mode->key(wp, c, s, key, m);
1089 		return;
1090 	}
1091 
1092 	if (wp->fd == -1 || wp->flags & PANE_INPUTOFF)
1093 		return;
1094 
1095 	input_key(wp, key, m);
1096 
1097 	if (KEYC_IS_MOUSE(key))
1098 		return;
1099 	if (options_get_number(&wp->window->options, "synchronize-panes")) {
1100 		TAILQ_FOREACH(wp2, &wp->window->panes, entry) {
1101 			if (wp2 == wp || wp2->mode != NULL)
1102 				continue;
1103 			if (wp2->fd != -1 && window_pane_visible(wp2))
1104 				input_key(wp2, key, NULL);
1105 		}
1106 	}
1107 }
1108 
1109 int
1110 window_pane_visible(struct window_pane *wp)
1111 {
1112 	struct window	*w = wp->window;
1113 
1114 	if (wp->layout_cell == NULL)
1115 		return (0);
1116 	if (wp->xoff >= w->sx || wp->yoff >= w->sy)
1117 		return (0);
1118 	if (wp->xoff + wp->sx > w->sx || wp->yoff + wp->sy > w->sy)
1119 		return (0);
1120 	return (1);
1121 }
1122 
1123 char *
1124 window_pane_search(struct window_pane *wp, const char *searchstr,
1125     u_int *lineno)
1126 {
1127 	struct screen	*s = &wp->base;
1128 	char		*newsearchstr, *line, *msg;
1129 	u_int	 	 i;
1130 
1131 	msg = NULL;
1132 	xasprintf(&newsearchstr, "*%s*", searchstr);
1133 
1134 	for (i = 0; i < screen_size_y(s); i++) {
1135 		line = grid_view_string_cells(s->grid, 0, i, screen_size_x(s));
1136 		if (fnmatch(newsearchstr, line, 0) == 0) {
1137 			msg = line;
1138 			if (lineno != NULL)
1139 				*lineno = i;
1140 			break;
1141 		}
1142 		free(line);
1143 	}
1144 
1145 	free(newsearchstr);
1146 	return (msg);
1147 }
1148 
1149 /* Get MRU pane from a list. */
1150 struct window_pane *
1151 window_pane_choose_best(struct window_pane **list, u_int size)
1152 {
1153 	struct window_pane	*next, *best;
1154 	u_int			 i;
1155 
1156 	if (size == 0)
1157 		return (NULL);
1158 
1159 	best = list[0];
1160 	for (i = 1; i < size; i++) {
1161 		next = list[i];
1162 		if (next->active_point > best->active_point)
1163 			best = next;
1164 	}
1165 	return (best);
1166 }
1167 
1168 /*
1169  * Find the pane directly above another. We build a list of those adjacent to
1170  * top edge and then choose the best.
1171  */
1172 struct window_pane *
1173 window_pane_find_up(struct window_pane *wp)
1174 {
1175 	struct window_pane	*next, *best, **list;
1176 	u_int			 edge, left, right, end, size;
1177 	int			 found;
1178 
1179 	if (wp == NULL || !window_pane_visible(wp))
1180 		return (NULL);
1181 
1182 	list = NULL;
1183 	size = 0;
1184 
1185 	edge = wp->yoff;
1186 	if (edge == 0)
1187 		edge = wp->window->sy + 1;
1188 
1189 	left = wp->xoff;
1190 	right = wp->xoff + wp->sx;
1191 
1192 	TAILQ_FOREACH(next, &wp->window->panes, entry) {
1193 		if (next == wp || !window_pane_visible(next))
1194 			continue;
1195 		if (next->yoff + next->sy + 1 != edge)
1196 			continue;
1197 		end = next->xoff + next->sx - 1;
1198 
1199 		found = 0;
1200 		if (next->xoff < left && end > right)
1201 			found = 1;
1202 		else if (next->xoff >= left && next->xoff <= right)
1203 			found = 1;
1204 		else if (end >= left && end <= right)
1205 			found = 1;
1206 		if (!found)
1207 			continue;
1208 		list = xreallocarray(list, size + 1, sizeof *list);
1209 		list[size++] = next;
1210 	}
1211 
1212 	best = window_pane_choose_best(list, size);
1213 	free(list);
1214 	return (best);
1215 }
1216 
1217 /* Find the pane directly below another. */
1218 struct window_pane *
1219 window_pane_find_down(struct window_pane *wp)
1220 {
1221 	struct window_pane	*next, *best, **list;
1222 	u_int			 edge, left, right, end, size;
1223 	int			 found;
1224 
1225 	if (wp == NULL || !window_pane_visible(wp))
1226 		return (NULL);
1227 
1228 	list = NULL;
1229 	size = 0;
1230 
1231 	edge = wp->yoff + wp->sy + 1;
1232 	if (edge >= wp->window->sy)
1233 		edge = 0;
1234 
1235 	left = wp->xoff;
1236 	right = wp->xoff + wp->sx;
1237 
1238 	TAILQ_FOREACH(next, &wp->window->panes, entry) {
1239 		if (next == wp || !window_pane_visible(next))
1240 			continue;
1241 		if (next->yoff != edge)
1242 			continue;
1243 		end = next->xoff + next->sx - 1;
1244 
1245 		found = 0;
1246 		if (next->xoff < left && end > right)
1247 			found = 1;
1248 		else if (next->xoff >= left && next->xoff <= right)
1249 			found = 1;
1250 		else if (end >= left && end <= right)
1251 			found = 1;
1252 		if (!found)
1253 			continue;
1254 		list = xreallocarray(list, size + 1, sizeof *list);
1255 		list[size++] = next;
1256 	}
1257 
1258 	best = window_pane_choose_best(list, size);
1259 	free(list);
1260 	return (best);
1261 }
1262 
1263 /* Find the pane directly to the left of another. */
1264 struct window_pane *
1265 window_pane_find_left(struct window_pane *wp)
1266 {
1267 	struct window_pane	*next, *best, **list;
1268 	u_int			 edge, top, bottom, end, size;
1269 	int			 found;
1270 
1271 	if (wp == NULL || !window_pane_visible(wp))
1272 		return (NULL);
1273 
1274 	list = NULL;
1275 	size = 0;
1276 
1277 	edge = wp->xoff;
1278 	if (edge == 0)
1279 		edge = wp->window->sx + 1;
1280 
1281 	top = wp->yoff;
1282 	bottom = wp->yoff + wp->sy;
1283 
1284 	TAILQ_FOREACH(next, &wp->window->panes, entry) {
1285 		if (next == wp || !window_pane_visible(next))
1286 			continue;
1287 		if (next->xoff + next->sx + 1 != edge)
1288 			continue;
1289 		end = next->yoff + next->sy - 1;
1290 
1291 		found = 0;
1292 		if (next->yoff < top && end > bottom)
1293 			found = 1;
1294 		else if (next->yoff >= top && next->yoff <= bottom)
1295 			found = 1;
1296 		else if (end >= top && end <= bottom)
1297 			found = 1;
1298 		if (!found)
1299 			continue;
1300 		list = xreallocarray(list, size + 1, sizeof *list);
1301 		list[size++] = next;
1302 	}
1303 
1304 	best = window_pane_choose_best(list, size);
1305 	free(list);
1306 	return (best);
1307 }
1308 
1309 /* Find the pane directly to the right of another. */
1310 struct window_pane *
1311 window_pane_find_right(struct window_pane *wp)
1312 {
1313 	struct window_pane	*next, *best, **list;
1314 	u_int			 edge, top, bottom, end, size;
1315 	int			 found;
1316 
1317 	if (wp == NULL || !window_pane_visible(wp))
1318 		return (NULL);
1319 
1320 	list = NULL;
1321 	size = 0;
1322 
1323 	edge = wp->xoff + wp->sx + 1;
1324 	if (edge >= wp->window->sx)
1325 		edge = 0;
1326 
1327 	top = wp->yoff;
1328 	bottom = wp->yoff + wp->sy;
1329 
1330 	TAILQ_FOREACH(next, &wp->window->panes, entry) {
1331 		if (next == wp || !window_pane_visible(next))
1332 			continue;
1333 		if (next->xoff != edge)
1334 			continue;
1335 		end = next->yoff + next->sy - 1;
1336 
1337 		found = 0;
1338 		if (next->yoff < top && end > bottom)
1339 			found = 1;
1340 		else if (next->yoff >= top && next->yoff <= bottom)
1341 			found = 1;
1342 		else if (end >= top && end <= bottom)
1343 			found = 1;
1344 		if (!found)
1345 			continue;
1346 		list = xreallocarray(list, size + 1, sizeof *list);
1347 		list[size++] = next;
1348 	}
1349 
1350 	best = window_pane_choose_best(list, size);
1351 	free(list);
1352 	return (best);
1353 }
1354 
1355 /* Clear alert flags for a winlink */
1356 void
1357 winlink_clear_flags(struct winlink *wl)
1358 {
1359 	struct session	*s;
1360 	struct winlink	*wl_loop;
1361 
1362 	RB_FOREACH(s, sessions, &sessions) {
1363 		RB_FOREACH(wl_loop, winlinks, &s->windows) {
1364 			if (wl_loop->window != wl->window)
1365 				continue;
1366 			if ((wl_loop->flags & WINLINK_ALERTFLAGS) == 0)
1367 				continue;
1368 
1369 			wl_loop->flags &= ~WINLINK_ALERTFLAGS;
1370 			wl_loop->window->flags &= ~WINDOW_ALERTFLAGS;
1371 			server_status_session(s);
1372 		}
1373 	}
1374 }
1375 
1376 int
1377 winlink_shuffle_up(struct session *s, struct winlink *wl)
1378 {
1379 	int	 idx, last;
1380 
1381 	idx = wl->idx + 1;
1382 
1383 	/* Find the next free index. */
1384 	for (last = idx; last < INT_MAX; last++) {
1385 		if (winlink_find_by_index(&s->windows, last) == NULL)
1386 			break;
1387 	}
1388 	if (last == INT_MAX)
1389 		return (-1);
1390 
1391 	/* Move everything from last - 1 to idx up a bit. */
1392 	for (; last > idx; last--) {
1393 		wl = winlink_find_by_index(&s->windows, last - 1);
1394 		server_link_window(s, wl, s, last, 0, 0, NULL);
1395 		server_unlink_window(s, wl);
1396 	}
1397 
1398 	return (idx);
1399 }
1400