session.c - tmux - Rivoreo Source Code Repositories

 /* $OpenBSD$ */

 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
  *
  * 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/time.h>

 #include <paths.h>
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <time.h>

 #include "tmux.h"

 /* Global session list. */
 struct sessions	sessions;
 struct sessions dead_sessions;
 struct session_groups session_groups;

 struct winlink *session_next_activity(struct session *, struct winlink *);
 struct winlink *session_previous_activity(struct session *, struct winlink *);

 void
 session_alert_cancel(struct session *s, struct winlink *wl)
 {
 	struct session_alert	*sa, *sb;

 	sa = SLIST_FIRST(&s->alerts);
 	while (sa != NULL) {
 		sb = sa;
 		sa = SLIST_NEXT(sa, entry);

 		if (wl == NULL || sb->wl == wl) {
 			SLIST_REMOVE(&s->alerts, sb, session_alert, entry);
 			xfree(sb);
 		}
 	}
 }

 void
 session_alert_add(struct session *s, struct window *w, int type)
 {
 	struct session_alert	*sa;
 	struct winlink		*wl;

 	RB_FOREACH(wl, winlinks, &s->windows) {
 		if (wl == s->curw)
 			continue;

 		if (wl->window == w &&
 		    !session_alert_has(s, wl, type)) {
 			sa = xmalloc(sizeof *sa);
 			sa->wl = wl;
 			sa->type = type;
 			SLIST_INSERT_HEAD(&s->alerts, sa, entry);
 		}
 	}
 }

 int
 session_alert_has(struct session *s, struct winlink *wl, int type)
 {
 	struct session_alert	*sa;

 	SLIST_FOREACH(sa, &s->alerts, entry) {
 		if (sa->wl == wl && sa->type == type)
 			return (1);
 	}

 	return (0);
 }

 int
 session_alert_has_window(struct session *s, struct window *w, int type)
 {
 	struct session_alert	*sa;

 	SLIST_FOREACH(sa, &s->alerts, entry) {
 		if (sa->wl->window == w && sa->type == type)
 			return (1);
 	}

 	return (0);
 }

 /* Find session by name. */
 struct session *
 session_find(const char *name)
 {
 	struct session	*s;
 	u_int		 i;

 	for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
 		s = ARRAY_ITEM(&sessions, i);
 		if (s != NULL && strcmp(s->name, name) == 0)
 			return (s);
 	}

 	return (NULL);
 }

 /* Create a new session. */
 struct session *
 session_create(const char *name, const char *cmd, const char *cwd,
     struct environ *env, struct termios *tio, int idx, u_int sx, u_int sy,
     char **cause)
 {
 	struct session	*s;
 	u_int		 i;

 	s = xmalloc(sizeof *s);
 	s->references = 0;
 	s->flags = 0;
 	s->activity = time(NULL);

 	if (gettimeofday(&s->tv, NULL) != 0)
 		fatal("gettimeofday failed");

 	s->curw = NULL;
 	TAILQ_INIT(&s->lastw);
 	RB_INIT(&s->windows);
 	SLIST_INIT(&s->alerts);

 	paste_init_stack(&s->buffers);

 	options_init(&s->options, &global_s_options);
 	environ_init(&s->environ);
 	if (env != NULL)
 		environ_copy(env, &s->environ);

 	s->tio = NULL;
 	if (tio != NULL) {
 		s->tio = xmalloc(sizeof *s->tio);
 		memcpy(s->tio, tio, sizeof *s->tio);
 	}

 	s->sx = sx;
 	s->sy = sy;

 	for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
 		if (ARRAY_ITEM(&sessions, i) == NULL) {
 			ARRAY_SET(&sessions, i, s);
 			break;
 		}
 	}
 	if (i == ARRAY_LENGTH(&sessions))
 		ARRAY_ADD(&sessions, s);

 	if (name != NULL)
 		s->name = xstrdup(name);
 	else
 		xasprintf(&s->name, "%u", i);

 	if (cmd != NULL) {
 		if (session_new(s, NULL, cmd, cwd, idx, cause) == NULL) {
 			session_destroy(s);
 			return (NULL);
 		}
 		session_select(s, RB_ROOT(&s->windows)->idx);
 	}

 	log_debug("session %s created", s->name);

 	return (s);
 }

 /* Destroy a session. */
 void
 session_destroy(struct session *s)
 {
 	u_int	i;

 	log_debug("session %s destroyed", s->name);

 	if (session_index(s, &i) != 0)
 		fatalx("session not found");
 	ARRAY_SET(&sessions, i, NULL);
 	while (!ARRAY_EMPTY(&sessions) && ARRAY_LAST(&sessions) == NULL)
 		ARRAY_TRUNC(&sessions, 1);

 	if (s->tio != NULL)
 		xfree(s->tio);

 	session_group_remove(s);
 	session_alert_cancel(s, NULL);
 	environ_free(&s->environ);
 	options_free(&s->options);
 	paste_free_stack(&s->buffers);

 	while (!TAILQ_EMPTY(&s->lastw))
 		winlink_stack_remove(&s->lastw, TAILQ_FIRST(&s->lastw));
 	while (!RB_EMPTY(&s->windows))
 		winlink_remove(&s->windows, RB_ROOT(&s->windows));

 	xfree(s->name);

 	for (i = 0; i < ARRAY_LENGTH(&dead_sessions); i++) {
 		if (ARRAY_ITEM(&dead_sessions, i) == NULL) {
 			ARRAY_SET(&dead_sessions, i, s);
 			break;
 		}
 	}
 	if (i == ARRAY_LENGTH(&dead_sessions))
 		ARRAY_ADD(&dead_sessions, s);
 	s->flags |= SESSION_DEAD;
 }

 /* Find session index. */
 int
 session_index(struct session *s, u_int *i)
 {
 	for (*i = 0; *i < ARRAY_LENGTH(&sessions); (*i)++) {
 		if (s == ARRAY_ITEM(&sessions, *i))
 			return (0);
 	}
 	return (-1);
 }

 /* Create a new window on a session. */
 struct winlink *
 session_new(struct session *s,
     const char *name, const char *cmd, const char *cwd, int idx, char **cause)
 {
 	struct window	*w;
 	struct environ	 env;
 	const char	*shell;
 	u_int		 hlimit;

 	environ_init(&env);
 	environ_copy(&global_environ, &env);
 	environ_copy(&s->environ, &env);
 	server_fill_environ(s, &env);

 	shell = options_get_string(&s->options, "default-shell");
 	if (*shell == '\0' || areshell(shell))
 		shell = _PATH_BSHELL;

 	hlimit = options_get_number(&s->options, "history-limit");
 	w = window_create(
 	    name, cmd, shell, cwd, &env, s->tio, s->sx, s->sy, hlimit, cause);
 	if (w == NULL) {
 		environ_free(&env);
 		return (NULL);
 	}
 	environ_free(&env);

 	if (options_get_number(&s->options, "set-remain-on-exit"))
 		options_set_number(&w->options, "remain-on-exit", 1);

 	return (session_attach(s, w, idx, cause));
 }

 /* Attach a window to a session. */
 struct winlink *
 session_attach(struct session *s, struct window *w, int idx, char **cause)
 {
 	struct winlink	*wl;

 	if ((wl = winlink_add(&s->windows, w, idx)) == NULL)
 		xasprintf(cause, "index in use: %d", idx);
 	session_group_synchronize_from(s);
 	return (wl);
 }

 /* Detach a window from a session. */
 int
 session_detach(struct session *s, struct winlink *wl)
 {
 	if (s->curw == wl &&
 	    session_last(s) != 0 && session_previous(s, 0) != 0)
 		session_next(s, 0);

 	session_alert_cancel(s, wl);
 	winlink_stack_remove(&s->lastw, wl);
 	winlink_remove(&s->windows, wl);
 	session_group_synchronize_from(s);
 	if (RB_EMPTY(&s->windows)) {
 		session_destroy(s);
 		return (1);
 	}
 	return (0);
 }

 /* Return if session has window. */
 int
 session_has(struct session *s, struct window *w)
 {
 	struct winlink	*wl;

 	RB_FOREACH(wl, winlinks, &s->windows) {
 		if (wl->window == w)
 			return (1);
 	}
 	return (0);
 }

 struct winlink *
 session_next_activity(struct session *s, struct winlink *wl)
 {
 	while (wl != NULL) {
 		if (session_alert_has(s, wl, WINDOW_BELL))
 			break;
 		if (session_alert_has(s, wl, WINDOW_ACTIVITY))
 			break;
 		if (session_alert_has(s, wl, WINDOW_CONTENT))
 			break;
 		wl = winlink_next(&s->windows, wl);
 	}
 	return (wl);
 }

 /* Move session to next window. */
 int
 session_next(struct session *s, int activity)
 {
 	struct winlink	*wl;

 	if (s->curw == NULL)
 		return (-1);

 	wl = winlink_next(&s->windows, s->curw);
 	if (activity)
 		wl = session_next_activity(s, wl);
 	if (wl == NULL) {
 		wl = RB_MIN(winlinks, &s->windows);
 		if (activity && ((wl = session_next_activity(s, wl)) == NULL))
 			return (-1);
 	}
 	if (wl == s->curw)
 		return (1);
 	winlink_stack_remove(&s->lastw, wl);
 	winlink_stack_push(&s->lastw, s->curw);
 	s->curw = wl;
 	session_alert_cancel(s, wl);
 	return (0);
 }

 struct winlink *
 session_previous_activity(struct session *s, struct winlink *wl)
 {
 	while (wl != NULL) {
 		if (session_alert_has(s, wl, WINDOW_BELL))
 			break;
 		if (session_alert_has(s, wl, WINDOW_ACTIVITY))
 			break;
 		if (session_alert_has(s, wl, WINDOW_CONTENT))
 			break;
 		wl = winlink_previous(&s->windows, wl);
 	}
 	return (wl);
 }

 /* Move session to previous window. */
 int
 session_previous(struct session *s, int activity)
 {
 	struct winlink	*wl;

 	if (s->curw == NULL)
 		return (-1);

 	wl = winlink_previous(&s->windows, s->curw);
 	if (activity)
 		wl = session_previous_activity(s, wl);
 	if (wl == NULL) {
 		wl = RB_MAX(winlinks, &s->windows);
 		if (activity && (wl = session_previous_activity(s, wl)) == NULL)
 			return (-1);
 	}
 	if (wl == s->curw)
 		return (1);
 	winlink_stack_remove(&s->lastw, wl);
 	winlink_stack_push(&s->lastw, s->curw);
 	s->curw = wl;
 	session_alert_cancel(s, wl);
 	return (0);
 }

 /* Move session to specific window. */
 int
 session_select(struct session *s, int idx)
 {
 	struct winlink	*wl;

 	wl = winlink_find_by_index(&s->windows, idx);
 	if (wl == NULL)
 		return (-1);
 	if (wl == s->curw)
 		return (1);
 	winlink_stack_remove(&s->lastw, wl);
 	winlink_stack_push(&s->lastw, s->curw);
 	s->curw = wl;
 	session_alert_cancel(s, wl);
 	return (0);
 }

 /* Move session to last used window. */
 int
 session_last(struct session *s)
 {
 	struct winlink	*wl;

 	wl = TAILQ_FIRST(&s->lastw);
 	if (wl == NULL)
 		return (-1);
 	if (wl == s->curw)
 		return (1);

 	winlink_stack_remove(&s->lastw, wl);
 	winlink_stack_push(&s->lastw, s->curw);
 	s->curw = wl;
 	session_alert_cancel(s, wl);
 	return (0);
 }

 /* Find the session group containing a session. */
 struct session_group *
 session_group_find(struct session *target)
 {
 	struct session_group	*sg;
 	struct session		*s;

 	TAILQ_FOREACH(sg, &session_groups, entry) {
 		TAILQ_FOREACH(s, &sg->sessions, gentry) {
 			if (s == target)
 				return (sg);
 		}
 	}
 	return (NULL);
 }

 /* Find session group index. */
 u_int
 session_group_index(struct session_group *sg)
 {
 	struct session_group   *sg2;
 	u_int			i;

 	i = 0;
 	TAILQ_FOREACH(sg2, &session_groups, entry) {
 		if (sg == sg2)
 			return (i);
 		i++;
 	}

 	fatalx("session group not found");
 }

 /*
  * Add a session to the session group containing target, creating it if
  * necessary.
  */
 void
 session_group_add(struct session *target, struct session *s)
 {
 	struct session_group	*sg;

 	if ((sg = session_group_find(target)) == NULL) {
 		sg = xmalloc(sizeof *sg);
 		TAILQ_INSERT_TAIL(&session_groups, sg, entry);
 		TAILQ_INIT(&sg->sessions);
 		TAILQ_INSERT_TAIL(&sg->sessions, target, gentry);
 	}
 	TAILQ_INSERT_TAIL(&sg->sessions, s, gentry);
 }

 /* Remove a session from its group and destroy the group if empty. */
 void
 session_group_remove(struct session *s)
 {
 	struct session_group	*sg;

 	if ((sg = session_group_find(s)) == NULL)
 		return;
 	TAILQ_REMOVE(&sg->sessions, s, gentry);
 	if (TAILQ_NEXT(TAILQ_FIRST(&sg->sessions), gentry) == NULL)
 		TAILQ_REMOVE(&sg->sessions, TAILQ_FIRST(&sg->sessions), gentry);
 	if (TAILQ_EMPTY(&sg->sessions)) {
 		TAILQ_REMOVE(&session_groups, sg, entry);
 		xfree(sg);
 	}
 }

 /* Synchronize a session to its session group. */
 void
 session_group_synchronize_to(struct session *s)
 {
 	struct session_group	*sg;
 	struct session		*target;

 	if ((sg = session_group_find(s)) == NULL)
 		return;

 	target = NULL;
 	TAILQ_FOREACH(target, &sg->sessions, gentry) {
 		if (target != s)
 			break;
 	}
 	session_group_synchronize1(target, s);
 }

 /* Synchronize a session group to a session. */
 void
 session_group_synchronize_from(struct session *target)
 {
 	struct session_group	*sg;
 	struct session		*s;

 	if ((sg = session_group_find(target)) == NULL)
 		return;

 	TAILQ_FOREACH(s, &sg->sessions, gentry) {
 		if (s != target)
 			session_group_synchronize1(target, s);
 	}
 }

 /*
  * Synchronize a session with a target session. This means destroying all
  * winlinks then recreating them, then updating the current window, last window
  * stack and alerts.
  */
 void
 session_group_synchronize1(struct session *target, struct session *s)
 {
 	struct winlinks		 old_windows, *ww;
 	struct winlink_stack	 old_lastw;
 	struct winlink		*wl, *wl2;
 	struct session_alert	*sa;

 	/* Don't do anything if the session is empty (it'll be destroyed). */
 	ww = &target->windows;
 	if (RB_EMPTY(ww))
 		return;

 	/* If the current window has vanished, move to the next now. */
 	if (s->curw != NULL) {
 		while (winlink_find_by_index(ww, s->curw->idx) == NULL)
 			session_next(s, 0);
 	}

 	/* Save the old pointer and reset it. */
 	memcpy(&old_windows, &s->windows, sizeof old_windows);
 	RB_INIT(&s->windows);

 	/* Link all the windows from the target. */
 	RB_FOREACH(wl, winlinks, ww)
 		winlink_add(&s->windows, wl->window, wl->idx);

 	/* Fix up the current window. */
 	if (s->curw != NULL)
 		s->curw = winlink_find_by_index(&s->windows, s->curw->idx);
 	else
 		s->curw = winlink_find_by_index(&s->windows, target->curw->idx);

 	/* Fix up the last window stack. */
 	memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
 	TAILQ_INIT(&s->lastw);
 	TAILQ_FOREACH(wl, &old_lastw, sentry) {
 		wl2 = winlink_find_by_index(&s->windows, wl->idx);
 		if (wl2 != NULL)
 			TAILQ_INSERT_TAIL(&s->lastw, wl2, sentry);
 	}

 	/* And update the alerts list. */
 	SLIST_FOREACH(sa, &s->alerts, entry) {
 		wl = winlink_find_by_index(&s->windows, sa->wl->idx);
 		if (wl == NULL)
 			session_alert_cancel(s, sa->wl);
 		else
 			sa->wl = wl;
 	}

 	/* Then free the old winlinks list. */
 	while (!RB_EMPTY(&old_windows)) {
 		wl = RB_ROOT(&old_windows);
 		RB_REMOVE(winlinks, &old_windows, wl);
 		xfree(wl);
 	}
 }
	/* $OpenBSD$ */

	/*
	* Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
	*
	* 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/time.h>

	#include <paths.h>
	#include <string.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <time.h>

	#include "tmux.h"

	/* Global session list. */
	struct sessions sessions;
	struct sessions dead_sessions;
	struct session_groups session_groups;

	struct winlink session_next_activity(struct session , struct winlink *);
	struct winlink session_previous_activity(struct session , struct winlink *);

	void
	session_alert_cancel(struct session s, struct winlink wl)
	{
	struct session_alert sa, sb;

	sa = SLIST_FIRST(&s->alerts);
	while (sa != NULL) {
	sb = sa;
	sa = SLIST_NEXT(sa, entry);

	if (wl == NULL \|\| sb->wl == wl) {
	SLIST_REMOVE(&s->alerts, sb, session_alert, entry);
	xfree(sb);
	}
	}
	}

	void
	session_alert_add(struct session s, struct window w, int type)
	{
	struct session_alert *sa;
	struct winlink *wl;

	RB_FOREACH(wl, winlinks, &s->windows) {
	if (wl == s->curw)
	continue;

	if (wl->window == w &&
	!session_alert_has(s, wl, type)) {
	sa = xmalloc(sizeof *sa);
	sa->wl = wl;
	sa->type = type;
	SLIST_INSERT_HEAD(&s->alerts, sa, entry);
	}
	}
	}

	int
	session_alert_has(struct session s, struct winlink wl, int type)
	{
	struct session_alert *sa;

	SLIST_FOREACH(sa, &s->alerts, entry) {
	if (sa->wl == wl && sa->type == type)
	return (1);
	}

	return (0);
	}

	int
	session_alert_has_window(struct session s, struct window w, int type)
	{
	struct session_alert *sa;

	SLIST_FOREACH(sa, &s->alerts, entry) {
	if (sa->wl->window == w && sa->type == type)
	return (1);
	}

	return (0);
	}

	/* Find session by name. */
	struct session *
	session_find(const char *name)
	{
	struct session *s;
	u_int i;

	for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
	s = ARRAY_ITEM(&sessions, i);
	if (s != NULL && strcmp(s->name, name) == 0)
	return (s);
	}

	return (NULL);
	}

	/* Create a new session. */
	struct session *
	session_create(const char name, const char cmd, const char *cwd,
	struct environ env, struct termios tio, int idx, u_int sx, u_int sy,
	char **cause)
	{
	struct session *s;
	u_int i;

	s = xmalloc(sizeof *s);
	s->references = 0;
	s->flags = 0;
	s->activity = time(NULL);

	if (gettimeofday(&s->tv, NULL) != 0)
	fatal("gettimeofday failed");

	s->curw = NULL;
	TAILQ_INIT(&s->lastw);
	RB_INIT(&s->windows);
	SLIST_INIT(&s->alerts);

	paste_init_stack(&s->buffers);

	options_init(&s->options, &global_s_options);
	environ_init(&s->environ);
	if (env != NULL)
	environ_copy(env, &s->environ);

	s->tio = NULL;
	if (tio != NULL) {
	s->tio = xmalloc(sizeof *s->tio);
	memcpy(s->tio, tio, sizeof *s->tio);
	}

	s->sx = sx;
	s->sy = sy;

	for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
	if (ARRAY_ITEM(&sessions, i) == NULL) {
	ARRAY_SET(&sessions, i, s);
	break;
	}
	}
	if (i == ARRAY_LENGTH(&sessions))
	ARRAY_ADD(&sessions, s);

	if (name != NULL)
	s->name = xstrdup(name);
	else
	xasprintf(&s->name, "%u", i);

	if (cmd != NULL) {
	if (session_new(s, NULL, cmd, cwd, idx, cause) == NULL) {
	session_destroy(s);
	return (NULL);
	}
	session_select(s, RB_ROOT(&s->windows)->idx);
	}

	log_debug("session %s created", s->name);

	return (s);
	}

	/* Destroy a session. */
	void
	session_destroy(struct session *s)
	{
	u_int i;

	log_debug("session %s destroyed", s->name);

	if (session_index(s, &i) != 0)
	fatalx("session not found");
	ARRAY_SET(&sessions, i, NULL);
	while (!ARRAY_EMPTY(&sessions) && ARRAY_LAST(&sessions) == NULL)
	ARRAY_TRUNC(&sessions, 1);

	if (s->tio != NULL)
	xfree(s->tio);

	session_group_remove(s);
	session_alert_cancel(s, NULL);
	environ_free(&s->environ);
	options_free(&s->options);
	paste_free_stack(&s->buffers);

	while (!TAILQ_EMPTY(&s->lastw))
	winlink_stack_remove(&s->lastw, TAILQ_FIRST(&s->lastw));
	while (!RB_EMPTY(&s->windows))
	winlink_remove(&s->windows, RB_ROOT(&s->windows));

	xfree(s->name);

	for (i = 0; i < ARRAY_LENGTH(&dead_sessions); i++) {
	if (ARRAY_ITEM(&dead_sessions, i) == NULL) {
	ARRAY_SET(&dead_sessions, i, s);
	break;
	}
	}
	if (i == ARRAY_LENGTH(&dead_sessions))
	ARRAY_ADD(&dead_sessions, s);
	s->flags \|= SESSION_DEAD;
	}

	/* Find session index. */
	int
	session_index(struct session s, u_int i)
	{
	for (i = 0; i < ARRAY_LENGTH(&sessions); (*i)++) {
	if (s == ARRAY_ITEM(&sessions, *i))
	return (0);
	}
	return (-1);
	}

	/* Create a new window on a session. */
	struct winlink *
	session_new(struct session *s,
	const char name, const char cmd, const char cwd, int idx, char *cause)
	{
	struct window *w;
	struct environ env;
	const char *shell;
	u_int hlimit;

	environ_init(&env);
	environ_copy(&global_environ, &env);
	environ_copy(&s->environ, &env);
	server_fill_environ(s, &env);

	shell = options_get_string(&s->options, "default-shell");
	if (*shell == '\0' \|\| areshell(shell))
	shell = _PATH_BSHELL;

	hlimit = options_get_number(&s->options, "history-limit");
	w = window_create(
	name, cmd, shell, cwd, &env, s->tio, s->sx, s->sy, hlimit, cause);
	if (w == NULL) {
	environ_free(&env);
	return (NULL);
	}
	environ_free(&env);

	if (options_get_number(&s->options, "set-remain-on-exit"))
	options_set_number(&w->options, "remain-on-exit", 1);

	return (session_attach(s, w, idx, cause));
	}

	/* Attach a window to a session. */
	struct winlink *
	session_attach(struct session s, struct window w, int idx, char **cause)
	{
	struct winlink *wl;

	if ((wl = winlink_add(&s->windows, w, idx)) == NULL)
	xasprintf(cause, "index in use: %d", idx);
	session_group_synchronize_from(s);
	return (wl);
	}

	/* Detach a window from a session. */
	int
	session_detach(struct session s, struct winlink wl)
	{
	if (s->curw == wl &&
	session_last(s) != 0 && session_previous(s, 0) != 0)
	session_next(s, 0);

	session_alert_cancel(s, wl);
	winlink_stack_remove(&s->lastw, wl);
	winlink_remove(&s->windows, wl);
	session_group_synchronize_from(s);
	if (RB_EMPTY(&s->windows)) {
	session_destroy(s);
	return (1);
	}
	return (0);
	}

	/* Return if session has window. */
	int
	session_has(struct session s, struct window w)
	{
	struct winlink *wl;

	RB_FOREACH(wl, winlinks, &s->windows) {
	if (wl->window == w)
	return (1);
	}
	return (0);
	}

	struct winlink *
	session_next_activity(struct session s, struct winlink wl)
	{
	while (wl != NULL) {
	if (session_alert_has(s, wl, WINDOW_BELL))
	break;
	if (session_alert_has(s, wl, WINDOW_ACTIVITY))
	break;
	if (session_alert_has(s, wl, WINDOW_CONTENT))
	break;
	wl = winlink_next(&s->windows, wl);
	}
	return (wl);
	}

	/* Move session to next window. */
	int
	session_next(struct session *s, int activity)
	{
	struct winlink *wl;

	if (s->curw == NULL)
	return (-1);

	wl = winlink_next(&s->windows, s->curw);
	if (activity)
	wl = session_next_activity(s, wl);
	if (wl == NULL) {
	wl = RB_MIN(winlinks, &s->windows);
	if (activity && ((wl = session_next_activity(s, wl)) == NULL))
	return (-1);
	}
	if (wl == s->curw)
	return (1);
	winlink_stack_remove(&s->lastw, wl);
	winlink_stack_push(&s->lastw, s->curw);
	s->curw = wl;
	session_alert_cancel(s, wl);
	return (0);
	}

	struct winlink *
	session_previous_activity(struct session s, struct winlink wl)
	{
	while (wl != NULL) {
	if (session_alert_has(s, wl, WINDOW_BELL))
	break;
	if (session_alert_has(s, wl, WINDOW_ACTIVITY))
	break;
	if (session_alert_has(s, wl, WINDOW_CONTENT))
	break;
	wl = winlink_previous(&s->windows, wl);
	}
	return (wl);
	}

	/* Move session to previous window. */
	int
	session_previous(struct session *s, int activity)
	{
	struct winlink *wl;

	if (s->curw == NULL)
	return (-1);

	wl = winlink_previous(&s->windows, s->curw);
	if (activity)
	wl = session_previous_activity(s, wl);
	if (wl == NULL) {
	wl = RB_MAX(winlinks, &s->windows);
	if (activity && (wl = session_previous_activity(s, wl)) == NULL)
	return (-1);
	}
	if (wl == s->curw)
	return (1);
	winlink_stack_remove(&s->lastw, wl);
	winlink_stack_push(&s->lastw, s->curw);
	s->curw = wl;
	session_alert_cancel(s, wl);
	return (0);
	}

	/* Move session to specific window. */
	int
	session_select(struct session *s, int idx)
	{
	struct winlink *wl;

	wl = winlink_find_by_index(&s->windows, idx);
	if (wl == NULL)
	return (-1);
	if (wl == s->curw)
	return (1);
	winlink_stack_remove(&s->lastw, wl);
	winlink_stack_push(&s->lastw, s->curw);
	s->curw = wl;
	session_alert_cancel(s, wl);
	return (0);
	}

	/* Move session to last used window. */
	int
	session_last(struct session *s)
	{
	struct winlink *wl;

	wl = TAILQ_FIRST(&s->lastw);
	if (wl == NULL)
	return (-1);
	if (wl == s->curw)
	return (1);

	winlink_stack_remove(&s->lastw, wl);
	winlink_stack_push(&s->lastw, s->curw);
	s->curw = wl;
	session_alert_cancel(s, wl);
	return (0);
	}

	/* Find the session group containing a session. */
	struct session_group *
	session_group_find(struct session *target)
	{
	struct session_group *sg;
	struct session *s;

	TAILQ_FOREACH(sg, &session_groups, entry) {
	TAILQ_FOREACH(s, &sg->sessions, gentry) {
	if (s == target)
	return (sg);
	}
	}
	return (NULL);
	}

	/* Find session group index. */
	u_int
	session_group_index(struct session_group *sg)
	{
	struct session_group *sg2;
	u_int i;

	i = 0;
	TAILQ_FOREACH(sg2, &session_groups, entry) {
	if (sg == sg2)
	return (i);
	i++;
	}

	fatalx("session group not found");
	}

	/*
	* Add a session to the session group containing target, creating it if
	* necessary.
	*/
	void
	session_group_add(struct session target, struct session s)
	{
	struct session_group *sg;

	if ((sg = session_group_find(target)) == NULL) {
	sg = xmalloc(sizeof *sg);
	TAILQ_INSERT_TAIL(&session_groups, sg, entry);
	TAILQ_INIT(&sg->sessions);
	TAILQ_INSERT_TAIL(&sg->sessions, target, gentry);
	}
	TAILQ_INSERT_TAIL(&sg->sessions, s, gentry);
	}

	/* Remove a session from its group and destroy the group if empty. */
	void
	session_group_remove(struct session *s)
	{
	struct session_group *sg;

	if ((sg = session_group_find(s)) == NULL)
	return;
	TAILQ_REMOVE(&sg->sessions, s, gentry);
	if (TAILQ_NEXT(TAILQ_FIRST(&sg->sessions), gentry) == NULL)
	TAILQ_REMOVE(&sg->sessions, TAILQ_FIRST(&sg->sessions), gentry);
	if (TAILQ_EMPTY(&sg->sessions)) {
	TAILQ_REMOVE(&session_groups, sg, entry);
	xfree(sg);
	}
	}

	/* Synchronize a session to its session group. */
	void
	session_group_synchronize_to(struct session *s)
	{
	struct session_group *sg;
	struct session *target;

	if ((sg = session_group_find(s)) == NULL)
	return;

	target = NULL;
	TAILQ_FOREACH(target, &sg->sessions, gentry) {
	if (target != s)
	break;
	}
	session_group_synchronize1(target, s);
	}

	/* Synchronize a session group to a session. */
	void
	session_group_synchronize_from(struct session *target)
	{
	struct session_group *sg;
	struct session *s;

	if ((sg = session_group_find(target)) == NULL)
	return;

	TAILQ_FOREACH(s, &sg->sessions, gentry) {
	if (s != target)
	session_group_synchronize1(target, s);
	}
	}

	/*
	* Synchronize a session with a target session. This means destroying all
	* winlinks then recreating them, then updating the current window, last window
	* stack and alerts.
	*/
	void
	session_group_synchronize1(struct session target, struct session s)
	{
	struct winlinks old_windows, *ww;
	struct winlink_stack old_lastw;
	struct winlink wl, wl2;
	struct session_alert *sa;

	/* Don't do anything if the session is empty (it'll be destroyed). */
	ww = &target->windows;
	if (RB_EMPTY(ww))
	return;

	/* If the current window has vanished, move to the next now. */
	if (s->curw != NULL) {
	while (winlink_find_by_index(ww, s->curw->idx) == NULL)
	session_next(s, 0);
	}

	/* Save the old pointer and reset it. */
	memcpy(&old_windows, &s->windows, sizeof old_windows);
	RB_INIT(&s->windows);

	/* Link all the windows from the target. */
	RB_FOREACH(wl, winlinks, ww)
	winlink_add(&s->windows, wl->window, wl->idx);

	/* Fix up the current window. */
	if (s->curw != NULL)
	s->curw = winlink_find_by_index(&s->windows, s->curw->idx);
	else
	s->curw = winlink_find_by_index(&s->windows, target->curw->idx);

	/* Fix up the last window stack. */
	memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
	TAILQ_INIT(&s->lastw);
	TAILQ_FOREACH(wl, &old_lastw, sentry) {
	wl2 = winlink_find_by_index(&s->windows, wl->idx);
	if (wl2 != NULL)
	TAILQ_INSERT_TAIL(&s->lastw, wl2, sentry);
	}

	/* And update the alerts list. */
	SLIST_FOREACH(sa, &s->alerts, entry) {
	wl = winlink_find_by_index(&s->windows, sa->wl->idx);
	if (wl == NULL)
	session_alert_cancel(s, sa->wl);
	else
	sa->wl = wl;
	}

	/* Then free the old winlinks list. */
	while (!RB_EMPTY(&old_windows)) {
	wl = RB_ROOT(&old_windows);
	RB_REMOVE(winlinks, &old_windows, wl);
	xfree(wl);
	}
	}