tmux.c - tmux - Rivoreo Source Code Repositories

 /* $OpenBSD$ */

 /*
  * Copyright (c) 2007 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/stat.h>
 #include <sys/utsname.h>

 #include <errno.h>
 #include <fcntl.h>
 #include <langinfo.h>
 #include <locale.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <unistd.h>

 #include "tmux.h"

 struct options	*global_options;	/* server options */
 struct options	*global_s_options;	/* session options */
 struct options	*global_w_options;	/* window options */
 struct environ	*global_environ;

 struct timeval	 start_time;
 const char	*socket_path;
 int		 ptm_fd = -1;
 const char	*shell_command;

 static __dead void	 usage(void);
 static char		*make_label(const char *, char **);

 static int		 areshell(const char *);
 static const char	*getshell(void);

 static __dead void
 usage(void)
 {
 	fprintf(stderr,
 	    "usage: %s [-2CDlNuVv] [-c shell-command] [-f file] [-L socket-name]\n"
 	    "            [-S socket-path] [-T features] [command [flags]]\n",
 	    getprogname());
 	exit(1);
 }

 static const char *
 getshell(void)
 {
 	struct passwd	*pw;
 	const char	*shell;

 	shell = getenv("SHELL");
 	if (checkshell(shell))
 		return (shell);

 	pw = getpwuid(getuid());
 	if (pw != NULL && checkshell(pw->pw_shell))
 		return (pw->pw_shell);

 	return (_PATH_BSHELL);
 }

 int
 checkshell(const char *shell)
 {
 	if (shell == NULL || *shell != '/')
 		return (0);
 	if (areshell(shell))
 		return (0);
 	if (access(shell, X_OK) != 0)
 		return (0);
 	return (1);
 }

 static int
 areshell(const char *shell)
 {
 	const char	*progname, *ptr;

 	if ((ptr = strrchr(shell, '/')) != NULL)
 		ptr++;
 	else
 		ptr = shell;
 	progname = getprogname();
 	if (*progname == '-')
 		progname++;
 	if (strcmp(ptr, progname) == 0)
 		return (1);
 	return (0);
 }

 static char *
 expand_path(const char *path, const char *home)
 {
 	char			*expanded, *name;
 	const char		*end;
 	struct environ_entry	*value;

 	if (strncmp(path, "~/", 2) == 0) {
 		if (home == NULL)
 			return (NULL);
 		xasprintf(&expanded, "%s%s", home, path + 1);
 		return (expanded);
 	}

 	if (*path == '$') {
 		end = strchr(path, '/');
 		if (end == NULL)
 			name = xstrdup(path + 1);
 		else
 			name = xstrndup(path + 1, end - path - 1);
 		value = environ_find(global_environ, name);
 		free(name);
 		if (value == NULL)
 			return (NULL);
 		if (end == NULL)
 			end = "";
 		xasprintf(&expanded, "%s%s", value->value, end);
 		return (expanded);
 	}

 	return (xstrdup(path));
 }

 static void
 expand_paths(const char *s, char ***paths, u_int *n, int ignore_errors)
 {
 	const char	*home = find_home();
 	char		*copy, *next, *tmp, resolved[PATH_MAX], *expanded;
 	char		*path;
 	u_int		 i;

 	*paths = NULL;
 	*n = 0;

 	copy = tmp = xstrdup(s);
 	while ((next = strsep(&tmp, ":")) != NULL) {
 		expanded = expand_path(next, home);
 		if (expanded == NULL) {
 			log_debug("%s: invalid path: %s", __func__, next);
 			continue;
 		}
 		if (realpath(expanded, resolved) == NULL) {
 			log_debug("%s: realpath(\"%s\") failed: %s", __func__,
 			    expanded, strerror(errno));
 			if (ignore_errors) {
 				free(expanded);
 				continue;
 			}
 			path = expanded;
 		} else {
 			path = xstrdup(resolved);
 			free(expanded);
 		}
 		for (i = 0; i < *n; i++) {
 			if (strcmp(path, (*paths)[i]) == 0)
 				break;
 		}
 		if (i != *n) {
 			log_debug("%s: duplicate path: %s", __func__, path);
 			free(path);
 			continue;
 		}
 		*paths = xreallocarray(*paths, (*n) + 1, sizeof *paths);
 		(*paths)[(*n)++] = path;
 	}
 	free(copy);
 }

 static char *
 make_label(const char *label, char **cause)
 {
 	char		**paths, *path, *base;
 	u_int		  i, n;
 	struct stat	  sb;
 	uid_t		  uid;

 	*cause = NULL;
 	if (label == NULL)
 		label = "default";
 	uid = getuid();

 	expand_paths(TMUX_SOCK, &paths, &n, 1);
 	if (n == 0) {
 		xasprintf(cause, "no suitable socket path");
 		return (NULL);
 	}
 	path = paths[0]; /* can only have one socket! */
 	for (i = 1; i < n; i++)
 		free(paths[i]);
 	free(paths);

 	xasprintf(&base, "%s/tmux-%ld", path, (long)uid);
 	free(path);
 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) {
 		xasprintf(cause, "couldn't create directory %s (%s)", base,
 		    strerror(errno));
 		goto fail;
 	}
 	if (lstat(base, &sb) != 0) {
 		xasprintf(cause, "couldn't read directory %s (%s)", base,
 		    strerror(errno));
 		goto fail;
 	}
 	if (!S_ISDIR(sb.st_mode)) {
 		xasprintf(cause, "%s is not a directory", base);
 		goto fail;
 	}
 	if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) {
 		xasprintf(cause, "directory %s has unsafe permissions", base);
 		goto fail;
 	}
 	xasprintf(&path, "%s/%s", base, label);
 	free(base);
 	return (path);

 fail:
 	free(base);
 	return (NULL);
 }

 void
 setblocking(int fd, int state)
 {
 	int mode;

 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
 		if (!state)
 			mode |= O_NONBLOCK;
 		else
 			mode &= ~O_NONBLOCK;
 		fcntl(fd, F_SETFL, mode);
 	}
 }

 uint64_t
 get_timer(void)
 {
 	struct timespec	ts;

 	/*
 	 * We want a timestamp in milliseconds suitable for time measurement,
 	 * so prefer the monotonic clock.
 	 */
 	if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
 		clock_gettime(CLOCK_REALTIME, &ts);
 	return ((ts.tv_sec * 1000ULL) + (ts.tv_nsec / 1000000ULL));
 }

 const char *
 sig2name(int signo)
 {
      static char	s[11];

 #ifdef HAVE_SYS_SIGNAME
      if (signo > 0 && signo < NSIG)
 	     return (sys_signame[signo]);
 #endif
      xsnprintf(s, sizeof s, "%d", signo);
      return (s);
 }

 const char *
 find_cwd(void)
 {
 	char		 resolved1[PATH_MAX], resolved2[PATH_MAX];
 	static char	 cwd[PATH_MAX];
 	const char	*pwd;

 	if (getcwd(cwd, sizeof cwd) == NULL)
 		return (NULL);
 	if ((pwd = getenv("PWD")) == NULL || *pwd == '\0')
 		return (cwd);

 	/*
 	 * We want to use PWD so that symbolic links are maintained,
 	 * but only if it matches the actual working directory.
 	 */
 	if (realpath(pwd, resolved1) == NULL)
 		return (cwd);
 	if (realpath(cwd, resolved2) == NULL)
 		return (cwd);
 	if (strcmp(resolved1, resolved2) != 0)
 		return (cwd);
 	return (pwd);
 }

 const char *
 find_home(void)
 {
 	struct passwd		*pw;
 	static const char	*home;

 	if (home != NULL)
 		return (home);

 	home = getenv("HOME");
 	if (home == NULL || *home == '\0') {
 		pw = getpwuid(getuid());
 		if (pw != NULL)
 			home = pw->pw_dir;
 		else
 			home = NULL;
 	}

 	return (home);
 }

 const char *
 getversion(void)
 {
 	return (TMUX_VERSION);
 }

 int
 main(int argc, char **argv)
 {
 	char					*path = NULL, *label = NULL;
 	char					*cause, **var;
 	const char				*s, *cwd;
 	int					 opt, keys, feat = 0, fflag = 0;
 	uint64_t				 flags = 0;
 	const struct options_table_entry	*oe;
 	u_int					 i;

 	if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
 	    setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
 		if (setlocale(LC_CTYPE, "") == NULL)
 			errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
 		s = nl_langinfo(CODESET);
 		if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
 			errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
 	}

 	setlocale(LC_TIME, "");
 	tzset();

 	if (**argv == '-')
 		flags = CLIENT_LOGIN;

 	global_environ = environ_create();
 	for (var = environ; *var != NULL; var++)
 		environ_put(global_environ, *var, 0);
 	if ((cwd = find_cwd()) != NULL)
 		environ_set(global_environ, "PWD", 0, "%s", cwd);
 	expand_paths(TMUX_CONF, &cfg_files, &cfg_nfiles, 1);

 	while ((opt = getopt(argc, argv, "2c:CDdf:lL:NqS:T:uUvV")) != -1) {
 		switch (opt) {
 		case '2':
 			tty_add_features(&feat, "256", ":,");
 			break;
 		case 'c':
 			shell_command = optarg;
 			break;
 		case 'D':
 			flags |= CLIENT_NOFORK;
 			break;
 		case 'C':
 			if (flags & CLIENT_CONTROL)
 				flags |= CLIENT_CONTROLCONTROL;
 			else
 				flags |= CLIENT_CONTROL;
 			break;
 		case 'f':
 			if (!fflag) {
 				fflag = 1;
 				for (i = 0; i < cfg_nfiles; i++)
 					free(cfg_files[i]);
 				cfg_nfiles = 0;
 			}
 			cfg_files = xreallocarray(cfg_files, cfg_nfiles + 1,
 			    sizeof *cfg_files);
 			cfg_files[cfg_nfiles++] = xstrdup(optarg);
 			cfg_quiet = 0;
 			break;
  		case 'V':
 			printf("%s %s\n", getprogname(), getversion());
  			exit(0);
 		case 'l':
 			flags |= CLIENT_LOGIN;
 			break;
 		case 'L':
 			free(label);
 			label = xstrdup(optarg);
 			break;
 		case 'N':
 			flags |= CLIENT_NOSTARTSERVER;
 			break;
 		case 'q':
 			break;
 		case 'S':
 			free(path);
 			path = xstrdup(optarg);
 			break;
 		case 'T':
 			tty_add_features(&feat, optarg, ":,");
 			break;
 		case 'u':
 			flags |= CLIENT_UTF8;
 			break;
 		case 'v':
 			log_add_level();
 			break;
 		default:
 			usage();
 		}
 	}
 	argc -= optind;
 	argv += optind;

 	if (shell_command != NULL && argc != 0)
 		usage();
 	if ((flags & CLIENT_NOFORK) && argc != 0)
 		usage();

 	if ((ptm_fd = getptmfd()) == -1)
 		err(1, "getptmfd");
 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
 	    "recvfd proc exec tty ps", NULL) != 0)
 		err(1, "pledge");

 	/*
 	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
 	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
 	 * UTF-8, it is a safe assumption that either they are using a UTF-8
 	 * terminal, or if not they know that output from UTF-8-capable
 	 * programs may be wrong.
 	 */
 	if (getenv("TMUX") != NULL)
 		flags |= CLIENT_UTF8;
 	else {
 		s = getenv("LC_ALL");
 		if (s == NULL || *s == '\0')
 			s = getenv("LC_CTYPE");
 		if (s == NULL || *s == '\0')
 			s = getenv("LANG");
 		if (s == NULL || *s == '\0')
 			s = "";
 		if (strcasestr(s, "UTF-8") != NULL ||
 		    strcasestr(s, "UTF8") != NULL)
 			flags |= CLIENT_UTF8;
 	}

 	global_options = options_create(NULL);
 	global_s_options = options_create(NULL);
 	global_w_options = options_create(NULL);
 	for (oe = options_table; oe->name != NULL; oe++) {
 		if (oe->scope & OPTIONS_TABLE_SERVER)
 			options_default(global_options, oe);
 		if (oe->scope & OPTIONS_TABLE_SESSION)
 			options_default(global_s_options, oe);
 		if (oe->scope & OPTIONS_TABLE_WINDOW)
 			options_default(global_w_options, oe);
 	}

 	/*
 	 * The default shell comes from SHELL or from the user's passwd entry
 	 * if available.
 	 */
 	options_set_string(global_s_options, "default-shell", 0, "%s",
 	    getshell());

 	/* Override keys to vi if VISUAL or EDITOR are set. */
 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
 		options_set_string(global_options, "editor", 0, "%s", s);
 		if (strrchr(s, '/') != NULL)
 			s = strrchr(s, '/') + 1;
 		if (strstr(s, "vi") != NULL)
 			keys = MODEKEY_VI;
 		else
 			keys = MODEKEY_EMACS;
 		options_set_number(global_s_options, "status-keys", keys);
 		options_set_number(global_w_options, "mode-keys", keys);
 	}

 	/*
 	 * If socket is specified on the command-line with -S or -L, it is
 	 * used. Otherwise, $TMUX is checked and if that fails "default" is
 	 * used.
 	 */
 	if (path == NULL && label == NULL) {
 		s = getenv("TMUX");
 		if (s != NULL && *s != '\0' && *s != ',') {
 			path = xstrdup(s);
 			path[strcspn(path, ",")] = '\0';
 		}
 	}
 	if (path == NULL) {
 		if ((path = make_label(label, &cause)) == NULL) {
 			if (cause != NULL) {
 				fprintf(stderr, "%s\n", cause);
 				free(cause);
 			}
 			exit(1);
 		}
 		flags |= CLIENT_DEFAULTSOCKET;
 	}
 	socket_path = path;
 	free(label);

 	/* Pass control to the client. */
 	exit(client_main(osdep_event_init(), argc, argv, flags, feat));
 }
	/* $OpenBSD$ */

	/*
	* Copyright (c) 2007 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/stat.h>
	#include <sys/utsname.h>

	#include <errno.h>
	#include <fcntl.h>
	#include <langinfo.h>
	#include <locale.h>
	#include <pwd.h>
	#include <signal.h>
	#include <stdlib.h>
	#include <string.h>
	#include <time.h>
	#include <unistd.h>

	#include "tmux.h"

	struct options global_options; / server options */
	struct options global_s_options; / session options */
	struct options global_w_options; / window options */
	struct environ *global_environ;

	struct timeval start_time;
	const char *socket_path;
	int ptm_fd = -1;
	const char *shell_command;

	static __dead void usage(void);
	static char make_label(const char , char **);

	static int areshell(const char *);
	static const char *getshell(void);

	static __dead void
	usage(void)
	{
	fprintf(stderr,
	"usage: %s [-2CDlNuVv] [-c shell-command] [-f file] [-L socket-name]\n"
	" [-S socket-path] [-T features] [command [flags]]\n",
	getprogname());
	exit(1);
	}

	static const char *
	getshell(void)
	{
	struct passwd *pw;
	const char *shell;

	shell = getenv("SHELL");
	if (checkshell(shell))
	return (shell);

	pw = getpwuid(getuid());
	if (pw != NULL && checkshell(pw->pw_shell))
	return (pw->pw_shell);

	return (_PATH_BSHELL);
	}

	int
	checkshell(const char *shell)
	{
	if (shell == NULL \|\| *shell != '/')
	return (0);
	if (areshell(shell))
	return (0);
	if (access(shell, X_OK) != 0)
	return (0);
	return (1);
	}

	static int
	areshell(const char *shell)
	{
	const char progname, ptr;

	if ((ptr = strrchr(shell, '/')) != NULL)
	ptr++;
	else
	ptr = shell;
	progname = getprogname();
	if (*progname == '-')
	progname++;
	if (strcmp(ptr, progname) == 0)
	return (1);
	return (0);
	}

	static char *
	expand_path(const char path, const char home)
	{
	char expanded, name;
	const char *end;
	struct environ_entry *value;

	if (strncmp(path, "~/", 2) == 0) {
	if (home == NULL)
	return (NULL);
	xasprintf(&expanded, "%s%s", home, path + 1);
	return (expanded);
	}

	if (*path == '$') {
	end = strchr(path, '/');
	if (end == NULL)
	name = xstrdup(path + 1);
	else
	name = xstrndup(path + 1, end - path - 1);
	value = environ_find(global_environ, name);
	free(name);
	if (value == NULL)
	return (NULL);
	if (end == NULL)
	end = "";
	xasprintf(&expanded, "%s%s", value->value, end);
	return (expanded);
	}

	return (xstrdup(path));
	}

	static void
	expand_paths(const char s, char *paths, u_int n, int ignore_errors)
	{
	const char *home = find_home();
	char copy, next, tmp, resolved[PATH_MAX], expanded;
	char *path;
	u_int i;

	*paths = NULL;
	*n = 0;

	copy = tmp = xstrdup(s);
	while ((next = strsep(&tmp, ":")) != NULL) {
	expanded = expand_path(next, home);
	if (expanded == NULL) {
	log_debug("%s: invalid path: %s", __func__, next);
	continue;
	}
	if (realpath(expanded, resolved) == NULL) {
	log_debug("%s: realpath(\"%s\") failed: %s", __func__,
	expanded, strerror(errno));
	if (ignore_errors) {
	free(expanded);
	continue;
	}
	path = expanded;
	} else {
	path = xstrdup(resolved);
	free(expanded);
	}
	for (i = 0; i < *n; i++) {
	if (strcmp(path, (*paths)[i]) == 0)
	break;
	}
	if (i != *n) {
	log_debug("%s: duplicate path: %s", __func__, path);
	free(path);
	continue;
	}
	paths = xreallocarray(paths, (n) + 1, sizeof paths);
	(paths)[(n)++] = path;
	}
	free(copy);
	}

	static char *
	make_label(const char label, char *cause)
	{
	char *paths, path, *base;
	u_int i, n;
	struct stat sb;
	uid_t uid;

	*cause = NULL;
	if (label == NULL)
	label = "default";
	uid = getuid();

	expand_paths(TMUX_SOCK, &paths, &n, 1);
	if (n == 0) {
	xasprintf(cause, "no suitable socket path");
	return (NULL);
	}
	path = paths[0]; /* can only have one socket! */
	for (i = 1; i < n; i++)
	free(paths[i]);
	free(paths);

	xasprintf(&base, "%s/tmux-%ld", path, (long)uid);
	free(path);
	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) {
	xasprintf(cause, "couldn't create directory %s (%s)", base,
	strerror(errno));
	goto fail;
	}
	if (lstat(base, &sb) != 0) {
	xasprintf(cause, "couldn't read directory %s (%s)", base,
	strerror(errno));
	goto fail;
	}
	if (!S_ISDIR(sb.st_mode)) {
	xasprintf(cause, "%s is not a directory", base);
	goto fail;
	}
	if (sb.st_uid != uid \|\| (sb.st_mode & S_IRWXO) != 0) {
	xasprintf(cause, "directory %s has unsafe permissions", base);
	goto fail;
	}
	xasprintf(&path, "%s/%s", base, label);
	free(base);
	return (path);

	fail:
	free(base);
	return (NULL);
	}

	void
	setblocking(int fd, int state)
	{
	int mode;

	if ((mode = fcntl(fd, F_GETFL)) != -1) {
	if (!state)
	mode \|= O_NONBLOCK;
	else
	mode &= ~O_NONBLOCK;
	fcntl(fd, F_SETFL, mode);
	}
	}

	uint64_t
	get_timer(void)
	{
	struct timespec ts;

	/*
	* We want a timestamp in milliseconds suitable for time measurement,
	* so prefer the monotonic clock.
	*/
	if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
	clock_gettime(CLOCK_REALTIME, &ts);
	return ((ts.tv_sec * 1000ULL) + (ts.tv_nsec / 1000000ULL));
	}

	const char *
	sig2name(int signo)
	{
	static char s[11];

	#ifdef HAVE_SYS_SIGNAME
	if (signo > 0 && signo < NSIG)
	return (sys_signame[signo]);
	#endif
	xsnprintf(s, sizeof s, "%d", signo);
	return (s);
	}

	const char *
	find_cwd(void)
	{
	char resolved1[PATH_MAX], resolved2[PATH_MAX];
	static char cwd[PATH_MAX];
	const char *pwd;

	if (getcwd(cwd, sizeof cwd) == NULL)
	return (NULL);
	if ((pwd = getenv("PWD")) == NULL \|\| *pwd == '\0')
	return (cwd);

	/*
	* We want to use PWD so that symbolic links are maintained,
	* but only if it matches the actual working directory.
	*/
	if (realpath(pwd, resolved1) == NULL)
	return (cwd);
	if (realpath(cwd, resolved2) == NULL)
	return (cwd);
	if (strcmp(resolved1, resolved2) != 0)
	return (cwd);
	return (pwd);
	}

	const char *
	find_home(void)
	{
	struct passwd *pw;
	static const char *home;

	if (home != NULL)
	return (home);

	home = getenv("HOME");
	if (home == NULL \|\| *home == '\0') {
	pw = getpwuid(getuid());
	if (pw != NULL)
	home = pw->pw_dir;
	else
	home = NULL;
	}

	return (home);
	}

	const char *
	getversion(void)
	{
	return (TMUX_VERSION);
	}

	int
	main(int argc, char **argv)
	{
	char path = NULL, label = NULL;
	char cause, *var;
	const char s, cwd;
	int opt, keys, feat = 0, fflag = 0;
	uint64_t flags = 0;
	const struct options_table_entry *oe;
	u_int i;

	if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
	setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
	if (setlocale(LC_CTYPE, "") == NULL)
	errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
	s = nl_langinfo(CODESET);
	if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
	errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
	}

	setlocale(LC_TIME, "");
	tzset();

	if (**argv == '-')
	flags = CLIENT_LOGIN;

	global_environ = environ_create();
	for (var = environ; *var != NULL; var++)
	environ_put(global_environ, *var, 0);
	if ((cwd = find_cwd()) != NULL)
	environ_set(global_environ, "PWD", 0, "%s", cwd);
	expand_paths(TMUX_CONF, &cfg_files, &cfg_nfiles, 1);

	while ((opt = getopt(argc, argv, "2c:CDdf:lL:NqS:T:uUvV")) != -1) {
	switch (opt) {
	case '2':
	tty_add_features(&feat, "256", ":,");
	break;
	case 'c':
	shell_command = optarg;
	break;
	case 'D':
	flags \|= CLIENT_NOFORK;
	break;
	case 'C':
	if (flags & CLIENT_CONTROL)
	flags \|= CLIENT_CONTROLCONTROL;
	else
	flags \|= CLIENT_CONTROL;
	break;
	case 'f':
	if (!fflag) {
	fflag = 1;
	for (i = 0; i < cfg_nfiles; i++)
	free(cfg_files[i]);
	cfg_nfiles = 0;
	}
	cfg_files = xreallocarray(cfg_files, cfg_nfiles + 1,
	sizeof *cfg_files);
	cfg_files[cfg_nfiles++] = xstrdup(optarg);
	cfg_quiet = 0;
	break;
	case 'V':
	printf("%s %s\n", getprogname(), getversion());
	exit(0);
	case 'l':
	flags \|= CLIENT_LOGIN;
	break;
	case 'L':
	free(label);
	label = xstrdup(optarg);
	break;
	case 'N':
	flags \|= CLIENT_NOSTARTSERVER;
	break;
	case 'q':
	break;
	case 'S':
	free(path);
	path = xstrdup(optarg);
	break;
	case 'T':
	tty_add_features(&feat, optarg, ":,");
	break;
	case 'u':
	flags \|= CLIENT_UTF8;
	break;
	case 'v':
	log_add_level();
	break;
	default:
	usage();
	}
	}
	argc -= optind;
	argv += optind;

	if (shell_command != NULL && argc != 0)
	usage();
	if ((flags & CLIENT_NOFORK) && argc != 0)
	usage();

	if ((ptm_fd = getptmfd()) == -1)
	err(1, "getptmfd");
	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
	"recvfd proc exec tty ps", NULL) != 0)
	err(1, "pledge");

	/*
	* tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
	* Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
	* UTF-8, it is a safe assumption that either they are using a UTF-8
	* terminal, or if not they know that output from UTF-8-capable
	* programs may be wrong.
	*/
	if (getenv("TMUX") != NULL)
	flags \|= CLIENT_UTF8;
	else {
	s = getenv("LC_ALL");
	if (s == NULL \|\| *s == '\0')
	s = getenv("LC_CTYPE");
	if (s == NULL \|\| *s == '\0')
	s = getenv("LANG");
	if (s == NULL \|\| *s == '\0')
	s = "";
	if (strcasestr(s, "UTF-8") != NULL \|\|
	strcasestr(s, "UTF8") != NULL)
	flags \|= CLIENT_UTF8;
	}

	global_options = options_create(NULL);
	global_s_options = options_create(NULL);
	global_w_options = options_create(NULL);
	for (oe = options_table; oe->name != NULL; oe++) {
	if (oe->scope & OPTIONS_TABLE_SERVER)
	options_default(global_options, oe);
	if (oe->scope & OPTIONS_TABLE_SESSION)
	options_default(global_s_options, oe);
	if (oe->scope & OPTIONS_TABLE_WINDOW)
	options_default(global_w_options, oe);
	}

	/*
	* The default shell comes from SHELL or from the user's passwd entry
	* if available.
	*/
	options_set_string(global_s_options, "default-shell", 0, "%s",
	getshell());

	/* Override keys to vi if VISUAL or EDITOR are set. */
	if ((s = getenv("VISUAL")) != NULL \|\| (s = getenv("EDITOR")) != NULL) {
	options_set_string(global_options, "editor", 0, "%s", s);
	if (strrchr(s, '/') != NULL)
	s = strrchr(s, '/') + 1;
	if (strstr(s, "vi") != NULL)
	keys = MODEKEY_VI;
	else
	keys = MODEKEY_EMACS;
	options_set_number(global_s_options, "status-keys", keys);
	options_set_number(global_w_options, "mode-keys", keys);
	}

	/*
	* If socket is specified on the command-line with -S or -L, it is
	* used. Otherwise, $TMUX is checked and if that fails "default" is
	* used.
	*/
	if (path == NULL && label == NULL) {
	s = getenv("TMUX");
	if (s != NULL && s != '\0' && s != ',') {
	path = xstrdup(s);
	path[strcspn(path, ",")] = '\0';
	}
	}
	if (path == NULL) {
	if ((path = make_label(label, &cause)) == NULL) {
	if (cause != NULL) {
	fprintf(stderr, "%s\n", cause);
	free(cause);
	}
	exit(1);
	}
	flags \|= CLIENT_DEFAULTSOCKET;
	}
	socket_path = path;
	free(label);

	/* Pass control to the client. */
	exit(client_main(osdep_event_init(), argc, argv, flags, feat));
	}