tmux.c - tmux - Rivoreo Source Code Repositories

 /* $Id: tmux.c,v 1.213 2010-07-02 02:52:13 tcunha Exp $ */

 /*
  * 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/stat.h>
 #include <sys/wait.h>

 #include <errno.h>
 #include <event.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <syslog.h>
 #include <unistd.h>

 #include "tmux.h"

 #if defined(DEBUG) && defined(__OpenBSD__)
 extern char	*malloc_options;
 #endif

 char		*cfg_file;
 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 event_base *ev_base;

 int		 debug_level;
 time_t		 start_time;
 char		*socket_path;
 int		 login_shell;

 struct env_data {
 	char	*path;
 	pid_t	 pid;
 	u_int	 idx;
 };

 __dead void	 usage(void);
 void	 	 parse_env(struct env_data *);
 char 		*makesockpath(const char *);
 __dead void	 shell_exec(const char *, const char *);

 struct imsgbuf	*main_ibuf;
 int	         main_exitval;

 void		 main_signal(int, short, unused void *);
 void		 main_callback(int, short, void *);
 void		 main_dispatch(const char *);

 #ifndef HAVE_PROGNAME
 char      *__progname = (char *) "tmux";
 #endif

 __dead void
 usage(void)
 {
 	fprintf(stderr,
 	    "usage: %s [-28lquv] [-c shell-command] [-f file] [-L socket-name]\n"
 	    "            [-S socket-path] [command [flags]]\n",
 	    __progname);
 	exit(1);
 }

 void
 logfile(const char *name)
 {
 	char	*path;

 	log_close();
 	if (debug_level > 0) {
 		xasprintf(&path, "tmux-%s-%ld.log", name, (long) getpid());
 		log_open_file(debug_level, path);
 		xfree(path);
 	}
 }

 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 == '\0' || areshell(shell))
 		return (0);
 	if (access(shell, X_OK) != 0)
 		return (0);
 	return (1);
 }

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

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

 void
 parse_env(struct env_data *data)
 {
 	char		*env, *path_pid, *pid_idx, buf[256];
 	size_t		 len;
 	const char	*errstr;
 	long long	 ll;

 	data->pid = -1;
 	if ((env = getenv("TMUX")) == NULL)
 		return;

 	if ((path_pid = strchr(env, ',')) == NULL || path_pid == env)
 		return;
 	if ((pid_idx = strchr(path_pid + 1, ',')) == NULL)
 		return;
 	if ((pid_idx == path_pid + 1 || pid_idx[1] == '\0'))
 		return;

 	/* path */
 	len = path_pid - env;
 	data->path = xmalloc (len + 1);
 	memcpy(data->path, env, len);
 	data->path[len] = '\0';

 	/* pid */
 	len = pid_idx - path_pid - 1;
 	if (len > (sizeof buf) - 1)
 		return;
 	memcpy(buf, path_pid + 1, len);
 	buf[len] = '\0';

 	ll = strtonum(buf, 0, LONG_MAX, &errstr);
 	if (errstr != NULL)
 		return;
 	data->pid = ll;

 	/* idx */
 	ll = strtonum(pid_idx+1, 0, UINT_MAX, &errstr);
 	if (errstr != NULL)
 		return;
 	data->idx = ll;
 }

 char *
 makesockpath(const char *label)
 {
 	char		base[MAXPATHLEN], *path;
 	struct stat	sb;
 	u_int		uid;

 	uid = getuid();
 	xsnprintf(base, MAXPATHLEN, "%s/tmux-%d", _PATH_TMP, uid);

 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
 		return (NULL);

 	if (lstat(base, &sb) != 0)
 		return (NULL);
 	if (!S_ISDIR(sb.st_mode)) {
 		errno = ENOTDIR;
 		return (NULL);
 	}
 	if (sb.st_uid != uid || (sb.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
 		errno = EACCES;
 		return (NULL);
 	}

 	xasprintf(&path, "%s/%s", base, label);
 	return (path);
 }

 __dead void
 shell_exec(const char *shell, const char *shellcmd)
 {
 	const char	*shellname, *ptr;
 	char		*argv0;

 	ptr = strrchr(shell, '/');
 	if (ptr != NULL && *(ptr + 1) != '\0')
 		shellname = ptr + 1;
 	else
 		shellname = shell;
 	if (login_shell)
 		xasprintf(&argv0, "-%s", shellname);
 	else
 		xasprintf(&argv0, "%s", shellname);
 	setenv("SHELL", shell, 1);

 	execl(shell, argv0, "-c", shellcmd, (char *) NULL);
 	fatal("execl failed");
 }

 int
 main(int argc, char **argv)
 {
 	struct cmd_list		*cmdlist;
 	struct cmd		*cmd;
 	enum msgtype		 msg;
 	struct passwd		*pw;
 	struct options		*oo, *so, *wo;
 	struct keylist		*keylist;
 	struct env_data		 envdata;
 	struct msg_command_data	 cmddata;
 	char			*s, *shellcmd, *path, *label, *home, *cause;
 	char		       **var;
 	void			*buf;
 	size_t			 len;
 	int	 		 opt, flags, quiet = 0, cmdflags = 0;
 	short		 	 events;

 #if defined(DEBUG) && defined(__OpenBSD__)
 	malloc_options = (char *) "AFGJPX";
 #endif

 	flags = 0;
 	shellcmd = label = path = NULL;
 	envdata.path = NULL;
 	login_shell = (**argv == '-');
 	while ((opt = getopt(argc, argv, "28c:df:lL:qS:uUv")) != -1) {
 		switch (opt) {
 		case '2':
 			flags |= IDENTIFY_256COLOURS;
 			flags &= ~IDENTIFY_88COLOURS;
 			break;
 		case '8':
 			flags |= IDENTIFY_88COLOURS;
 			flags &= ~IDENTIFY_256COLOURS;
 			break;
 		case 'c':
 			if (shellcmd != NULL)
 				xfree(shellcmd);
 			shellcmd = xstrdup(optarg);
 			break;
 		case 'f':
 			if (cfg_file != NULL)
 				xfree(cfg_file);
 			cfg_file = xstrdup(optarg);
 			break;
 		case 'l':
 			login_shell = 1;
 			break;
 		case 'L':
 			if (label != NULL)
 				xfree(label);
 			label = xstrdup(optarg);
 			break;
 		case 'q':
 			quiet = 1;
 			break;
 		case 'S':
 			if (path != NULL)
 				xfree(path);
 			path = xstrdup(optarg);
 			break;
 		case 'u':
 			flags |= IDENTIFY_UTF8;
 			break;
 		case 'v':
 			debug_level++;
 			break;
 		default:
 			usage();
 		}
 	}
 	argc -= optind;
 	argv += optind;

 	if (shellcmd != NULL && argc != 0)
 		usage();

 	log_open_tty(debug_level);

 	if (!(flags & IDENTIFY_UTF8)) {
 		/*
 		 * If the user has set whichever of LC_ALL, LC_CTYPE or LANG
 		 * exist (in that order) 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 ((s = getenv("LC_ALL")) == NULL) {
 			if ((s = getenv("LC_CTYPE")) == NULL)
 				s = getenv("LANG");
 		}
 		if (s != NULL && (strcasestr(s, "UTF-8") != NULL ||
 		    strcasestr(s, "UTF8") != NULL))
 			flags |= IDENTIFY_UTF8;
 	}

 	environ_init(&global_environ);
 	for (var = environ; *var != NULL; var++)
 		environ_put(&global_environ, *var);

 	options_init(&global_options, NULL);
 	oo = &global_options;
 	options_set_number(oo, "quiet", quiet);
 	options_set_number(oo, "escape-time", 500);

 	options_init(&global_s_options, NULL);
 	so = &global_s_options;
 	options_set_number(so, "base-index", 0);
 	options_set_number(so, "bell-action", BELL_ANY);
 	options_set_number(so, "buffer-limit", 9);
 	options_set_string(so, "default-command", "%s", "");
 	options_set_string(so, "default-path", "%s", "");
 	options_set_string(so, "default-shell", "%s", getshell());
 	options_set_string(so, "default-terminal", "screen");
 	options_set_number(so, "detach-on-destroy", 1);
 	options_set_number(so, "display-panes-active-colour", 1);
 	options_set_number(so, "display-panes-colour", 4);
 	options_set_number(so, "display-panes-time", 1000);
 	options_set_number(so, "display-time", 750);
 	options_set_number(so, "history-limit", 2000);
 	options_set_number(so, "lock-after-time", 0);
 	options_set_string(so, "lock-command", "lock -np");
 	options_set_number(so, "lock-server", 1);
 	options_set_number(so, "message-attr", 0);
 	options_set_number(so, "message-bg", 3);
 	options_set_number(so, "message-fg", 0);
 	options_set_number(so, "message-limit", 20);
 	options_set_number(so, "mouse-select-pane", 0);
 	options_set_number(so, "pane-active-border-bg", 8);
 	options_set_number(so, "pane-active-border-fg", 2);
 	options_set_number(so, "pane-border-bg", 8);
 	options_set_number(so, "pane-border-fg", 8);
 	options_set_number(so, "repeat-time", 500);
 	options_set_number(so, "set-remain-on-exit", 0);
 	options_set_number(so, "set-titles", 0);
 	options_set_string(so, "set-titles-string", "#S:#I:#W - \"#T\"");
 	options_set_number(so, "status", 1);
 	options_set_number(so, "status-attr", 0);
 	options_set_number(so, "status-bg", 2);
 	options_set_number(so, "status-fg", 0);
 	options_set_number(so, "status-interval", 15);
 	options_set_number(so, "status-justify", 0);
 	options_set_number(so, "status-keys", MODEKEY_EMACS);
 	options_set_string(so, "status-left", "[#S]");
 	options_set_number(so, "status-left-attr", 0);
 	options_set_number(so, "status-left-bg", 8);
 	options_set_number(so, "status-left-fg", 8);
 	options_set_number(so, "status-left-length", 10);
 	options_set_string(so, "status-right", "\"#22T\" %%H:%%M %%d-%%b-%%y");
 	options_set_number(so, "status-right-attr", 0);
 	options_set_number(so, "status-right-bg", 8);
 	options_set_number(so, "status-right-fg", 8);
 	options_set_number(so, "status-right-length", 40);
 	options_set_string(so, "terminal-overrides",
 	    "*88col*:colors=88,*256col*:colors=256");
 	options_set_string(so, "update-environment", "DISPLAY "
 	    "WINDOWID SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID SSH_CONNECTION");
 	options_set_number(so, "visual-activity", 0);
 	options_set_number(so, "visual-bell", 0);
 	options_set_number(so, "visual-content", 0);

 	keylist = xmalloc(sizeof *keylist);
 	ARRAY_INIT(keylist);
 	ARRAY_ADD(keylist, '\002');
 	options_set_data(so, "prefix", keylist, xfree);

 	options_init(&global_w_options, NULL);
 	wo = &global_w_options;
 	options_set_number(wo, "aggressive-resize", 0);
 	options_set_number(wo, "alternate-screen", 1);
 	options_set_number(wo, "automatic-rename", 1);
 	options_set_number(wo, "clock-mode-colour", 4);
 	options_set_number(wo, "clock-mode-style", 1);
 	options_set_number(wo, "force-height", 0);
 	options_set_number(wo, "force-width", 0);
 	options_set_number(wo, "main-pane-height", 24);
 	options_set_number(wo, "main-pane-width", 81);
 	options_set_number(wo, "mode-attr", 0);
 	options_set_number(wo, "mode-bg", 3);
 	options_set_number(wo, "mode-fg", 0);
 	options_set_number(wo, "mode-keys", MODEKEY_EMACS);
 	options_set_number(wo, "mode-mouse", 0);
 	options_set_number(wo, "monitor-activity", 0);
 	options_set_string(wo, "monitor-content", "%s", "");
 	options_set_number(wo, "window-status-attr", 0);
 	options_set_number(wo, "window-status-bg", 8);
 	options_set_number(wo, "window-status-current-attr", 0);
 	options_set_number(wo, "window-status-current-bg", 8);
 	options_set_number(wo, "window-status-current-fg", 8);
 	options_set_number(wo, "window-status-fg", 8);
 	options_set_number(wo, "window-status-alert-attr", GRID_ATTR_REVERSE);
 	options_set_number(wo, "window-status-alert-bg", 8);
 	options_set_number(wo, "window-status-alert-fg", 8);
 	options_set_string(wo, "window-status-format", "#I:#W#F");
 	options_set_string(wo, "window-status-current-format", "#I:#W#F");
 	options_set_string(wo, "word-separators", " -_@");
 	options_set_number(wo, "xterm-keys", 0);
 	options_set_number(wo, "remain-on-exit", 0);
 	options_set_number(wo, "synchronize-panes", 0);

 	if (flags & IDENTIFY_UTF8) {
 		options_set_number(so, "status-utf8", 1);
 		options_set_number(wo, "utf8", 1);
 	} else {
 		options_set_number(so, "status-utf8", 0);
 		options_set_number(wo, "utf8", 0);
 	}

 	if (cfg_file == NULL) {
 		home = getenv("HOME");
 		if (home == NULL || *home == '\0') {
 			pw = getpwuid(getuid());
 			if (pw != NULL)
 				home = pw->pw_dir;
 		}
 		xasprintf(&cfg_file, "%s/%s", home, DEFAULT_CFG);
 		if (access(cfg_file, R_OK) != 0 && errno == ENOENT) {
 			xfree(cfg_file);
 			cfg_file = NULL;
 		}
 	}

 	/*
 	 * Figure out the socket path. If specified on the command-line with
 	 * -S or -L, use it, otherwise try $TMUX or assume -L default.
 	 */
 	parse_env(&envdata);
 	if (path == NULL) {
 		/* No -L. Try $TMUX, or default. */
 		if (label == NULL) {
 			path = envdata.path;
 			if (path == NULL)
 				label = xstrdup("default");
 		}

 		/* -L or default set. */
 		if (label != NULL) {
 			if ((path = makesockpath(label)) == NULL) {
 				log_warn("can't create socket");
 				exit(1);
 			}
 		}
 	}
 	if (label != NULL)
 		xfree(label);

 	if (shellcmd != NULL) {
 		msg = MSG_SHELL;
 		buf = NULL;
 		len = 0;
 	} else {
 		cmddata.pid = envdata.pid;
 		cmddata.idx = envdata.idx;

 		/* Prepare command for server. */
 		cmddata.argc = argc;
 		if (cmd_pack_argv(
 		    argc, argv, cmddata.argv, sizeof cmddata.argv) != 0) {
 			log_warnx("command too long");
 			exit(1);
 		}

 		msg = MSG_COMMAND;
 		buf = &cmddata;
 		len = sizeof cmddata;
 	}

 	if (shellcmd != NULL)
 		cmdflags |= CMD_STARTSERVER;
 	else if (argc == 0)	/* new-session is the default */
 		cmdflags |= CMD_STARTSERVER|CMD_SENDENVIRON|CMD_CANTNEST;
 	else {
 		/*
 		 * It sucks parsing the command string twice (in client and
 		 * later in server) but it is necessary to get the start server
 		 * flag.
 		 */
 		if ((cmdlist = cmd_list_parse(argc, argv, &cause)) == NULL) {
 			log_warnx("%s", cause);
 			exit(1);
 		}
 		cmdflags &= ~CMD_STARTSERVER;
 		TAILQ_FOREACH(cmd, &cmdlist->list, qentry) {
 			if (cmd->entry->flags & CMD_STARTSERVER)
 				cmdflags |= CMD_STARTSERVER;
 			if (cmd->entry->flags & CMD_SENDENVIRON)
 				cmdflags |= CMD_SENDENVIRON;
 			if (cmd->entry->flags & CMD_CANTNEST)
 				cmdflags |= CMD_CANTNEST;
 		}
 		cmd_list_free(cmdlist);
 	}

 	/*
 	 * Check if this could be a nested session, if the command can't nest:
 	 * if the socket path matches $TMUX, this is probably the same server.
 	 */
 	if (shellcmd == NULL && envdata.path != NULL &&
 	    cmdflags & CMD_CANTNEST &&
 	    (path == envdata.path || strcmp(path, envdata.path) == 0)) {
 		log_warnx("sessions should be nested with care. "
 		    "unset $TMUX to force.");
 		exit(1);
 	}

 #ifdef HAVE_BROKEN_KQUEUE
 	if (setenv("EVENT_NOKQUEUE", "1", 1) != 0)
 		fatal("setenv failed");
 #endif
 #ifdef HAVE_BROKEN_POLL
 	if (setenv("EVENT_NOPOLL", "1", 1) != 0)
 		fatal("setenv failed");
 #endif
 	ev_base = event_init();
 #ifdef HAVE_BROKEN_KQUEUE
 	unsetenv("EVENT_NOKQUEUE");
 #endif
 #ifdef HAVE_BROKEN_POLL
 	unsetenv("EVENT_NOPOLL");
 #endif
 	set_signals(main_signal);

 	/* Initialise the client socket/start the server. */
 	if ((main_ibuf = client_init(path, cmdflags, flags)) == NULL)
 		exit(1);
 	xfree(path);

 	imsg_compose(main_ibuf, msg, PROTOCOL_VERSION, -1, -1, buf, len);

 	events = EV_READ;
 	if (main_ibuf->w.queued > 0)
 		events |= EV_WRITE;
 	event_once(main_ibuf->fd, events, main_callback, shellcmd, NULL);

 	main_exitval = 0;
 	event_dispatch();

 	clear_signals();

 	client_main();	/* doesn't return */
 }

 /* ARGSUSED */
 void
 main_signal(int sig, unused short events, unused void *data)
 {
 	int	status;

 	switch (sig) {
 	case SIGTERM:
 		exit(1);
 	case SIGCHLD:
 		waitpid(WAIT_ANY, &status, WNOHANG);
 		break;
 	}
 }

 /* ARGSUSED */
 void
 main_callback(unused int fd, short events, void *data)
 {
 	char	*shellcmd = data;

 	if (events & EV_READ)
 		main_dispatch(shellcmd);

 	if (events & EV_WRITE) {
 		if (msgbuf_write(&main_ibuf->w) < 0)
 			fatalx("msgbuf_write failed");
 	}

 	events = EV_READ;
 	if (main_ibuf->w.queued > 0)
 		events |= EV_WRITE;
 	event_once(main_ibuf->fd, events, main_callback, shellcmd, NULL);
 }

 void
 main_dispatch(const char *shellcmd)
 {
 	struct imsg		imsg;
 	ssize_t			n, datalen;
 	struct msg_shell_data	shelldata;

 	if ((n = imsg_read(main_ibuf)) == -1 || n == 0)
 		fatalx("imsg_read failed");

 	for (;;) {
 		if ((n = imsg_get(main_ibuf, &imsg)) == -1)
 			fatalx("imsg_get failed");
 		if (n == 0)
 			return;
 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;

 		switch (imsg.hdr.type) {
 		case MSG_EXIT:
 		case MSG_SHUTDOWN:
 			if (datalen != 0)
 				fatalx("bad MSG_EXIT size");

 			exit(main_exitval);
 		case MSG_READY:
 			if (datalen != 0)
 				fatalx("bad MSG_READY size");

 			event_loopexit(NULL);	/* move to client_main() */
 			break;
 		case MSG_VERSION:
 			if (datalen != 0)
 				fatalx("bad MSG_VERSION size");

 			log_warnx("protocol version mismatch (client %u, "
 			    "server %u)", PROTOCOL_VERSION, imsg.hdr.peerid);
 			exit(1);
 		case MSG_SHELL:
 			if (datalen != sizeof shelldata)
 				fatalx("bad MSG_SHELL size");
 			memcpy(&shelldata, imsg.data, sizeof shelldata);
 			shelldata.shell[(sizeof shelldata.shell) - 1] = '\0';

 			clear_signals();

 			shell_exec(shelldata.shell, shellcmd);
 		default:
 			fatalx("unexpected message");
 		}

 		imsg_free(&imsg);
 	}
 }
	/* $Id: tmux.c,v 1.213 2010-07-02 02:52:13 tcunha Exp $ */

	/*
	* 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/stat.h>
	#include <sys/wait.h>

	#include <errno.h>
	#include <event.h>
	#include <pwd.h>
	#include <signal.h>
	#include <stdlib.h>
	#include <string.h>
	#include <syslog.h>
	#include <unistd.h>

	#include "tmux.h"

	#if defined(DEBUG) && defined(__OpenBSD__)
	extern char *malloc_options;
	#endif

	char *cfg_file;
	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 event_base *ev_base;

	int debug_level;
	time_t start_time;
	char *socket_path;
	int login_shell;

	struct env_data {
	char *path;
	pid_t pid;
	u_int idx;
	};

	__dead void usage(void);
	void parse_env(struct env_data *);
	char makesockpath(const char );
	__dead void shell_exec(const char , const char );

	struct imsgbuf *main_ibuf;
	int main_exitval;

	void main_signal(int, short, unused void *);
	void main_callback(int, short, void *);
	void main_dispatch(const char *);

	#ifndef HAVE_PROGNAME
	char __progname = (char ) "tmux";
	#endif

	__dead void
	usage(void)
	{
	fprintf(stderr,
	"usage: %s [-28lquv] [-c shell-command] [-f file] [-L socket-name]\n"
	" [-S socket-path] [command [flags]]\n",
	__progname);
	exit(1);
	}

	void
	logfile(const char *name)
	{
	char *path;

	log_close();
	if (debug_level > 0) {
	xasprintf(&path, "tmux-%s-%ld.log", name, (long) getpid());
	log_open_file(debug_level, path);
	xfree(path);
	}
	}

	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 == '\0' \|\| areshell(shell))
	return (0);
	if (access(shell, X_OK) != 0)
	return (0);
	return (1);
	}

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

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

	void
	parse_env(struct env_data *data)
	{
	char env, path_pid, *pid_idx, buf[256];
	size_t len;
	const char *errstr;
	long long ll;

	data->pid = -1;
	if ((env = getenv("TMUX")) == NULL)
	return;

	if ((path_pid = strchr(env, ',')) == NULL \|\| path_pid == env)
	return;
	if ((pid_idx = strchr(path_pid + 1, ',')) == NULL)
	return;
	if ((pid_idx == path_pid + 1 \|\| pid_idx[1] == '\0'))
	return;

	/* path */
	len = path_pid - env;
	data->path = xmalloc (len + 1);
	memcpy(data->path, env, len);
	data->path[len] = '\0';

	/* pid */
	len = pid_idx - path_pid - 1;
	if (len > (sizeof buf) - 1)
	return;
	memcpy(buf, path_pid + 1, len);
	buf[len] = '\0';

	ll = strtonum(buf, 0, LONG_MAX, &errstr);
	if (errstr != NULL)
	return;
	data->pid = ll;

	/* idx */
	ll = strtonum(pid_idx+1, 0, UINT_MAX, &errstr);
	if (errstr != NULL)
	return;
	data->idx = ll;
	}

	char *
	makesockpath(const char *label)
	{
	char base[MAXPATHLEN], *path;
	struct stat sb;
	u_int uid;

	uid = getuid();
	xsnprintf(base, MAXPATHLEN, "%s/tmux-%d", _PATH_TMP, uid);

	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
	return (NULL);

	if (lstat(base, &sb) != 0)
	return (NULL);
	if (!S_ISDIR(sb.st_mode)) {
	errno = ENOTDIR;
	return (NULL);
	}
	if (sb.st_uid != uid \|\| (sb.st_mode & (S_IRWXG\|S_IRWXO)) != 0) {
	errno = EACCES;
	return (NULL);
	}

	xasprintf(&path, "%s/%s", base, label);
	return (path);
	}

	__dead void
	shell_exec(const char shell, const char shellcmd)
	{
	const char shellname, ptr;
	char *argv0;

	ptr = strrchr(shell, '/');
	if (ptr != NULL && *(ptr + 1) != '\0')
	shellname = ptr + 1;
	else
	shellname = shell;
	if (login_shell)
	xasprintf(&argv0, "-%s", shellname);
	else
	xasprintf(&argv0, "%s", shellname);
	setenv("SHELL", shell, 1);

	execl(shell, argv0, "-c", shellcmd, (char *) NULL);
	fatal("execl failed");
	}

	int
	main(int argc, char **argv)
	{
	struct cmd_list *cmdlist;
	struct cmd *cmd;
	enum msgtype msg;
	struct passwd *pw;
	struct options oo, so, *wo;
	struct keylist *keylist;
	struct env_data envdata;
	struct msg_command_data cmddata;
	char s, shellcmd, path, label, home, cause;
	char **var;
	void *buf;
	size_t len;
	int opt, flags, quiet = 0, cmdflags = 0;
	short events;

	#if defined(DEBUG) && defined(__OpenBSD__)
	malloc_options = (char *) "AFGJPX";
	#endif

	flags = 0;
	shellcmd = label = path = NULL;
	envdata.path = NULL;
	login_shell = (**argv == '-');
	while ((opt = getopt(argc, argv, "28c:df:lL:qS:uUv")) != -1) {
	switch (opt) {
	case '2':
	flags \|= IDENTIFY_256COLOURS;
	flags &= ~IDENTIFY_88COLOURS;
	break;
	case '8':
	flags \|= IDENTIFY_88COLOURS;
	flags &= ~IDENTIFY_256COLOURS;
	break;
	case 'c':
	if (shellcmd != NULL)
	xfree(shellcmd);
	shellcmd = xstrdup(optarg);
	break;
	case 'f':
	if (cfg_file != NULL)
	xfree(cfg_file);
	cfg_file = xstrdup(optarg);
	break;
	case 'l':
	login_shell = 1;
	break;
	case 'L':
	if (label != NULL)
	xfree(label);
	label = xstrdup(optarg);
	break;
	case 'q':
	quiet = 1;
	break;
	case 'S':
	if (path != NULL)
	xfree(path);
	path = xstrdup(optarg);
	break;
	case 'u':
	flags \|= IDENTIFY_UTF8;
	break;
	case 'v':
	debug_level++;
	break;
	default:
	usage();
	}
	}
	argc -= optind;
	argv += optind;

	if (shellcmd != NULL && argc != 0)
	usage();

	log_open_tty(debug_level);

	if (!(flags & IDENTIFY_UTF8)) {
	/*
	* If the user has set whichever of LC_ALL, LC_CTYPE or LANG
	* exist (in that order) 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 ((s = getenv("LC_ALL")) == NULL) {
	if ((s = getenv("LC_CTYPE")) == NULL)
	s = getenv("LANG");
	}
	if (s != NULL && (strcasestr(s, "UTF-8") != NULL \|\|
	strcasestr(s, "UTF8") != NULL))
	flags \|= IDENTIFY_UTF8;
	}

	environ_init(&global_environ);
	for (var = environ; *var != NULL; var++)
	environ_put(&global_environ, *var);

	options_init(&global_options, NULL);
	oo = &global_options;
	options_set_number(oo, "quiet", quiet);
	options_set_number(oo, "escape-time", 500);

	options_init(&global_s_options, NULL);
	so = &global_s_options;
	options_set_number(so, "base-index", 0);
	options_set_number(so, "bell-action", BELL_ANY);
	options_set_number(so, "buffer-limit", 9);
	options_set_string(so, "default-command", "%s", "");
	options_set_string(so, "default-path", "%s", "");
	options_set_string(so, "default-shell", "%s", getshell());
	options_set_string(so, "default-terminal", "screen");
	options_set_number(so, "detach-on-destroy", 1);
	options_set_number(so, "display-panes-active-colour", 1);
	options_set_number(so, "display-panes-colour", 4);
	options_set_number(so, "display-panes-time", 1000);
	options_set_number(so, "display-time", 750);
	options_set_number(so, "history-limit", 2000);
	options_set_number(so, "lock-after-time", 0);
	options_set_string(so, "lock-command", "lock -np");
	options_set_number(so, "lock-server", 1);
	options_set_number(so, "message-attr", 0);
	options_set_number(so, "message-bg", 3);
	options_set_number(so, "message-fg", 0);
	options_set_number(so, "message-limit", 20);
	options_set_number(so, "mouse-select-pane", 0);
	options_set_number(so, "pane-active-border-bg", 8);
	options_set_number(so, "pane-active-border-fg", 2);
	options_set_number(so, "pane-border-bg", 8);
	options_set_number(so, "pane-border-fg", 8);
	options_set_number(so, "repeat-time", 500);
	options_set_number(so, "set-remain-on-exit", 0);
	options_set_number(so, "set-titles", 0);
	options_set_string(so, "set-titles-string", "#S:#I:#W - \"#T\"");
	options_set_number(so, "status", 1);
	options_set_number(so, "status-attr", 0);
	options_set_number(so, "status-bg", 2);
	options_set_number(so, "status-fg", 0);
	options_set_number(so, "status-interval", 15);
	options_set_number(so, "status-justify", 0);
	options_set_number(so, "status-keys", MODEKEY_EMACS);
	options_set_string(so, "status-left", "[#S]");
	options_set_number(so, "status-left-attr", 0);
	options_set_number(so, "status-left-bg", 8);
	options_set_number(so, "status-left-fg", 8);
	options_set_number(so, "status-left-length", 10);
	options_set_string(so, "status-right", "\"#22T\" %%H:%%M %%d-%%b-%%y");
	options_set_number(so, "status-right-attr", 0);
	options_set_number(so, "status-right-bg", 8);
	options_set_number(so, "status-right-fg", 8);
	options_set_number(so, "status-right-length", 40);
	options_set_string(so, "terminal-overrides",
	"88col:colors=88,256col:colors=256");
	options_set_string(so, "update-environment", "DISPLAY "
	"WINDOWID SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID SSH_CONNECTION");
	options_set_number(so, "visual-activity", 0);
	options_set_number(so, "visual-bell", 0);
	options_set_number(so, "visual-content", 0);

	keylist = xmalloc(sizeof *keylist);
	ARRAY_INIT(keylist);
	ARRAY_ADD(keylist, '\002');
	options_set_data(so, "prefix", keylist, xfree);

	options_init(&global_w_options, NULL);
	wo = &global_w_options;
	options_set_number(wo, "aggressive-resize", 0);
	options_set_number(wo, "alternate-screen", 1);
	options_set_number(wo, "automatic-rename", 1);
	options_set_number(wo, "clock-mode-colour", 4);
	options_set_number(wo, "clock-mode-style", 1);
	options_set_number(wo, "force-height", 0);
	options_set_number(wo, "force-width", 0);
	options_set_number(wo, "main-pane-height", 24);
	options_set_number(wo, "main-pane-width", 81);
	options_set_number(wo, "mode-attr", 0);
	options_set_number(wo, "mode-bg", 3);
	options_set_number(wo, "mode-fg", 0);
	options_set_number(wo, "mode-keys", MODEKEY_EMACS);
	options_set_number(wo, "mode-mouse", 0);
	options_set_number(wo, "monitor-activity", 0);
	options_set_string(wo, "monitor-content", "%s", "");
	options_set_number(wo, "window-status-attr", 0);
	options_set_number(wo, "window-status-bg", 8);
	options_set_number(wo, "window-status-current-attr", 0);
	options_set_number(wo, "window-status-current-bg", 8);
	options_set_number(wo, "window-status-current-fg", 8);
	options_set_number(wo, "window-status-fg", 8);
	options_set_number(wo, "window-status-alert-attr", GRID_ATTR_REVERSE);
	options_set_number(wo, "window-status-alert-bg", 8);
	options_set_number(wo, "window-status-alert-fg", 8);
	options_set_string(wo, "window-status-format", "#I:#W#F");
	options_set_string(wo, "window-status-current-format", "#I:#W#F");
	options_set_string(wo, "word-separators", " -_@");
	options_set_number(wo, "xterm-keys", 0);
	options_set_number(wo, "remain-on-exit", 0);
	options_set_number(wo, "synchronize-panes", 0);

	if (flags & IDENTIFY_UTF8) {
	options_set_number(so, "status-utf8", 1);
	options_set_number(wo, "utf8", 1);
	} else {
	options_set_number(so, "status-utf8", 0);
	options_set_number(wo, "utf8", 0);
	}

	if (cfg_file == NULL) {
	home = getenv("HOME");
	if (home == NULL \|\| *home == '\0') {
	pw = getpwuid(getuid());
	if (pw != NULL)
	home = pw->pw_dir;
	}
	xasprintf(&cfg_file, "%s/%s", home, DEFAULT_CFG);
	if (access(cfg_file, R_OK) != 0 && errno == ENOENT) {
	xfree(cfg_file);
	cfg_file = NULL;
	}
	}

	/*
	* Figure out the socket path. If specified on the command-line with
	* -S or -L, use it, otherwise try $TMUX or assume -L default.
	*/
	parse_env(&envdata);
	if (path == NULL) {
	/* No -L. Try $TMUX, or default. */
	if (label == NULL) {
	path = envdata.path;
	if (path == NULL)
	label = xstrdup("default");
	}

	/* -L or default set. */
	if (label != NULL) {
	if ((path = makesockpath(label)) == NULL) {
	log_warn("can't create socket");
	exit(1);
	}
	}
	}
	if (label != NULL)
	xfree(label);

	if (shellcmd != NULL) {
	msg = MSG_SHELL;
	buf = NULL;
	len = 0;
	} else {
	cmddata.pid = envdata.pid;
	cmddata.idx = envdata.idx;

	/* Prepare command for server. */
	cmddata.argc = argc;
	if (cmd_pack_argv(
	argc, argv, cmddata.argv, sizeof cmddata.argv) != 0) {
	log_warnx("command too long");
	exit(1);
	}

	msg = MSG_COMMAND;
	buf = &cmddata;
	len = sizeof cmddata;
	}

	if (shellcmd != NULL)
	cmdflags \|= CMD_STARTSERVER;
	else if (argc == 0) /* new-session is the default */
	cmdflags \|= CMD_STARTSERVER\|CMD_SENDENVIRON\|CMD_CANTNEST;
	else {
	/*
	* It sucks parsing the command string twice (in client and
	* later in server) but it is necessary to get the start server
	* flag.
	*/
	if ((cmdlist = cmd_list_parse(argc, argv, &cause)) == NULL) {
	log_warnx("%s", cause);
	exit(1);
	}
	cmdflags &= ~CMD_STARTSERVER;
	TAILQ_FOREACH(cmd, &cmdlist->list, qentry) {
	if (cmd->entry->flags & CMD_STARTSERVER)
	cmdflags \|= CMD_STARTSERVER;
	if (cmd->entry->flags & CMD_SENDENVIRON)
	cmdflags \|= CMD_SENDENVIRON;
	if (cmd->entry->flags & CMD_CANTNEST)
	cmdflags \|= CMD_CANTNEST;
	}
	cmd_list_free(cmdlist);
	}

	/*
	* Check if this could be a nested session, if the command can't nest:
	* if the socket path matches $TMUX, this is probably the same server.
	*/
	if (shellcmd == NULL && envdata.path != NULL &&
	cmdflags & CMD_CANTNEST &&
	(path == envdata.path \|\| strcmp(path, envdata.path) == 0)) {
	log_warnx("sessions should be nested with care. "
	"unset $TMUX to force.");
	exit(1);
	}

	#ifdef HAVE_BROKEN_KQUEUE
	if (setenv("EVENT_NOKQUEUE", "1", 1) != 0)
	fatal("setenv failed");
	#endif
	#ifdef HAVE_BROKEN_POLL
	if (setenv("EVENT_NOPOLL", "1", 1) != 0)
	fatal("setenv failed");
	#endif
	ev_base = event_init();
	#ifdef HAVE_BROKEN_KQUEUE
	unsetenv("EVENT_NOKQUEUE");
	#endif
	#ifdef HAVE_BROKEN_POLL
	unsetenv("EVENT_NOPOLL");
	#endif
	set_signals(main_signal);

	/* Initialise the client socket/start the server. */
	if ((main_ibuf = client_init(path, cmdflags, flags)) == NULL)
	exit(1);
	xfree(path);

	imsg_compose(main_ibuf, msg, PROTOCOL_VERSION, -1, -1, buf, len);

	events = EV_READ;
	if (main_ibuf->w.queued > 0)
	events \|= EV_WRITE;
	event_once(main_ibuf->fd, events, main_callback, shellcmd, NULL);

	main_exitval = 0;
	event_dispatch();

	clear_signals();

	client_main(); /* doesn't return */
	}

	/* ARGSUSED */
	void
	main_signal(int sig, unused short events, unused void *data)
	{
	int status;

	switch (sig) {
	case SIGTERM:
	exit(1);
	case SIGCHLD:
	waitpid(WAIT_ANY, &status, WNOHANG);
	break;
	}
	}

	/* ARGSUSED */
	void
	main_callback(unused int fd, short events, void *data)
	{
	char *shellcmd = data;

	if (events & EV_READ)
	main_dispatch(shellcmd);

	if (events & EV_WRITE) {
	if (msgbuf_write(&main_ibuf->w) < 0)
	fatalx("msgbuf_write failed");
	}

	events = EV_READ;
	if (main_ibuf->w.queued > 0)
	events \|= EV_WRITE;
	event_once(main_ibuf->fd, events, main_callback, shellcmd, NULL);
	}

	void
	main_dispatch(const char *shellcmd)
	{
	struct imsg imsg;
	ssize_t n, datalen;
	struct msg_shell_data shelldata;

	if ((n = imsg_read(main_ibuf)) == -1 \|\| n == 0)
	fatalx("imsg_read failed");

	for (;;) {
	if ((n = imsg_get(main_ibuf, &imsg)) == -1)
	fatalx("imsg_get failed");
	if (n == 0)
	return;
	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;

	switch (imsg.hdr.type) {
	case MSG_EXIT:
	case MSG_SHUTDOWN:
	if (datalen != 0)
	fatalx("bad MSG_EXIT size");

	exit(main_exitval);
	case MSG_READY:
	if (datalen != 0)
	fatalx("bad MSG_READY size");

	event_loopexit(NULL); /* move to client_main() */
	break;
	case MSG_VERSION:
	if (datalen != 0)
	fatalx("bad MSG_VERSION size");

	log_warnx("protocol version mismatch (client %u, "
	"server %u)", PROTOCOL_VERSION, imsg.hdr.peerid);
	exit(1);
	case MSG_SHELL:
	if (datalen != sizeof shelldata)
	fatalx("bad MSG_SHELL size");
	memcpy(&shelldata, imsg.data, sizeof shelldata);
	shelldata.shell[(sizeof shelldata.shell) - 1] = '\0';

	clear_signals();

	shell_exec(shelldata.shell, shellcmd);
	default:
	fatalx("unexpected message");
	}

	imsg_free(&imsg);
	}
	}