X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=gui.c;h=69a9243da25245d5a4a67c1bf98deaef222dc593;hp=b2397146d425ef4144b31c7e36327dca78e197d0;hb=98dc2e1f173732411953da7300460cc419efd2bb;hpb=18daa9110808af03e0aa56b91c10df9dafec2135

diff --git a/gui.c b/gui.c
index b2397146..69a9243d 100644
--- a/gui.c
+++ b/gui.c
@@ -1,8 +1,4 @@
-/*
- * Copyright (C) 1998-2014 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 1998 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
 
 /** \file gui.c Curses-based interface for paraslash. */
 
@@ -12,8 +8,9 @@
 #include <curses.h>
 #include <locale.h>
 #include <sys/time.h>
+#include <lopsub.h>
 
-#include "gui.cmdline.h"
+#include "gui.lsg.h"
 #include "para.h"
 #include "gui.h"
 #include "string.h"
@@ -23,20 +20,30 @@
 #include "list.h"
 #include "sched.h"
 #include "signal.h"
-#include "ggo.h"
 #include "version.h"
 
-/** define the array of error lists needed by para_gui */
-INIT_GUI_ERRLISTS;
-static char *stat_content[NUM_STAT_ITEMS];
+/** Array of error strings. */
+DEFINE_PARA_ERRLIST;
+
+static struct lls_parse_result *cmdline_lpr, *lpr;
 
-static int signal_pipe;
+#define CMD_PTR (lls_cmd(0, gui_suite))
+#define OPT_RESULT(_name) (lls_opt_result(LSG_GUI_PARA_GUI_OPT_ ## _name, lpr))
+#define OPT_GIVEN(_name) (lls_opt_given(OPT_RESULT(_name)))
+#define OPT_STRING_VAL(_name) (lls_string_val(0, OPT_RESULT(_name)))
+#define OPT_UINT32_VAL(_name) (lls_uint32_val(0, OPT_RESULT(_name)))
+#define FOR_EACH_KEY_MAP(_i) for (_i = 0; _i < OPT_GIVEN(KEY_MAP); _i++)
+
+static char *stat_content[NUM_STAT_ITEMS];
 
 static struct gui_window {
 	WINDOW *win;
+	bool needs_update;
 } top, bot, sb, in, sep;
 
+/** How many lines of output to remember. */
 #define RINGBUFFER_SIZE 512
+
 struct rb_entry {
 	char *msg;
 	size_t len;
@@ -45,18 +52,15 @@ struct rb_entry {
 static struct ringbuffer *bot_win_rb;
 
 static unsigned scroll_position;
-
-static pid_t cmd_pid;
-
-static int command_fds[2] = {-1, -1};
-static int stat_pipe = -1;
-static struct gui_args_info conf;
+static pid_t exec_pid;
+static int exec_fds[2] = {-1, -1};
 static int loglevel;
 
-enum cmd_status {
-	CMDS_IDLE, /* no command running */
-	CMDS_DCMD, /* para or display command running */
-	CMDS_XCMD, /* external command running */
+/** Type of the process currently being executed. */
+enum exec_status {
+	EXEC_IDLE, /**< No process running. */
+	EXEC_DCMD, /**< para or display process running. */
+	EXEC_XCMD, /**< External process running. */
 };
 
 /**
@@ -122,7 +126,30 @@ GUI_COMMANDS
 
 static struct gui_command command_list[] = {GUI_COMMANDS {.name = NULL}};
 
-static int find_cmd_byname(char *name)
+struct input_task {
+	struct task *task;
+};
+
+struct status_task {
+	struct task *task;
+	pid_t pid;
+	char *buf;
+	int bufsize, loaded;
+	struct timeval next_exec;
+	int fd;
+};
+
+/** Stdout/stderr of the executing process is read in chunks of this size. */
+#define COMMAND_BUF_SIZE 32768
+
+struct exec_task {
+	struct task *task;
+	char command_buf[2][COMMAND_BUF_SIZE]; /* stdout/stderr of command */
+	int cbo[2]; /* command buf offsets */
+	unsigned flags[2]; /* passed to for_each_line() */
+};
+
+static int find_cmd_byname(const char *name)
 {
 	int i;
 
@@ -220,10 +247,10 @@ static char *km_keyname(int c)
 }
 
 /* Print given number of spaces to curses window. */
-static void add_spaces(WINDOW* win, unsigned int num)
+static void add_spaces(WINDOW *win, unsigned int num)
 {
-	char space[] = "                                ";
-	unsigned sz = sizeof(space) - 1; /* number of spaces */
+	const char space[] = "                                ";
+	const unsigned sz = sizeof(space) - 1; /* number of spaces */
 
 	while (num >= sz)  {
 		waddstr(win, space);
@@ -231,53 +258,57 @@ static void add_spaces(WINDOW* win, unsigned int num)
 	}
 	if (num > 0) {
 		assert(num < sz);
-		space[num] = '\0';
-		waddstr(win, space);
+		waddstr(win, space + sz - num);
 	}
 }
 
 /*
- * print aligned string to curses window. This function always prints
+ * Print aligned string to curses window. This function always prints
  * exactly len chars.
  */
-static int align_str(WINDOW* win, char *str, unsigned int len,
+static int align_str(WINDOW *win, const char *str, unsigned int len,
 		unsigned int align)
 {
-	int ret, i, num; /* of spaces */
+	int ret, num; /* of spaces */
 	size_t width;
+	char *sstr; /* sanitized string */
 
 	if (!win || !str)
 		return 0;
-	ret = strwidth(str, &width);
+	ret = sanitize_str(str, len, &sstr, &width);
 	if (ret < 0) {
 		PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 		width = 0;
-		str[0] = '\0';
+		sstr = para_strdup(NULL);
 	}
+	assert(width <= len);
 	num = len - width;
-	if (num < 0) {
-		str[len] = '\0';
-		num = 0;
-	}
-	/* replace control characters by spaces */
-	for (i = 0; i < len && str[i]; i++) {
-		if (str[i] == '\n' || str[i] == '\r' || str[i] == '\f')
-			str[i] = ' ';
-	}
 	if (align == LEFT) {
-		waddstr(win, str);
+		waddstr(win, sstr);
 		add_spaces(win, num);
 	} else if (align == RIGHT) {
 		add_spaces(win, num);
-		waddstr(win, str);
+		waddstr(win, sstr);
 	} else {
 		add_spaces(win, num / 2);
-		waddstr(win, str[0]? str: "");
+		waddstr(win, sstr);
 		add_spaces(win, num - num / 2);
 	}
+	free(sstr);
 	return 1;
 }
 
+static void refresh_window(struct gui_window *gw)
+{
+	gw->needs_update = true;
+}
+
+static bool window_update_needed(void)
+{
+	return top.needs_update || bot.needs_update || sb.needs_update ||
+		in.needs_update || sep.needs_update;
+}
+
 __printf_2_3 static void print_in_bar(int color, const char *fmt,...)
 {
 	char *msg;
@@ -292,7 +323,7 @@ __printf_2_3 static void print_in_bar(int color, const char *fmt,...)
 	wmove(in.win, 0, 0);
 	align_str(in.win, msg, get_num_cols(&in), LEFT);
 	free(msg);
-	wrefresh(in.win);
+	refresh_window(&in);
 }
 
 static void print_status_bar(void)
@@ -388,7 +419,7 @@ static void redraw_bot_win(void)
 		waddstr(bot.win, rbe->msg);
 	}
 out:
-	wrefresh(bot.win);
+	refresh_window(&bot);
 }
 
 static void rb_add_entry(int color, char *msg)
@@ -421,10 +452,8 @@ static void rb_add_entry(int color, char *msg)
 	waddstr(bot.win, msg);
 }
 
-/*
- * print formated output to bot win and refresh
- */
-__printf_2_3 static void outputf(int color, const char* fmt,...)
+/* Print formatted output to bot win and refresh. */
+__printf_2_3 static void outputf(int color, const char *fmt,...)
 {
 	char *msg;
 	va_list ap;
@@ -435,7 +464,7 @@ __printf_2_3 static void outputf(int color, const char* fmt,...)
 	xvasprintf(&msg, fmt, ap);
 	va_end(ap);
 	rb_add_entry(color, msg);
-	wrefresh(bot.win);
+	refresh_window(&bot);
 }
 
 static int add_output_line(char *line, void *data)
@@ -462,47 +491,55 @@ static __printf_2_3 void curses_log(int ll, const char *fmt,...)
 		if (bytes > 0 && msg[bytes - 1] == '\n')
 			msg[bytes - 1] = '\0'; /* cut trailing newline */
 		rb_add_entry(color, msg);
-		wrefresh(bot.win);
-	} else if (cmd_pid <= 0) /* no external command running */
+		refresh_window(&bot);
+	} else if (exec_pid <= 0) /* no external command running */
 		vfprintf(stderr, fmt, ap);
 	va_end(ap);
 }
-__printf_2_3 void (*para_log)(int, const char*, ...) = curses_log;
 
-static void setup_signal_handling(void)
-{
-	signal_pipe = para_signal_init();
-	para_install_sighandler(SIGINT);
-	para_install_sighandler(SIGTERM);
-	para_install_sighandler(SIGCHLD);
-	para_install_sighandler(SIGWINCH);
-	para_install_sighandler(SIGUSR1);
-}
+/** The log function of para_gui, always set to curses_log(). */
+__printf_2_3 void (*para_log)(int, const char *, ...) = curses_log;
 
+/* Call endwin() to reset the terminal into non-visual mode. */
 static void shutdown_curses(void)
 {
-	def_prog_mode();
+	/*
+	 * If para_gui received a terminating signal in external mode, the
+	 * terminal can be in an unusable state at this point because the child
+	 * process might not have caught the signal. In this case endwin() has
+	 * already been called and must not be called again. So we first return
+	 * to program mode, then call endwin().
+	 */
+	if (!curses_active())
+		reset_prog_mode();
 	endwin();
 }
 
-/* disable curses, print a message, kill running processes and exit */
-__noreturn __printf_2_3 static void die(int exit_code, const char* fmt, ...)
+/* Disable curses, print a message, kill running processes and exit. */
+__noreturn __printf_2_3 static void die(int exit_code, const char *fmt, ...)
 {
 	va_list argp;
 
+	/* Kill every process in our process group. */
+	para_sigaction(SIGTERM, SIG_IGN);
+	kill(0, SIGTERM);
+	/* Wait up to two seconds for child processes to die. */
+	alarm(2);
+	while (waitpid(0, NULL, 0) >= 0)
+		; /* nothing */
+	alarm(0);
+	/* mousemask() exists only in ncurses */
+#ifdef NCURSES_MOUSE_VERSION
+	mousemask(~(mmask_t)0, NULL); /* Avoid bad terminal state with xterm. */
+#endif
 	shutdown_curses();
 	va_start(argp, fmt);
 	vfprintf(stderr, fmt, argp);
 	va_end(argp);
-	/* kill every process in the process group and exit */
-	para_sigaction(SIGTERM, SIG_IGN);
-	kill(0, SIGTERM);
 	exit(exit_code);
 }
 
-/*
- * Print stat item #i to curses window
- */
+/* Print stat item #i to curses window. */
 static void print_stat_item(int i)
 {
 	char *tmp;
@@ -514,11 +551,10 @@ static void print_stat_item(int i)
 		return;
 	tmp = make_message("%s%s%s", d.prefix, c, d.postfix);
 	wmove(top.win, d.y * top_lines / 100, d.x * COLS / 100);
-	wrefresh(top.win);
 	wattron(top.win, COLOR_PAIR(i + 1));
 	align_str(top.win, tmp, d.len * COLS / 100, d.align);
 	free(tmp);
-	wrefresh(top.win);
+	refresh_window(&top);
 }
 
 static int update_item(int item_num, char *buf)
@@ -529,19 +565,19 @@ static int update_item(int item_num, char *buf)
 	if (buf && buf[0])
 		goto dup;
 	switch (item_num) {
-	case SI_ARTIST:
+	case SI_artist:
 		*c = para_strdup("(artist tag not set)");
 		goto print;
-	case SI_TITLE:
+	case SI_title:
 		*c = para_strdup("(title tag not set)");
 		goto print;
-	case SI_YEAR:
+	case SI_year:
 		*c = para_strdup("????");
 		goto print;
-	case SI_ALBUM:
+	case SI_album:
 		*c = para_strdup("(album tag not set)");
 		goto print;
-	case SI_COMMENT:
+	case SI_comment:
 		*c = para_strdup("(comment tag not set)");
 		goto print;
 	}
@@ -572,84 +608,88 @@ static void clear_all_items(void)
 	}
 }
 
-static struct timeval next_exec;
-
-static void status_pre_select(fd_set *rfds, int *max_fileno, struct timeval *tv)
+static void status_pre_select(struct sched *s, void *context)
 {
-	struct timeval atm, diff;
+	struct status_task *st = context;
 
-	if (stat_pipe >= 0)
-		return para_fd_set(stat_pipe, rfds, max_fileno);
-	gettimeofday(&atm, NULL);
-	if (tv_diff(&next_exec, &atm, &diff) > 0) {
-		*tv = diff;
-		return;
-	}
-	tv->tv_sec = tv->tv_usec = 0; /* min delay */
+	if (st->fd >= 0)
+		para_fd_set(st->fd, &s->rfds, &s->max_fileno);
+	if (task_get_notification(st->task) < 0)
+		return sched_min_delay(s);
+	if (st->fd < 0)
+		sched_request_barrier_or_min_delay(&st->next_exec, s);
 }
 
-static void status_post_select(fd_set *rfds)
+static int status_post_select(struct sched *s, void *context)
 {
-	static char *buf;
-	static int bufsize, loaded;
+	struct status_task *st = context;
 	size_t sz;
-	pid_t pid;
 	int ret, ret2;
 
-	if (stat_pipe < 0) {
-		struct timeval atm;
+	ret = task_get_notification(st->task);
+	if (ret == -E_GUI_SIGCHLD && st->pid > 0) {
+		int exit_status;
+		if (waitpid(st->pid, &exit_status, WNOHANG) == st->pid) {
+			st->pid = 0;
+			PARA_ERROR_LOG("stat command exit status: %d",
+				exit_status);
+		}
+	}
+	if (st->fd < 0) {
 		int fds[3] = {0, 1, 0};
+		if (st->pid > 0)
+			return 0;
 		/* Avoid busy loop */
-		gettimeofday(&atm, NULL);
-		if (tv_diff(&next_exec, &atm, NULL) > 0)
-			return;
-		next_exec.tv_sec = atm.tv_sec + 2;
-		ret = para_exec_cmdline_pid(&pid, conf.stat_cmd_arg, fds);
+		if (tv_diff(&st->next_exec, now, NULL) > 0)
+			return 0;
+		st->next_exec.tv_sec = now->tv_sec + 2;
+		ret = para_exec_cmdline_pid(&st->pid,
+			OPT_STRING_VAL(STAT_CMD), fds);
 		if (ret < 0)
-			return;
+			return 0;
 		ret = mark_fd_nonblocking(fds[1]);
 		if (ret < 0) {
 			close(fds[1]);
-			return;
+			return 0;
 		}
-		stat_pipe = fds[1];
-		return;
+		st->fd = fds[1];
+		return 0;
 	}
 
-	if (loaded >= bufsize) {
-		if (bufsize > 1000 * 1000) {
-			loaded = 0;
-			return;
+	if (st->loaded >= st->bufsize) {
+		if (st->bufsize > 1000 * 1000) {
+			st->loaded = 0;
+			return 0;
 		}
-		bufsize += bufsize + 1000;
-		buf = para_realloc(buf, bufsize);
+		st->bufsize += st->bufsize + 1000;
+		st->buf = para_realloc(st->buf, st->bufsize);
 	}
-	assert(loaded < bufsize);
-	ret = read_nonblock(stat_pipe, buf + loaded, bufsize - loaded,
-		rfds, &sz);
-	loaded += sz;
-	ret2 = for_each_stat_item(buf, loaded, update_item);
+	assert(st->loaded < st->bufsize);
+	ret = read_nonblock(st->fd, st->buf + st->loaded,
+		st->bufsize - st->loaded, &s->rfds, &sz);
+	st->loaded += sz;
+	ret2 = for_each_stat_item(st->buf, st->loaded, update_item);
 	if (ret < 0 || ret2 < 0) {
-		loaded = 0;
-		PARA_NOTICE_LOG("closing stat pipe: %s\n", para_strerror(-ret));
-		close(stat_pipe);
-		stat_pipe = -1;
+		st->loaded = 0;
+		PARA_NOTICE_LOG("closing stat pipe: %s\n",
+			para_strerror(ret < 0? -ret : -ret2));
+		close(st->fd);
+		st->fd = -1;
 		clear_all_items();
-		free(stat_content[SI_BASENAME]);
-		stat_content[SI_BASENAME] =
+		free(stat_content[SI_basename]);
+		stat_content[SI_basename] =
 			para_strdup("stat command terminated!?");
 		print_all_items();
-		return;
+		return 0;
 	}
 	sz = ret2; /* what is left */
-	if (sz > 0 && sz < loaded)
-		memmove(buf, buf + loaded - sz, sz);
-	loaded = sz;
+	if (sz > 0 && sz < st->loaded)
+		memmove(st->buf, st->buf + st->loaded - sz, sz);
+	st->loaded = sz;
+	return 0;
 }
 
-/*
- * init all windows
- */
+/* Initialize all windows. */
 static void init_wins(int top_lines)
 {
 	int top_y = 0, bot_y = top_lines + 1, sb_y = LINES - 2,
@@ -657,7 +697,7 @@ static void init_wins(int top_lines)
 	int bot_lines = LINES - top_lines - 3, sb_lines = 1, in_lines = 1,
 		sep_lines = 1;
 
-	assume_default_colors(theme.default_fg, theme.default_bg);
+	assume_default_colors(theme.dflt.fg, theme.dflt.bg);
 	if (top.win) {
 		wresize(top.win, top_lines, COLS);
 		mvwin(top.win, top_y, 0);
@@ -729,16 +769,16 @@ static void init_colors_or_die(void)
 		die(EXIT_FAILURE, "fatal: failed to start colors\n");
 	FOR_EACH_STATUS_ITEM(i)
 		if (theme.data[i].len)
-			init_pair_or_die(i + 1, theme.data[i].fg,
-				theme.data[i].bg);
-	init_pair_or_die(COLOR_STATUSBAR, theme.sb_fg, theme.sb_bg);
-	init_pair_or_die(COLOR_COMMAND, theme.cmd_fg, theme.cmd_bg);
-	init_pair_or_die(COLOR_OUTPUT, theme.output_fg, theme.output_bg);
-	init_pair_or_die(COLOR_MSG, theme.msg_fg, theme.msg_bg);
-	init_pair_or_die(COLOR_ERRMSG, theme.err_msg_fg, theme.err_msg_bg);
-	init_pair_or_die(COLOR_SEPARATOR, theme.sep_fg, theme.sep_bg);
-	init_pair_or_die(COLOR_TOP, theme.default_fg, theme.default_bg);
-	init_pair_or_die(COLOR_BOT, theme.default_fg, theme.default_bg);
+			init_pair_or_die(i + 1, theme.data[i].color.fg,
+				theme.data[i].color.bg);
+	init_pair_or_die(COLOR_STATUSBAR, theme.sb.fg, theme.sb.bg);
+	init_pair_or_die(COLOR_COMMAND, theme.cmd.fg, theme.cmd.bg);
+	init_pair_or_die(COLOR_OUTPUT, theme.output.fg, theme.output.bg);
+	init_pair_or_die(COLOR_MSG, theme.msg.fg, theme.msg.bg);
+	init_pair_or_die(COLOR_ERRMSG, theme.err_msg.fg, theme.err_msg.bg);
+	init_pair_or_die(COLOR_SEPARATOR, theme.sep.fg, theme.sep.bg);
+	init_pair_or_die(COLOR_TOP, theme.dflt.fg, theme.dflt.bg);
+	init_pair_or_die(COLOR_BOT, theme.dflt.fg, theme.dflt.bg);
 }
 
 /* (Re-)initialize the curses library. */
@@ -746,7 +786,7 @@ static void init_curses(void)
 {
 	if (curses_active())
 		return;
-	if (top.win && refresh() == ERR) /* refresh is really needed */
+	if (refresh() == ERR) /* refresh is really needed */
 		die(EXIT_FAILURE, "refresh() failed\n");
 	if (LINES < theme.lines_min || COLS < theme.cols_min)
 		die(EXIT_FAILURE, "Terminal (%dx%d) too small"
@@ -766,23 +806,6 @@ static void init_curses(void)
 	// noecho(); /* don't echo input */
 }
 
-static void check_sigchld(void)
-{
-	int ret;
-	pid_t pid;
-
-reap_next_child:
-	ret = para_reap_child(&pid);
-	if (ret <= 0)
-		return;
-	if (pid == cmd_pid) {
-		cmd_pid = 0;
-		init_curses();
-		print_in_bar(COLOR_MSG, " ");
-	}
-	goto reap_next_child;
-}
-
 /*
  * This sucker modifies its first argument. *handler and *arg are
  * pointers to 0-terminated strings (inside line). Crap.
@@ -806,12 +829,13 @@ static void check_key_map_args_or_die(void)
 {
 	int i;
 	char *tmp = NULL;
+	const struct lls_opt_result *lor = OPT_RESULT(KEY_MAP);
 
-	for (i = 0; i < conf.key_map_given; ++i) {
+	FOR_EACH_KEY_MAP(i) {
 		char *handler, *arg;
 
 		free(tmp);
-		tmp = para_strdup(conf.key_map_arg[i]);
+		tmp = para_strdup(lls_string_val(i, lor));
 		if (!split_key_map(tmp, &handler, &arg))
 			break;
 		if (strlen(handler) != 1)
@@ -824,181 +848,205 @@ static void check_key_map_args_or_die(void)
 		if (find_cmd_byname(arg) < 0)
 			break;
 	}
-	if (i != conf.key_map_given)
-		die(EXIT_FAILURE, "invalid key map: %s\n", conf.key_map_arg[i]);
+	if (i != OPT_GIVEN(KEY_MAP))
+		die(EXIT_FAILURE, "invalid key map: %s\n",
+			lls_string_val(i, lor));
 	free(tmp);
 }
 
-static void parse_config_file_or_die(bool override)
+static void parse_config_file_or_die(bool reload)
 {
-	bool err;
-	char *config_file;
-	struct gui_cmdline_parser_params params = {
-		.override = override,
-		.initialize = 0,
-		.check_required = !override,
-		.check_ambiguity = 0,
-		.print_errors = 1,
-	};
+	int ret;
+	char *cf = NULL, *errctx = NULL;
+	void *map;
+	size_t sz;
+	int cf_argc;
+	char **cf_argv;
+	struct lls_parse_result *cf_lpr, *merged_lpr;
 
-	if (conf.config_file_given)
-		config_file = para_strdup(conf.config_file_arg);
+	if (OPT_GIVEN(CONFIG_FILE))
+		cf = para_strdup(OPT_STRING_VAL(CONFIG_FILE));
 	else {
 		char *home = para_homedir();
-		config_file = make_message("%s/.paraslash/gui.conf", home);
+		cf = make_message("%s/.paraslash/gui.conf", home);
 		free(home);
 	}
-	if (!file_exists(config_file)) {
-		if (!conf.config_file_given)
-			err = false;
-		else {
-			PARA_EMERG_LOG("config file %s does not exist\n",
-				config_file);
-			err = true;
-		}
-		goto out;
+	ret = mmap_full_file(cf, O_RDONLY, &map, &sz, NULL);
+	if (ret < 0) {
+		if (ret != -E_EMPTY && ret != -ERRNO_TO_PARA_ERROR(ENOENT))
+			goto free_cf;
+		if (ret == -ERRNO_TO_PARA_ERROR(ENOENT) && OPT_GIVEN(CONFIG_FILE))
+			goto free_cf;
+		ret = 0;
+		lpr = cmdline_lpr;
+		goto success;
 	}
-	gui_cmdline_parser_config_file(config_file, &conf, &params);
-	loglevel = get_loglevel_by_name(conf.loglevel_arg);
+	ret = lls(lls_convert_config(map, sz, NULL, &cf_argv, &errctx));
+	para_munmap(map, sz);
+	if (ret < 0)
+		goto free_cf;
+	cf_argc = ret;
+	ret = lls(lls_parse(cf_argc, cf_argv, CMD_PTR, &cf_lpr, &errctx));
+	lls_free_argv(cf_argv);
+	if (ret < 0)
+		goto free_cf;
+	if (reload) /* config file overrides command line */
+		ret = lls(lls_merge(cf_lpr, cmdline_lpr, CMD_PTR, &merged_lpr,
+			&errctx));
+	else /* command line options override config file options */
+		ret = lls(lls_merge(cmdline_lpr, cf_lpr, CMD_PTR, &merged_lpr,
+			&errctx));
+	lls_free_parse_result(cf_lpr, CMD_PTR);
+	if (ret < 0)
+		goto free_cf;
+	if (lpr != cmdline_lpr)
+		lls_free_parse_result(lpr, CMD_PTR);
+	lpr = merged_lpr;
+success:
+	loglevel = OPT_UINT32_VAL(LOGLEVEL);
 	check_key_map_args_or_die();
-	theme_init(conf.theme_arg, &theme);
-	err = false;
-out:
-	free(config_file);
-	if (err)
+	theme_init(OPT_STRING_VAL(THEME), &theme);
+free_cf:
+	free(cf);
+	if (ret < 0) {
+		if (errctx)
+			PARA_ERROR_LOG("%s\n", errctx);
+		free(errctx);
+		PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 		exit(EXIT_FAILURE);
+	}
 }
 
-/* reread configuration, terminate on errors */
+/* Reread configuration, terminate on errors. */
 static void reread_conf(void)
 {
 	/*
-	 * gengetopt might print to stderr and exit on errors. So we have to
-	 * shutdown curses first.
+	 * If the reload of the config file fails, we are about to exit. In
+	 * this case we print the error message to stderr rather than to the
+	 * curses window.  So we have to shutdown curses first.
 	 */
 	shutdown_curses();
-	parse_config_file_or_die(true /* override */);
+	parse_config_file_or_die(true);
 	init_curses();
 	print_in_bar(COLOR_MSG, "config file reloaded\n");
 }
 
-/*
- * React to various signal-related events
- */
-static void signal_post_select(fd_set *rfds)
+/* React to various signal-related events. */
+static int signal_post_select(struct sched *s, __a_unused void *context)
 {
-	int ret = para_next_signal(rfds);
+	int ret = para_next_signal(&s->rfds);
+
 	if (ret <= 0)
-		return;
+		return 0;
 	switch (ret) {
 	case SIGTERM:
 		die(EXIT_FAILURE, "only the good die young (caught SIGTERM)\n");
-		return;
 	case SIGWINCH:
+		PARA_NOTICE_LOG("got SIGWINCH\n");
 		if (curses_active()) {
 			shutdown_curses();
 			init_curses();
 			redraw_bot_win();
 		}
-		return;
+		return 1;
 	case SIGINT:
-		PARA_WARNING_LOG("caught SIGINT, reset\n");
-		/* Nothing to do. SIGINT killed our child which gets noticed
-		 * by do_select and resets everything.
-		 */
-		return;
+		return 1;
 	case SIGUSR1:
 		PARA_NOTICE_LOG("got SIGUSR1, rereading configuration\n");
 		reread_conf();
-		return;
+		return 1;
 	case SIGCHLD:
-		check_sigchld();
-		return;
+		task_notify_all(s, E_GUI_SIGCHLD);
+		return 1;
 	}
+	return 1;
 }
 
-#define COMMAND_BUF_SIZE 32768
-
-static enum cmd_status cmd_status(void)
+static enum exec_status exec_status(void)
 {
-	if (command_fds[0] >= 0 || command_fds[1] >= 0)
-		return CMDS_DCMD;
-	if (cmd_pid > 0)
-		return CMDS_XCMD;
-	return CMDS_IDLE;
+	if (exec_fds[0] >= 0 || exec_fds[1] >= 0)
+		return EXEC_DCMD;
+	if (exec_pid > 0)
+		return EXEC_XCMD;
+	return EXEC_IDLE;
 }
 
-static void command_pre_select(fd_set *rfds, int *max_fileno)
+static void exec_pre_select(struct sched *s, void *context)
 {
-	enum cmd_status cmds = cmd_status();
-
-	if (cmds != CMDS_DCMD)
-		return;
-	if (command_fds[0] >= 0)
-		para_fd_set(command_fds[0], rfds, max_fileno);
-	if (command_fds[1] >= 0)
-		para_fd_set(command_fds[1], rfds, max_fileno);
+	struct exec_task *et = context;
+	if (exec_fds[0] >= 0)
+		para_fd_set(exec_fds[0], &s->rfds, &s->max_fileno);
+	if (exec_fds[1] >= 0)
+		para_fd_set(exec_fds[1], &s->rfds, &s->max_fileno);
+	if (task_get_notification(et->task) < 0)
+		sched_min_delay(s);
 }
 
-static void command_post_select(fd_set *rfds)
+static int exec_post_select(struct sched *s, void *context)
 {
+	struct exec_task *ct = context;
 	int i, ret;
-	static char command_buf[2][COMMAND_BUF_SIZE];
-	static int cbo[2]; /* command buf offsets */
-	static unsigned flags[2]; /* for for_each_line() */
-	enum cmd_status cmds = cmd_status();
 
-	if (cmds != CMDS_DCMD)
-		return;
+	ret = task_get_notification(ct->task);
+	if (ret == -E_GUI_SIGCHLD && exec_pid > 0) {
+		int exit_status;
+		if (waitpid(exec_pid, &exit_status, WNOHANG) == exec_pid) {
+			exec_pid = 0;
+			init_curses();
+			PARA_INFO_LOG("command exit status: %d", exit_status);
+			print_in_bar(COLOR_MSG, " ");
+		}
+	}
 	for (i = 0; i < 2; i++) {
 		size_t sz;
-		if (command_fds[i] < 0)
+		if (exec_fds[i] < 0)
 			continue;
-		ret = read_nonblock(command_fds[i],
-			command_buf[i] + cbo[i],
-			COMMAND_BUF_SIZE - 1 - cbo[i], rfds, &sz);
-		cbo[i] += sz;
-		sz = cbo[i];
-		cbo[i] = for_each_line(flags[i], command_buf[i], cbo[i],
-			add_output_line, &i);
-		if (sz != cbo[i]) { /* at least one line found */
-			wrefresh(bot.win);
-			flags[i] = 0;
+		ret = read_nonblock(exec_fds[i],
+			ct->command_buf[i] + ct->cbo[i],
+			COMMAND_BUF_SIZE - 1 - ct->cbo[i], &s->rfds, &sz);
+		ct->cbo[i] += sz;
+		sz = ct->cbo[i];
+		ct->cbo[i] = for_each_line(ct->flags[i], ct->command_buf[i],
+			ct->cbo[i], add_output_line, &i);
+		if (sz != ct->cbo[i]) { /* at least one line found */
+			refresh_window(&bot);
+			ct->flags[i] = 0;
 		}
-		if (ret < 0 || cmd_pid == 0) {
+		if (ret < 0 || exec_pid == 0) {
 			if (ret < 0)
 				PARA_NOTICE_LOG("closing command fd %d: %s",
 					i, para_strerror(-ret));
-			close(command_fds[i]);
-			command_fds[i] = -1;
-			flags[i] = 0;
-			cbo[i] = 0;
-			if (command_fds[!i] < 0) /* both fds closed */
-				return;
+			close(exec_fds[i]);
+			exec_fds[i] = -1;
+			ct->flags[i] = 0;
+			ct->cbo[i] = 0;
+			if (exec_fds[!i] < 0) /* both fds closed */
+				return 1;
 		}
-		if (cbo[i] == COMMAND_BUF_SIZE - 1) {
+		if (ct->cbo[i] == COMMAND_BUF_SIZE - 1) {
 			PARA_NOTICE_LOG("discarding overlong line");
-			cbo[i] = 0;
-			flags[i] = FELF_DISCARD_FIRST;
+			ct->cbo[i] = 0;
+			ct->flags[i] = FELF_DISCARD_FIRST;
 		}
 	}
+	return 0;
 }
 
-static void input_pre_select(fd_set *rfds, int *max_fileno)
+static void input_pre_select(struct sched *s, __a_unused void *context)
 {
-	enum cmd_status cmds = cmd_status();
-
-	if (cmds != CMDS_XCMD)
-		para_fd_set(STDIN_FILENO, rfds, max_fileno);
+	if (exec_status() != EXEC_XCMD)
+		para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno);
+	if (window_update_needed())
+		sched_min_delay(s);
 }
 
-/* read from command pipe and print data to bot window */
-static void exec_and_display_cmd(const char *cmd)
+/* Read from command pipe and print data to bot window. */
+static void exec_and_display(const char *file_and_args)
 {
 	int ret, fds[3] = {0, 1, 1};
 
-	outputf(COLOR_COMMAND, "%s", cmd);
-	ret = para_exec_cmdline_pid(&cmd_pid, cmd, fds);
+	outputf(COLOR_COMMAND, "%s", file_and_args);
+	ret = para_exec_cmdline_pid(&exec_pid, file_and_args, fds);
 	if (ret < 0)
 		return;
 	ret = mark_fd_nonblocking(fds[1]);
@@ -1007,53 +1055,46 @@ static void exec_and_display_cmd(const char *cmd)
 	ret = mark_fd_nonblocking(fds[2]);
 	if (ret < 0)
 		goto fail;
-	command_fds[0] = fds[1];
-	command_fds[1] = fds[2];
+	exec_fds[0] = fds[1];
+	exec_fds[1] = fds[2];
+	print_in_bar(COLOR_MSG, "hit any key to abort\n");
 	return;
 fail:
 	PARA_ERROR_LOG("%s\n", para_strerror(-ret));
-	close(command_fds[0]);
-	close(command_fds[1]);
+	close(exec_fds[0]);
+	close(exec_fds[1]);
 }
 
-static void para_cmd(char *cmd)
+static void exec_para(const char *args)
 {
-	char *c;
+	char *file_and_args;
 
-	print_in_bar(COLOR_MSG, "executing client command, hit any key to abort\n");
-	c = make_message(BINDIR "/para_client -- %s", cmd);
-	exec_and_display_cmd(c);
-	free(c);
+	file_and_args = make_message(BINDIR "/para_client -- %s", args);
+	exec_and_display(file_and_args);
+	free(file_and_args);
 }
 
-static void display_cmd(char *cmd)
-{
-	print_in_bar(COLOR_MSG, "executing display command, hit any key to abort");
-	exec_and_display_cmd(cmd);
-}
-
-/*
- * shutdown curses and stat pipe before executing external commands
- */
-static void external_cmd(char *cmd)
+/* Shutdown curses and stat pipe before executing external commands. */
+static void exec_external(char *file_and_args)
 {
 	int fds[3] = {-1, -1, -1};
 
-	if (cmd_pid)
+	if (exec_pid)
 		return;
 	shutdown_curses();
-	para_exec_cmdline_pid(&cmd_pid, cmd, fds);
+	para_exec_cmdline_pid(&exec_pid, file_and_args, fds);
 }
 
 static void handle_command(int c)
 {
 	int i;
+	const struct lls_opt_result *lor = OPT_RESULT(KEY_MAP);
 
 	/* first check user-defined key bindings */
-	for (i = 0; i < conf.key_map_given; ++i) {
+	FOR_EACH_KEY_MAP(i) {
 		char *tmp, *handler, *arg;
 
-		tmp = para_strdup(conf.key_map_arg[i]);
+		tmp = para_strdup(lls_string_val(i, lor));
 		if (!split_key_map(tmp, &handler, &arg)) {
 			free(tmp);
 			return;
@@ -1063,11 +1104,11 @@ static void handle_command(int c)
 			continue;
 		}
 		if (*handler == 'd')
-			display_cmd(arg);
+			exec_and_display(arg);
 		else if (*handler == 'x')
-			external_cmd(arg);
+			exec_external(arg);
 		else if (*handler == 'p')
-			para_cmd(arg);
+			exec_para(arg);
 		else if (*handler == 'i') {
 			int num = find_cmd_byname(arg);
 			if (num >= 0)
@@ -1087,57 +1128,39 @@ static void handle_command(int c)
 		km_keyname(c));
 }
 
-static void input_post_select(void)
+static int input_post_select(__a_unused struct sched *s,
+		__a_unused void *context)
 {
 	int ret;
-	enum cmd_status cmds = cmd_status();
+	enum exec_status exs = exec_status();
 
-	if (cmds == CMDS_XCMD)
-		return;
+	if (exs == EXEC_XCMD)
+		return 0;
+	if (window_update_needed()) {
+		if (top.needs_update)
+			assert(wnoutrefresh(top.win) == OK);
+		if (bot.needs_update)
+			assert(wnoutrefresh(bot.win) == OK);
+		if (sep.needs_update)
+			assert(wnoutrefresh(sep.win) == OK);
+		if (sb.needs_update)
+			assert(wnoutrefresh(sb.win) == OK);
+		if (in.needs_update)
+			assert(wnoutrefresh(in.win) == OK);
+		doupdate();
+		top.needs_update = bot.needs_update = sb.needs_update =
+			in.needs_update = sep.needs_update = false;
+	}
 	ret = wgetch(top.win);
-	if (ret == ERR || ret == KEY_RESIZE)
-		return;
-	if (cmds == CMDS_IDLE)
-		return handle_command(ret);
-	if (cmd_pid != 0)
-		kill(cmd_pid, SIGTERM);
-}
-
-static void signal_pre_select(fd_set *rfds, int *max_fileno)
-{
-	para_fd_set(signal_pipe, rfds, max_fileno);
-}
-
-/*
- * This is the core select loop. It checks the following fds:
- *
- * - signal pipe
- * - stdin
- * - stdout/stderr of display or internal commands
- */
-__noreturn static void do_select(void)
-{
-	fd_set rfds;
-	int ret, max_fileno;
-	struct timeval tv;
-
-repeat:
-	tv.tv_sec = conf.timeout_arg  / 1000;
-	tv.tv_usec = (conf.timeout_arg % 1000) * 1000;
-	FD_ZERO(&rfds);
-	max_fileno = 0;
-	status_pre_select(&rfds, &max_fileno, &tv);
-	signal_pre_select(&rfds, &max_fileno);
-	command_pre_select(&rfds, &max_fileno);
-	input_pre_select(&rfds, &max_fileno);
-	ret = para_select(max_fileno + 1, &rfds, NULL, &tv);
-	if (ret <= 0)
-		goto repeat; /* skip fd checks */
-	signal_post_select(&rfds);
-	command_post_select(&rfds);
-	status_post_select(&rfds);
-	input_post_select();
-	goto repeat;
+	if (ret == ERR)
+		return 0;
+	if (ret == KEY_RESIZE) /* already handled in signal_post_select() */
+		return 0;
+	if (exs == EXEC_IDLE)
+		handle_command(ret);
+	else if (exec_pid > 0)
+		kill(exec_pid, SIGTERM);
+	return 0;
 }
 
 static void print_scroll_msg(void)
@@ -1145,7 +1168,7 @@ static void print_scroll_msg(void)
 	unsigned lines_total, filled = ringbuffer_filled(bot_win_rb);
 	int first_rbe = first_visible_rbe(&lines_total);
 
-	print_in_bar(COLOR_MSG, "scrolled view: %d-%d/%d\n", filled - first_rbe,
+	print_in_bar(COLOR_MSG, "scrolled view: %u-%u/%u\n", filled - first_rbe,
 		filled - scroll_position, ringbuffer_filled(bot_win_rb));
 }
 
@@ -1239,7 +1262,7 @@ static void com_scroll_down(void)
 	wmove(bot.win, bot_lines - rbe_lines, 0);
 	wattron(bot.win, COLOR_PAIR(rbe->color));
 	waddstr(bot.win, rbe->msg);
-	wrefresh(bot.win);
+	refresh_window(&bot);
 	print_scroll_msg();
 }
 
@@ -1276,7 +1299,7 @@ static void com_scroll_up(void)
 			break;
 		i--;
 	}
-	wrefresh(bot.win);
+	refresh_window(&bot);
 	print_scroll_msg();
 	return;
 err_out:
@@ -1313,9 +1336,10 @@ static void com_reread_conf(void)
 static void com_help(void)
 {
 	int i;
+	const struct lls_opt_result *lor = OPT_RESULT(KEY_MAP);
 
-	for (i = 0; i < conf.key_map_given; ++i) {
-		char *handler, *arg, *tmp = para_strdup(conf.key_map_arg[i]);
+	FOR_EACH_KEY_MAP(i) {
+		char *handler, *arg, *tmp = para_strdup(lls_string_val(i, lor));
 		const char *handler_text = "???", *desc = NULL;
 
 		if (!split_key_map(tmp, &handler, &arg)) {
@@ -1399,27 +1423,121 @@ static void com_prev_theme(void)
 	com_refresh();
 }
 
-__noreturn static void print_help_and_die(void)
+static int setup_tasks_and_schedule(void)
 {
-	struct ggo_help h = DEFINE_GGO_HELP(gui);
-	bool d = conf.detailed_help_given;
-
-	ggo_print_help(&h, d? GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS);
-	exit(0);
+	int ret;
+	struct exec_task exec_task = {.task = NULL};
+	struct status_task status_task = {.fd = -1};
+	struct input_task input_task = {.task = NULL};
+	struct signal_task *signal_task;
+	struct sched sched = {.default_timeout = {.tv_sec = 1}};
+
+	exec_task.task = task_register(&(struct task_info) {
+		.name = "exec",
+		.pre_select = exec_pre_select,
+		.post_select = exec_post_select,
+		.context = &exec_task,
+	}, &sched);
+
+	status_task.task = task_register(&(struct task_info) {
+		.name = "status",
+		.pre_select = status_pre_select,
+		.post_select = status_post_select,
+		.context = &status_task,
+	}, &sched);
+
+	input_task.task = task_register(&(struct task_info) {
+		.name = "input",
+		.pre_select = input_pre_select,
+		.post_select = input_post_select,
+		.context = &input_task,
+	}, &sched);
+
+	signal_task = signal_init_or_die();
+	para_install_sighandler(SIGINT);
+	para_install_sighandler(SIGTERM);
+	para_install_sighandler(SIGCHLD);
+	para_install_sighandler(SIGUSR1);
+	para_install_sighandler(SIGWINCH);
+	signal_task->task = task_register(&(struct task_info) {
+		.name = "signal",
+		.pre_select = signal_pre_select,
+		.post_select = signal_post_select,
+		.context = signal_task,
+	}, &sched);
+	ret = schedule(&sched);
+	sched_shutdown(&sched);
+	signal_shutdown(signal_task);
+	return ret;
+}
+
+static void handle_help_flags(void)
+{
+	char *help;
+
+	if (OPT_GIVEN(DETAILED_HELP))
+		help = lls_long_help(CMD_PTR);
+	else if (OPT_GIVEN(HELP))
+		help = lls_short_help(CMD_PTR);
+	else
+		return;
+	printf("%s\n", help);
+	free(help);
+	exit(EXIT_SUCCESS);
 }
 
+/**
+ * The main function of para_gui.
+ *
+ * \param argc Usual argument count.
+ * \param argv Usual argument vector.
+ *
+ * After initialization para_gui registers the following tasks to the paraslash
+ * scheduler: status, exec, signal, input.
+ *
+ * The status task executes the para_audioc stat command to obtain the status
+ * of para_server and para_audiod, and displays this information in the top
+ * window of para_gui.
+ *
+ * The exec task is responsible for printing the output of the currently
+ * running executable to the bottom window.
+ *
+ * The signal task performs various actions according to signals received. For
+ * example, it reloads the configuration file on SIGUSR1, and it shuts down the
+ * curses system on SIGTERM to restore the terminal settings before exit.
+ *
+ * The input task reads single key strokes from stdin. For each key pressed, it
+ * executes the command handler associated with this key.
+ *
+ * \return \p EXIT_SUCCESS or \p EXIT_FAILURE.
+ */
 int main(int argc, char *argv[])
 {
-	gui_cmdline_parser(argc, argv, &conf); /* exits on errors */
-	loglevel = get_loglevel_by_name(conf.loglevel_arg);
-	version_handle_flag("gui", conf.version_given);
-	if (conf.help_given || conf.detailed_help_given)
-		print_help_and_die();
-	parse_config_file_or_die(false /* override */);
-	setup_signal_handling();
+	int ret;
+	char *errctx;
+
+	ret = lls(lls_parse(argc, argv, CMD_PTR, &cmdline_lpr, &errctx));
+	if (ret < 0)
+		goto out;
+	lpr = cmdline_lpr;
+	loglevel = OPT_UINT32_VAL(LOGLEVEL);
+	version_handle_flag("gui", OPT_GIVEN(VERSION));
+	handle_help_flags();
+	parse_config_file_or_die(false);
 	bot_win_rb = ringbuffer_new(RINGBUFFER_SIZE);
 	setlocale(LC_CTYPE, "");
 	initscr(); /* needed only once, always successful */
 	init_curses();
-	do_select();
+	ret = setup_tasks_and_schedule();
+out:
+	lls_free_parse_result(lpr, CMD_PTR);
+	if (lpr != cmdline_lpr)
+		lls_free_parse_result(cmdline_lpr, CMD_PTR);
+	if (ret < 0) {
+		if (errctx)
+			PARA_ERROR_LOG("%s\n", errctx);
+		free(errctx);
+		PARA_EMERG_LOG("%s\n", para_strerror(-ret));
+	}
+	return ret < 0? EXIT_FAILURE : EXIT_SUCCESS;
 }