Merge branch 'refs/heads/t/format-signedness'
[paraslash.git] / gui.c
diff --git a/gui.c b/gui.c
index e41977efa9b90a3afc95b72434de935125c95685..3e01340a4b1b910245f22be77e75945ae25bc1ca 100644 (file)
--- a/gui.c
+++ b/gui.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1998-2014 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 1998 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
 INIT_GUI_ERRLISTS;
 static char *stat_content[NUM_STAT_ITEMS];
 
-#define STANDARD_STATUS_BAR "para_gui " PACKAGE_VERSION " (hit ? for help)"
-
-static int signal_pipe;
-
 static struct gui_window {
        WINDOW *win;
-       size_t begx;
-       size_t begy;
-       size_t cols;
-       size_t lines;
+       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;
        int color;
 };
 static struct ringbuffer *bot_win_rb;
-#define NUM_LINES(len) (1 + (len) / bot.cols)
 
 static unsigned scroll_position;
 
-static int curses_active;
-static pid_t cmd_pid;
+static pid_t exec_pid;
 
-static int command_fds[2] = {-1, -1};
-static int stat_pipe = -1;
+static int exec_fds[2] = {-1, -1};
 static struct gui_args_info conf;
+static int loglevel;
 
-enum {GETCH_MODE, COMMAND_MODE, EXTERNAL_MODE};
-
+/** 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. */
+};
 
-#define COLOR_STATUSBAR 52
-#define COLOR_COMMAND 53
-#define COLOR_OUTPUT 54
-#define COLOR_MSG 55
-#define COLOR_ERRMSG 56
-#define COLOR_WELCOME 57
-#define COLOR_SEPARATOR 58
-#define COLOR_TOP 59
-#define COLOR_BOT 60
+/**
+ * Codes for various colors.
+ *
+ * Each status item has its own color pair. The ones defined here start at a
+ * higher number so that they do not overlap with these.
+ */
+enum gui_color_pair {
+       COLOR_STATUSBAR = NUM_STAT_ITEMS + 1,
+       COLOR_COMMAND,
+       COLOR_OUTPUT,
+       COLOR_MSG,
+       COLOR_ERRMSG,
+       COLOR_SEPARATOR,
+       COLOR_TOP,
+       COLOR_BOT,
+};
 
 struct gui_command {
        const char *key;
@@ -82,119 +86,67 @@ struct gui_command {
 
 static struct gui_theme theme;
 
-static int _argc;
-static char **_argv;
-
-static void com_help(void);
-static void com_reread_conf(void);
-static void com_enlarge_top_win(void);
-static void com_shrink_top_win(void);
-static void com_version(void);
-__noreturn static void com_quit(void);
-static void com_refresh(void);
-static void com_ll_incr(void);
-static void com_ll_decr(void);
-static void com_prev_theme(void);
-static void com_next_theme(void);
-static void com_scroll_up(void);
-static void com_scroll_down(void);
-static void com_page_up(void);
-static void com_page_down(void);
-static void com_cancel_scrolling(void);
-static void com_scroll_top(void);
-
-static struct gui_command command_list[] = {
-       {
-               .key = "?",
-               .name = "help",
-               .description = "print help",
-               .handler = com_help
-       }, {
-               .key = "+",
-               .name = "enlarge_win",
-               .description = "enlarge the top window",
-               .handler = com_enlarge_top_win
-       }, {
-               .key = "-",
-               .name = "shrink_win",
-               .description = "shrink the top window",
-               .handler = com_shrink_top_win
-       }, {
-               .key = "r",
-               .name = "reread_conf",
-               .description = "reread configuration file",
-               .handler = com_reread_conf
-       }, {
-               .key = "q",
-               .name = "quit",
-               .description = "exit para_gui",
-               .handler = com_quit
-       }, {
-               .key = "^L",
-               .name = "refresh",
-               .description = "redraw the screen",
-               .handler = com_refresh
-       }, {
-               .key = ".",
-               .name = "next_theme",
-               .description = "switch to next theme",
-               .handler = com_next_theme
-       }, {
-               .key = ",",
-               .name = "prev_theme",
-               .description = "switch to previous stream",
-               .handler = com_prev_theme
-       }, {
-               .key = ">",
-               .name = "ll_incr",
-               .description = "increase loglevel (decreases verbosity)",
-               .handler = com_ll_incr
-       }, {
-               .key = "<",
-               .name = "ll_decr",
-               .description = "decrease loglevel (increases verbosity)",
-               .handler = com_ll_decr
-       }, {
-               .key = "V",
-               .name = "version",
-               .description = "show the para_gui version",
-               .handler = com_version
-       }, {
-               .key = "<up>",
-               .name = "scroll_up",
-               .description = "scroll up one line",
-               .handler = com_scroll_up
-       }, {
-               .key = "<down>",
-               .name = "scroll_down",
-               .description = "scroll down one line",
-               .handler = com_scroll_down
-       }, {
-               .key = "<ppage>",
-               .name = "page_up",
-               .description = "scroll up one page",
-               .handler = com_page_up
-       }, {
-               .key = "<npage>",
-               .name = "page_down",
-               .description = "scroll down one page",
-               .handler = com_page_down
-       }, {
-               .key = "<home>",
-               .name = "scroll_top",
-               .description = "scroll to top of buffer",
-               .handler = com_scroll_top
-       }, {
-               .key = "<end>",
-               .name = "cancel_scroll",
-               .description = "deactivate scroll mode",
-               .handler = com_cancel_scrolling
-       }, {
-               .handler = NULL
-       }
+#define GUI_COMMANDS \
+       GUI_COMMAND(help, "?", "print help") \
+       GUI_COMMAND(enlarge_top_win, "+", "enlarge the top window") \
+       GUI_COMMAND(shrink_top_win, "-", "shrink the top window") \
+       GUI_COMMAND(reread_conf, "r", "reread configuration file") \
+       GUI_COMMAND(quit, "q", "exit para_gui") \
+       GUI_COMMAND(refresh, "^L", "redraw the screen") \
+       GUI_COMMAND(next_theme, ".", "switch to next theme") \
+       GUI_COMMAND(prev_theme, ",", "switch to previous theme") \
+       GUI_COMMAND(ll_incr, ">", "increase loglevel (decreases verbosity)") \
+       GUI_COMMAND(ll_decr, "<", "decrease loglevel (increases verbosity)") \
+       GUI_COMMAND(version, "V", "show the para_gui version") \
+       GUI_COMMAND(scroll_up, "<up>", "scroll up one line") \
+       GUI_COMMAND(scroll_down, "<down>", "scroll_down") \
+       GUI_COMMAND(page_up, "<ppage>", "scroll up one page") \
+       GUI_COMMAND(page_down, "<npage>", "scroll down one page") \
+       GUI_COMMAND(scroll_top, "<home>", "scroll to top of buffer") \
+       GUI_COMMAND(cancel_scroll, "<end>", "deactivate scroll mode") \
+
+/* declare command handlers */
+#define GUI_COMMAND(_c, _k, _d) \
+       static void com_ ## _c(void);
+GUI_COMMANDS
+
+#undef GUI_COMMAND
+
+/* define command array */
+#define GUI_COMMAND(_c, _k, _d) \
+       { \
+               .key = _k, \
+               .name = #_c, \
+               .description = _d, \
+               .handler = com_ ## _c \
+       },
+
+static struct gui_command command_list[] = {GUI_COMMANDS {.name = NULL}};
+
+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;
 };
 
-static int find_cmd_byname(char *name)
+/** 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;
 
@@ -204,6 +156,37 @@ static int find_cmd_byname(char *name)
        return -1;
 }
 
+/*
+ * Even though ncurses provides getmaxx and getmaxy, these functions/macros are
+ * not described in the XSI Curses standard.
+ */
+static int get_num_lines(struct gui_window *w)
+{
+       int lines;
+       __a_unused int cols; /* avoid "set but not used" warnings */
+
+       getmaxyx(w->win, lines, cols);
+       return lines;
+}
+
+static int get_num_cols(struct gui_window *w)
+{
+       __a_unused int lines; /* avoid "set but not used" warnings */
+       int cols;
+
+       getmaxyx(w->win, lines, cols);
+       return cols;
+}
+
+/** Number of lines of the window are occupied by an output line. */
+#define NUM_LINES(len) (1 + (len) / get_num_cols(&bot))
+
+/* isendwin() returns false before initscr() was called */
+static bool curses_active(void)
+{
+       return top.win && !isendwin();
+}
+
 /* taken from mutt */
 static char *km_keyname(int c)
 {
@@ -260,29 +243,11 @@ static char *km_keyname(int c)
        return buf;
 }
 
-static char *configfile_exists(void)
-{
-       static char *config_file;
-       char *tmp;
-
-       if (!conf.config_file_given) {
-               if (!config_file) {
-                       char *home = para_homedir();
-                       config_file = make_message("%s/.paraslash/gui.conf",
-                               home);
-                       free(home);
-               }
-               tmp = config_file;
-       } else
-               tmp = conf.config_file_arg;
-       return file_exists(tmp)? tmp: NULL;
-}
-
 /* Print given number of spaces to curses window. */
 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);
@@ -290,8 +255,7 @@ 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);
        }
 }
 
@@ -299,75 +263,74 @@ static void add_spaces(WINDOW* win, unsigned int num)
  * 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;
        va_list ap;
 
-       if (!curses_active)
+       if (!curses_active())
                return;
        wattron(in.win, COLOR_PAIR(color));
        va_start(ap, fmt);
        xvasprintf(&msg, fmt, ap);
        va_end(ap);
        wmove(in.win, 0, 0);
-       align_str(in.win, msg, in.cols, LEFT);
+       align_str(in.win, msg, get_num_cols(&in), LEFT);
        free(msg);
-       wrefresh(in.win);
+       refresh_window(&in);
 }
 
-/*
- * update the status bar
- */
 static void print_status_bar(void)
 {
        char *tmp;
 
-       if (!curses_active)
-               return;
-       tmp = para_strdup(STANDARD_STATUS_BAR);
+       tmp = para_strdup("para_gui " PACKAGE_VERSION " (hit ? for help)");
        wmove(sb.win, 0, 0);
-       align_str(sb.win, tmp, sb.cols, CENTER);
+       align_str(sb.win, tmp, get_num_cols(&sb), CENTER);
        free(tmp);
-       wrefresh(sb.win);
 }
 
 /*
@@ -377,19 +340,19 @@ static void print_status_bar(void)
  */
 static int first_visible_rbe(unsigned *lines)
 {
-       int i;
+       int i, bot_lines = get_num_lines(&bot);
+
        *lines = 0;
        for (i = scroll_position; i < RINGBUFFER_SIZE; i++) {
                struct rb_entry *rbe = ringbuffer_get(bot_win_rb, i);
                int rbe_lines;
                if (!rbe)
                        return i - 1;
-//             fprintf(stderr, "found: %s\n", rbe->msg);
                rbe_lines = NUM_LINES(rbe->len);
-               if (rbe_lines > bot.lines)
+               if (rbe_lines > bot_lines)
                        return -1;
                *lines += rbe_lines;
-               if (*lines >= bot.lines)
+               if (*lines >= bot_lines)
                        return i;
        }
        return RINGBUFFER_SIZE - 1;
@@ -400,7 +363,7 @@ returns number of first visible rbe, *lines is the number of lines drawn.
  */
 static int draw_top_rbe(unsigned *lines)
 {
-       int ret, fvr = first_visible_rbe(lines);
+       int bot_cols, bot_lines, ret, fvr = first_visible_rbe(lines);
        struct rb_entry *rbe;
        size_t bytes_to_skip, cells_to_skip, width;
 
@@ -410,9 +373,10 @@ static int draw_top_rbe(unsigned *lines)
        rbe = ringbuffer_get(bot_win_rb, fvr);
        if (!rbe)
                return -1;
-       if (*lines > bot.lines) {
+       getmaxyx(bot.win, bot_lines, bot_cols);
+       if (*lines > bot_lines) {
                /* rbe is partially visible multi-line */
-               cells_to_skip = (*lines - bot.lines) * bot.cols;
+               cells_to_skip = (*lines - bot_lines) * bot_cols;
                ret = skip_cells(rbe->msg, cells_to_skip, &bytes_to_skip);
                if (ret < 0)
                        return ret;
@@ -432,14 +396,14 @@ static int draw_top_rbe(unsigned *lines)
 static void redraw_bot_win(void)
 {
        unsigned lines;
-       int i;
+       int i, bot_lines = get_num_lines(&bot);
 
        wmove(bot.win, 0, 0);
        wclear(bot.win);
        i = draw_top_rbe(&lines);
        if (i <= 0)
                goto out;
-       while (i > 0 && lines < bot.lines) {
+       while (i > 0 && lines < bot_lines) {
                struct rb_entry *rbe = ringbuffer_get(bot_win_rb, --i);
                if (!rbe) {
                        lines++;
@@ -452,7 +416,7 @@ 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)
@@ -468,7 +432,6 @@ static void rb_add_entry(int color, char *msg)
        new->len = len;
        new->msg = msg;
        old = ringbuffer_add(bot_win_rb, new);
-//     fprintf(stderr, "added: %s\n", new->msg);
        if (old) {
                free(old->msg);
                free(old);
@@ -494,197 +457,84 @@ __printf_2_3 static void outputf(int color, const char* fmt,...)
        char *msg;
        va_list ap;
 
-       if (!curses_active)
+       if (!curses_active())
                return;
        va_start(ap, 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)
 {
        int color = *(int *)data? COLOR_ERRMSG : COLOR_OUTPUT;
 
-       if (!curses_active)
+       if (!curses_active())
                return 1;
        rb_add_entry(color, para_strdup(line));
        return 1;
 }
 
-static int loglevel;
-
 static __printf_2_3 void curses_log(int ll, const char *fmt,...)
 {
-       int color;
-       char *msg;
        va_list ap;
 
-       if (ll < loglevel || !curses_active)
+       if (ll < loglevel)
                return;
-       switch (ll) {
-               case LL_DEBUG:
-               case LL_INFO:
-               case LL_NOTICE:
-                       color = COLOR_MSG;
-                       break;
-               default:
-                       color = COLOR_ERRMSG;
-       }
        va_start(ap, fmt);
-       xvasprintf(&msg, fmt, ap);
+       if (curses_active()) {
+               int color = ll <= LL_NOTICE? COLOR_MSG : COLOR_ERRMSG;
+               char *msg;
+               unsigned bytes = xvasprintf(&msg, fmt, ap);
+               if (bytes > 0 && msg[bytes - 1] == '\n')
+                       msg[bytes - 1] = '\0'; /* cut trailing newline */
+               rb_add_entry(color, msg);
+               refresh_window(&bot);
+       } else if (exec_pid <= 0) /* no external command running */
+               vfprintf(stderr, fmt, ap);
        va_end(ap);
-       chop(msg);
-       rb_add_entry(color, msg);
-       wrefresh(bot.win);
 }
+/** The log function of para_gui, always set to curses_log(). */
 __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);
-}
-
-/* kill every process in the process group and exit */
-__noreturn static void kill_pg_and_die(int ret)
-{
-       para_sigaction(SIGTERM, SIG_IGN);
-       kill(0, SIGTERM);
-       exit(ret);
-}
-
+/* Call endwin() to reset the terminal into non-visual mode. */
 static void shutdown_curses(void)
 {
-       if (!curses_active)
-               return;
-       def_prog_mode();
-       curses_active = 0;
+       /*
+        * 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();
 }
 
-__noreturn static void finish(int ret)
-{
-       shutdown_curses();
-       kill_pg_and_die(ret);
-}
-
-/*
- * exit curses and print given message to stdout/stderr
- */
-__noreturn __printf_2_3 static void msg_n_exit(int ret, 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;
-       FILE *outfd = ret? stderr: stdout;
 
+       /* 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(outfd, fmt, argp);
+       vfprintf(stderr, fmt, argp);
        va_end(argp);
-       kill_pg_and_die(ret);
-}
-
-static void print_welcome(void)
-{
-       if (loglevel > LL_NOTICE)
-               return;
-       outputf(COLOR_WELCOME, "Welcome to %s. Theme: %s",
-               version_single_line("gui"), theme.name);
-       wclrtoeol(bot.win);
-}
-
-/*
- * init all windows
- */
-static void init_wins(int top_lines)
-{
-       int i;
-
-       top.lines = top_lines;
-       top.cols = COLS;
-       top.begy = 0;
-       top.begx = 0;
-
-       bot.lines = LINES - top.lines - 3;
-       bot.cols = COLS;
-       bot.begy = top.lines + 1;
-       bot.begx = 0;
-
-       sb.lines = 1;
-       sb.cols = COLS;
-       sb.begy = LINES - 2;
-       sb.begx = 0;
-
-       in.lines = 1;
-       in.cols = COLS;
-       in.begy = LINES - 1;
-       in.begx = 0;
-
-       sep.lines = 1;
-       sep.cols = COLS;
-       sep.begy = top.lines;
-       sep.begx = 0;
-
-       assume_default_colors(theme.default_fg, theme.default_bg);
-       if (top.win) {
-               mvwin(top.win, top.begy, top.begx);
-               wresize(top.win, top.lines, top.cols);
-
-               mvwin(sb.win, sb.begy, sb.begx);
-               wresize(sb.win, sb.lines, sb.cols);
-
-               mvwin(sep.win, sep.begy, sep.begx);
-               wresize(sep.win, sep.lines, sep.cols);
-
-               mvwin(bot.win, bot.begy, bot.begx);
-               wresize(bot.win, bot.lines, bot.cols);
-
-               mvwin(in.win, in.begy, in.begx);
-               wresize(in.win, in.lines, in.cols);
-       } else {
-               sep.win = newwin(sep.lines, sep.cols, sep.begy, sep.begx);
-               top.win = newwin(top.lines, top.cols, top.begy, top.begx);
-               bot.win = newwin(bot.lines, bot.cols, bot.begy, bot.begx);
-               sb.win = newwin(sb.lines, sb.cols, sb.begy, sb.begx);
-               in.win = newwin(in.lines, in.cols, in.begy, in.begx);
-               if (!top.win || !bot.win || !sb.win || !in.win || !sep.win)
-                       msg_n_exit(1, "Error: Cannot create curses windows\n");
-               wclear(bot.win);
-               wclear(sb.win);
-               wclear(in.win);
-               scrollok(bot.win, 1);
-               wattron(sb.win, COLOR_PAIR(COLOR_STATUSBAR));
-               wattron(sep.win, COLOR_PAIR(COLOR_SEPARATOR));
-               wattron(bot.win, COLOR_PAIR(COLOR_BOT));
-               wattron(top.win, COLOR_PAIR(COLOR_TOP));
-               nodelay(top.win, 1);
-               nodelay(bot.win, 1);
-               nodelay(sb.win, 1);
-               nodelay(in.win, 0);
-
-               keypad(top.win, 1);
-               keypad(bot.win, 1);
-               keypad(sb.win, 1);
-               keypad(in.win, 1);
-               print_status_bar();
-       }
-       wmove(sep.win, 0, 0);
-       for (i = 1; i <= COLS; i++)
-               waddstr(sep.win, theme.sep_str);
-       wclear(top.win);
-       //wclear(bot.win);
-       wnoutrefresh(top.win);
-       wnoutrefresh(bot.win);
-       //wnoutrefresh(sb.win);
-       print_status_bar();
-       wnoutrefresh(in.win);
-       wnoutrefresh(sep.win);
-       doupdate();
+       exit(exit_code);
 }
 
 /*
@@ -695,16 +545,16 @@ static void print_stat_item(int i)
        char *tmp;
        struct stat_item_data d = theme.data[i];
        char *c = stat_content[i];
+       int top_lines = get_num_lines(&top);
 
-       if (!curses_active || !d.len || !c)
+       if (!curses_active() || !d.len || !c)
                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);
+       wmove(top.win, d.y * top_lines / 100, d.x * COLS / 100);
        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)
@@ -738,44 +588,11 @@ print:
        return 1;
 }
 
-static int read_stat_pipe(fd_set *rfds)
-{
-       static char *buf;
-       static int bufsize, loaded;
-       int ret, ret2;
-       size_t sz;
-
-       if (stat_pipe < 0)
-               return 0;
-       if (loaded >= bufsize) {
-               if (bufsize > 1000 * 1000) {
-                       loaded = 0;
-                       return 0;
-               }
-               bufsize += bufsize + 1000;
-               buf = para_realloc(buf, 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);
-       if (ret < 0 || ret2 < 0) {
-               loaded = 0;
-               return ret2 < 0? ret2 : ret;
-       }
-       sz = ret2; /* what is left */
-       if (sz > 0 && sz < loaded)
-               memmove(buf, buf + loaded - sz, sz);
-       loaded = sz;
-       return 1;
-}
-
 static void print_all_items(void)
 {
        int i;
 
-       if (!curses_active)
+       if (!curses_active())
                return;
        FOR_EACH_STATUS_ITEM(i)
                print_stat_item(i);
@@ -791,10 +608,156 @@ static void clear_all_items(void)
        }
 }
 
+static void status_pre_select(struct sched *s, void *context)
+{
+       struct status_task *st = context;
+
+       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 int status_post_select(struct sched *s, void *context)
+{
+       struct status_task *st = context;
+       size_t sz;
+       int ret, ret2;
+
+       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 */
+               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, conf.stat_cmd_arg, fds);
+               if (ret < 0)
+                       return 0;
+               ret = mark_fd_nonblocking(fds[1]);
+               if (ret < 0) {
+                       close(fds[1]);
+                       return 0;
+               }
+               st->fd = fds[1];
+               return 0;
+       }
+
+       if (st->loaded >= st->bufsize) {
+               if (st->bufsize > 1000 * 1000) {
+                       st->loaded = 0;
+                       return 0;
+               }
+               st->bufsize += st->bufsize + 1000;
+               st->buf = para_realloc(st->buf, st->bufsize);
+       }
+       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) {
+               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] =
+                       para_strdup("stat command terminated!?");
+               print_all_items();
+               return 0;
+       }
+       sz = ret2; /* what is left */
+       if (sz > 0 && sz < st->loaded)
+               memmove(st->buf, st->buf + st->loaded - sz, sz);
+       st->loaded = sz;
+       return 0;
+}
+
+/*
+ * init all windows
+ */
+static void init_wins(int top_lines)
+{
+       int top_y = 0, bot_y = top_lines + 1, sb_y = LINES - 2,
+               in_y = LINES - 1, sep_y = top_lines;
+       int bot_lines = LINES - top_lines - 3, sb_lines = 1, in_lines = 1,
+               sep_lines = 1;
+
+       assume_default_colors(theme.dflt.fg, theme.dflt.bg);
+       if (top.win) {
+               wresize(top.win, top_lines, COLS);
+               mvwin(top.win, top_y, 0);
+
+               wresize(sb.win, sb_lines, COLS);
+               mvwin(sb.win, sb_y, 0);
+
+               wresize(sep.win, sep_lines, COLS);
+               mvwin(sep.win, sep_y, 0);
+
+               wresize(bot.win, bot_lines, COLS);
+               mvwin(bot.win, bot_y, 0);
+
+               wresize(in.win, in_lines, COLS);
+               mvwin(in.win, in_y, 0);
+       } else {
+               sep.win = newwin(sep_lines, COLS, sep_y, 0);
+               top.win = newwin(top_lines, COLS, top_y, 0);
+               bot.win = newwin(bot_lines, COLS, bot_y, 0);
+               sb.win = newwin(sb_lines, COLS, sb_y, 0);
+               in.win = newwin(in_lines, COLS, in_y, 0);
+               if (!top.win || !bot.win || !sb.win || !in.win || !sep.win)
+                       die(EXIT_FAILURE, "Error: Cannot create curses windows\n");
+               wclear(bot.win);
+               wclear(sb.win);
+               wclear(in.win);
+               scrollok(bot.win, 1);
+               wattron(sb.win, COLOR_PAIR(COLOR_STATUSBAR));
+               wattron(sep.win, COLOR_PAIR(COLOR_SEPARATOR));
+               wattron(bot.win, COLOR_PAIR(COLOR_BOT));
+               wattron(top.win, COLOR_PAIR(COLOR_TOP));
+               nodelay(top.win, 1);
+               nodelay(bot.win, 1);
+               nodelay(sb.win, 1);
+               nodelay(in.win, 0);
+
+               keypad(top.win, 1);
+               keypad(bot.win, 1);
+               keypad(sb.win, 1);
+               keypad(in.win, 1);
+       }
+       wmove(sep.win, 0, 0);
+       whline(sep.win, theme.sep_char, COLS);
+       wclear(top.win);
+       print_all_items();
+       //wclear(bot.win);
+       wnoutrefresh(top.win);
+       wnoutrefresh(bot.win);
+       print_status_bar();
+       wnoutrefresh(sb.win);
+       wnoutrefresh(in.win);
+       wnoutrefresh(sep.win);
+       doupdate();
+}
+
 static void init_pair_or_die(short pair, short f, short b)
 {
        if (init_pair(pair, f, b) == ERR)
-               msg_n_exit(EXIT_FAILURE, "fatal: init_pair() failed\n");
+               die(EXIT_FAILURE, "fatal: init_pair() failed\n");
 }
 
 static void init_colors_or_die(void)
@@ -802,63 +765,48 @@ static void init_colors_or_die(void)
        int i;
 
        if (!has_colors())
-               msg_n_exit(EXIT_FAILURE, "fatal: No color term\n");
+               die(EXIT_FAILURE, "fatal: No color term\n");
        if (start_color() == ERR)
-               msg_n_exit(EXIT_FAILURE, "fatal: failed to start colors\n");
+               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_WELCOME, theme.welcome_fg, theme.welcome_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. */
 static void init_curses(void)
 {
-       curses_active = 1;
-       if (top.win && refresh() == ERR) /* refresh is really needed */
-               msg_n_exit(EXIT_FAILURE, "refresh() failed\n");
+       if (curses_active())
+               return;
+       if (refresh() == ERR) /* refresh is really needed */
+               die(EXIT_FAILURE, "refresh() failed\n");
        if (LINES < theme.lines_min || COLS < theme.cols_min)
-               msg_n_exit(EXIT_FAILURE, "Error: Terminal (%dx%d) too small"
+               die(EXIT_FAILURE, "Terminal (%dx%d) too small"
                        " (need at least %dx%d)\n", COLS, LINES,
                        theme.cols_min, theme.lines_min);
        curs_set(0); /* make cursor invisible, ignore errors */
        nonl(); /* do not NL->CR/NL on output, always returns OK */
        /* don't echo input */
        if (noecho() == ERR)
-               msg_n_exit(EXIT_FAILURE, "fatal: noecho() failed\n");
+               die(EXIT_FAILURE, "fatal: noecho() failed\n");
        /* take input chars one at a time, no wait for \n */
        if (cbreak() == ERR)
-               msg_n_exit(EXIT_FAILURE, "fatal: cbreak() failed\n");
+               die(EXIT_FAILURE, "fatal: cbreak() failed\n");
        init_colors_or_die();
        clear(); /* ignore non-fatal errors */
        init_wins(theme.top_lines_default);
-       print_all_items();
        // 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;
-       goto reap_next_child;
-}
-
 /*
  * This sucker modifies its first argument. *handler and *arg are
  * pointers to 0-terminated strings (inside line). Crap.
@@ -878,295 +826,333 @@ err_out:
        return 0;
 }
 
-static int check_key_map_args(void)
+static void check_key_map_args_or_die(void)
 {
-       char *s;
-       int i, ret = -1;
-       char *tmp = NULL, *handler, *arg;
+       int i;
+       char *tmp = NULL;
 
        for (i = 0; i < conf.key_map_given; ++i) {
-               s = conf.key_map_arg[i];
-               if (!(*s))
-                       goto out;
+               char *handler, *arg;
+
                free(tmp);
-               tmp = para_strdup(s);
+               tmp = para_strdup(conf.key_map_arg[i]);
                if (!split_key_map(tmp, &handler, &arg))
-                       goto out;
+                       break;
                if (strlen(handler) != 1)
-                       goto out;
-               if (*handler != 'x'
-                       && *handler != 'd'
-                       && *handler != 'i'
-                       && *handler != 'p')
-                       goto out;
+                       break;
+               if (*handler != 'x' && *handler != 'd' && *handler != 'i'
+                               && *handler != 'p')
+                       break;
                if (*handler != 'i')
                        continue;
                if (find_cmd_byname(arg) < 0)
-                       goto out;
+                       break;
        }
-       ret = 0;
-out:
+       if (i != conf.key_map_given)
+               die(EXIT_FAILURE, "invalid key map: %s\n", conf.key_map_arg[i]);
        free(tmp);
-       return ret;
+}
+
+static void parse_config_file_or_die(bool override)
+{
+       bool err;
+       char *config_file;
+       struct gui_cmdline_parser_params params = {
+               .override = override,
+               .initialize = 0,
+               .check_required = !override,
+               .check_ambiguity = 0,
+               .print_errors = 1,
+       };
+
+       if (conf.config_file_given)
+               config_file = para_strdup(conf.config_file_arg);
+       else {
+               char *home = para_homedir();
+               config_file = 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;
+       }
+       /*
+        * When the gengetopt config file parser is called more than once, any
+        * key map arguments found in the config file are _appended_ to the old
+        * values, even though we turn on ->override. We want the new arguments
+        * to replace the old ones, so we must empty the key_map_arg array
+        * first. Unfortunately, this also clears any key map arguments given
+        * at the command line.
+        */
+       if (override) {
+               int i;
+               for (i = 0; i < conf.key_map_given; i++) {
+                       free(conf.key_map_arg[i]);
+                       conf.key_map_arg[i] = NULL;
+               }
+               conf.key_map_given = 0;
+       }
+
+       gui_cmdline_parser_config_file(config_file, &conf, &params);
+       loglevel = get_loglevel_by_name(conf.loglevel_arg);
+       check_key_map_args_or_die();
+       err = false;
+out:
+       free(config_file);
+       if (err)
+               exit(EXIT_FAILURE);
+       theme_init(conf.theme_arg, &theme);
+}
+
+/* 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.
+        */
+       shutdown_curses();
+       parse_config_file_or_die(true /* override */);
+       init_curses();
+       print_in_bar(COLOR_MSG, "config file reloaded\n");
 }
 
 /*
  * React to various signal-related events
  */
-static void handle_signal(int sig)
+static int signal_post_select(struct sched *s, __a_unused void *context)
 {
-       switch (sig) {
+       int ret = para_next_signal(&s->rfds);
+
+       if (ret <= 0)
+               return 0;
+       switch (ret) {
        case SIGTERM:
-               msg_n_exit(EXIT_FAILURE,
-                       "only the good die young (caught SIGTERM))\n");
-               return;
-       case SIGWINCH:
-               if (curses_active) {
-                       shutdown_curses();
-                       init_curses();
-                       redraw_bot_win();
-               }
-               return;
+               die(EXIT_FAILURE, "only the good die young (caught SIGTERM)\n");
        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");
-               com_reread_conf();
-               return;
+               reread_conf();
+               return 1;
        case SIGCHLD:
-               check_sigchld();
-               return;
+               task_notify_all(s, E_GUI_SIGCHLD);
+               return 1;
        }
+       return 1;
 }
 
-static void status_pre_select(fd_set *rfds, int *max_fileno, struct timeval *tv)
+static enum exec_status exec_status(void)
 {
-       static struct timeval next_exec, atm, diff;
-       int ret, fds[3] = {0, 1, 0};
-       pid_t pid;
-
-       if (stat_pipe >= 0)
-               goto success;
-       /* Avoid busy loop */
-       gettimeofday(&atm, NULL);
-       if (tv_diff(&next_exec, &atm, &diff) > 0) {
-               if (tv_diff(&diff, tv, NULL) < 0)
-                       *tv = diff;
-               return;
-       }
-       next_exec.tv_sec = atm.tv_sec + 2;
-       ret = para_exec_cmdline_pid(&pid, conf.stat_cmd_arg, fds);
-       if (ret < 0)
-               return;
-       ret = mark_fd_nonblocking(fds[1]);
-       if (ret < 0) {
-               close(fds[1]);
-               return;
-       }
-       stat_pipe = fds[1];
-success:
-       para_fd_set(stat_pipe, rfds, max_fileno);
+       if (exec_fds[0] >= 0 || exec_fds[1] >= 0)
+               return EXEC_DCMD;
+       if (exec_pid > 0)
+               return EXEC_XCMD;
+       return EXEC_IDLE;
 }
 
-#define COMMAND_BUF_SIZE 32768
+static void exec_pre_select(struct sched *s, void *context)
+{
+       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);
+}
 
-/*
- * This is the core select loop. Besides the (internal) signal
- * pipe, the following other fds are checked according to the mode:
- *
- * GETCH_MODE: check stdin, return when key is pressed
- *
- * COMMAND_MODE: check command fds and stdin. Return when peer has closed both
- * stdout and stderr or when any key is pressed.
- *
- * EXTERNAL_MODE: Check only signal pipe. Used when an external command
- * is running. During that time curses is disabled.  Returns when
- * cmd_pid == 0.
- */
-static int do_select(int mode)
-{
-       fd_set rfds;
-       int ret, i, max_fileno;
-       char command_buf[2][COMMAND_BUF_SIZE] = {"", ""};
-       int cbo[2] = {0, 0}; /* command buf offsets */
-       struct timeval tv;
-       unsigned flags[2] = {0, 0}; /* for for_each_line() */
-
-repeat:
-       tv.tv_sec = conf.timeout_arg  / 1000;
-       tv.tv_usec = (conf.timeout_arg % 1000) * 1000;
-//     ret = refresh_status();
-       FD_ZERO(&rfds);
-       max_fileno = 0;
-       status_pre_select(&rfds, &max_fileno, &tv);
-       /* signal pipe */
-       para_fd_set(signal_pipe, &rfds, &max_fileno);
-       /* command pipe only for COMMAND_MODE */
-       if (mode == COMMAND_MODE) {
-               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);
+static int exec_post_select(struct sched *s, void *context)
+{
+       struct exec_task *ct = context;
+       int i, ret;
+
+       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, " ");
+               }
        }
-       if (mode == GETCH_MODE || mode == COMMAND_MODE)
-               para_fd_set(STDIN_FILENO, &rfds, &max_fileno);
-       ret = para_select(max_fileno + 1, &rfds, NULL, &tv);
-       if (ret <= 0)
-               goto check_return; /* skip fd checks */
-       /* signals */
-       ret = para_next_signal(&rfds);
-       if (ret > 0)
-               handle_signal(ret);
-       /* read command pipe if ready */
-       if (mode == COMMAND_MODE) {
-               for (i = 0; i < 2; i++) {
-                       size_t sz;
-                       if (command_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;
-                       }
-                       if (ret < 0) {
-                               PARA_NOTICE_LOG("closing command fd %d: %s\n",
+       for (i = 0; i < 2; i++) {
+               size_t sz;
+               if (exec_fds[i] < 0)
+                       continue;
+               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 || 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 0;
-                       }
-                       if (cbo[i] == COMMAND_BUF_SIZE - 1) {
-                               PARA_NOTICE_LOG("discarding overlong line\n");
-                               cbo[i] = 0;
-                               flags[i] = FELF_DISCARD_FIRST;
-                       }
+                       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;
                }
-       }
-       ret = read_stat_pipe(&rfds);
-       if (ret < 0) {
-               PARA_NOTICE_LOG("closing stat pipe: %s\n", para_strerror(-ret));
-               close(stat_pipe);
-               stat_pipe = -1;
-               clear_all_items();
-               free(stat_content[SI_BASENAME]);
-               stat_content[SI_BASENAME] =
-                       para_strdup("stat command terminated!?");
-               print_all_items();
-       }
-check_return:
-       switch (mode) {
-       case COMMAND_MODE:
-               ret = wgetch(top.win);
-               if (ret != ERR && ret != KEY_RESIZE) {
-                       if (command_fds[0] >= 0) {
-                               close(command_fds[0]);
-                               command_fds[0] = -1;
-                       }
-                       if (command_fds[1] >= 0) {
-                               close(command_fds[1]);
-                               command_fds[1] = -1;
-                       }
-                       if (cmd_pid)
-                               kill(cmd_pid, SIGTERM);
-                       return -1;
+               if (ct->cbo[i] == COMMAND_BUF_SIZE - 1) {
+                       PARA_NOTICE_LOG("discarding overlong line");
+                       ct->cbo[i] = 0;
+                       ct->flags[i] = FELF_DISCARD_FIRST;
                }
-               break;
-       case GETCH_MODE:
-               ret = wgetch(top.win);
-               if (ret != ERR && ret != KEY_RESIZE)
-                       return ret;
-               break;
-       case EXTERNAL_MODE:
-               if (cmd_pid == 0)
-                       return 0;
        }
-       goto repeat;
+       return 0;
 }
 
-/*
- * read from command pipe and print data to bot window
- */
-static void send_output(void)
+static void input_pre_select(struct sched *s, __a_unused void *context)
 {
-       int ret;
+       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(const char *file_and_args)
+{
+       int ret, fds[3] = {0, 1, 1};
 
-       ret = mark_fd_nonblocking(command_fds[0]);
+       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]);
        if (ret < 0)
                goto fail;
-       ret = mark_fd_nonblocking(command_fds[1]);
+       ret = mark_fd_nonblocking(fds[2]);
        if (ret < 0)
                goto fail;
-       if (do_select(COMMAND_MODE) >= 0)
-               PARA_INFO_LOG("command complete\n");
-       else
-               PARA_NOTICE_LOG("command aborted\n");
-       print_in_bar(COLOR_MSG, " ");
+       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)
 {
-       int ret, fds[3] = {0, 1, 1};
-       char *c = make_message(BINDIR "/para_client -- %s", cmd);
+       char *file_and_args;
 
-       outputf(COLOR_COMMAND, "%s", c);
-       print_in_bar(COLOR_MSG, "executing client command, hit any key to abort\n");
-       ret = para_exec_cmdline_pid(&cmd_pid, c, fds);
-       free(c);
-       if (ret < 0)
-               return;
-       command_fds[0] = fds[1];
-       command_fds[1] = fds[2];
-       send_output();
+       file_and_args = make_message(BINDIR "/para_client -- %s", args);
+       exec_and_display(file_and_args);
+       free(file_and_args);
 }
 
 /*
- * exec command and print output to bot win
+ * shutdown curses and stat pipe before executing external commands
  */
-static void display_cmd(char *cmd)
+static void exec_external(char *file_and_args)
 {
-       int fds[3] = {0, 1, 1};
+       int fds[3] = {-1, -1, -1};
 
-       print_in_bar(COLOR_MSG, "executing display command, hit any key to abort");
-       outputf(COLOR_COMMAND, "%s", cmd);
-       if (para_exec_cmdline_pid(&cmd_pid, cmd, fds) < 0)
+       if (exec_pid)
                return;
-       command_fds[0] = fds[1];
-       command_fds[1] = fds[2];
-       send_output();
+       shutdown_curses();
+       para_exec_cmdline_pid(&exec_pid, file_and_args, fds);
 }
 
-/*
- * shutdown curses and stat pipe before executing external commands
- */
-static void external_cmd(char *cmd)
+static void handle_command(int c)
 {
-       int fds[3] = {-1, -1, -1};
+       int i;
 
-       if (cmd_pid)
-               return;
-       shutdown_curses();
-       if (para_exec_cmdline_pid(&cmd_pid, cmd, fds) < 0)
+       /* first check user-defined key bindings */
+       for (i = 0; i < conf.key_map_given; ++i) {
+               char *tmp, *handler, *arg;
+
+               tmp = para_strdup(conf.key_map_arg[i]);
+               if (!split_key_map(tmp, &handler, &arg)) {
+                       free(tmp);
+                       return;
+               }
+               if (strcmp(tmp, km_keyname(c))) {
+                       free(tmp);
+                       continue;
+               }
+               if (*handler == 'd')
+                       exec_and_display(arg);
+               else if (*handler == 'x')
+                       exec_external(arg);
+               else if (*handler == 'p')
+                       exec_para(arg);
+               else if (*handler == 'i') {
+                       int num = find_cmd_byname(arg);
+                       if (num >= 0)
+                               command_list[num].handler();
+               }
+               free(tmp);
                return;
-       do_select(EXTERNAL_MODE);
-       init_curses();
+       }
+       /* not found, check internal key bindings */
+       for (i = 0; command_list[i].handler; i++) {
+               if (!strcmp(km_keyname(c), command_list[i].key)) {
+                       command_list[i].handler();
+                       return;
+               }
+       }
+       print_in_bar(COLOR_ERRMSG, "key '%s' is not bound, press ? for help",
+               km_keyname(c));
+}
+
+static int input_post_select(__a_unused struct sched *s, __a_unused void *context)
+{
+       int ret;
+       enum exec_status exs = exec_status();
+
+       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)
+               return 0;
+       if (ret == KEY_RESIZE) {
+               if (curses_active()) {
+                       shutdown_curses();
+                       init_curses();
+                       redraw_bot_win();
+               }
+               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)
@@ -1174,19 +1160,19 @@ 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));
 }
 
 static void com_scroll_top(void)
 {
-       int i = RINGBUFFER_SIZE - 1;
+       int i = RINGBUFFER_SIZE - 1, bot_lines = get_num_lines(&bot);
        unsigned lines = 0;
 
        while (i > 0 && !ringbuffer_get(bot_win_rb, i))
                i--;
        /* i is oldest entry */
-       for (; lines < bot.lines && i >= 0; i--) {
+       for (; lines < bot_lines && i >= 0; i--) {
                struct rb_entry *rbe = ringbuffer_get(bot_win_rb, i);
                if (!rbe)
                        break;
@@ -1202,7 +1188,7 @@ static void com_scroll_top(void)
        print_in_bar(COLOR_ERRMSG, "top of buffer is shown\n");
 }
 
-static void com_cancel_scrolling(void)
+static void com_cancel_scroll(void)
 {
 
        if (scroll_position == 0) {
@@ -1216,9 +1202,9 @@ static void com_cancel_scrolling(void)
 static void com_page_down(void)
 {
        unsigned lines = 0;
-       int i = scroll_position;
+       int i = scroll_position, bot_lines = get_num_lines(&bot);
 
-       while (lines < bot.lines && --i > 0) {
+       while (lines < bot_lines && --i > 0) {
                struct rb_entry *rbe = ringbuffer_get(bot_win_rb, i);
                if (!rbe)
                        break;
@@ -1236,7 +1222,7 @@ static void com_page_down(void)
 static void com_page_up(void)
 {
        unsigned lines;
-       int fvr = first_visible_rbe(&lines);
+       int fvr = first_visible_rbe(&lines), bot_lines = get_num_lines(&bot);
 
        if (fvr < 0 || fvr + 1 >= ringbuffer_filled(bot_win_rb)) {
                print_in_bar(COLOR_ERRMSG, "top of buffer is shown\n");
@@ -1245,7 +1231,7 @@ static void com_page_up(void)
        scroll_position = fvr + 1;
        for (; scroll_position > 0; scroll_position--) {
                first_visible_rbe(&lines);
-               if (lines == bot.lines)
+               if (lines == bot_lines)
                        break;
        }
        redraw_bot_win();
@@ -1255,7 +1241,7 @@ static void com_page_up(void)
 static void com_scroll_down(void)
 {
        struct rb_entry *rbe;
-       int rbe_lines;
+       int rbe_lines, bot_lines = get_num_lines(&bot);
 
        if (!scroll_position) {
                print_in_bar(COLOR_ERRMSG, "bottom of buffer is shown\n");
@@ -1265,10 +1251,10 @@ static void com_scroll_down(void)
        rbe = ringbuffer_get(bot_win_rb, scroll_position);
        rbe_lines = NUM_LINES(rbe->len);
        wscrl(bot.win, rbe_lines);
-       wmove(bot.win, bot.lines - rbe_lines, 0);
+       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();
 }
 
@@ -1298,7 +1284,6 @@ static void com_scroll_up(void)
                        break;
                rbe_lines = NUM_LINES(rbe->len);
                lines += rbe_lines;
-//             fprintf(stderr, "msg: %s\n", rbe->msg);
                wattron(bot.win, COLOR_PAIR(rbe->color));
                waddstr(bot.win, "\n");
                waddstr(bot.win, rbe->msg);
@@ -1306,7 +1291,7 @@ static void com_scroll_up(void)
                        break;
                i--;
        }
-       wrefresh(bot.win);
+       refresh_window(&bot);
        print_scroll_msg();
        return;
 err_out:
@@ -1335,36 +1320,9 @@ static void com_ll_incr(void)
        print_in_bar(COLOR_MSG, "loglevel set to %d\n", loglevel);
 }
 
-/*
- * reread configuration, terminate on errors
- */
 static void com_reread_conf(void)
 {
-       char *cf = configfile_exists();
-       struct gui_cmdline_parser_params params = {
-               .override = 1,
-               .initialize = 1,
-               .check_required = 0,
-               .check_ambiguity = 0,
-               .print_errors = 0,
-       };
-
-       if (!cf) {
-               PARA_WARNING_LOG("there is no configuration to read\n");
-               return;
-       }
-       PARA_INFO_LOG("rereading command line options and config file\n");
-       gui_cmdline_parser_ext(_argc, _argv, &conf, &params);
-       /*
-        * Despite .print_errors is set to 0, gengetopt will print to stderr
-        * anyway, and exit on errors. So we have to shutdown curses first.
-        */
-       shutdown_curses();
-       gui_cmdline_parser_config_file(cf, &conf, &params);
-       init_curses();
-       PARA_NOTICE_LOG("config file reloaded\n");
-       if (check_key_map_args() < 0)
-               finish(EXIT_FAILURE);
+       reread_conf();
 }
 
 static void com_help(void)
@@ -1406,25 +1364,25 @@ static void com_help(void)
 
 static void com_shrink_top_win(void)
 {
-       if (top.lines <= theme.top_lines_min) {
+       int top_lines = get_num_lines(&top);
+
+       if (top_lines <= theme.top_lines_min) {
                PARA_WARNING_LOG("can not decrease top window\n");
                return;
        }
-       init_wins(top.lines - 1);
-       wclear(top.win);
-       print_all_items();
+       init_wins(top_lines - 1);
        print_in_bar(COLOR_MSG, "%s", "decreased top window");
 }
 
 static void com_enlarge_top_win(void)
 {
-       if (bot.lines < 3) {
+       int top_lines = get_num_lines(&top), bot_lines = get_num_lines(&bot);
+
+       if (bot_lines < 3) {
                PARA_WARNING_LOG("can not increase top window\n");
                return;
        }
-       init_wins(top.lines + 1);
-       wclear(top.win);
-       print_all_items();
+       init_wins(top_lines + 1);
        print_in_bar(COLOR_MSG, "increased top window");
 }
 
@@ -1435,7 +1393,7 @@ static void com_version(void)
 
 __noreturn static void com_quit(void)
 {
-       finish(0);
+       die(EXIT_SUCCESS, "%s", "");
 }
 
 static void com_refresh(void)
@@ -1444,69 +1402,16 @@ static void com_refresh(void)
        init_curses();
 }
 
-static void change_theme(int next)
-{
-       if (next)
-               next_theme(&theme);
-       else
-               prev_theme(&theme);
-       /* This seems to be needed twice, why? */
-       com_refresh();
-       com_refresh();
-       PARA_NOTICE_LOG("new theme: %s\n", theme.name);
-}
-
 static void com_next_theme(void)
 {
-       change_theme(1);
+       theme_next(&theme);
+       com_refresh();
 }
 
 static void com_prev_theme(void)
 {
-       change_theme(0);
-}
-
-
-static void handle_command(int c)
-{
-       int i;
-
-       /* first check user-defined key bindings */
-       for (i = 0; i < conf.key_map_given; ++i) {
-               char *tmp, *handler, *arg;
-
-               tmp = para_strdup(conf.key_map_arg[i]);
-               if (!split_key_map(tmp, &handler, &arg)) {
-                       free(tmp);
-                       return;
-               }
-               if (strcmp(tmp, km_keyname(c))) {
-                       free(tmp);
-                       continue;
-               }
-               if (*handler == 'd')
-                       display_cmd(arg);
-               else if (*handler == 'x')
-                       external_cmd(arg);
-               else if (*handler == 'p')
-                       para_cmd(arg);
-               else if (*handler == 'i') {
-                       int num = find_cmd_byname(arg);
-                       if (num >= 0)
-                               command_list[num].handler();
-               }
-               free(tmp);
-               return;
-       }
-       /* not found, check internal key bindings */
-       for (i = 0; command_list[i].handler; i++) {
-               if (!strcmp(km_keyname(c), command_list[i].key)) {
-                       command_list[i].handler();
-                       return;
-               }
-       }
-       print_in_bar(COLOR_ERRMSG, "key '%s' is not bound, press ? for help",
-               km_keyname(c));
+       theme_prev(&theme);
+       com_refresh();
 }
 
 __noreturn static void print_help_and_die(void)
@@ -1518,54 +1423,94 @@ __noreturn static void print_help_and_die(void)
        exit(0);
 }
 
-int main(int argc, char *argv[])
+static int setup_tasks_and_schedule(void)
 {
        int ret;
-       char *cf;
+       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 = conf.timeout_arg  / 1000,
+                       .tv_usec = (conf.timeout_arg % 1000) * 1000,
+               },
+       };
 
-       _argc = argc;
-       _argv = argv;
+       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);
+       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;
+}
 
+/**
+ * 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();
-       cf = configfile_exists();
-       if (!cf && conf.config_file_given) {
-               fprintf(stderr, "can not read config file %s\n",
-                       conf.config_file_arg);
-               exit(EXIT_FAILURE);
-       }
-       if (cf) {
-               struct gui_cmdline_parser_params params = {
-                       .override = 0,
-                       .initialize = 0,
-                       .check_required = 0,
-                       .check_ambiguity = 0,
-                       .print_errors = 1,
-               };
-               gui_cmdline_parser_config_file(cf, &conf, &params);
-               loglevel = get_loglevel_by_name(conf.loglevel_arg);
-       }
-       if (check_key_map_args() < 0) {
-               fprintf(stderr, "invalid key map\n");
-               exit(EXIT_FAILURE);
-       }
-       init_theme_or_die(conf.theme_arg, &theme);
-       top.lines = theme.top_lines_default;
-       setup_signal_handling();
+       parse_config_file_or_die(false /* override */);
        bot_win_rb = ringbuffer_new(RINGBUFFER_SIZE);
        setlocale(LC_CTYPE, "");
        initscr(); /* needed only once, always successful */
        init_curses();
-       print_welcome();
-       for (;;) {
-               print_status_bar();
-               ret = do_select(GETCH_MODE);
-               if (!ret)
-                       continue;
-               print_in_bar(COLOR_MSG, " ");
-               handle_command(ret);
-       }
+       return setup_tasks_and_schedule() < 0? EXIT_FAILURE : EXIT_SUCCESS;
 }