Change terminal-overrides to a server option (now that we have them), it

[tmux-openbsd.git] / tty.c

/* $OpenBSD$ */

/*
 * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/ioctl.h>

#include <netinet/in.h>

#include <errno.h>
#include <fcntl.h>
#include <resolv.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

#include "tmux.h"

void    tty_read_callback(struct bufferevent *, void *);
void    tty_error_callback(struct bufferevent *, short, void *);

int     tty_try_256(struct tty *, u_char, const char *);

void    tty_colours(struct tty *, const struct grid_cell *);
void    tty_check_fg(struct tty *, struct grid_cell *);
void    tty_check_bg(struct tty *, struct grid_cell *);
void    tty_colours_fg(struct tty *, const struct grid_cell *);
void    tty_colours_bg(struct tty *, const struct grid_cell *);

int     tty_large_region(struct tty *, const struct tty_ctx *);
void    tty_redraw_region(struct tty *, const struct tty_ctx *);
void    tty_emulate_repeat(
            struct tty *, enum tty_code_code, enum tty_code_code, u_int);
void    tty_repeat_space(struct tty *, u_int);
void    tty_cell(struct tty *, const struct grid_cell *);

#define tty_use_acs(tty) \
        (tty_term_has((tty)->term, TTYC_ACSC) && !((tty)->flags & TTY_UTF8))

#define tty_pane_full_width(tty, ctx) \
        ((ctx)->xoff == 0 && screen_size_x((ctx)->wp->screen) >= (tty)->sx)

void
tty_init(struct tty *tty, struct client *c, int fd, char *term)
{
        char    *path;

        memset(tty, 0, sizeof *tty);
        tty->log_fd = -1;

        if (term == NULL || *term == '\0')
                tty->termname = xstrdup("unknown");
        else
                tty->termname = xstrdup(term);
        tty->fd = fd;
        tty->client = c;

        if ((path = ttyname(fd)) == NULL)
                fatalx("ttyname failed");
        tty->path = xstrdup(path);
        tty->cstyle = 0;
        tty->ccolour = xstrdup("");

        tty->flags = 0;
        tty->term_flags = 0;
}

int
tty_resize(struct tty *tty)
{
        struct winsize  ws;
        u_int           sx, sy;

        if (ioctl(tty->fd, TIOCGWINSZ, &ws) != -1) {
                sx = ws.ws_col;
                if (sx == 0)
                        sx = 80;
                sy = ws.ws_row;
                if (sy == 0)
                        sy = 24;
        } else {
                sx = 80;
                sy = 24;
        }
        if (!tty_set_size(tty, sx, sy))
                return (0);

        tty->cx = UINT_MAX;
        tty->cy = UINT_MAX;

        tty->rupper = UINT_MAX;
        tty->rlower = UINT_MAX;

        /*
         * If the terminal has been started, reset the actual scroll region and
         * cursor position, as this may not have happened.
         */
        if (tty->flags & TTY_STARTED) {
                tty_cursor(tty, 0, 0);
                tty_region(tty, 0, tty->sy - 1);
        }

        return (1);
}

int
tty_set_size(struct tty *tty, u_int sx, u_int sy) {
        if (sx == tty->sx && sy == tty->sy)
                return (0);
        tty->sx = sx;
        tty->sy = sy;
        return (1);
}

int
tty_open(struct tty *tty, char **cause)
{
        char    out[64];
        int     fd;

        if (debug_level > 3) {
                xsnprintf(out, sizeof out, "tmux-out-%ld.log", (long) getpid());
                fd = open(out, O_WRONLY|O_CREAT|O_TRUNC, 0644);
                if (fd != -1 && fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
                        fatal("fcntl failed");
                tty->log_fd = fd;
        }

        tty->term = tty_term_find(tty->termname, tty->fd, cause);
        if (tty->term == NULL) {
                tty_close(tty);
                return (-1);
        }
        tty->flags |= TTY_OPENED;

        tty->flags &= ~(TTY_NOCURSOR|TTY_FREEZE|TTY_TIMER);

        tty->event = bufferevent_new(
            tty->fd, tty_read_callback, NULL, tty_error_callback, tty);

        tty_start_tty(tty);

        tty_keys_build(tty);

        return (0);
}

void
tty_read_callback(unused struct bufferevent *bufev, void *data)
{
        struct tty      *tty = data;

        while (tty_keys_next(tty))
                ;
}

void
tty_error_callback(
    unused struct bufferevent *bufev, unused short what, unused void *data)
{
}

void
tty_init_termios(int fd, struct termios *orig_tio, struct bufferevent *bufev)
{
        struct termios  tio;

        if (fd == -1 || tcgetattr(fd, orig_tio) != 0)
                return;

        setblocking(fd, 0);

        if (bufev != NULL)
                bufferevent_enable(bufev, EV_READ|EV_WRITE);

        memcpy(&tio, orig_tio, sizeof tio);
        tio.c_iflag &= ~(IXON|IXOFF|ICRNL|INLCR|IGNCR|IMAXBEL|ISTRIP);
        tio.c_iflag |= IGNBRK;
        tio.c_oflag &= ~(OPOST|ONLCR|OCRNL|ONLRET);
        tio.c_lflag &= ~(IEXTEN|ICANON|ECHO|ECHOE|ECHONL|ECHOCTL|
            ECHOPRT|ECHOKE|ECHOCTL|ISIG);
        tio.c_cc[VMIN] = 1;
        tio.c_cc[VTIME] = 0;
        if (tcsetattr(fd, TCSANOW, &tio) == 0)
                tcflush(fd, TCIOFLUSH);
}

void
tty_start_tty(struct tty *tty)
{
        tty_init_termios(tty->fd, &tty->tio, tty->event);

        tty_putcode(tty, TTYC_SMCUP);

        tty_putcode(tty, TTYC_SGR0);
        memcpy(&tty->cell, &grid_default_cell, sizeof tty->cell);

        tty_putcode(tty, TTYC_RMKX);
        if (tty_use_acs(tty))
                tty_putcode(tty, TTYC_ENACS);
        tty_putcode(tty, TTYC_CLEAR);

        tty_putcode(tty, TTYC_CNORM);
        if (tty_term_has(tty->term, TTYC_KMOUS))
                tty_puts(tty, "\033[?1000l\033[?1006l\033[?1005l");

        if (tty_term_has(tty->term, TTYC_XT)) {
                if (options_get_number(&global_options, "focus-events")) {
                        tty->flags |= TTY_FOCUS;
                        tty_puts(tty, "\033[?1004h");
                }
                tty_puts(tty, "\033[c");
        }

        tty->cx = UINT_MAX;
        tty->cy = UINT_MAX;

        tty->rlower = UINT_MAX;
        tty->rupper = UINT_MAX;

        tty->mode = MODE_CURSOR;

        tty->flags |= TTY_STARTED;

        tty_force_cursor_colour(tty, "");
}

void
tty_set_class(struct tty *tty, u_int class)
{
        if (tty->class != 0)
                return;
        tty->class = class;
}

void
tty_stop_tty(struct tty *tty)
{
        struct winsize  ws;

        if (!(tty->flags & TTY_STARTED))
                return;
        tty->flags &= ~TTY_STARTED;

        bufferevent_disable(tty->event, EV_READ|EV_WRITE);

        /*
         * Be flexible about error handling and try not kill the server just
         * because the fd is invalid. Things like ssh -t can easily leave us
         * with a dead tty.
         */
        if (ioctl(tty->fd, TIOCGWINSZ, &ws) == -1)
                return;
        if (tcsetattr(tty->fd, TCSANOW, &tty->tio) == -1)
                return;

        tty_raw(tty, tty_term_string2(tty->term, TTYC_CSR, 0, ws.ws_row - 1));
        if (tty_use_acs(tty))
                tty_raw(tty, tty_term_string(tty->term, TTYC_RMACS));
        tty_raw(tty, tty_term_string(tty->term, TTYC_SGR0));
        tty_raw(tty, tty_term_string(tty->term, TTYC_RMKX));
        tty_raw(tty, tty_term_string(tty->term, TTYC_CLEAR));
        if (tty_term_has(tty->term, TTYC_SS) && tty->cstyle != 0) {
                if (tty_term_has(tty->term, TTYC_SE))
                        tty_raw(tty, tty_term_string(tty->term, TTYC_SE));
                else
                        tty_raw(tty, tty_term_string1(tty->term, TTYC_SS, 0));
        }
        tty_raw(tty, tty_term_string(tty->term, TTYC_CR));

        tty_raw(tty, tty_term_string(tty->term, TTYC_CNORM));
        if (tty_term_has(tty->term, TTYC_KMOUS))
                tty_raw(tty, "\033[?1000l\033[?1006l\033[?1005l");

        if (tty_term_has(tty->term, TTYC_XT)) {
                if (tty->flags & TTY_FOCUS) {
                        tty->flags &= ~TTY_FOCUS;
                        tty_puts(tty, "\033[?1004l");
                }
        }

        tty_raw(tty, tty_term_string(tty->term, TTYC_RMCUP));

        setblocking(tty->fd, 1);
}

void
tty_close(struct tty *tty)
{
        if (tty->log_fd != -1) {
                close(tty->log_fd);
                tty->log_fd = -1;
        }

        if (event_initialized(&tty->key_timer))
                evtimer_del(&tty->key_timer);
        tty_stop_tty(tty);

        if (tty->flags & TTY_OPENED) {
                bufferevent_free(tty->event);

                tty_term_free(tty->term);
                tty_keys_free(tty);

                tty->flags &= ~TTY_OPENED;
        }

        if (tty->fd != -1) {
                close(tty->fd);
                tty->fd = -1;
        }
}

void
tty_free(struct tty *tty)
{
        tty_close(tty);

        free(tty->ccolour);
        if (tty->path != NULL)
                free(tty->path);
        if (tty->termname != NULL)
                free(tty->termname);
}

void
tty_raw(struct tty *tty, const char *s)
{
        ssize_t n, slen;
        u_int   i;

        slen = strlen(s);
        for (i = 0; i < 5; i++) {
                n = write(tty->fd, s, slen);
                if (n >= 0) {
                        s += n;
                        slen -= n;
                        if (slen == 0)
                                break;
                } else if (n == -1 && errno != EAGAIN)
                        break;
                usleep(100);
        }
}

void
tty_putcode(struct tty *tty, enum tty_code_code code)
{
        tty_puts(tty, tty_term_string(tty->term, code));
}

void
tty_putcode1(struct tty *tty, enum tty_code_code code, int a)
{
        if (a < 0)
                return;
        tty_puts(tty, tty_term_string1(tty->term, code, a));
}

void
tty_putcode2(struct tty *tty, enum tty_code_code code, int a, int b)
{
        if (a < 0 || b < 0)
                return;
        tty_puts(tty, tty_term_string2(tty->term, code, a, b));
}

void
tty_putcode_ptr1(struct tty *tty, enum tty_code_code code, const void *a)
{
        if (a != NULL)
                tty_puts(tty, tty_term_ptr1(tty->term, code, a));
}

void
tty_putcode_ptr2(struct tty *tty, enum tty_code_code code, const void *a, const void *b)
{
        if (a != NULL && b != NULL)
                tty_puts(tty, tty_term_ptr2(tty->term, code, a, b));
}

void
tty_puts(struct tty *tty, const char *s)
{
        if (*s == '\0')
                return;
        bufferevent_write(tty->event, s, strlen(s));

        if (tty->log_fd != -1)
                write(tty->log_fd, s, strlen(s));
}

void
tty_putc(struct tty *tty, u_char ch)
{
        const char      *acs;
        u_int            sx;

        if (tty->cell.attr & GRID_ATTR_CHARSET) {
                acs = tty_acs_get(tty, ch);
                if (acs != NULL)
                        bufferevent_write(tty->event, acs, strlen(acs));
                else
                        bufferevent_write(tty->event, &ch, 1);
        } else
                bufferevent_write(tty->event, &ch, 1);

        if (ch >= 0x20 && ch != 0x7f) {
                sx = tty->sx;
                if (tty->term->flags & TERM_EARLYWRAP)
                        sx--;

                if (tty->cx >= sx) {
                        tty->cx = 1;
                        if (tty->cy != tty->rlower)
                                tty->cy++;
                } else
                        tty->cx++;
        }

        if (tty->log_fd != -1)
                write(tty->log_fd, &ch, 1);
}

void
tty_putn(struct tty *tty, const void *buf, size_t len, u_int width)
{
        bufferevent_write(tty->event, buf, len);
        if (tty->log_fd != -1)
                write(tty->log_fd, buf, len);
        tty->cx += width;
}

void
tty_set_title(struct tty *tty, const char *title)
{
        if (!tty_term_has(tty->term, TTYC_TSL) ||
            !tty_term_has(tty->term, TTYC_FSL))
                return;

        tty_putcode(tty, TTYC_TSL);
        tty_puts(tty, title);
        tty_putcode(tty, TTYC_FSL);
}

void
tty_force_cursor_colour(struct tty *tty, const char *ccolour)
{
        if (*ccolour == '\0')
                tty_putcode(tty, TTYC_CR);
        else
                tty_putcode_ptr1(tty, TTYC_CS, ccolour);
        free(tty->ccolour);
        tty->ccolour = xstrdup(ccolour);
}

void
tty_update_mode(struct tty *tty, int mode, struct screen *s)
{
        int     changed;

        if (strcmp(s->ccolour, tty->ccolour))
                tty_force_cursor_colour(tty, s->ccolour);

        if (tty->flags & TTY_NOCURSOR)
                mode &= ~MODE_CURSOR;

        changed = mode ^ tty->mode;
        if (changed & MODE_CURSOR) {
                if (mode & MODE_CURSOR)
                        tty_putcode(tty, TTYC_CNORM);
                else
                        tty_putcode(tty, TTYC_CIVIS);
        }
        if (tty->cstyle != s->cstyle) {
                if (tty_term_has(tty->term, TTYC_SS)) {
                        if (s->cstyle == 0 &&
                            tty_term_has(tty->term, TTYC_SE))
                                tty_putcode(tty, TTYC_SE);
                        else
                                tty_putcode1(tty, TTYC_SS, s->cstyle);
                }
                tty->cstyle = s->cstyle;
        }
        if (changed & (ALL_MOUSE_MODES|MODE_MOUSE_UTF8)) {
                if (mode & ALL_MOUSE_MODES) {
                        /*
                         * Enable the UTF-8 (1005) extension if configured to.
                         * Enable the SGR (1006) extension unconditionally, as
                         * this is safe from misinterpretation. Do it in this
                         * order, because in some terminals it's the last one
                         * that takes effect and SGR is the preferred one.
                         */
                        if (mode & MODE_MOUSE_UTF8)
                                tty_puts(tty, "\033[?1005h");
                        else
                                tty_puts(tty, "\033[?1005l");
                        tty_puts(tty, "\033[?1006h");

                        if (mode & MODE_MOUSE_ANY)
                                tty_puts(tty, "\033[?1003h");
                        else if (mode & MODE_MOUSE_BUTTON)
                                tty_puts(tty, "\033[?1002h");
                        else if (mode & MODE_MOUSE_STANDARD)
                                tty_puts(tty, "\033[?1000h");
                } else {
                        if (tty->mode & MODE_MOUSE_ANY)
                                tty_puts(tty, "\033[?1003l");
                        else if (tty->mode & MODE_MOUSE_BUTTON)
                                tty_puts(tty, "\033[?1002l");
                        else if (tty->mode & MODE_MOUSE_STANDARD)
                                tty_puts(tty, "\033[?1000l");

                        tty_puts(tty, "\033[?1006l");
                        if (tty->mode & MODE_MOUSE_UTF8)
                                tty_puts(tty, "\033[?1005l");
                }
        }
        if (changed & MODE_KKEYPAD) {
                if (mode & MODE_KKEYPAD)
                        tty_putcode(tty, TTYC_SMKX);
                else
                        tty_putcode(tty, TTYC_RMKX);
        }
        if (changed & MODE_BRACKETPASTE) {
                if (mode & MODE_BRACKETPASTE)
                        tty_puts(tty, "\033[?2004h");
                else
                        tty_puts(tty, "\033[?2004l");
        }
        tty->mode = mode;
}

void
tty_emulate_repeat(
    struct tty *tty, enum tty_code_code code, enum tty_code_code code1, u_int n)
{
        if (tty_term_has(tty->term, code))
                tty_putcode1(tty, code, n);
        else {
                while (n-- > 0)
                        tty_putcode(tty, code1);
        }
}

void
tty_repeat_space(struct tty *tty, u_int n)
{
        while (n-- > 0)
                tty_putc(tty, ' ');
}

/*
 * Is the region large enough to be worth redrawing once later rather than
 * probably several times now? Currently yes if it is more than 50% of the
 * pane.
 */
int
tty_large_region(unused struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;

        return (ctx->orlower - ctx->orupper >= screen_size_y(wp->screen) / 2);
}

/*
 * Redraw scroll region using data from screen (already updated). Used when
 * CSR not supported, or window is a pane that doesn't take up the full
 * width of the terminal.
 */
void
tty_redraw_region(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;
        struct screen           *s = wp->screen;
        u_int                    i;

        /*
         * If region is large, schedule a window redraw. In most cases this is
         * likely to be followed by some more scrolling.
         */
        if (tty_large_region(tty, ctx)) {
                wp->flags |= PANE_REDRAW;
                return;
        }

        if (ctx->ocy < ctx->orupper || ctx->ocy > ctx->orlower) {
                for (i = ctx->ocy; i < screen_size_y(s); i++)
                        tty_draw_line(tty, s, i, ctx->xoff, ctx->yoff);
        } else {
                for (i = ctx->orupper; i <= ctx->orlower; i++)
                        tty_draw_line(tty, s, i, ctx->xoff, ctx->yoff);
        }
}

void
tty_draw_line(struct tty *tty, struct screen *s, u_int py, u_int ox, u_int oy)
{
        const struct grid_cell  *gc;
        struct grid_line        *gl;
        struct grid_cell         tmpgc;
        struct utf8_data         ud;
        u_int                    i, sx;

        tty_update_mode(tty, tty->mode & ~MODE_CURSOR, s);

        sx = screen_size_x(s);
        if (sx > s->grid->linedata[s->grid->hsize + py].cellsize)
                sx = s->grid->linedata[s->grid->hsize + py].cellsize;
        if (sx > tty->sx)
                sx = tty->sx;

        /*
         * Don't move the cursor to the start permission if it will wrap there
         * itself.
         */
        gl = NULL;
        if (py != 0)
                gl = &s->grid->linedata[s->grid->hsize + py - 1];
        if (oy + py == 0 || gl == NULL || !(gl->flags & GRID_LINE_WRAPPED) ||
            tty->cx < tty->sx || ox != 0 ||
            (oy + py != tty->cy + 1 && tty->cy != s->rlower + oy))
                tty_cursor(tty, ox, oy + py);

        for (i = 0; i < sx; i++) {
                gc = grid_view_peek_cell(s->grid, i, py);
                if (screen_check_selection(s, i, py)) {
                        memcpy(&tmpgc, &s->sel.cell, sizeof tmpgc);
                        grid_cell_get(gc, &ud);
                        grid_cell_set(&tmpgc, &ud);
                        tmpgc.flags = gc->flags &
                            ~(GRID_FLAG_FG256|GRID_FLAG_BG256);
                        tmpgc.flags |= s->sel.cell.flags &
                            (GRID_FLAG_FG256|GRID_FLAG_BG256);
                        tty_cell(tty, &tmpgc);
                } else
                        tty_cell(tty, gc);
        }

        if (sx >= tty->sx) {
                tty_update_mode(tty, tty->mode, s);
                return;
        }
        tty_reset(tty);

        tty_cursor(tty, ox + sx, oy + py);
        if (sx != screen_size_x(s) && ox + screen_size_x(s) >= tty->sx &&
            tty_term_has(tty->term, TTYC_EL))
                tty_putcode(tty, TTYC_EL);
        else
                tty_repeat_space(tty, screen_size_x(s) - sx);
        tty_update_mode(tty, tty->mode, s);
}

void
tty_write(
    void (*cmdfn)(struct tty *, const struct tty_ctx *), struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;
        struct client           *c;
        u_int                    i;

        /* wp can be NULL if updating the screen but not the terminal. */
        if (wp == NULL)
                return;

        if (wp->window->flags & WINDOW_REDRAW || wp->flags & PANE_REDRAW)
                return;
        if (!window_pane_visible(wp) || wp->flags & PANE_DROP)
                return;

        for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
                c = ARRAY_ITEM(&clients, i);
                if (c == NULL || c->session == NULL || c->tty.term == NULL)
                        continue;
                if (c->flags & CLIENT_SUSPENDED)
                        continue;
                if (c->tty.flags & TTY_FREEZE)
                        continue;
                if (c->session->curw->window != wp->window)
                        continue;

                ctx->xoff = wp->xoff;
                ctx->yoff = wp->yoff;
                if (status_at_line(c) == 0)
                        ctx->yoff++;

                cmdfn(&c->tty, ctx);
        }
}

void
tty_cmd_insertcharacter(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;

        if (!tty_pane_full_width(tty, ctx)) {
                tty_draw_line(tty, wp->screen, ctx->ocy, ctx->xoff, ctx->yoff);
                return;
        }

        tty_reset(tty);

        tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

        if (tty_term_has(tty->term, TTYC_ICH) ||
            tty_term_has(tty->term, TTYC_ICH1))
                tty_emulate_repeat(tty, TTYC_ICH, TTYC_ICH1, ctx->num);
        else
                tty_draw_line(tty, wp->screen, ctx->ocy, ctx->xoff, ctx->yoff);
}

void
tty_cmd_deletecharacter(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;

        if (!tty_pane_full_width(tty, ctx) ||
            (!tty_term_has(tty->term, TTYC_DCH) &&
            !tty_term_has(tty->term, TTYC_DCH1))) {
                tty_draw_line(tty, wp->screen, ctx->ocy, ctx->xoff, ctx->yoff);
                return;
        }

        tty_reset(tty);

        tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

        if (tty_term_has(tty->term, TTYC_DCH) ||
            tty_term_has(tty->term, TTYC_DCH1))
                tty_emulate_repeat(tty, TTYC_DCH, TTYC_DCH1, ctx->num);
}

void
tty_cmd_clearcharacter(struct tty *tty, const struct tty_ctx *ctx)
{
        u_int   i;

        tty_reset(tty);

        tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

        if (tty_term_has(tty->term, TTYC_ECH))
                tty_putcode1(tty, TTYC_ECH, ctx->num);
        else {
                for (i = 0; i < ctx->num; i++)
                        tty_putc(tty, ' ');
        }
}

void
tty_cmd_insertline(struct tty *tty, const struct tty_ctx *ctx)
{
        if (!tty_pane_full_width(tty, ctx) ||
            !tty_term_has(tty->term, TTYC_CSR) ||
            !tty_term_has(tty->term, TTYC_IL1)) {
                tty_redraw_region(tty, ctx);
                return;
        }

        tty_reset(tty);

        tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
        tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

        tty_emulate_repeat(tty, TTYC_IL, TTYC_IL1, ctx->num);
}

void
tty_cmd_deleteline(struct tty *tty, const struct tty_ctx *ctx)
{
        if (!tty_pane_full_width(tty, ctx) ||
            !tty_term_has(tty->term, TTYC_CSR) ||
            !tty_term_has(tty->term, TTYC_DL1)) {
                tty_redraw_region(tty, ctx);
                return;
        }

        tty_reset(tty);

        tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
        tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

        tty_emulate_repeat(tty, TTYC_DL, TTYC_DL1, ctx->num);
}

void
tty_cmd_clearline(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;
        struct screen           *s = wp->screen;

        tty_reset(tty);

        tty_cursor_pane(tty, ctx, 0, ctx->ocy);

        if (tty_pane_full_width(tty, ctx) && tty_term_has(tty->term, TTYC_EL))
                tty_putcode(tty, TTYC_EL);
        else
                tty_repeat_space(tty, screen_size_x(s));
}

void
tty_cmd_clearendofline(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;
        struct screen           *s = wp->screen;

        tty_reset(tty);

        tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

        if (tty_pane_full_width(tty, ctx) && tty_term_has(tty->term, TTYC_EL))
                tty_putcode(tty, TTYC_EL);
        else
                tty_repeat_space(tty, screen_size_x(s) - ctx->ocx);
}

void
tty_cmd_clearstartofline(struct tty *tty, const struct tty_ctx *ctx)
{
        tty_reset(tty);

        if (ctx->xoff == 0 && tty_term_has(tty->term, TTYC_EL1)) {
                tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);
                tty_putcode(tty, TTYC_EL1);
        } else {
                tty_cursor_pane(tty, ctx, 0, ctx->ocy);
                tty_repeat_space(tty, ctx->ocx + 1);
        }
}

void
tty_cmd_reverseindex(struct tty *tty, const struct tty_ctx *ctx)
{
        if (ctx->ocy != ctx->orupper)
                return;

        if (!tty_pane_full_width(tty, ctx) ||
            !tty_term_has(tty->term, TTYC_CSR) ||
            !tty_term_has(tty->term, TTYC_RI)) {
                tty_redraw_region(tty, ctx);
                return;
        }

        tty_reset(tty);

        tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
        tty_cursor_pane(tty, ctx, ctx->ocx, ctx->orupper);

        tty_putcode(tty, TTYC_RI);
}

void
tty_cmd_linefeed(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;

        if (ctx->ocy != ctx->orlower)
                return;

        if (!tty_pane_full_width(tty, ctx) ||
            !tty_term_has(tty->term, TTYC_CSR)) {
                if (tty_large_region(tty, ctx))
                        wp->flags |= PANE_REDRAW;
                else
                        tty_redraw_region(tty, ctx);
                return;
        }

        /*
         * If this line wrapped naturally (ctx->num is nonzero), don't do
         * anything - the cursor can just be moved to the last cell and wrap
         * naturally.
         */
        if (ctx->num && !(tty->term->flags & TERM_EARLYWRAP))
                return;

        tty_reset(tty);

        tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
        tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

        tty_putc(tty, '\n');
}

void
tty_cmd_clearendofscreen(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;
        struct screen           *s = wp->screen;
        u_int                    i, j;

        tty_reset(tty);

        tty_region_pane(tty, ctx, 0, screen_size_y(s) - 1);
        tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

        if (tty_pane_full_width(tty, ctx) && tty_term_has(tty->term, TTYC_EL)) {
                tty_putcode(tty, TTYC_EL);
                if (ctx->ocy != screen_size_y(s) - 1) {
                        tty_cursor_pane(tty, ctx, 0, ctx->ocy + 1);
                        for (i = ctx->ocy + 1; i < screen_size_y(s); i++) {
                                tty_putcode(tty, TTYC_EL);
                                if (i == screen_size_y(s) - 1)
                                        continue;
                                tty_emulate_repeat(tty, TTYC_CUD, TTYC_CUD1, 1);
                                tty->cy++;
                        }
                }
        } else {
                tty_repeat_space(tty, screen_size_x(s) - ctx->ocx);
                for (j = ctx->ocy + 1; j < screen_size_y(s); j++) {
                        tty_cursor_pane(tty, ctx, 0, j);
                        tty_repeat_space(tty, screen_size_x(s));
                }
        }
}

void
tty_cmd_clearstartofscreen(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;
        struct screen           *s = wp->screen;
        u_int                    i, j;

        tty_reset(tty);

        tty_region_pane(tty, ctx, 0, screen_size_y(s) - 1);
        tty_cursor_pane(tty, ctx, 0, 0);

        if (tty_pane_full_width(tty, ctx) && tty_term_has(tty->term, TTYC_EL)) {
                for (i = 0; i < ctx->ocy; i++) {
                        tty_putcode(tty, TTYC_EL);
                        tty_emulate_repeat(tty, TTYC_CUD, TTYC_CUD1, 1);
                        tty->cy++;
                }
        } else {
                for (j = 0; j < ctx->ocy; j++) {
                        tty_cursor_pane(tty, ctx, 0, j);
                        tty_repeat_space(tty, screen_size_x(s));
                }
        }
        tty_repeat_space(tty, ctx->ocx + 1);
}

void
tty_cmd_clearscreen(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;
        struct screen           *s = wp->screen;
        u_int                    i, j;

        tty_reset(tty);

        tty_region_pane(tty, ctx, 0, screen_size_y(s) - 1);
        tty_cursor_pane(tty, ctx, 0, 0);

        if (tty_pane_full_width(tty, ctx) && tty_term_has(tty->term, TTYC_EL)) {
                for (i = 0; i < screen_size_y(s); i++) {
                        tty_putcode(tty, TTYC_EL);
                        if (i != screen_size_y(s) - 1) {
                                tty_emulate_repeat(tty, TTYC_CUD, TTYC_CUD1, 1);
                                tty->cy++;
                        }
                }
        } else {
                for (j = 0; j < screen_size_y(s); j++) {
                        tty_cursor_pane(tty, ctx, 0, j);
                        tty_repeat_space(tty, screen_size_x(s));
                }
        }
}

void
tty_cmd_alignmenttest(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;
        struct screen           *s = wp->screen;
        u_int                    i, j;

        tty_reset(tty);

        tty_region_pane(tty, ctx, 0, screen_size_y(s) - 1);

        for (j = 0; j < screen_size_y(s); j++) {
                tty_cursor_pane(tty, ctx, 0, j);
                for (i = 0; i < screen_size_x(s); i++)
                        tty_putc(tty, 'E');
        }
}

void
tty_cmd_cell(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;
        struct screen           *s = wp->screen;
        u_int                    cx;
        u_int                    width;

        tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);

        /* Is the cursor in the very last position? */
        width = grid_cell_width(ctx->cell);
        if (ctx->ocx > wp->sx - width) {
                if (ctx->xoff != 0 || wp->sx != tty->sx) {
                        /*
                         * The pane doesn't fill the entire line, the linefeed
                         * will already have happened, so just move the cursor.
                         */
                        if (ctx->ocy != wp->yoff + wp->screen->rlower)
                                tty_cursor_pane(tty, ctx, 0, ctx->ocy + 1);
                        else
                                tty_cursor_pane(tty, ctx, 0, ctx->ocy);
                } else if (tty->cx < tty->sx) {
                        /*
                         * The cursor isn't in the last position already, so
                         * move as far left as possible and redraw the last
                         * cell to move into the last position.
                         */
                        cx = screen_size_x(s) - grid_cell_width(&ctx->last_cell);
                        tty_cursor_pane(tty, ctx, cx, ctx->ocy);
                        tty_cell(tty, &ctx->last_cell);
                }
        } else
                tty_cursor_pane(tty, ctx, ctx->ocx, ctx->ocy);

        tty_cell(tty, ctx->cell);
}

void
tty_cmd_utf8character(struct tty *tty, const struct tty_ctx *ctx)
{
        struct window_pane      *wp = ctx->wp;

        /*
         * Cannot rely on not being a partial character, so just redraw the
         * whole line.
         */
        tty_draw_line(tty, wp->screen, ctx->ocy, ctx->xoff, ctx->yoff);
}

void
tty_cmd_setselection(struct tty *tty, const struct tty_ctx *ctx)
{
        char    *buf;
        size_t   off;

        if (!tty_term_has(tty->term, TTYC_MS))
                return;

        off = 4 * ((ctx->num + 2) / 3) + 1; /* storage for base64 */
        buf = xmalloc(off);

        b64_ntop(ctx->ptr, ctx->num, buf, off);
        tty_putcode_ptr2(tty, TTYC_MS, "", buf);

        free(buf);
}

void
tty_cmd_rawstring(struct tty *tty, const struct tty_ctx *ctx)
{
        u_int    i;
        u_char  *str = ctx->ptr;

        for (i = 0; i < ctx->num; i++)
                tty_putc(tty, str[i]);

        tty->cx = tty->cy = UINT_MAX;
        tty->rupper = tty->rlower = UINT_MAX;

        tty_reset(tty);
        tty_cursor(tty, 0, 0);
}

void
tty_cell(struct tty *tty, const struct grid_cell *gc)
{
        struct utf8_data        ud;
        u_int                   i;

        /* Skip last character if terminal is stupid. */
        if (tty->term->flags & TERM_EARLYWRAP &&
            tty->cy == tty->sy - 1 && tty->cx == tty->sx - 1)
                return;

        /* If this is a padding character, do nothing. */
        if (gc->flags & GRID_FLAG_PADDING)
                return;

        /* Set the attributes. */
        tty_attributes(tty, gc);

        /* Get the cell and if ASCII write with putc to do ACS translation. */
        grid_cell_get(gc, &ud);
        if (ud.size == 1) {
                if (*ud.data < 0x20 || *ud.data == 0x7f)
                        return;
                tty_putc(tty, *ud.data);
                return;
        }

        /* If not UTF-8, write _. */
        if (!(tty->flags & TTY_UTF8)) {
                for (i = 0; i < ud.width; i++)
                        tty_putc(tty, '_');
                return;
        }

        /* Write the data. */
        tty_putn(tty, ud.data, ud.size, ud.width);
}

void
tty_reset(struct tty *tty)
{
        struct grid_cell        *gc = &tty->cell;

        if (memcmp(gc, &grid_default_cell, sizeof *gc) == 0)
                return;

        if ((gc->attr & GRID_ATTR_CHARSET) && tty_use_acs(tty))
                tty_putcode(tty, TTYC_RMACS);
        tty_putcode(tty, TTYC_SGR0);
        memcpy(gc, &grid_default_cell, sizeof *gc);
}

/* Set region inside pane. */
void
tty_region_pane(
    struct tty *tty, const struct tty_ctx *ctx, u_int rupper, u_int rlower)
{
        tty_region(tty, ctx->yoff + rupper, ctx->yoff + rlower);
}

/* Set region at absolute position. */
void
tty_region(struct tty *tty, u_int rupper, u_int rlower)
{
        if (tty->rlower == rlower && tty->rupper == rupper)
                return;
        if (!tty_term_has(tty->term, TTYC_CSR))
                return;

        tty->rupper = rupper;
        tty->rlower = rlower;

        /*
         * Some terminals (such as PuTTY) do not correctly reset the cursor to
         * 0,0 if it is beyond the last column (they do not reset their wrap
         * flag so further output causes a line feed). As a workaround, do an
         * explicit move to 0 first.
         */
        if (tty->cx >= tty->sx)
                tty_cursor(tty, 0, tty->cy);

        tty_putcode2(tty, TTYC_CSR, tty->rupper, tty->rlower);
        tty_cursor(tty, 0, 0);
}

/* Move cursor inside pane. */
void
tty_cursor_pane(struct tty *tty, const struct tty_ctx *ctx, u_int cx, u_int cy)
{
        tty_cursor(tty, ctx->xoff + cx, ctx->yoff + cy);
}

/* Move cursor to absolute position. */
void
tty_cursor(struct tty *tty, u_int cx, u_int cy)
{
        struct tty_term *term = tty->term;
        u_int            thisx, thisy;
        int              change;

        if (cx > tty->sx - 1)
                cx = tty->sx - 1;

        thisx = tty->cx;
        thisy = tty->cy;

        /* No change. */
        if (cx == thisx && cy == thisy)
                return;

        /* Very end of the line, just use absolute movement. */
        if (thisx > tty->sx - 1)
                goto absolute;

        /* Move to home position (0, 0). */
        if (cx == 0 && cy == 0 && tty_term_has(term, TTYC_HOME)) {
                tty_putcode(tty, TTYC_HOME);
                goto out;
        }

        /* Zero on the next line. */
        if (cx == 0 && cy == thisy + 1 && thisy != tty->rlower) {
                tty_putc(tty, '\r');
                tty_putc(tty, '\n');
                goto out;
        }

        /* Moving column or row. */
        if (cy == thisy) {
                /*
                 * Moving column only, row staying the same.
                 */

                /* To left edge. */
                if (cx == 0)    {
                        tty_putc(tty, '\r');
                        goto out;
                }

                /* One to the left. */
                if (cx == thisx - 1 && tty_term_has(term, TTYC_CUB1)) {
                        tty_putcode(tty, TTYC_CUB1);
                        goto out;
                }

                /* One to the right. */
                if (cx == thisx + 1 && tty_term_has(term, TTYC_CUF1)) {
                        tty_putcode(tty, TTYC_CUF1);
                        goto out;
                }

                /* Calculate difference. */
                change = thisx - cx;    /* +ve left, -ve right */

                /*
                 * Use HPA if change is larger than absolute, otherwise move
                 * the cursor with CUB/CUF.
                 */
                if ((u_int) abs(change) > cx && tty_term_has(term, TTYC_HPA)) {
                        tty_putcode1(tty, TTYC_HPA, cx);
                        goto out;
                } else if (change > 0 && tty_term_has(term, TTYC_CUB)) {
                        tty_putcode1(tty, TTYC_CUB, change);
                        goto out;
                } else if (change < 0 && tty_term_has(term, TTYC_CUF)) {
                        tty_putcode1(tty, TTYC_CUF, -change);
                        goto out;
                }
        } else if (cx == thisx) {
                /*
                 * Moving row only, column staying the same.
                 */

                /* One above. */
                if (thisy != tty->rupper &&
                    cy == thisy - 1 && tty_term_has(term, TTYC_CUU1)) {
                        tty_putcode(tty, TTYC_CUU1);
                        goto out;
                }

                /* One below. */
                if (thisy != tty->rlower &&
                    cy == thisy + 1 && tty_term_has(term, TTYC_CUD1)) {
                        tty_putcode(tty, TTYC_CUD1);
                        goto out;
                }

                /* Calculate difference. */
                change = thisy - cy;    /* +ve up, -ve down */

                /*
                 * Try to use VPA if change is larger than absolute or if this
                 * change would cross the scroll region, otherwise use CUU/CUD.
                 */
                if ((u_int) abs(change) > cy ||
                    (change < 0 && cy - change > tty->rlower) ||
                    (change > 0 && cy - change < tty->rupper)) {
                            if (tty_term_has(term, TTYC_VPA)) {
                                    tty_putcode1(tty, TTYC_VPA, cy);
                                    goto out;
                            }
                } else if (change > 0 && tty_term_has(term, TTYC_CUU)) {
                        tty_putcode1(tty, TTYC_CUU, change);
                        goto out;
                } else if (change < 0 && tty_term_has(term, TTYC_CUD)) {
                        tty_putcode1(tty, TTYC_CUD, -change);
                        goto out;
                }
        }

absolute:
        /* Absolute movement. */
        tty_putcode2(tty, TTYC_CUP, cy, cx);

out:
        tty->cx = cx;
        tty->cy = cy;
}

void
tty_attributes(struct tty *tty, const struct grid_cell *gc)
{
        struct grid_cell        *tc = &tty->cell, gc2;
        u_char                   changed;

        memcpy(&gc2, gc, sizeof gc2);

        /*
         * If no setab, try to use the reverse attribute as a best-effort for a
         * non-default background. This is a bit of a hack but it doesn't do
         * any serious harm and makes a couple of applications happier.
         */
        if (!tty_term_has(tty->term, TTYC_SETAB)) {
                if (gc2.attr & GRID_ATTR_REVERSE) {
                        if (gc2.fg != 7 && gc2.fg != 8)
                                gc2.attr &= ~GRID_ATTR_REVERSE;
                } else {
                        if (gc2.bg != 0 && gc2.bg != 8)
                                gc2.attr |= GRID_ATTR_REVERSE;
                }
        }

        /* Fix up the colours if necessary. */
        tty_check_fg(tty, &gc2);
        tty_check_bg(tty, &gc2);

        /* If any bits are being cleared, reset everything. */
        if (tc->attr & ~gc2.attr)
                tty_reset(tty);

        /*
         * Set the colours. This may call tty_reset() (so it comes next) and
         * may add to (NOT remove) the desired attributes by changing new_attr.
         */
        tty_colours(tty, &gc2);

        /* Filter out attribute bits already set. */
        changed = gc2.attr & ~tc->attr;
        tc->attr = gc2.attr;

        /* Set the attributes. */
        if (changed & GRID_ATTR_BRIGHT)
                tty_putcode(tty, TTYC_BOLD);
        if (changed & GRID_ATTR_DIM)
                tty_putcode(tty, TTYC_DIM);
        if (changed & GRID_ATTR_ITALICS) {
                if (tty_term_has(tty->term, TTYC_SITM))
                        tty_putcode(tty, TTYC_SITM);
                else
                        tty_putcode(tty, TTYC_SMSO);
        }
        if (changed & GRID_ATTR_UNDERSCORE)
                tty_putcode(tty, TTYC_SMUL);
        if (changed & GRID_ATTR_BLINK)
                tty_putcode(tty, TTYC_BLINK);
        if (changed & GRID_ATTR_REVERSE) {
                if (tty_term_has(tty->term, TTYC_REV))
                        tty_putcode(tty, TTYC_REV);
                else if (tty_term_has(tty->term, TTYC_SMSO))
                        tty_putcode(tty, TTYC_SMSO);
        }
        if (changed & GRID_ATTR_HIDDEN)
                tty_putcode(tty, TTYC_INVIS);
        if ((changed & GRID_ATTR_CHARSET) && tty_use_acs(tty))
                tty_putcode(tty, TTYC_SMACS);
}

void
tty_colours(struct tty *tty, const struct grid_cell *gc)
{
        struct grid_cell        *tc = &tty->cell;
        u_char                   fg = gc->fg, bg = gc->bg, flags = gc->flags;
        int                      have_ax, fg_default, bg_default;

        /* No changes? Nothing is necessary. */
        if (fg == tc->fg && bg == tc->bg &&
            ((flags ^ tc->flags) & (GRID_FLAG_FG256|GRID_FLAG_BG256)) == 0)
                return;

        /*
         * Is either the default colour? This is handled specially because the
         * best solution might be to reset both colours to default, in which
         * case if only one is default need to fall onward to set the other
         * colour.
         */
        fg_default = (fg == 8 && !(flags & GRID_FLAG_FG256));
        bg_default = (bg == 8 && !(flags & GRID_FLAG_BG256));
        if (fg_default || bg_default) {
                /*
                 * If don't have AX but do have op, send sgr0 (op can't
                 * actually be used because it is sometimes the same as sgr0
                 * and sometimes isn't). This resets both colours to default.
                 *
                 * Otherwise, try to set the default colour only as needed.
                 */
                have_ax = tty_term_has(tty->term, TTYC_AX);
                if (!have_ax && tty_term_has(tty->term, TTYC_OP))
                        tty_reset(tty);
                else {
                        if (fg_default &&
                            (tc->fg != 8 || tc->flags & GRID_FLAG_FG256)) {
                                if (have_ax)
                                        tty_puts(tty, "\033[39m");
                                else if (tc->fg != 7 ||
                                    tc->flags & GRID_FLAG_FG256)
                                        tty_putcode1(tty, TTYC_SETAF, 7);
                                tc->fg = 8;
                                tc->flags &= ~GRID_FLAG_FG256;
                        }
                        if (bg_default &&
                            (tc->bg != 8 || tc->flags & GRID_FLAG_BG256)) {
                                if (have_ax)
                                        tty_puts(tty, "\033[49m");
                                else if (tc->bg != 0 ||
                                    tc->flags & GRID_FLAG_BG256)
                                        tty_putcode1(tty, TTYC_SETAB, 0);
                                tc->bg = 8;
                                tc->flags &= ~GRID_FLAG_BG256;
                        }
                }
        }

        /* Set the foreground colour. */
        if (!fg_default && (fg != tc->fg ||
            ((flags & GRID_FLAG_FG256) != (tc->flags & GRID_FLAG_FG256))))
                tty_colours_fg(tty, gc);

        /*
         * Set the background colour. This must come after the foreground as
         * tty_colour_fg() can call tty_reset().
         */
        if (!bg_default && (bg != tc->bg ||
            ((flags & GRID_FLAG_BG256) != (tc->flags & GRID_FLAG_BG256))))
                tty_colours_bg(tty, gc);
}

void
tty_check_fg(struct tty *tty, struct grid_cell *gc)
{
        u_int   colours;

        /* Is this a 256-colour colour? */
        if (gc->flags & GRID_FLAG_FG256) {
                /* And not a 256 colour mode? */
                if (!(tty->term->flags & TERM_256COLOURS) &&
                    !(tty->term_flags & TERM_256COLOURS)) {
                        gc->fg = colour_256to16(gc->fg);
                        if (gc->fg & 8) {
                                gc->fg &= 7;
                                gc->attr |= GRID_ATTR_BRIGHT;
                        } else
                                gc->attr &= ~GRID_ATTR_BRIGHT;
                        gc->flags &= ~GRID_FLAG_FG256;
                }
                return;
        }

        /* Is this an aixterm colour? */
        colours = tty_term_number(tty->term, TTYC_COLORS);
        if (gc->fg >= 90 && gc->fg <= 97 && colours < 16) {
                gc->fg -= 90;
                gc->attr |= GRID_ATTR_BRIGHT;
        }
}

void
tty_check_bg(struct tty *tty, struct grid_cell *gc)
{
        u_int   colours;

        /* Is this a 256-colour colour? */
        if (gc->flags & GRID_FLAG_BG256) {
                /*
                 * And not a 256 colour mode? Translate to 16-colour
                 * palette. Bold background doesn't exist portably, so just
                 * discard the bold bit if set.
                 */
                if (!(tty->term->flags & TERM_256COLOURS) &&
                    !(tty->term_flags & TERM_256COLOURS)) {
                        gc->bg = colour_256to16(gc->bg);
                        if (gc->bg & 8)
                                gc->bg &= 7;
                        gc->attr &= ~GRID_ATTR_BRIGHT;
                        gc->flags &= ~GRID_FLAG_BG256;
                }
                return;
        }

        /* Is this an aixterm colour? */
        colours = tty_term_number(tty->term, TTYC_COLORS);
        if (gc->bg >= 90 && gc->bg <= 97 && colours < 16) {
                gc->bg -= 90;
                gc->attr |= GRID_ATTR_BRIGHT;
        }
}

void
tty_colours_fg(struct tty *tty, const struct grid_cell *gc)
{
        struct grid_cell        *tc = &tty->cell;
        u_char                   fg = gc->fg;
        char                     s[32];

        /* Is this a 256-colour colour? */
        if (gc->flags & GRID_FLAG_FG256) {
                /* Try as 256 colours. */
                if (tty_try_256(tty, fg, "38") == 0)
                        goto save_fg;
                /* Else already handled by tty_check_fg. */
                return;
        }

        /* Is this an aixterm bright colour? */
        if (fg >= 90 && fg <= 97) {
                xsnprintf(s, sizeof s, "\033[%dm", fg);
                tty_puts(tty, s);
                goto save_fg;
        }

        /* Otherwise set the foreground colour. */
        tty_putcode1(tty, TTYC_SETAF, fg);

save_fg:
        /* Save the new values in the terminal current cell. */
        tc->fg = fg;
        tc->flags &= ~GRID_FLAG_FG256;
        tc->flags |= gc->flags & GRID_FLAG_FG256;
}

void
tty_colours_bg(struct tty *tty, const struct grid_cell *gc)
{
        struct grid_cell        *tc = &tty->cell;
        u_char                   bg = gc->bg;
        char                     s[32];

        /* Is this a 256-colour colour? */
        if (gc->flags & GRID_FLAG_BG256) {
                /* Try as 256 colours. */
                if (tty_try_256(tty, bg, "48") == 0)
                        goto save_bg;
                /* Else already handled by tty_check_bg. */
                return;
        }

        /* Is this an aixterm bright colour? */
        if (bg >= 90 && bg <= 97) {
                /* 16 colour terminals or above only. */
                if (tty_term_number(tty->term, TTYC_COLORS) >= 16) {
                        xsnprintf(s, sizeof s, "\033[%dm", bg + 10);
                        tty_puts(tty, s);
                        goto save_bg;
                }
                bg -= 90;
                /* no such thing as a bold background */
        }

        /* Otherwise set the background colour. */
        tty_putcode1(tty, TTYC_SETAB, bg);

save_bg:
        /* Save the new values in the terminal current cell. */
        tc->bg = bg;
        tc->flags &= ~GRID_FLAG_BG256;
        tc->flags |= gc->flags & GRID_FLAG_BG256;
}

int
tty_try_256(struct tty *tty, u_char colour, const char *type)
{
        char    s[32];

        /*
         * If the terminfo entry has 256 colours, assume that setaf and setab
         * work correctly.
         */
        if (tty->term->flags & TERM_256COLOURS) {
                if (*type == '3')
                        tty_putcode1(tty, TTYC_SETAF, colour);
                else
                        tty_putcode1(tty, TTYC_SETAB, colour);
                return (0);
        }

        /*
         * If the user has specified -2 to the client, setaf and setab may not
         * work, so send the usual sequence.
         */
        if (tty->term_flags & TERM_256COLOURS) {
                xsnprintf(s, sizeof s, "\033[%s;5;%hhum", type, colour);
                tty_puts(tty, s);
                return (0);
        }

        return (-1);
}

void
tty_bell(struct tty *tty)
{
        tty_putcode(tty, TTYC_BEL);
}