Fix leak in format_get_command.

[tmux-openbsd.git] / status.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/time.h>

#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "tmux.h"

char   *status_redraw_get_left(
            struct client *, time_t, int, struct grid_cell *, size_t *);
char   *status_redraw_get_right(
            struct client *, time_t, int, struct grid_cell *, size_t *);
char   *status_find_job(struct client *, char **);
void    status_job_free(void *);
void    status_job_callback(struct job *);
char   *status_print(
            struct client *, struct winlink *, time_t, struct grid_cell *);
void    status_replace1(struct client *, char **, char **, char *, size_t, int);
void    status_message_callback(int, short, void *);

const char *status_prompt_up_history(u_int *);
const char *status_prompt_down_history(u_int *);
void    status_prompt_add_history(const char *);
char   *status_prompt_complete(const char *);

/* Status prompt history. */
ARRAY_DECL(, char *) status_prompt_history = ARRAY_INITIALIZER;

/* Status output tree. */
RB_GENERATE(status_out_tree, status_out, entry, status_out_cmp);

/* Output tree comparison function. */
int
status_out_cmp(struct status_out *so1, struct status_out *so2)
{
        return (strcmp(so1->cmd, so2->cmd));
}

/* Get screen line of status line. -1 means off. */
int
status_at_line(struct client *c)
{
        struct session  *s = c->session;

        if (!options_get_number(&s->options, "status"))
                return (-1);

        if (options_get_number(&s->options, "status-position") == 0)
                return (0);
        return (c->tty.sy - 1);
}

/* Retrieve options for left string. */
char *
status_redraw_get_left(struct client *c,
    time_t t, int utf8flag, struct grid_cell *gc, size_t *size)
{
        struct session  *s = c->session;
        char            *left;
        int              fg, bg, attr;
        size_t           leftlen;

        fg = options_get_number(&s->options, "status-left-fg");
        if (fg != 8)
                colour_set_fg(gc, fg);
        bg = options_get_number(&s->options, "status-left-bg");
        if (bg != 8)
                colour_set_bg(gc, bg);
        attr = options_get_number(&s->options, "status-left-attr");
        if (attr != 0)
                gc->attr = attr;

        left = status_replace(c, NULL,
            NULL, NULL, options_get_string(&s->options, "status-left"), t, 1);

        *size = options_get_number(&s->options, "status-left-length");
        leftlen = screen_write_cstrlen(utf8flag, "%s", left);
        if (leftlen < *size)
                *size = leftlen;
        return (left);
}

/* Retrieve options for right string. */
char *
status_redraw_get_right(struct client *c,
    time_t t, int utf8flag, struct grid_cell *gc, size_t *size)
{
        struct session  *s = c->session;
        char            *right;
        int              fg, bg, attr;
        size_t           rightlen;

        fg = options_get_number(&s->options, "status-right-fg");
        if (fg != 8)
                colour_set_fg(gc, fg);
        bg = options_get_number(&s->options, "status-right-bg");
        if (bg != 8)
                colour_set_bg(gc, bg);
        attr = options_get_number(&s->options, "status-right-attr");
        if (attr != 0)
                gc->attr = attr;

        right = status_replace(c, NULL,
            NULL, NULL, options_get_string(&s->options, "status-right"), t, 1);

        *size = options_get_number(&s->options, "status-right-length");
        rightlen = screen_write_cstrlen(utf8flag, "%s", right);
        if (rightlen < *size)
                *size = rightlen;
        return (right);
}

/* Set window at window list position. */
void
status_set_window_at(struct client *c, u_int x)
{
        struct session  *s = c->session;
        struct winlink  *wl;

        x += c->wlmouse;
        RB_FOREACH(wl, winlinks, &s->windows) {
                if (x < wl->status_width && session_select(s, wl->idx) == 0)
                        server_redraw_session(s);
                x -= wl->status_width + 1;
        }
}

/* Draw status for client on the last lines of given context. */
int
status_redraw(struct client *c)
{
        struct screen_write_ctx ctx;
        struct session         *s = c->session;
        struct winlink         *wl;
        struct screen           old_status, window_list;
        struct grid_cell        stdgc, lgc, rgc, gc;
        struct options         *oo;
        time_t                  t;
        char                   *left, *right, *sep;
        u_int                   offset, needed;
        u_int                   wlstart, wlwidth, wlavailable, wloffset, wlsize;
        size_t                  llen, rlen, seplen;
        int                     larrow, rarrow, utf8flag;

        /* No status line? */
        if (c->tty.sy == 0 || !options_get_number(&s->options, "status"))
                return (1);
        left = right = NULL;
        larrow = rarrow = 0;

        /* Update status timer. */
        if (gettimeofday(&c->status_timer, NULL) != 0)
                fatal("gettimeofday failed");
        t = c->status_timer.tv_sec;

        /* Set up default colour. */
        memcpy(&stdgc, &grid_default_cell, sizeof gc);
        colour_set_fg(&stdgc, options_get_number(&s->options, "status-fg"));
        colour_set_bg(&stdgc, options_get_number(&s->options, "status-bg"));
        stdgc.attr |= options_get_number(&s->options, "status-attr");

        /* Create the target screen. */
        memcpy(&old_status, &c->status, sizeof old_status);
        screen_init(&c->status, c->tty.sx, 1, 0);
        screen_write_start(&ctx, NULL, &c->status);
        for (offset = 0; offset < c->tty.sx; offset++)
                screen_write_putc(&ctx, &stdgc, ' ');
        screen_write_stop(&ctx);

        /* If the height is one line, blank status line. */
        if (c->tty.sy <= 1)
                goto out;

        /* Get UTF-8 flag. */
        utf8flag = options_get_number(&s->options, "status-utf8");

        /* Work out left and right strings. */
        memcpy(&lgc, &stdgc, sizeof lgc);
        left = status_redraw_get_left(c, t, utf8flag, &lgc, &llen);
        memcpy(&rgc, &stdgc, sizeof rgc);
        right = status_redraw_get_right(c, t, utf8flag, &rgc, &rlen);

        /*
         * Figure out how much space we have for the window list. If there
         * isn't enough space, just show a blank status line.
         */
        needed = 0;
        if (llen != 0)
                needed += llen + 1;
        if (rlen != 0)
                needed += rlen + 1;
        if (c->tty.sx == 0 || c->tty.sx <= needed)
                goto out;
        wlavailable = c->tty.sx - needed;

        /* Calculate the total size needed for the window list. */
        wlstart = wloffset = wlwidth = 0;
        RB_FOREACH(wl, winlinks, &s->windows) {
                free(wl->status_text);
                memcpy(&wl->status_cell, &stdgc, sizeof wl->status_cell);
                wl->status_text = status_print(c, wl, t, &wl->status_cell);
                wl->status_width =
                    screen_write_cstrlen(utf8flag, "%s", wl->status_text);

                if (wl == s->curw)
                        wloffset = wlwidth;

                oo = &wl->window->options;
                sep = options_get_string(oo, "window-status-separator");
                seplen = screen_write_strlen(utf8flag, "%s", sep);
                wlwidth += wl->status_width + seplen;
        }

        /* Create a new screen for the window list. */
        screen_init(&window_list, wlwidth, 1, 0);

        /* And draw the window list into it. */
        screen_write_start(&ctx, NULL, &window_list);
        RB_FOREACH(wl, winlinks, &s->windows) {
                screen_write_cnputs(&ctx,
                    -1, &wl->status_cell, utf8flag, "%s", wl->status_text);

                oo = &wl->window->options;
                sep = options_get_string(oo, "window-status-separator");
                screen_write_nputs(&ctx, -1, &stdgc, utf8flag, "%s", sep);
        }
        screen_write_stop(&ctx);

        /* If there is enough space for the total width, skip to draw now. */
        if (wlwidth <= wlavailable)
                goto draw;

        /* Find size of current window text. */
        wlsize = s->curw->status_width;

        /*
         * If the current window is already on screen, good to draw from the
         * start and just leave off the end.
         */
        if (wloffset + wlsize < wlavailable) {
                if (wlavailable > 0) {
                        rarrow = 1;
                        wlavailable--;
                }
                wlwidth = wlavailable;
        } else {
                /*
                 * Work out how many characters we need to omit from the
                 * start. There are wlavailable characters to fill, and
                 * wloffset + wlsize must be the last. So, the start character
                 * is wloffset + wlsize - wlavailable.
                 */
                if (wlavailable > 0) {
                        larrow = 1;
                        wlavailable--;
                }

                wlstart = wloffset + wlsize - wlavailable;
                if (wlavailable > 0 && wlwidth > wlstart + wlavailable + 1) {
                        rarrow = 1;
                        wlstart++;
                        wlavailable--;
                }
                wlwidth = wlavailable;
        }

        /* Bail if anything is now too small too. */
        if (wlwidth == 0 || wlavailable == 0) {
                screen_free(&window_list);
                goto out;
        }

        /*
         * Now the start position is known, work out the state of the left and
         * right arrows.
         */
        offset = 0;
        RB_FOREACH(wl, winlinks, &s->windows) {
                if (wl->flags & WINLINK_ALERTFLAGS &&
                    larrow == 1 && offset < wlstart)
                        larrow = -1;

                offset += wl->status_width;

                if (wl->flags & WINLINK_ALERTFLAGS &&
                    rarrow == 1 && offset > wlstart + wlwidth)
                        rarrow = -1;
        }

draw:
        /* Begin drawing. */
        screen_write_start(&ctx, NULL, &c->status);

        /* Draw the left string and arrow. */
        screen_write_cursormove(&ctx, 0, 0);
        if (llen != 0) {
                screen_write_cnputs(&ctx, llen, &lgc, utf8flag, "%s", left);
                screen_write_putc(&ctx, &stdgc, ' ');
        }
        if (larrow != 0) {
                memcpy(&gc, &stdgc, sizeof gc);
                if (larrow == -1)
                        gc.attr ^= GRID_ATTR_REVERSE;
                screen_write_putc(&ctx, &gc, '<');
        }

        /* Draw the right string and arrow. */
        if (rarrow != 0) {
                screen_write_cursormove(&ctx, c->tty.sx - rlen - 2, 0);
                memcpy(&gc, &stdgc, sizeof gc);
                if (rarrow == -1)
                        gc.attr ^= GRID_ATTR_REVERSE;
                screen_write_putc(&ctx, &gc, '>');
        } else
                screen_write_cursormove(&ctx, c->tty.sx - rlen - 1, 0);
        if (rlen != 0) {
                screen_write_putc(&ctx, &stdgc, ' ');
                screen_write_cnputs(&ctx, rlen, &rgc, utf8flag, "%s", right);
        }

        /* Figure out the offset for the window list. */
        if (llen != 0)
                wloffset = llen + 1;
        else
                wloffset = 0;
        if (wlwidth < wlavailable) {
                switch (options_get_number(&s->options, "status-justify")) {
                case 1: /* centered */
                        wloffset += (wlavailable - wlwidth) / 2;
                        break;
                case 2: /* right */
                        wloffset += (wlavailable - wlwidth);
                        break;
                }
        }
        if (larrow != 0)
                wloffset++;

        /* Copy the window list. */
        c->wlmouse = -wloffset + wlstart;
        screen_write_cursormove(&ctx, wloffset, 0);
        screen_write_copy(&ctx, &window_list, wlstart, 0, wlwidth, 1);
        screen_free(&window_list);

        screen_write_stop(&ctx);

out:
        free(left);
        free(right);

        if (grid_compare(c->status.grid, old_status.grid) == 0) {
                screen_free(&old_status);
                return (0);
        }
        screen_free(&old_status);
        return (1);
}

/* Replace a single special sequence (prefixed by #). */
void
status_replace1(struct client *c, char **iptr, char **optr, char *out,
    size_t outsize, int jobsflag)
{
        char    ch, tmp[256], *ptr, *endptr;
        size_t  ptrlen;
        long    limit;

        errno = 0;
        limit = strtol(*iptr, &endptr, 10);
        if ((limit == 0 && errno != EINVAL) ||
            (limit == LONG_MIN && errno != ERANGE) ||
            (limit == LONG_MAX && errno != ERANGE) ||
            limit != 0)
                *iptr = endptr;
        if (limit <= 0)
                limit = LONG_MAX;

        switch (*(*iptr)++) {
        case '(':
                if (!jobsflag) {
                        ch = ')';
                        goto skip_to;
                }
                if ((ptr = status_find_job(c, iptr)) == NULL)
                        return;
                goto do_replace;
        case '[':
                /*
                 * Embedded style, handled at display time. Leave present and
                 * skip input until ].
                 */
                ch = ']';
                goto skip_to;
        case '{':
                ptr = (char *) "#{";
                goto do_replace;
        case '#':
                *(*optr)++ = '#';
                break;
        default:
                xsnprintf(tmp, sizeof tmp, "#%c", *(*iptr - 1));
                ptr = tmp;
                goto do_replace;
        }

        return;

do_replace:
        ptrlen = strlen(ptr);
        if ((size_t) limit < ptrlen)
                ptrlen = limit;

        if (*optr + ptrlen >= out + outsize - 1)
                return;
        while (ptrlen > 0 && *ptr != '\0') {
                *(*optr)++ = *ptr++;
                ptrlen--;
        }

        return;

skip_to:
        *(*optr)++ = '#';

        (*iptr)--;      /* include ch */
        while (**iptr != ch && **iptr != '\0') {
                if (*optr >=  out + outsize - 1)
                        break;
                *(*optr)++ = *(*iptr)++;
        }
}

/* Replace special sequences in fmt. */
char *
status_replace(struct client *c, struct session *s, struct winlink *wl,
    struct window_pane *wp, const char *fmt, time_t t, int jobsflag)
{
        static char              out[BUFSIZ];
        char                     in[BUFSIZ], ch, *iptr, *optr, *expanded;
        size_t                   len;
        struct format_tree      *ft;

        if (fmt == NULL)
                return (xstrdup(""));

        if (s == NULL)
                s = c->session;
        if (wl == NULL)
                wl = s->curw;
        if (wp == NULL)
                wp = wl->window->active;

        len = strftime(in, sizeof in, fmt, localtime(&t));
        in[len] = '\0';

        iptr = in;
        optr = out;

        while (*iptr != '\0') {
                if (optr >= out + (sizeof out) - 1)
                        break;
                ch = *iptr++;

                if (ch != '#' || *iptr == '\0') {
                        *optr++ = ch;
                        continue;
                }
                status_replace1(c, &iptr, &optr, out, sizeof out, jobsflag);
        }
        *optr = '\0';

        ft = format_create();
        format_client(ft, c);
        format_session(ft, s);
        format_winlink(ft, s, wl);
        format_window_pane(ft, wp);
        expanded = format_expand(ft, out);
        format_free(ft);
        return (expanded);
}

/* Figure out job name and get its result, starting it off if necessary. */
char *
status_find_job(struct client *c, char **iptr)
{
        struct status_out       *so, so_find;
        char                    *cmd;
        int                      lastesc;
        size_t                   len;

        if (**iptr == '\0')
                return (NULL);
        if (**iptr == ')') {            /* no command given */
                (*iptr)++;
                return (NULL);
        }

        cmd = xmalloc(strlen(*iptr) + 1);
        len = 0;

        lastesc = 0;
        for (; **iptr != '\0'; (*iptr)++) {
                if (!lastesc && **iptr == ')')
                        break;          /* unescaped ) is the end */
                if (!lastesc && **iptr == '\\') {
                        lastesc = 1;
                        continue;       /* skip \ if not escaped */
                }
                lastesc = 0;
                cmd[len++] = **iptr;
        }
        if (**iptr == '\0')             /* no terminating ) */ {
                free(cmd);
                return (NULL);
        }
        (*iptr)++;                      /* skip final ) */
        cmd[len] = '\0';

        /* First try in the new tree. */
        so_find.cmd = cmd;
        so = RB_FIND(status_out_tree, &c->status_new, &so_find);
        if (so != NULL && so->out != NULL) {
                free(cmd);
                return (so->out);
        }

        /* If not found at all, start the job and add to the tree. */
        if (so == NULL) {
                job_run(cmd, NULL, status_job_callback, status_job_free, c);
                c->references++;

                so = xmalloc(sizeof *so);
                so->cmd = xstrdup(cmd);
                so->out = NULL;
                RB_INSERT(status_out_tree, &c->status_new, so);
        }

        /* Lookup in the old tree. */
        so_find.cmd = cmd;
        so = RB_FIND(status_out_tree, &c->status_old, &so_find);
        free(cmd);
        if (so != NULL)
                return (so->out);
        return (NULL);
}

/* Free job tree. */
void
status_free_jobs(struct status_out_tree *sotree)
{
        struct status_out       *so, *so_next;

        so_next = RB_MIN(status_out_tree, sotree);
        while (so_next != NULL) {
                so = so_next;
                so_next = RB_NEXT(status_out_tree, sotree, so);

                RB_REMOVE(status_out_tree, sotree, so);
                free(so->out);
                free(so->cmd);
                free(so);
        }
}

/* Update jobs on status interval. */
void
status_update_jobs(struct client *c)
{
        /* Free the old tree. */
        status_free_jobs(&c->status_old);

        /* Move the new to old. */
        memcpy(&c->status_old, &c->status_new, sizeof c->status_old);
        RB_INIT(&c->status_new);
}

/* Free status job. */
void
status_job_free(void *data)
{
        struct client   *c = data;

        c->references--;
}

/* Job has finished: save its result. */
void
status_job_callback(struct job *job)
{
        struct client           *c = job->data;
        struct status_out       *so, so_find;
        char                    *line, *buf;
        size_t                   len;

        if (c->flags & CLIENT_DEAD)
                return;

        so_find.cmd = job->cmd;
        so = RB_FIND(status_out_tree, &c->status_new, &so_find);
        if (so == NULL || so->out != NULL)
                return;

        buf = NULL;
        if ((line = evbuffer_readline(job->event->input)) == NULL) {
                len = EVBUFFER_LENGTH(job->event->input);
                buf = xmalloc(len + 1);
                if (len != 0)
                        memcpy(buf, EVBUFFER_DATA(job->event->input), len);
                buf[len] = '\0';
        } else
                buf = line;

        so->out = buf;
        server_status_client(c);
}

/* Return winlink status line entry and adjust gc as necessary. */
char *
status_print(
    struct client *c, struct winlink *wl, time_t t, struct grid_cell *gc)
{
        struct options  *oo = &wl->window->options;
        struct session  *s = c->session;
        const char      *fmt;
        char            *text;
        int              fg, bg, attr;

        fg = options_get_number(oo, "window-status-fg");
        if (fg != 8)
                colour_set_fg(gc, fg);
        bg = options_get_number(oo, "window-status-bg");
        if (bg != 8)
                colour_set_bg(gc, bg);
        attr = options_get_number(oo, "window-status-attr");
        if (attr != 0)
                gc->attr = attr;
        fmt = options_get_string(oo, "window-status-format");
        if (wl == s->curw) {
                fg = options_get_number(oo, "window-status-current-fg");
                if (fg != 8)
                        colour_set_fg(gc, fg);
                bg = options_get_number(oo, "window-status-current-bg");
                if (bg != 8)
                        colour_set_bg(gc, bg);
                attr = options_get_number(oo, "window-status-current-attr");
                if (attr != 0)
                        gc->attr = attr;
                fmt = options_get_string(oo, "window-status-current-format");
        }
        if (wl == TAILQ_FIRST(&s->lastw)) {
                fg = options_get_number(oo, "window-status-last-fg");
                if (fg != 8)
                        colour_set_fg(gc, fg);
                bg = options_get_number(oo, "window-status-last-bg");
                if (bg != 8)
                        colour_set_bg(gc, bg);
                attr = options_get_number(oo, "window-status-last-attr");
                if (attr != 0)
                        gc->attr = attr;
        }

        if (wl->flags & WINLINK_BELL) {
                fg = options_get_number(oo, "window-status-bell-fg");
                if (fg != 8)
                        colour_set_fg(gc, fg);
                bg = options_get_number(oo, "window-status-bell-bg");
                if (bg != 8)
                        colour_set_bg(gc, bg);
                attr = options_get_number(oo, "window-status-bell-attr");
                if (attr != 0)
                        gc->attr = attr;
        } else if (wl->flags & WINLINK_CONTENT) {
                fg = options_get_number(oo, "window-status-content-fg");
                if (fg != 8)
                        colour_set_fg(gc, fg);
                bg = options_get_number(oo, "window-status-content-bg");
                if (bg != 8)
                        colour_set_bg(gc, bg);
                attr = options_get_number(oo, "window-status-content-attr");
                if (attr != 0)
                        gc->attr = attr;
        } else if (wl->flags & (WINLINK_ACTIVITY|WINLINK_SILENCE)) {
                fg = options_get_number(oo, "window-status-activity-fg");
                if (fg != 8)
                        colour_set_fg(gc, fg);
                bg = options_get_number(oo, "window-status-activity-bg");
                if (bg != 8)
                        colour_set_bg(gc, bg);
                attr = options_get_number(oo, "window-status-activity-attr");
                if (attr != 0)
                        gc->attr = attr;
        }

        text = status_replace(c, NULL, wl, NULL, fmt, t, 1);
        return (text);
}

/* Set a status line message. */
void printflike2
status_message_set(struct client *c, const char *fmt, ...)
{
        struct timeval           tv;
        struct session          *s = c->session;
        struct message_entry    *msg;
        va_list                  ap;
        int                      delay;
        u_int                    i, limit;

        status_prompt_clear(c);
        status_message_clear(c);

        va_start(ap, fmt);
        xvasprintf(&c->message_string, fmt, ap);
        va_end(ap);

        ARRAY_EXPAND(&c->message_log, 1);
        msg = &ARRAY_LAST(&c->message_log);
        msg->msg_time = time(NULL);
        msg->msg = xstrdup(c->message_string);

        if (s == NULL)
                limit = 0;
        else
                limit = options_get_number(&s->options, "message-limit");
        if (ARRAY_LENGTH(&c->message_log) > limit) {
                limit = ARRAY_LENGTH(&c->message_log) - limit;
                for (i = 0; i < limit; i++) {
                        msg = &ARRAY_FIRST(&c->message_log);
                        free(msg->msg);
                        ARRAY_REMOVE(&c->message_log, 0);
                }
        }

        delay = options_get_number(&c->session->options, "display-time");
        tv.tv_sec = delay / 1000;
        tv.tv_usec = (delay % 1000) * 1000L;

        if (event_initialized (&c->message_timer))
                evtimer_del(&c->message_timer);
        evtimer_set(&c->message_timer, status_message_callback, c);
        evtimer_add(&c->message_timer, &tv);

        c->tty.flags |= (TTY_NOCURSOR|TTY_FREEZE);
        c->flags |= CLIENT_STATUS;
}

/* Clear status line message. */
void
status_message_clear(struct client *c)
{
        if (c->message_string == NULL)
                return;

        free(c->message_string);
        c->message_string = NULL;

        c->tty.flags &= ~(TTY_NOCURSOR|TTY_FREEZE);
        c->flags |= CLIENT_REDRAW; /* screen was frozen and may have changed */

        screen_reinit(&c->status);
}

/* Clear status line message after timer expires. */
void
status_message_callback(unused int fd, unused short event, void *data)
{
        struct client   *c = data;

        status_message_clear(c);
}

/* Draw client message on status line of present else on last line. */
int
status_message_redraw(struct client *c)
{
        struct screen_write_ctx         ctx;
        struct session                 *s = c->session;
        struct screen                   old_status;
        size_t                          len;
        struct grid_cell                gc;
        int                             utf8flag;

        if (c->tty.sx == 0 || c->tty.sy == 0)
                return (0);
        memcpy(&old_status, &c->status, sizeof old_status);
        screen_init(&c->status, c->tty.sx, 1, 0);

        utf8flag = options_get_number(&s->options, "status-utf8");

        len = screen_write_strlen(utf8flag, "%s", c->message_string);
        if (len > c->tty.sx)
                len = c->tty.sx;

        memcpy(&gc, &grid_default_cell, sizeof gc);
        colour_set_fg(&gc, options_get_number(&s->options, "message-fg"));
        colour_set_bg(&gc, options_get_number(&s->options, "message-bg"));
        gc.attr |= options_get_number(&s->options, "message-attr");

        screen_write_start(&ctx, NULL, &c->status);

        screen_write_cursormove(&ctx, 0, 0);
        screen_write_nputs(&ctx, len, &gc, utf8flag, "%s", c->message_string);
        for (; len < c->tty.sx; len++)
                screen_write_putc(&ctx, &gc, ' ');

        screen_write_stop(&ctx);

        if (grid_compare(c->status.grid, old_status.grid) == 0) {
                screen_free(&old_status);
                return (0);
        }
        screen_free(&old_status);
        return (1);
}

/* Enable status line prompt. */
void
status_prompt_set(struct client *c, const char *msg, const char *input,
    int (*callbackfn)(void *, const char *), void (*freefn)(void *),
    void *data, int flags)
{
        int     keys;

        status_message_clear(c);
        status_prompt_clear(c);

        c->prompt_string = status_replace(c, NULL, NULL, NULL, msg,
            time(NULL), 0);

        c->prompt_buffer = status_replace(c, NULL, NULL, NULL, input,
            time(NULL), 0);
        c->prompt_index = strlen(c->prompt_buffer);

        c->prompt_callbackfn = callbackfn;
        c->prompt_freefn = freefn;
        c->prompt_data = data;

        c->prompt_hindex = 0;

        c->prompt_flags = flags;

        keys = options_get_number(&c->session->options, "status-keys");
        if (keys == MODEKEY_EMACS)
                mode_key_init(&c->prompt_mdata, &mode_key_tree_emacs_edit);
        else
                mode_key_init(&c->prompt_mdata, &mode_key_tree_vi_edit);

        c->tty.flags |= (TTY_NOCURSOR|TTY_FREEZE);
        c->flags |= CLIENT_STATUS;
}

/* Remove status line prompt. */
void
status_prompt_clear(struct client *c)
{
        if (c->prompt_string == NULL)
                return;

        if (c->prompt_freefn != NULL && c->prompt_data != NULL)
                c->prompt_freefn(c->prompt_data);

        free(c->prompt_string);
        c->prompt_string = NULL;

        free(c->prompt_buffer);
        c->prompt_buffer = NULL;

        c->tty.flags &= ~(TTY_NOCURSOR|TTY_FREEZE);
        c->flags |= CLIENT_REDRAW; /* screen was frozen and may have changed */

        screen_reinit(&c->status);
}

/* Update status line prompt with a new prompt string. */
void
status_prompt_update(struct client *c, const char *msg, const char *input)
{
        free(c->prompt_string);
        c->prompt_string = status_replace(c, NULL, NULL, NULL, msg,
            time(NULL), 0);

        free(c->prompt_buffer);
        c->prompt_buffer = status_replace(c, NULL, NULL, NULL, input,
            time(NULL), 0);
        c->prompt_index = strlen(c->prompt_buffer);

        c->prompt_hindex = 0;

        c->flags |= CLIENT_STATUS;
}

/* Draw client prompt on status line of present else on last line. */
int
status_prompt_redraw(struct client *c)
{
        struct screen_write_ctx         ctx;
        struct session                 *s = c->session;
        struct screen                   old_status;
        size_t                          i, size, left, len, off;
        struct grid_cell                gc, *gcp;
        int                             utf8flag;

        if (c->tty.sx == 0 || c->tty.sy == 0)
                return (0);
        memcpy(&old_status, &c->status, sizeof old_status);
        screen_init(&c->status, c->tty.sx, 1, 0);

        utf8flag = options_get_number(&s->options, "status-utf8");

        len = screen_write_strlen(utf8flag, "%s", c->prompt_string);
        if (len > c->tty.sx)
                len = c->tty.sx;
        off = 0;

        memcpy(&gc, &grid_default_cell, sizeof gc);

        /* Change colours for command mode. */
        if (c->prompt_mdata.mode == 1) {
                colour_set_fg(&gc, options_get_number(&s->options, "message-command-fg"));
                colour_set_bg(&gc, options_get_number(&s->options, "message-command-bg"));
                gc.attr |= options_get_number(&s->options, "message-command-attr");
        } else {
                colour_set_fg(&gc, options_get_number(&s->options, "message-fg"));
                colour_set_bg(&gc, options_get_number(&s->options, "message-bg"));
                gc.attr |= options_get_number(&s->options, "message-attr");
        }

        screen_write_start(&ctx, NULL, &c->status);

        screen_write_cursormove(&ctx, 0, 0);
        screen_write_nputs(&ctx, len, &gc, utf8flag, "%s", c->prompt_string);

        left = c->tty.sx - len;
        if (left != 0) {
                size = screen_write_strlen(utf8flag, "%s", c->prompt_buffer);
                if (c->prompt_index >= left) {
                        off = c->prompt_index - left + 1;
                        if (c->prompt_index == size)
                                left--;
                        size = left;
                }
                screen_write_nputs(
                    &ctx, left, &gc, utf8flag, "%s", c->prompt_buffer + off);

                for (i = len + size; i < c->tty.sx; i++)
                        screen_write_putc(&ctx, &gc, ' ');
        }

        screen_write_stop(&ctx);

        /* Apply fake cursor. */
        off = len + c->prompt_index - off;
        gcp = grid_view_get_cell(c->status.grid, off, 0);
        gcp->attr ^= GRID_ATTR_REVERSE;

        if (grid_compare(c->status.grid, old_status.grid) == 0) {
                screen_free(&old_status);
                return (0);
        }
        screen_free(&old_status);
        return (1);
}

/* Handle keys in prompt. */
void
status_prompt_key(struct client *c, int key)
{
        struct session          *sess = c->session;
        struct options          *oo = &sess->options;
        struct paste_buffer     *pb;
        char                    *s, *first, *last, word[64], swapc;
        const char              *histstr;
        const char              *wsep = NULL;
        u_char                   ch;
        size_t                   size, n, off, idx;

        size = strlen(c->prompt_buffer);
        switch (mode_key_lookup(&c->prompt_mdata, key, NULL)) {
        case MODEKEYEDIT_CURSORLEFT:
                if (c->prompt_index > 0) {
                        c->prompt_index--;
                        c->flags |= CLIENT_STATUS;
                }
                break;
        case MODEKEYEDIT_SWITCHMODE:
                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_SWITCHMODEAPPEND:
                c->flags |= CLIENT_STATUS;
                /* FALLTHROUGH */
        case MODEKEYEDIT_CURSORRIGHT:
                if (c->prompt_index < size) {
                        c->prompt_index++;
                        c->flags |= CLIENT_STATUS;
                }
                break;
        case MODEKEYEDIT_SWITCHMODEBEGINLINE:
                c->flags |= CLIENT_STATUS;
                /* FALLTHROUGH */
        case MODEKEYEDIT_STARTOFLINE:
                if (c->prompt_index != 0) {
                        c->prompt_index = 0;
                        c->flags |= CLIENT_STATUS;
                }
                break;
        case MODEKEYEDIT_SWITCHMODEAPPENDLINE:
                c->flags |= CLIENT_STATUS;
                /* FALLTHROUGH */
        case MODEKEYEDIT_ENDOFLINE:
                if (c->prompt_index != size) {
                        c->prompt_index = size;
                        c->flags |= CLIENT_STATUS;
                }
                break;
        case MODEKEYEDIT_COMPLETE:
                if (*c->prompt_buffer == '\0')
                        break;

                idx = c->prompt_index;
                if (idx != 0)
                        idx--;

                /* Find the word we are in. */
                first = c->prompt_buffer + idx;
                while (first > c->prompt_buffer && *first != ' ')
                        first--;
                while (*first == ' ')
                        first++;
                last = c->prompt_buffer + idx;
                while (*last != '\0' && *last != ' ')
                        last++;
                while (*last == ' ')
                        last--;
                if (*last != '\0')
                        last++;
                if (last <= first ||
                    ((size_t) (last - first)) > (sizeof word) - 1)
                        break;
                memcpy(word, first, last - first);
                word[last - first] = '\0';

                /* And try to complete it. */
                if ((s = status_prompt_complete(word)) == NULL)
                        break;

                /* Trim out word. */
                n = size - (last - c->prompt_buffer) + 1; /* with \0 */
                memmove(first, last, n);
                size -= last - first;

                /* Insert the new word. */
                size += strlen(s);
                off = first - c->prompt_buffer;
                c->prompt_buffer = xrealloc(c->prompt_buffer, 1, size + 1);
                first = c->prompt_buffer + off;
                memmove(first + strlen(s), first, n);
                memcpy(first, s, strlen(s));

                c->prompt_index = (first - c->prompt_buffer) + strlen(s);
                free(s);

                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_BACKSPACE:
                if (c->prompt_index != 0) {
                        if (c->prompt_index == size)
                                c->prompt_buffer[--c->prompt_index] = '\0';
                        else {
                                memmove(c->prompt_buffer + c->prompt_index - 1,
                                    c->prompt_buffer + c->prompt_index,
                                    size + 1 - c->prompt_index);
                                c->prompt_index--;
                        }
                        c->flags |= CLIENT_STATUS;
                }
                break;
        case MODEKEYEDIT_DELETE:
        case MODEKEYEDIT_SWITCHMODESUBSTITUTE:
                if (c->prompt_index != size) {
                        memmove(c->prompt_buffer + c->prompt_index,
                            c->prompt_buffer + c->prompt_index + 1,
                            size + 1 - c->prompt_index);
                        c->flags |= CLIENT_STATUS;
                }
                break;
        case MODEKEYEDIT_DELETELINE:
        case MODEKEYEDIT_SWITCHMODESUBSTITUTELINE:
                *c->prompt_buffer = '\0';
                c->prompt_index = 0;
                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_DELETETOENDOFLINE:
        case MODEKEYEDIT_SWITCHMODECHANGELINE:
                if (c->prompt_index < size) {
                        c->prompt_buffer[c->prompt_index] = '\0';
                        c->flags |= CLIENT_STATUS;
                }
                break;
        case MODEKEYEDIT_DELETEWORD:
                wsep = options_get_string(oo, "word-separators");
                idx = c->prompt_index;

                /* Find a non-separator. */
                while (idx != 0) {
                        idx--;
                        if (!strchr(wsep, c->prompt_buffer[idx]))
                                break;
                }

                /* Find the separator at the beginning of the word. */
                while (idx != 0) {
                        idx--;
                        if (strchr(wsep, c->prompt_buffer[idx])) {
                                /* Go back to the word. */
                                idx++;
                                break;
                        }
                }

                memmove(c->prompt_buffer + idx,
                    c->prompt_buffer + c->prompt_index,
                    size + 1 - c->prompt_index);
                memset(c->prompt_buffer + size - (c->prompt_index - idx),
                    '\0', c->prompt_index - idx);
                c->prompt_index = idx;
                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_NEXTSPACE:
                wsep = " ";
                /* FALLTHROUGH */
        case MODEKEYEDIT_NEXTWORD:
                if (wsep == NULL)
                        wsep = options_get_string(oo, "word-separators");

                /* Find a separator. */
                while (c->prompt_index != size) {
                        c->prompt_index++;
                        if (strchr(wsep, c->prompt_buffer[c->prompt_index]))
                                break;
                }

                /* Find the word right after the separation. */
                while (c->prompt_index != size) {
                        c->prompt_index++;
                        if (!strchr(wsep, c->prompt_buffer[c->prompt_index]))
                                break;
                }

                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_NEXTSPACEEND:
                wsep = " ";
                /* FALLTHROUGH */
        case MODEKEYEDIT_NEXTWORDEND:
                if (wsep == NULL)
                        wsep = options_get_string(oo, "word-separators");

                /* Find a word. */
                while (c->prompt_index != size) {
                        c->prompt_index++;
                        if (!strchr(wsep, c->prompt_buffer[c->prompt_index]))
                                break;
                }

                /* Find the separator at the end of the word. */
                while (c->prompt_index != size) {
                        c->prompt_index++;
                        if (strchr(wsep, c->prompt_buffer[c->prompt_index]))
                                break;
                }

                /* Back up to the end-of-word like vi. */
                if (options_get_number(oo, "status-keys") == MODEKEY_VI &&
                    c->prompt_index != 0)
                        c->prompt_index--;

                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_PREVIOUSSPACE:
                wsep = " ";
                /* FALLTHROUGH */
        case MODEKEYEDIT_PREVIOUSWORD:
                if (wsep == NULL)
                        wsep = options_get_string(oo, "word-separators");

                /* Find a non-separator. */
                while (c->prompt_index != 0) {
                        c->prompt_index--;
                        if (!strchr(wsep, c->prompt_buffer[c->prompt_index]))
                                break;
                }

                /* Find the separator at the beginning of the word. */
                while (c->prompt_index != 0) {
                        c->prompt_index--;
                        if (strchr(wsep, c->prompt_buffer[c->prompt_index])) {
                                /* Go back to the word. */
                                c->prompt_index++;
                                break;
                        }
                }

                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_HISTORYUP:
                histstr = status_prompt_up_history(&c->prompt_hindex);
                if (histstr == NULL)
                        break;
                free(c->prompt_buffer);
                c->prompt_buffer = xstrdup(histstr);
                c->prompt_index = strlen(c->prompt_buffer);
                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_HISTORYDOWN:
                histstr = status_prompt_down_history(&c->prompt_hindex);
                if (histstr == NULL)
                        break;
                free(c->prompt_buffer);
                c->prompt_buffer = xstrdup(histstr);
                c->prompt_index = strlen(c->prompt_buffer);
                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_PASTE:
                if ((pb = paste_get_top(&global_buffers)) == NULL)
                        break;
                for (n = 0; n < pb->size; n++) {
                        ch = (u_char) pb->data[n];
                        if (ch < 32 || ch == 127)
                                break;
                }

                c->prompt_buffer = xrealloc(c->prompt_buffer, 1, size + n + 1);
                if (c->prompt_index == size) {
                        memcpy(c->prompt_buffer + c->prompt_index, pb->data, n);
                        c->prompt_index += n;
                        c->prompt_buffer[c->prompt_index] = '\0';
                } else {
                        memmove(c->prompt_buffer + c->prompt_index + n,
                            c->prompt_buffer + c->prompt_index,
                            size + 1 - c->prompt_index);
                        memcpy(c->prompt_buffer + c->prompt_index, pb->data, n);
                        c->prompt_index += n;
                }

                c->flags |= CLIENT_STATUS;
                break;
        case MODEKEYEDIT_TRANSPOSECHARS:
                idx = c->prompt_index;
                if (idx < size)
                        idx++;
                if (idx >= 2) {
                        swapc = c->prompt_buffer[idx - 2];
                        c->prompt_buffer[idx - 2] = c->prompt_buffer[idx - 1];
                        c->prompt_buffer[idx - 1] = swapc;
                        c->prompt_index = idx;
                        c->flags |= CLIENT_STATUS;
                }
                break;
        case MODEKEYEDIT_ENTER:
                if (*c->prompt_buffer != '\0')
                        status_prompt_add_history(c->prompt_buffer);
                if (c->prompt_callbackfn(c->prompt_data, c->prompt_buffer) == 0)
                        status_prompt_clear(c);
                break;
        case MODEKEYEDIT_CANCEL:
                if (c->prompt_callbackfn(c->prompt_data, NULL) == 0)
                        status_prompt_clear(c);
                break;
        case MODEKEY_OTHER:
                if ((key & 0xff00) != 0 || key < 32 || key == 127)
                        break;
                c->prompt_buffer = xrealloc(c->prompt_buffer, 1, size + 2);

                if (c->prompt_index == size) {
                        c->prompt_buffer[c->prompt_index++] = key;
                        c->prompt_buffer[c->prompt_index] = '\0';
                } else {
                        memmove(c->prompt_buffer + c->prompt_index + 1,
                            c->prompt_buffer + c->prompt_index,
                            size + 1 - c->prompt_index);
                        c->prompt_buffer[c->prompt_index++] = key;
                }

                if (c->prompt_flags & PROMPT_SINGLE) {
                        if (c->prompt_callbackfn(
                            c->prompt_data, c->prompt_buffer) == 0)
                                status_prompt_clear(c);
                }

                c->flags |= CLIENT_STATUS;
                break;
        default:
                break;
        }
}

/* Get previous line from the history. */
const char *
status_prompt_up_history(u_int *idx)
{
        u_int size;

        /*
         * History runs from 0 to size - 1.
         *
         * Index is from 0 to size. Zero is empty.
         */

        size = ARRAY_LENGTH(&status_prompt_history);
        if (size == 0 || *idx == size)
                return (NULL);
        (*idx)++;
        return (ARRAY_ITEM(&status_prompt_history, size - *idx));
}

/* Get next line from the history. */
const char *
status_prompt_down_history(u_int *idx)
{
        u_int size;

        size = ARRAY_LENGTH(&status_prompt_history);
        if (size == 0 || *idx == 0)
                return ("");
        (*idx)--;
        if (*idx == 0)
                return ("");
        return (ARRAY_ITEM(&status_prompt_history, size - *idx));
}

/* Add line to the history. */
void
status_prompt_add_history(const char *line)
{
        u_int size;

        size = ARRAY_LENGTH(&status_prompt_history);
        if (size > 0 && strcmp(ARRAY_LAST(&status_prompt_history), line) == 0)
                return;

        if (size == PROMPT_HISTORY) {
                free(ARRAY_FIRST(&status_prompt_history));
                ARRAY_REMOVE(&status_prompt_history, 0);
        }

        ARRAY_ADD(&status_prompt_history, xstrdup(line));
}

/* Complete word. */
char *
status_prompt_complete(const char *s)
{
        const struct cmd_entry                 **cmdent;
        const struct options_table_entry        *oe;
        ARRAY_DECL(, const char *)               list;
        char                                    *prefix, *s2;
        u_int                                    i;
        size_t                                   j;

        if (*s == '\0')
                return (NULL);

        /* First, build a list of all the possible matches. */
        ARRAY_INIT(&list);
        for (cmdent = cmd_table; *cmdent != NULL; cmdent++) {
                if (strncmp((*cmdent)->name, s, strlen(s)) == 0)
                        ARRAY_ADD(&list, (*cmdent)->name);
        }
        for (oe = server_options_table; oe->name != NULL; oe++) {
                if (strncmp(oe->name, s, strlen(s)) == 0)
                        ARRAY_ADD(&list, oe->name);
        }
        for (oe = session_options_table; oe->name != NULL; oe++) {
                if (strncmp(oe->name, s, strlen(s)) == 0)
                        ARRAY_ADD(&list, oe->name);
        }
        for (oe = window_options_table; oe->name != NULL; oe++) {
                if (strncmp(oe->name, s, strlen(s)) == 0)
                        ARRAY_ADD(&list, oe->name);
        }

        /* If none, bail now. */
        if (ARRAY_LENGTH(&list) == 0) {
                ARRAY_FREE(&list);
                return (NULL);
        }

        /* If an exact match, return it, with a trailing space. */
        if (ARRAY_LENGTH(&list) == 1) {
                xasprintf(&s2, "%s ", ARRAY_FIRST(&list));
                ARRAY_FREE(&list);
                return (s2);
        }

        /* Now loop through the list and find the longest common prefix. */
        prefix = xstrdup(ARRAY_FIRST(&list));
        for (i = 1; i < ARRAY_LENGTH(&list); i++) {
                s = ARRAY_ITEM(&list, i);

                j = strlen(s);
                if (j > strlen(prefix))
                        j = strlen(prefix);
                for (; j > 0; j--) {
                        if (prefix[j - 1] != s[j - 1])
                                prefix[j - 1] = '\0';
                }
        }

        ARRAY_FREE(&list);
        return (prefix);
}