OS/2 Spezial/SPEZIAL2_97.zip/SPEZIAL2_97.iso/ANWEND/EDITOR/NVI179B/NVI179B.ZIP/vi/v_txt.c

C/C++ Source or Header | 1996-10-13 | 80KB | 2,951 lines

/*-
 * Copyright (c) 1993, 1994
 *    The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *    Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)v_txt.c    10.87 (Berkeley) 10/13/96";
#endif /* not lint */

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/time.h>

#include <bitstring.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "../common/common.h"
#include "vi.h"

static int     txt_abbrev __P((SCR *, TEXT *, CHAR_T *, int, int *, int *));
static void     txt_ai_resolve __P((SCR *, TEXT *, int *));
static TEXT    *txt_backup __P((SCR *, TEXTH *, TEXT *, u_int32_t *));
static int     txt_dent __P((SCR *, TEXT *, int));
static int     txt_emark __P((SCR *, TEXT *, size_t));
static void     txt_err __P((SCR *, TEXTH *));
static int     txt_fc __P((SCR *, TEXT *, int *));
static int     txt_fc_col __P((SCR *, int, ARGS **));
static int     txt_hex __P((SCR *, TEXT *));
static int     txt_insch __P((SCR *, TEXT *, CHAR_T *, u_int));
static int     txt_isrch __P((SCR *, VICMD *, TEXT *, u_int8_t *));
static int     txt_map_end __P((SCR *));
static int     txt_map_init __P((SCR *));
static int     txt_margin __P((SCR *, TEXT *, TEXT *, int *, u_int32_t));
static void     txt_nomorech __P((SCR *));
static void     txt_Rresolve __P((SCR *, TEXTH *, TEXT *, const size_t));
static int     txt_resolve __P((SCR *, TEXTH *, u_int32_t));
static int     txt_showmatch __P((SCR *, TEXT *));
static void     txt_unmap __P((SCR *, TEXT *, u_int32_t *));

/* Cursor character (space is hard to track on the screen). */
#if defined(DEBUG) && 0
#undef    CH_CURSOR
#define    CH_CURSOR    '+'
#endif

/*
 * v_tcmd --
 *    Fill a buffer from the terminal for vi.
 *
 * PUBLIC: int v_tcmd __P((SCR *, VICMD *, ARG_CHAR_T, u_int));
 */
int
v_tcmd(sp, vp, prompt, flags)
    SCR *sp;
    VICMD *vp;
    ARG_CHAR_T prompt;
    u_int flags;
{
    /* Normally, we end up where we started. */
    vp->m_final.lno = sp->lno;
    vp->m_final.cno = sp->cno;

    /* Initialize the map. */
    if (txt_map_init(sp))
        return (1);

    /* Move to the last line. */
    sp->lno = TMAP[0].lno;
    sp->cno = 0;

    /* Don't update the modeline for now. */
    F_SET(sp, SC_TINPUT_INFO);

    /* Set the input flags. */
    LF_SET(TXT_APPENDEOL |
        TXT_CR | TXT_ESCAPE | TXT_INFOLINE | TXT_MAPINPUT);
    if (O_ISSET(sp, O_ALTWERASE))
        LF_SET(TXT_ALTWERASE);
    if (O_ISSET(sp, O_TTYWERASE))
        LF_SET(TXT_TTYWERASE);

    /* Do the input thing. */
    if (v_txt(sp, vp, NULL, NULL, 0, prompt, 0, 1, flags))
        return (1);

    /* Reenable the modeline updates. */
    F_CLR(sp, SC_TINPUT_INFO);

    /* Clean up the map. */
    if (txt_map_end(sp))
        return (1);

    if (IS_ONELINE(sp))
        F_SET(sp, SC_SCR_REDRAW);    /* XXX */

    /* Set the cursor to the resulting position. */
    sp->lno = vp->m_final.lno;
    sp->cno = vp->m_final.cno;

    return (0);
}

/*
 * txt_map_init
 *    Initialize the screen map for colon command-line input.
 */
static int
txt_map_init(sp)
    SCR *sp;
{
    SMAP *esmp;
    VI_PRIVATE *vip;

    vip = VIP(sp);
    if (!IS_ONELINE(sp)) {
        /*
         * Fake like the user is doing input on the last line of the
         * screen.  This makes all of the scrolling work correctly,
         * and allows us the use of the vi text editing routines, not
         * to mention practically infinite length ex commands.
         *
         * Save the current location.
         */
        vip->sv_tm_lno = TMAP->lno;
        vip->sv_tm_soff = TMAP->soff;
        vip->sv_tm_coff = TMAP->coff;
        vip->sv_t_maxrows = sp->t_maxrows;
        vip->sv_t_minrows = sp->t_minrows;
        vip->sv_t_rows = sp->t_rows;

        /*
         * If it's a small screen, TMAP may be small for the screen.
         * Fix it, filling in fake lines as we go.
         */
        if (IS_SMALL(sp))
            for (esmp =
                HMAP + (sp->t_maxrows - 1); TMAP < esmp; ++TMAP) {
                TMAP[1].lno = TMAP[0].lno + 1;
                TMAP[1].coff = HMAP->coff;
                TMAP[1].soff = 1;
            }

        /* Build the fake entry. */
        TMAP[1].lno = TMAP[0].lno + 1;
        TMAP[1].soff = 1;
        TMAP[1].coff = 0;
        SMAP_FLUSH(&TMAP[1]);
        ++TMAP;

        /* Reset the screen information. */
        sp->t_rows = sp->t_minrows = ++sp->t_maxrows;
    }
    return (0);
}

/*
 * txt_map_end
 *    Reset the screen map for colon command-line input.
 */
static int
txt_map_end(sp)
    SCR *sp;
{
    VI_PRIVATE *vip;
    size_t cnt;

    vip = VIP(sp);
    if (!IS_ONELINE(sp)) {
        /* Restore the screen information. */
        sp->t_rows = vip->sv_t_rows;
        sp->t_minrows = vip->sv_t_minrows;
        sp->t_maxrows = vip->sv_t_maxrows;

        /*
         * If it's a small screen, TMAP may be wrong.  Clear any
         * lines that might have been overwritten.
         */
        if (IS_SMALL(sp)) {
            for (cnt = sp->t_rows; cnt <= sp->t_maxrows; ++cnt) {
                (void)sp->gp->scr_move(sp, cnt, 0);
                (void)sp->gp->scr_clrtoeol(sp);
            }
            TMAP = HMAP + (sp->t_rows - 1);
        } else
            --TMAP;

        /*
         * The map may be wrong if the user entered more than one
         * (logical) line.  Fix it.  If the user entered a whole
         * screen, this will be slow, but we probably don't care.
         */
        if (!O_ISSET(sp, O_LEFTRIGHT))
            while (vip->sv_tm_lno != TMAP->lno ||
                vip->sv_tm_soff != TMAP->soff)
                if (vs_sm_1down(sp))
                    return (1);
    }

    /*
     * Invalidate the cursor and the line size cache, the line never
     * really existed.  This fixes bugs where the user searches for
     * the last line on the screen + 1 and the refresh routine thinks
     * that's where we just were.
     */
    VI_SCR_CFLUSH(vip);
    F_SET(vip, VIP_CUR_INVALID);

    return (0);
}

/*
 * If doing input mapping on the colon command line, may need to unmap
 * based on the command.
 */
#define    UNMAP_TST                            \
    FL_ISSET(ec_flags, EC_MAPINPUT) && LF_ISSET(TXT_INFOLINE)

/*
 * Internally, we maintain tp->lno and tp->cno, externally, everyone uses
 * sp->lno and sp->cno.  Make them consistent as necessary.
 */
#define    UPDATE_POSITION(sp, tp) {                    \
    (sp)->lno = (tp)->lno;                        \
    (sp)->cno = (tp)->cno;                        \
}

/*
 * v_txt --
 *    Vi text input.
 *
 * PUBLIC: int v_txt __P((SCR *, VICMD *, MARK *,
 * PUBLIC:    const char *, size_t, ARG_CHAR_T, recno_t, u_long, u_int32_t));
 */
int
v_txt(sp, vp, tm, lp, len, prompt, ai_line, rcount, flags)
    SCR *sp;
    VICMD *vp;
    MARK *tm;        /* To MARK. */
    const char *lp;        /* Input line. */
    size_t len;        /* Input line length. */
    ARG_CHAR_T prompt;    /* Prompt to display. */
    recno_t ai_line;    /* Line number to use for autoindent count. */
    u_long rcount;        /* Replay count. */
    u_int32_t flags;    /* TXT_* flags. */
{
    EVENT ev, *evp;        /* Current event. */
    EVENT fc;        /* File name completion event. */
    GS *gp;
    TEXT *ntp, *tp;        /* Input text structures. */
    TEXT ait;        /* Autoindent text structure. */
    TEXT wmt;        /* Wrapmargin text structure. */
    TEXTH *tiqh;
    VI_PRIVATE *vip;
    abb_t abb;        /* State of abbreviation checks. */
    carat_t carat;        /* State of the "[^0]^D" sequences. */
    quote_t quote;        /* State of quotation. */
    size_t owrite, insert;    /* Temporary copies of TEXT fields. */
    size_t margin;        /* Wrapmargin value. */
    size_t rcol;        /* 0-N: insert offset in the replay buffer. */
    size_t tcol;        /* Temporary column. */
    u_int32_t ec_flags;    /* Input mapping flags. */
#define    IS_RESTART    0x01    /* Reset the incremental search. */
#define    IS_RUNNING    0x02    /* Incremental search turned on. */
    u_int8_t is_flags;
    int abcnt, ab_turnoff;    /* Abbreviation character count, switch. */
    int filec_redraw;    /* Redraw after the file completion routine. */
    int hexcnt;        /* Hex character count. */
    int showmatch;        /* Showmatch set on this character. */
    int wm_set, wm_skip;    /* Wrapmargin happened, blank skip flags. */
    int max, tmp;
    char *p;

    gp = sp->gp;
    vip = VIP(sp);

    /*
     * Set the input flag, so tabs get displayed correctly
     * and everyone knows that the text buffer is in use.
     */
    F_SET(sp, SC_TINPUT);

    /*
     * Get one TEXT structure with some initial buffer space, reusing
     * the last one if it's big enough.  (All TEXT bookkeeping fields
     * default to 0 -- text_init() handles this.)  If changing a line,
     * copy it into the TEXT buffer.
     */
    tiqh = &sp->tiq;
    if (tiqh->cqh_first != (void *)tiqh) {
        tp = tiqh->cqh_first;
        if (tp->q.cqe_next != (void *)tiqh || tp->lb_len < len + 32) {
            text_lfree(tiqh);
            goto newtp;
        }
        tp->ai = tp->insert = tp->offset = tp->owrite = 0;
        if (lp != NULL) {
            tp->len = len;
            memmove(tp->lb, lp, len);
        } else
            tp->len = 0;
    } else {
newtp:        if ((tp = text_init(sp, lp, len, len + 32)) == NULL)
            return (1);
        CIRCLEQ_INSERT_HEAD(tiqh, tp, q);
    }

    /* Set default termination condition. */
    tp->term = TERM_OK;

    /* Set the starting line, column. */
    tp->lno = sp->lno;
    tp->cno = sp->cno;

    /*
     * Set the insert and overwrite counts.  If overwriting characters,
     * do insertion afterward.  If not overwriting characters, assume
     * doing insertion.  If change is to a mark, emphasize it with an
     * CH_ENDMARK character.
     */
    if (len) {
        if (LF_ISSET(TXT_OVERWRITE)) {
            tp->owrite = (tm->cno - tp->cno) + 1;
            tp->insert = (len - tm->cno) - 1;
        } else
            tp->insert = len - tp->cno;

        if (LF_ISSET(TXT_EMARK) && txt_emark(sp, tp, tm->cno))
            return (1);
    }

    /*
     * Many of the special cases in text input are to handle autoindent
     * support.  Somebody decided that it would be a good idea if "^^D"
     * and "0^D" deleted all of the autoindented characters.  In an editor
     * that takes single character input from the user, this beggars the
     * imagination.  Note also, "^^D" resets the next lines' autoindent,
     * but "0^D" doesn't.
     *
     * We assume that autoindent only happens on empty lines, so insert
     * and overwrite will be zero.  If doing autoindent, figure out how
     * much indentation we need and fill it in.  Update input column and
     * screen cursor as necessary.
     */
    if (LF_ISSET(TXT_AUTOINDENT) && ai_line != OOBLNO) {
        if (v_txt_auto(sp, ai_line, NULL, 0, tp))
            return (1);
        tp->cno = tp->ai;
    } else {
        /*
         * The cc and S commands have a special feature -- leading
         * <blank> characters are handled as autoindent characters.
         * Beauty!
         */
        if (LF_ISSET(TXT_AICHARS)) {
            tp->offset = 0;
            tp->ai = tp->cno;
        } else
            tp->offset = tp->cno;
    }

    /* If getting a command buffer from the user, there may be a prompt. */
    if (LF_ISSET(TXT_PROMPT)) {
        tp->lb[tp->cno++] = prompt;
        ++tp->len;
        ++tp->offset;
    }

    /*
     * If appending after the end-of-line, add a space into the buffer
     * and move the cursor right.  This space is inserted, i.e. pushed
     * along, and then deleted when the line is resolved.  Assumes that
     * the cursor is already positioned at the end of the line.  This
     * avoids the nastiness of having the cursor reside on a magical
     * column, i.e. a column that doesn't really exist.  The only down
     * side is that we may wrap lines or scroll the screen before it's
     * strictly necessary.  Not a big deal.
     */
    if (LF_ISSET(TXT_APPENDEOL)) {
        tp->lb[tp->cno] = CH_CURSOR;
        ++tp->len;
        ++tp->insert;
        (void)vs_change(sp, tp->lno, LINE_RESET);
    }

    /*
     * Historic practice is that the wrapmargin value was a distance
     * from the RIGHT-HAND margin, not the left.  It's more useful to
     * us as a distance from the left-hand margin, i.e. the same as
     * the wraplen value.  The wrapmargin option is historic practice.
     * Nvi added the wraplen option so that it would be possible to
     * edit files with consistent margins without knowing the number of
     * columns in the window.
     *
     * XXX
     * Setting margin causes a significant performance hit.  Normally
     * we don't update the screen if there are keys waiting, but we
     * have to if margin is set, otherwise the screen routines don't
     * know where the cursor is.
     *
     * !!!
     * Abbreviated keys were affected by the wrapmargin option in the
     * historic 4BSD vi.  Mapped keys were usually, but sometimes not.
     * See the comment in vi/v_text():set_txt_std for more information.
     *
     * !!!
     * One more special case.  If an inserted <blank> character causes
     * wrapmargin to split the line, the next user entered character is
     * discarded if it's a <space> character.
     */
    wm_set = wm_skip = 0;
    if (LF_ISSET(TXT_WRAPMARGIN))
        if ((margin = O_VAL(sp, O_WRAPMARGIN)) != 0)
            margin = sp->cols - margin;
        else
            margin = O_VAL(sp, O_WRAPLEN);
    else
        margin = 0;

    /* Initialize abbreviation checks. */
    abcnt = ab_turnoff = 0;
    abb = F_ISSET(gp, G_ABBREV) &&
        LF_ISSET(TXT_MAPINPUT) ? AB_INWORD : AB_NOTSET;

    /*
     * Set up the dot command.  Dot commands are done by saving the actual
     * characters and then reevaluating them so that things like wrapmargin
     * can change between the insert and the replay.
     *
     * !!!
     * Historically, vi did not remap or reabbreviate replayed input.  (It
     * did beep at you if you changed an abbreviation and then replayed the
     * input.  We're not that compatible.)  We don't have to do anything to
     * avoid remapping, as we're not getting characters from the terminal
     * routines.  Turn the abbreviation check off.
     *
     * XXX
     * It would be nice if we could swallow backspaces and such, but it's
     * not all that easy to do.  What we can do is turn off the common
     * error messages during the replay.  Otherwise, when the user enters
     * an illegal command, e.g., "Ia<erase><erase><erase><erase>b<escape>",
     * and then does a '.', they get a list of error messages after command
     * completion.
     */
    rcol = 0;
    if (LF_ISSET(TXT_REPLAY)) {
        abb = AB_NOTSET;
        LF_CLR(TXT_RECORD);
    }

    /* Other text input mode setup. */
    quote = Q_NOTSET;
    carat = C_NOTSET;
    FL_INIT(is_flags,
        LF_ISSET(TXT_SEARCHINCR) ? IS_RESTART | IS_RUNNING : 0);
    filec_redraw = hexcnt = showmatch = 0;

    /* Initialize input flags. */
    ec_flags = LF_ISSET(TXT_MAPINPUT) ? EC_MAPINPUT : 0;

    /* Refresh the screen. */
    UPDATE_POSITION(sp, tp);
    if (vs_refresh(sp, 1))
        return (1);

    /* If it's dot, just do it now. */
    if (F_ISSET(vp, VC_ISDOT))
        goto replay;

    /* Get an event. */
    evp = &ev;
next:    if (v_event_get(sp, evp, 0, ec_flags))
        return (1);

    /*
     * If file completion overwrote part of the screen and nothing else has
     * been displayed, clean up.  We don't do this as part of the normal
     * message resolution because we know the user is on the colon command
     * line and there's no reason to enter explicit characters to continue.
     */
    if (filec_redraw && !F_ISSET(sp, SC_SCR_EXWROTE)) {
        filec_redraw = 0;

        fc.e_event = E_REPAINT;
        fc.e_flno = vip->totalcount >=
            sp->rows ? 1 : sp->rows - vip->totalcount;
        fc.e_tlno = sp->rows;
        vip->linecount = vip->lcontinue = vip->totalcount = 0;
        (void)vs_repaint(sp, &fc);
        (void)vs_refresh(sp, 1);
    }

    /* Deal with all non-character events. */
    switch (evp->e_event) {
    case E_CHARACTER:
        break;
    case E_ERR:
    case E_EOF:
        F_SET(sp, SC_EXIT_FORCE);
        return (1);
    case E_INTERRUPT:
        /*
         * !!!
         * Historically, <interrupt> exited the user from text input
         * mode or cancelled a colon command, and returned to command
         * mode.  It also beeped the terminal, but that seems a bit
         * excessive.
         */
        goto k_escape;
    case E_REPAINT:
        if (vs_repaint(sp, &ev))
            return (1);
        goto next;
    case E_WRESIZE:
        /* <resize> interrupts the input mode. */
        v_emsg(sp, NULL, VIM_WRESIZE);
        goto k_escape;
    default:
        v_event_err(sp, evp);
        goto k_escape;
    }

    /*
     * !!!
     * If the first character of the input is a nul, replay the previous
     * input.  (Historically, it's okay to replay non-existent input.)
     * This was not documented as far as I know, and is a great test of vi
     * clones.
     */
    if (rcol == 0 && !LF_ISSET(TXT_REPLAY) && evp->e_c == '\0') {
        if (vip->rep == NULL)
            goto done;

        abb = AB_NOTSET;
        LF_CLR(TXT_RECORD);
        LF_SET(TXT_REPLAY);
        goto replay;
    }

    /*
     * File name completion and colon command-line editing.   We don't
     * have enough meta characters, so we expect people to overload
     * them.  If the two characters are the same, then we do file name
     * completion if the cursor is past the first column, and do colon
     * command-line editing if it's not.
     */
    if (quote == Q_NOTSET) {
        int L__cedit, L__filec;

        L__cedit = L__filec = 0;
        if (LF_ISSET(TXT_CEDIT) && O_STR(sp, O_CEDIT) != NULL &&
            O_STR(sp, O_CEDIT)[0] == evp->e_c)
            L__cedit = 1;
        if (LF_ISSET(TXT_FILEC) && O_STR(sp, O_FILEC) != NULL &&
            O_STR(sp, O_FILEC)[0] == evp->e_c)
            L__filec = 1;
        if (L__cedit == 1 && (L__filec == 0 || tp->cno == tp->offset)) {
            tp->term = TERM_CEDIT;
            goto k_escape;
        }
        if (L__filec == 1) {
            if (txt_fc(sp, tp, &filec_redraw))
                goto err;
            goto resolve;
        }
    }

    /* Abbreviation overflow check.  See comment in txt_abbrev(). */
#define    MAX_ABBREVIATION_EXPANSION    256
    if (F_ISSET(&evp->e_ch, CH_ABBREVIATED)) {
        if (++abcnt > MAX_ABBREVIATION_EXPANSION) {
            if (v_event_flush(sp, CH_ABBREVIATED))
                msgq(sp, M_ERR,
"191|Abbreviation exceeded expansion limit: characters discarded");
            abcnt = 0;
            if (LF_ISSET(TXT_REPLAY))
                goto done;
            goto resolve;
        }
    } else
        abcnt = 0;

    /* Check to see if the character fits into the replay buffers. */
    if (LF_ISSET(TXT_RECORD)) {
        BINC_GOTO(sp, vip->rep,
            vip->rep_len, (rcol + 1) * sizeof(EVENT));
        vip->rep[rcol++] = *evp;
    }

replay:    if (LF_ISSET(TXT_REPLAY))
        evp = vip->rep + rcol++;

    /* Wrapmargin check for leading space. */
    if (wm_skip) {
        wm_skip = 0;
        if (evp->e_c == ' ')
            goto resolve;
    }

    /* If quoted by someone else, simply insert the character. */
    if (F_ISSET(&evp->e_ch, CH_QUOTED))
        goto insq_ch;

    /*
     * !!!
     * If this character was quoted by a K_VLNEXT or a backslash, replace
     * the placeholder (a carat or a backslash) with the new character.
     * If it was quoted by a K_VLNEXT, we've already adjusted the cursor
     * because it has to appear on top of the placeholder character.  If
     * it was quoted by a backslash, adjust the cursor now, the cursor
     * doesn't appear on top of it.  Historic practice in both cases.
     *
     * Skip tests for abbreviations; ":ab xa XA" followed by "ixa^V<space>"
     * doesn't perform an abbreviation.  Special case, ^V^J (not ^V^M) is
     * the same as ^J, historically.
     */
    if (quote == Q_BTHIS || quote == Q_VTHIS) {
        FL_CLR(ec_flags, EC_QUOTED);
        if (LF_ISSET(TXT_MAPINPUT))
            FL_SET(ec_flags, EC_MAPINPUT);

        if (quote == Q_BTHIS &&
            (evp->e_value == K_VERASE || evp->e_value == K_VKILL)) {
            quote = Q_NOTSET;
            --tp->cno;
            ++tp->owrite;
            goto insl_ch;
        }
        if (quote == Q_VTHIS && evp->e_value != K_NL) {
            quote = Q_NOTSET;
            goto insl_ch;
        }
        quote = Q_NOTSET;
    }

    /*
     * !!!
     * Translate "<CH_HEX>[isxdigit()]*" to a character with a hex value:
     * this test delimits the value by any non-hex character.  Offset by
     * one, we use 0 to mean that we've found <CH_HEX>.
     */
    if (hexcnt > 1 && !isxdigit(evp->e_c)) {
        hexcnt = 0;
        if (txt_hex(sp, tp))
            goto err;
    }

    switch (evp->e_value) {
    case K_CR:                /* Carriage return. */
    case K_NL:                /* New line. */
        /* Return in script windows and the command line. */
k_cr:        if (LF_ISSET(TXT_CR)) {
            /*
             * If this was a map, we may have not displayed
             * the line.  Display it, just in case.
             *
             * If a script window and not the colon line,
             * push a <cr> so it gets executed.
             */
            if (LF_ISSET(TXT_INFOLINE)) {
                if (vs_change(sp, tp->lno, LINE_RESET))
                    goto err;
            } else if (F_ISSET(sp, SC_SCRIPT))
                (void)v_event_push(sp, NULL, "\r", 1, CH_NOMAP);

            /* Set term condition: if empty. */
            if (tp->cno <= tp->offset)
                tp->term = TERM_CR;
            /*
             * Set term condition: if searching incrementally and
             * the user entered a pattern, return a completed
             * search, regardless if the entire pattern was found.
             */
            if (FL_ISSET(is_flags, IS_RUNNING) &&
                tp->cno >= tp->offset + 1)
                tp->term = TERM_SEARCH;

            goto k_escape;
        }

#define    LINE_RESOLVE {                            \
        /*                            \
         * Handle abbreviations.  If there was one, discard the    \
         * replay characters.                    \
         */                            \
        if (abb == AB_INWORD &&                    \
            !LF_ISSET(TXT_REPLAY) && F_ISSET(gp, G_ABBREV)) {    \
            if (txt_abbrev(sp, tp, &evp->e_c,        \
                LF_ISSET(TXT_INFOLINE), &tmp,        \
                &ab_turnoff))                \
                goto err;                \
            if (tmp) {                    \
                if (LF_ISSET(TXT_RECORD))        \
                    rcol -= tmp + 1;        \
                goto resolve;                \
            }                        \
        }                            \
        if (abb != AB_NOTSET)                    \
            abb = AB_NOTWORD;                \
        if (UNMAP_TST)                        \
            txt_unmap(sp, tp, &ec_flags);            \
        /*                            \
         * Delete any appended cursor.  It's possible to get in    \
         * situations where TXT_APPENDEOL is set but tp->insert    \
         * is 0 when using the R command and all the characters    \
         * are tp->owrite characters.                \
         */                            \
        if (LF_ISSET(TXT_APPENDEOL) && tp->insert > 0) {    \
            --tp->len;                    \
            --tp->insert;                    \
        }                            \
}
        LINE_RESOLVE;

        /*
         * Save the current line information for restoration in
         * txt_backup(), and set the line final length.
         */
        tp->sv_len = tp->len;
        tp->sv_cno = tp->cno;
        tp->len = tp->cno;

        /* Update the old line. */
        if (vs_change(sp, tp->lno, LINE_RESET))
            goto err;

        /*
         * Historic practice, when the autoindent edit option was set,
         * was to delete <blank> characters following the inserted
         * newline.  This affected the 'R', 'c', and 's' commands; 'c'
         * and 's' retained the insert characters only, 'R' moved the
         * overwrite and insert characters into the next TEXT structure.
         * We keep track of the number of characters erased for the 'R'
         * command so that the final resolution of the line is correct.
         */
        tp->R_erase = 0;
        owrite = tp->owrite;
        insert = tp->insert;
        if (LF_ISSET(TXT_REPLACE) && owrite != 0) {
            for (p = tp->lb + tp->cno; owrite > 0 && isblank(*p);
                ++p, --owrite, ++tp->R_erase);
            if (owrite == 0)
                for (; insert > 0 && isblank(*p);
                    ++p, ++tp->R_erase, --insert);
        } else {
            p = tp->lb + tp->cno + owrite;
            if (O_ISSET(sp, O_AUTOINDENT))
                for (; insert > 0 &&
                    isblank(*p); ++p, --insert);
            owrite = 0;
        }

        /*
         * !!!
         * Create a new line and insert the new TEXT into the queue.
         * DON'T insert until the old line has been updated, or the
         * inserted line count in line.c:db_get() will be wrong.
         */
        if ((ntp = text_init(sp, p,
            insert + owrite, insert + owrite + 32)) == NULL)
            goto err;
        CIRCLEQ_INSERT_TAIL(&sp->tiq, ntp, q);

        /* Set up bookkeeping for the new line. */
        ntp->insert = insert;
        ntp->owrite = owrite;
        ntp->lno = tp->lno + 1;

        /*
         * Reset the autoindent line value.  0^D keeps the autoindent
         * line from changing, ^D changes the level, even if there were
         * no characters in the old line.  Note, if using the current
         * tp structure, use the cursor as the length, the autoindent
         * characters may have been erased.
         */
        if (LF_ISSET(TXT_AUTOINDENT)) {
            if (carat == C_NOCHANGE) {
                if (v_txt_auto(sp, OOBLNO, &ait, ait.ai, ntp))
                    goto err;
                FREE_SPACE(sp, ait.lb, ait.lb_len);
            } else
                if (v_txt_auto(sp, OOBLNO, tp, tp->cno, ntp))
                    goto err;
            carat = C_NOTSET;
        }

        /* Reset the cursor. */
        ntp->cno = ntp->ai;

        /*
         * If we're here because wrapmargin was set and we've broken a
         * line, there may be additional information (i.e. the start of
         * a line) in the wmt structure.
         */
        if (wm_set) {
            if (wmt.offset != 0 ||
                wmt.owrite != 0 || wmt.insert != 0) {
#define    WMTSPACE    wmt.offset + wmt.owrite + wmt.insert
                BINC_GOTO(sp, ntp->lb,
                    ntp->lb_len, ntp->len + WMTSPACE + 32);
                memmove(ntp->lb + ntp->cno, wmt.lb, WMTSPACE);
                ntp->len += WMTSPACE;
                ntp->cno += wmt.offset;
                ntp->owrite = wmt.owrite;
                ntp->insert = wmt.insert;
            }
            wm_set = 0;
        }

        /* New lines are TXT_APPENDEOL. */
        if (ntp->owrite == 0 && ntp->insert == 0) {
            BINC_GOTO(sp, ntp->lb, ntp->lb_len, ntp->len + 1);
            LF_SET(TXT_APPENDEOL);
            ntp->lb[ntp->cno] = CH_CURSOR;
            ++ntp->insert;
            ++ntp->len;
        }

        /* Swap old and new TEXT's, and update the new line. */
        tp = ntp;
        if (vs_change(sp, tp->lno, LINE_INSERT))
            goto err;

        goto resolve;
    case K_ESCAPE:                /* Escape. */
        if (!LF_ISSET(TXT_ESCAPE))
            goto ins_ch;

        /* If we have a count, start replaying the input. */
        if (rcount > 1) {
            --rcount;

            rcol = 0;
            abb = AB_NOTSET;
            LF_CLR(TXT_RECORD);
            LF_SET(TXT_REPLAY);

            /*
             * Some commands (e.g. 'o') need a <newline> for each
             * repetition.
             */
            if (LF_ISSET(TXT_ADDNEWLINE))
                goto k_cr;

            /*
             * The R command turns into the 'a' command after the
             * first repetition.
             */
            if (LF_ISSET(TXT_REPLACE)) {
                tp->insert = tp->owrite;
                tp->owrite = 0;
                LF_CLR(TXT_REPLACE);
            }
            goto replay;
        }

        /* Set term condition: if empty. */
        if (tp->cno <= tp->offset)
            tp->term = TERM_ESC;
        /*
         * Set term condition: if searching incrementally and the user
         * entered a pattern, return a completed search, regardless if
         * the entire pattern was found.
         */
        if (FL_ISSET(is_flags, IS_RUNNING) && tp->cno >= tp->offset + 1)
            tp->term = TERM_SEARCH;

k_escape:    LINE_RESOLVE;

        /*
         * Clean up for the 'R' command, restoring overwrite
         * characters, and making them into insert characters.
         */
        if (LF_ISSET(TXT_REPLACE))
            txt_Rresolve(sp, &sp->tiq, tp, len);

        /*
         * If there are any overwrite characters, copy down
         * any insert characters, and decrement the length.
         */
        if (tp->owrite) {
            if (tp->insert)
                memmove(tp->lb + tp->cno,
                    tp->lb + tp->cno + tp->owrite, tp->insert);
            tp->len -= tp->owrite;
        }

        /*
         * Optionally resolve the lines into the file.  If not
         * resolving the lines into the file, end the line with
         * a nul.  If the line is empty, then set the length to
         * 0, the termination condition has already been set.
         *
         * XXX
         * This is wrong, should pass back a length.
         */
        if (LF_ISSET(TXT_RESOLVE)) {
            if (txt_resolve(sp, &sp->tiq, flags))
                goto err;
        } else {
            BINC_GOTO(sp, tp->lb, tp->lb_len, tp->len + 1);
            tp->lb[tp->len] = '\0';
        }

        /*
         * Set the return cursor position to rest on the last
         * inserted character.
         */
        if (tp->cno != 0)
            --tp->cno;

        /* Update the last line. */
        if (vs_change(sp, tp->lno, LINE_RESET))
            return (1);
        goto done;
    case K_CARAT:            /* Delete autoindent chars. */
        if (tp->cno <= tp->ai && LF_ISSET(TXT_AUTOINDENT))
            carat = C_CARATSET;
        goto ins_ch;
    case K_ZERO:            /* Delete autoindent chars. */
        if (tp->cno <= tp->ai && LF_ISSET(TXT_AUTOINDENT))
            carat = C_ZEROSET;
        goto ins_ch;
    case K_CNTRLD:            /* Delete autoindent char. */
        /*
         * If in the first column or no characters to erase, ignore
         * the ^D (this matches historic practice).  If not doing
         * autoindent or already inserted non-ai characters, it's a
         * literal.  The latter test is done in the switch, as the
         * CARAT forms are N + 1, not N.
         */
        if (!LF_ISSET(TXT_AUTOINDENT))
            goto ins_ch;
        if (tp->cno == 0)
            goto resolve;

        switch (carat) {
        case C_CARATSET:    /* ^^D */
            if (tp->ai == 0 || tp->cno > tp->ai + tp->offset + 1)
                goto ins_ch;

            /* Save the ai string for later. */
            ait.lb = NULL;
            ait.lb_len = 0;
            BINC_GOTO(sp, ait.lb, ait.lb_len, tp->ai);
            memmove(ait.lb, tp->lb, tp->ai);
            ait.ai = ait.len = tp->ai;

            carat = C_NOCHANGE;
            goto leftmargin;
        case C_ZEROSET:        /* 0^D */
            if (tp->ai == 0 || tp->cno > tp->ai + tp->offset + 1)
                goto ins_ch;

            carat = C_NOTSET;
leftmargin:        tp->lb[tp->cno - 1] = ' ';
            tp->owrite += tp->cno - tp->offset;
            tp->ai = 0;
            tp->cno = tp->offset;
            break;
        case C_NOTSET:        /* ^D */
            if (tp->ai == 0 || tp->cno > tp->ai + tp->offset)
                goto ins_ch;

            (void)txt_dent(sp, tp, 0);
            break;
        default:
            abort();
        }
        break;
    case K_VERASE:            /* Erase the last character. */
        /* If can erase over the prompt, return. */
        if (tp->cno <= tp->offset && LF_ISSET(TXT_BS)) {
            tp->term = TERM_BS;
            goto done;
        }

        /*
         * If at the beginning of the line, try and drop back to a
         * previously inserted line.
         */
        if (tp->cno == 0) {
            if ((ntp =
                txt_backup(sp, &sp->tiq, tp, &flags)) == NULL)
                goto err;
            tp = ntp;
            break;
        }

        /* If nothing to erase, bell the user. */
        if (tp->cno <= tp->offset) {
            if (!LF_ISSET(TXT_REPLAY))
                txt_nomorech(sp);
            break;
        }

        /* Drop back one character. */
        --tp->cno;

        /*
         * Historically, vi didn't replace the erased characters with
         * <blank>s, presumably because it's easier to fix a minor
         * typing mistake and continue on if the previous letters are
         * already there.  This is a problem for incremental searching,
         * because the user can no longer tell where they are in the
         * colon command line because the cursor is at the last search
         * point in the screen.  So, if incrementally searching, erase
         * the erased characters from the screen.
         */
        if (FL_ISSET(is_flags, IS_RUNNING))
            tp->lb[tp->cno] = ' ';

        /*
         * Increment overwrite, decrement ai if deleted.
         *
         * !!!
         * Historic vi did not permit users to use erase characters
         * to delete autoindent characters.  We do.  Eat hot death,
         * POSIX.
         */
        ++tp->owrite;
        if (tp->cno < tp->ai)
            --tp->ai;

        /* Reset if we deleted an incremental search character. */
        if (FL_ISSET(is_flags, IS_RUNNING))
            FL_SET(is_flags, IS_RESTART);
        break;
    case K_VWERASE:            /* Skip back one word. */
        /*
         * If at the beginning of the line, try and drop back to a
         * previously inserted line.
         */
        if (tp->cno == 0) {
            if ((ntp =
                txt_backup(sp, &sp->tiq, tp, &flags)) == NULL)
                goto err;
            tp = ntp;
        }

        /*
         * If at offset, nothing to erase so bell the user.
         */
        if (tp->cno <= tp->offset) {
            if (!LF_ISSET(TXT_REPLAY))
                txt_nomorech(sp);
            break;
        }

        /*
         * The first werase goes back to any autoindent column and the
         * second werase goes back to the offset.
         *
         * !!!
         * Historic vi did not permit users to use erase characters to
         * delete autoindent characters.
         */
        if (tp->ai && tp->cno > tp->ai)
            max = tp->ai;
        else {
            tp->ai = 0;
            max = tp->offset;
        }

        /* Skip over trailing space characters. */
        while (tp->cno > max && isblank(tp->lb[tp->cno - 1])) {
            --tp->cno;
            ++tp->owrite;
        }
        if (tp->cno == max)
            break;
        /*
         * There are three types of word erase found on UNIX systems.
         * They can be identified by how the string /a/b/c is treated
         * -- as 1, 3, or 6 words.  Historic vi had two classes of
         * characters, and strings were delimited by them and
         * <blank>'s, so, 6 words.  The historic tty interface used
         * <blank>'s to delimit strings, so, 1 word.  The algorithm
         * offered in the 4.4BSD tty interface (as stty altwerase)
         * treats it as 3 words -- there are two classes of
         * characters, and strings are delimited by them and
         * <blank>'s.  The difference is that the type of the first
         * erased character erased is ignored, which is exactly right
         * when erasing pathname components.  The edit options
         * TXT_ALTWERASE and TXT_TTYWERASE specify the 4.4BSD tty
         * interface and the historic tty driver behavior,
         * respectively, and the default is the same as the historic
         * vi behavior.
         *
         * Overwrite erased characters if doing incremental search;
         * see comment above.
         */
        if (LF_ISSET(TXT_TTYWERASE))
            while (tp->cno > max) {
                --tp->cno;
                ++tp->owrite;
                if (FL_ISSET(is_flags, IS_RUNNING))
                    tp->lb[tp->cno] = ' ';
                if (isblank(tp->lb[tp->cno - 1]))
                    break;
            }
        else {
            if (LF_ISSET(TXT_ALTWERASE)) {
                --tp->cno;
                ++tp->owrite;
                if (FL_ISSET(is_flags, IS_RUNNING))
                    tp->lb[tp->cno] = ' ';
                if (isblank(tp->lb[tp->cno - 1]))
                    break;
            }
            if (tp->cno > max)
                tmp = inword(tp->lb[tp->cno - 1]);
            while (tp->cno > max) {
                --tp->cno;
                ++tp->owrite;
                if (FL_ISSET(is_flags, IS_RUNNING))
                    tp->lb[tp->cno] = ' ';
                if (tmp != inword(tp->lb[tp->cno - 1])
                    || isblank(tp->lb[tp->cno - 1]))
                    break;
            }
        }

        /* Reset if we deleted an incremental search character. */
        if (FL_ISSET(is_flags, IS_RUNNING))
            FL_SET(is_flags, IS_RESTART);
        break;
    case K_VKILL:            /* Restart this line. */
        /*
         * !!!
         * If at the beginning of the line, try and drop back to a
         * previously inserted line.  Historic vi did not permit
         * users to go back to previous lines.
         */
        if (tp->cno == 0) {
            if ((ntp =
                txt_backup(sp, &sp->tiq, tp, &flags)) == NULL)
                goto err;
            tp = ntp;
        }

        /* If at offset, nothing to erase so bell the user. */
        if (tp->cno <= tp->offset) {
            if (!LF_ISSET(TXT_REPLAY))
                txt_nomorech(sp);
            break;
        }

        /*
         * First kill goes back to any autoindent and second kill goes
         * back to the offset.
         *
         * !!!
         * Historic vi did not permit users to use erase characters to
         * delete autoindent characters.
         */
        if (tp->ai && tp->cno > tp->ai)
            max = tp->ai;
        else {
            tp->ai = 0;
            max = tp->offset;
        }
        tp->owrite += tp->cno - max;

        /*
         * Overwrite erased characters if doing incremental search;
         * see comment above.
         */
        if (FL_ISSET(is_flags, IS_RUNNING))
            do {
                tp->lb[--tp->cno] = ' ';
            } while (tp->cno > max);
        else
            tp->cno = max;

        /* Reset if we deleted an incremental search character. */
        if (FL_ISSET(is_flags, IS_RUNNING))
            FL_SET(is_flags, IS_RESTART);
        break;
    case K_CNTRLT:            /* Add autoindent characters. */
        if (!LF_ISSET(TXT_CNTRLT))
            goto ins_ch;
        if (txt_dent(sp, tp, 1))
            goto err;
        goto ebuf_chk;
    case K_RIGHTBRACE:
    case K_RIGHTPAREN:
        if (LF_ISSET(TXT_SHOWMATCH))
            showmatch = 1;
        goto ins_ch;
    case K_BACKSLASH:        /* Quote next erase/kill. */
        /*
         * !!!
         * Historic vi tried to make abbreviations after a backslash
         * escape work.  If you did ":ab x y", and inserted "x\^H",
         * (assuming the erase character was ^H) you got "x^H", and
         * no abbreviation was done.  If you inserted "x\z", however,
         * it tried to back up and do the abbreviation, i.e. replace
         * 'x' with 'y'.  The problem was it got it wrong, and you
         * ended up with "zy\".
         *
         * This is really hard to do (you have to remember the
         * word/non-word state, for example), and doesn't make any
         * sense to me.  Both backslash and the characters it
         * (usually) escapes will individually trigger the
         * abbreviation, so I don't see why the combination of them
         * wouldn't.  I don't expect to get caught on this one,
         * particularly since it never worked right, but I've been
         * wrong before.
         *
         * Do the tests for abbreviations, so ":ab xa XA",
         * "ixa\<K_VERASE>" performs the abbreviation.
         */
        quote = Q_BNEXT;
        goto insq_ch;
    case K_VLNEXT:            /* Quote next character. */
        evp->e_c = '^';
        quote = Q_VNEXT;
        /*
         * Turn on the quote flag so that the underlying routines
         * quote the next character where it's possible. Turn off
         * the input mapbiting flag so that we don't remap the next
         * character.
         */
        FL_SET(ec_flags, EC_QUOTED);
        FL_CLR(ec_flags, EC_MAPINPUT);

        /*
         * !!!
         * Skip the tests for abbreviations, so ":ab xa XA",
         * "ixa^V<space>" doesn't perform the abbreviation.
         */
        goto insl_ch;
    case K_HEXCHAR:
        hexcnt = 1;
        goto insq_ch;
    default:            /* Insert the character. */
ins_ch:        /*
         * Historically, vi eliminated nul's out of hand.  If the
         * beautify option was set, it also deleted any unknown
         * ASCII value less than space (040) and the del character
         * (0177), except for tabs.  Unknown is a key word here.
         * Most vi documentation claims that it deleted everything
         * but <tab>, <nl> and <ff>, as that's what the original
         * 4BSD documentation said.  This is obviously wrong,
         * however, as <esc> would be included in that list.  What
         * we do is eliminate any unquoted, iscntrl() character that
         * wasn't a replay and wasn't handled specially, except
         * <tab> or <ff>.
         */
        if (LF_ISSET(TXT_BEAUTIFY) && iscntrl(evp->e_c) &&
            evp->e_value != K_FORMFEED && evp->e_value != K_TAB) {
            msgq(sp, M_BERR,
                "192|Illegal character; quote to enter");
            if (LF_ISSET(TXT_REPLAY))
                goto done;
            break;
        }

insq_ch:    /*
         * If entering a non-word character after a word, check for
         * abbreviations.  If there was one, discard replay characters.
         * If entering a blank character, check for unmap commands,
         * as well.
         */
        if (!inword(evp->e_c)) {
            if (abb == AB_INWORD &&
                !LF_ISSET(TXT_REPLAY) && F_ISSET(gp, G_ABBREV)) {
                if (txt_abbrev(sp, tp, &evp->e_c,
                    LF_ISSET(TXT_INFOLINE), &tmp, &ab_turnoff))
                    goto err;
                if (tmp) {
                    if (LF_ISSET(TXT_RECORD))
                        rcol -= tmp + 1;
                    goto resolve;
                }
            }
            if (isblank(evp->e_c) && UNMAP_TST)
                txt_unmap(sp, tp, &ec_flags);
        }
        if (abb != AB_NOTSET)
            abb = inword(evp->e_c) ? AB_INWORD : AB_NOTWORD;

insl_ch:    if (txt_insch(sp, tp, &evp->e_c, flags))
            goto err;

        /*
         * If we're using K_VLNEXT to quote the next character, then
         * we want the cursor to position itself on the ^ placeholder
         * we're displaying, to match historic practice.
         */
        if (quote == Q_VNEXT) {
            --tp->cno;
            ++tp->owrite;
        }

        /*
         * !!!
         * Translate "<CH_HEX>[isxdigit()]*" to a character with
         * a hex value: this test delimits the value by the max
         * number of hex bytes.  Offset by one, we use 0 to mean
         * that we've found <CH_HEX>.
         */
        if (hexcnt != 0 && hexcnt++ == sizeof(CHAR_T) * 2 + 1) {
            hexcnt = 0;
            if (txt_hex(sp, tp))
                goto err;
        }

        /*
         * Check to see if we've crossed the margin.
         *
         * !!!
         * In the historic vi, the wrapmargin value was figured out
         * using the display widths of the characters, i.e. <tab>
         * characters were counted as two characters if the list edit
         * option is set, but as the tabstop edit option number of
         * characters otherwise.  That's what the vs_column() function
         * gives us, so we use it.
         */
        if (margin != 0) {
            if (vs_column(sp, &tcol))
                goto err;
            if (tcol >= margin) {
                if (txt_margin(sp, tp, &wmt, &tmp, flags))
                    goto err;
                if (tmp) {
                    if (isblank(evp->e_c))
                        wm_skip = 1;
                    wm_set = 1;
                    goto k_cr;
                }
            }
        }

        /*
         * If we've reached the end of the buffer, then we need to
         * switch into insert mode.  This happens when there's a
         * change to a mark and the user puts in more characters than
         * the length of the motion.
         */
ebuf_chk:    if (tp->cno >= tp->len) {
            BINC_GOTO(sp, tp->lb, tp->lb_len, tp->len + 1);
            LF_SET(TXT_APPENDEOL);

            tp->lb[tp->cno] = CH_CURSOR;
            ++tp->insert;
            ++tp->len;
        }

        /* Step the quote state forward. */
        if (quote != Q_NOTSET) {
            if (quote == Q_BNEXT)
                quote = Q_BTHIS;
            if (quote == Q_VNEXT)
                quote = Q_VTHIS;
        }
        break;
    }

#ifdef DEBUG
    if (tp->cno + tp->insert + tp->owrite != tp->len) {
        msgq(sp, M_ERR,
            "len %u != cno: %u ai: %u insert %u overwrite %u",
            tp->len, tp->cno, tp->ai, tp->insert, tp->owrite);
        if (LF_ISSET(TXT_REPLAY))
            goto done;
        tp->len = tp->cno + tp->insert + tp->owrite;
    }
#endif

resolve:/*
     * 1: If we don't need to know where the cursor really is and we're
     *    replaying text, keep going.
     */
    if (margin == 0 && LF_ISSET(TXT_REPLAY))
        goto replay;

    /*
     * 2: Reset the line.  Don't bother unless we're about to wait on
     *    a character or we need to know where the cursor really is.
     *    We have to do this before showing matching characters so the
     *    user can see what they're matching.
     */
    if ((margin != 0 || !KEYS_WAITING(sp)) &&
        vs_change(sp, tp->lno, LINE_RESET))
        return (1);

    /*
     * 3: If there aren't keys waiting, display the matching character.
     *    We have to do this before resolving any messages, otherwise
     *    the error message from a missing match won't appear correctly.
     */
    if (showmatch) {
        if (!KEYS_WAITING(sp) && txt_showmatch(sp, tp))
            return (1);
        showmatch = 0;
    }

    /*
     * 4: If there have been messages and we're not editing on the colon
     *    command line or doing file name completion, resolve them.
     */
    if ((vip->totalcount != 0 || F_ISSET(gp, G_BELLSCHED)) &&
        !F_ISSET(sp, SC_TINPUT_INFO) && !filec_redraw &&
        vs_resolve(sp, NULL, 0))
        return (1);

    /*
     * 5: Refresh the screen if we're about to wait on a character or we
     *    need to know where the cursor really is.
     */
    if (margin != 0 || !KEYS_WAITING(sp)) {
        UPDATE_POSITION(sp, tp);
        if (vs_refresh(sp, margin != 0))
            return (1);
    }

    /* 6: Proceed with the incremental search. */
    if (FL_ISSET(is_flags, IS_RUNNING) && txt_isrch(sp, vp, tp, &is_flags))
        return (1);

    /* 7: Next character... */
    if (LF_ISSET(TXT_REPLAY))
        goto replay;
    goto next;

done:    /* Leave input mode. */
    F_CLR(sp, SC_TINPUT);

    /* If recording for playback, save it. */
    if (LF_ISSET(TXT_RECORD))
        vip->rep_cnt = rcol;

    /*
     * If not working on the colon command line, set the final cursor
     * position.
     */
    if (!F_ISSET(sp, SC_TINPUT_INFO)) {
        vp->m_final.lno = tp->lno;
        vp->m_final.cno = tp->cno;
    }
    return (0);

err:
alloc_err:
    txt_err(sp, &sp->tiq);
    return (1);
}

/*
 * txt_abbrev --
 *    Handle abbreviations.
 */
static int
txt_abbrev(sp, tp, pushcp, isinfoline, didsubp, turnoffp)
    SCR *sp;
    TEXT *tp;
    CHAR_T *pushcp;
    int isinfoline, *didsubp, *turnoffp;
{
    VI_PRIVATE *vip;
    CHAR_T ch, *p;
    SEQ *qp;
    size_t len, off;

    /* Check to make sure we're not at the start of an append. */
    *didsubp = 0;
    if (tp->cno == tp->offset)
        return (0);

    vip = VIP(sp);

    /*
     * Find the start of the "word".
     *
     * !!!
     * We match historic practice, which, as far as I can tell, had an
     * off-by-one error.  The way this worked was that when the inserted
     * text switched from a "word" character to a non-word character,
     * vi would check for possible abbreviations.  It would then take the
     * type (i.e. word/non-word) of the character entered TWO characters
     * ago, and move backward in the text until reaching a character that
     * was not that type, or the beginning of the insert, the line, or
     * the file.  For example, in the string "abc<space>", when the <space>
     * character triggered the abbreviation check, the type of the 'b'
     * character was used for moving through the string.  Maybe there's a
     * reason for not using the first (i.e. 'c') character, but I can't
     * think of one.
     *
     * Terminate at the beginning of the insert or the character after the
     * offset character -- both can be tested for using tp->offset.
     */
    off = tp->cno - 1;            /* Previous character. */
    p = tp->lb + off;
    len = 1;                /* One character test. */
    if (off == tp->offset || isblank(p[-1]))
        goto search;
    if (inword(p[-1]))            /* Move backward to change. */
        for (;;) {
            --off; --p; ++len;
            if (off == tp->offset || !inword(p[-1]))
                break;
        }
    else
        for (;;) {
            --off; --p; ++len;
            if (off == tp->offset ||
                inword(p[-1]) || isblank(p[-1]))
                break;
        }

    /*
     * !!!
     * Historic vi exploded abbreviations on the command line.  This has
     * obvious problems in that unabbreviating the string can be extremely
     * tricky, particularly if the string has, say, an embedded escape
     * character.  Personally, I think it's a stunningly bad idea.  Other
     * examples of problems this caused in historic vi are:
     *    :ab foo bar
     *    :ab foo baz
     * results in "bar" being abbreviated to "baz", which wasn't what the
     * user had in mind at all.  Also, the commands:
     *    :ab foo bar
     *    :unab foo<space>
     * resulted in an error message that "bar" wasn't mapped.  Finally,
     * since the string was already exploded by the time the unabbreviate
     * command got it, all it knew was that an abbreviation had occurred.
     * Cleverly, it checked the replacement string for its unabbreviation
     * match, which meant that the commands:
     *    :ab foo1 bar
     *    :ab foo2 bar
     *    :unab foo2
     * unabbreviate "foo1", and the commands:
     *    :ab foo bar
     *    :ab bar baz
     * unabbreviate "foo"!
     *
     * Anyway, people neglected to first ask my opinion before they wrote
     * macros that depend on this stuff, so, we make this work as follows.
     * When checking for an abbreviation on the command line, if we get a
     * string which is <blank> terminated and which starts at the beginning
     * of the line, we check to see it is the abbreviate or unabbreviate
     * commands.  If it is, turn abbreviations off and return as if no
     * abbreviation was found.  Note also, minor trickiness, so that if
     * the user erases the line and starts another command, we turn the
     * abbreviations back on.
     *
     * This makes the layering look like a Nachos Supreme.
     */
search:    if (isinfoline)
        if (off == tp->ai || off == tp->offset)
            if (ex_is_abbrev(p, len)) {
                *turnoffp = 1;
                return (0);
            } else
                *turnoffp = 0;
        else
            if (*turnoffp)
                return (0);

    /* Check for any abbreviations. */
    if ((qp = seq_find(sp, NULL, NULL, p, len, SEQ_ABBREV, NULL)) == NULL)
        return (0);

    /*
     * Push the abbreviation onto the tty stack.  Historically, characters
     * resulting from an abbreviation expansion were themselves subject to
     * map expansions, O_SHOWMATCH matching etc.  This means the expanded
     * characters will be re-tested for abbreviations.  It's difficult to
     * know what historic practice in this case was, since abbreviations
     * were applied to :colon command lines, so entering abbreviations that
     * looped was tricky, although possible.  In addition, obvious loops
     * didn't work as expected.  (The command ':ab a b|ab b c|ab c a' will
     * silently only implement and/or display the last abbreviation.)
     *
     * This implementation doesn't recover well from such abbreviations.
     * The main input loop counts abbreviated characters, and, when it
     * reaches a limit, discards any abbreviated characters on the queue.
     * It's difficult to back up to the original position, as the replay
     * queue would have to be adjusted, and the line state when an initial
     * abbreviated character was received would have to be saved.
     */
    ch = *pushcp;
    if (v_event_push(sp, NULL, &ch, 1, CH_ABBREVIATED))
        return (1);
    if (v_event_push(sp, NULL, qp->output, qp->olen, CH_ABBREVIATED))
        return (1);

    /*
     * If the size of the abbreviation is larger than or equal to the size
     * of the original text, move to the start of the replaced characters,
     * and add their length to the overwrite count.
     *
     * If the abbreviation is smaller than the original text, we have to
     * delete the additional overwrite characters and copy down any insert
     * characters.
     */
    tp->cno -= len;
    if (qp->olen >= len)
        tp->owrite += len;
    else {
        if (tp->insert)
            memmove(tp->lb + tp->cno + qp->olen,
                tp->lb + tp->cno + tp->owrite + len, tp->insert);
        tp->owrite += qp->olen;
        tp->len -= len - qp->olen;
    }

    /*
     * We return the length of the abbreviated characters.  This is so
     * the calling routine can replace the replay characters with the
     * abbreviation.  This means that subsequent '.' commands will produce
     * the same text, regardless of intervening :[un]abbreviate commands.
     * This is historic practice.
     */
    *didsubp = len;
    return (0);
}

/*
 * txt_unmap --
 *    Handle the unmap command.
 */
static void
txt_unmap(sp, tp, ec_flagsp)
    SCR *sp;
    TEXT *tp;
    u_int32_t *ec_flagsp;
{
    size_t len, off;
    char *p;

    /* Find the beginning of this "word". */
    for (off = tp->cno - 1, p = tp->lb + off, len = 0;; --p, --off) {
        if (isblank(*p)) {
            ++p;
            break;
        }
        ++len;
        if (off == tp->ai || off == tp->offset)
            break;
    }

    /*
     * !!!
     * Historic vi exploded input mappings on the command line.  See the
     * txt_abbrev() routine for an explanation of the problems inherent
     * in this.
     *
     * We make this work as follows.  If we get a string which is <blank>
     * terminated and which starts at the beginning of the line, we check
     * to see it is the unmap command.  If it is, we return that the input
     * mapping should be turned off.  Note also, minor trickiness, so that
     * if the user erases the line and starts another command, we go ahead
     * an turn mapping back on.
     */
    if ((off == tp->ai || off == tp->offset) && ex_is_unmap(p, len))
        FL_CLR(*ec_flagsp, EC_MAPINPUT);
    else
        FL_SET(*ec_flagsp, EC_MAPINPUT);
}

/*
 * txt_ai_resolve --
 *    When a line is resolved by <esc>, review autoindent characters.
 */
static void
txt_ai_resolve(sp, tp, changedp)
    SCR *sp;
    TEXT *tp;
    int *changedp;
{
    u_long ts;
    int del;
    size_t cno, len, new, old, scno, spaces, tab_after_sp, tabs;
    char *p;

    *changedp = 0;

    /*
     * If the line is empty, has an offset, or no autoindent
     * characters, we're done.
     */
    if (!tp->len || tp->offset || !tp->ai)
        return;

    /*
     * If the length is less than or equal to the autoindent
     * characters, delete them.
     */
    if (tp->len <= tp->ai) {
        tp->ai = tp->cno = tp->len = 0;
        return;
    }

    /*
     * The autoindent characters plus any leading <blank> characters
     * in the line are resolved into the minimum number of characters.
     * Historic practice.
     */
    ts = O_VAL(sp, O_TABSTOP);

    /* Figure out the last <blank> screen column. */
    for (p = tp->lb, scno = 0, len = tp->len,
        spaces = tab_after_sp = 0; len-- && isblank(*p); ++p)
        if (*p == '\t') {
            if (spaces)
                tab_after_sp = 1;
            scno += COL_OFF(scno, ts);
        } else {
            ++spaces;
            ++scno;
        }

    /*
     * If there are no spaces, or no tabs after spaces and less than
     * ts spaces, it's already minimal.
     */
    if (!spaces || !tab_after_sp && spaces < ts)
        return;

    /* Count up spaces/tabs needed to get to the target. */
    for (cno = 0, tabs = 0; cno + COL_OFF(cno, ts) <= scno; ++tabs)
        cno += COL_OFF(cno, ts);
    spaces = scno - cno;

    /*
     * Figure out how many characters we're dropping -- if we're not
     * dropping any, it's already minimal, we're done.
     */
    old = p - tp->lb;
    new = spaces + tabs;
    if (old == new)
        return;

    /* Shift the rest of the characters down, adjust the counts. */
    del = old - new;
    memmove(p - del, p, tp->len - old);
    tp->len -= del;
    tp->cno -= del;

    /* Fill in space/tab characters. */
    for (p = tp->lb; tabs--;)
        *p++ = '\t';
    while (spaces--)
        *p++ = ' ';
    *changedp = 1;
}

/*
 * v_txt_auto --
 *    Handle autoindent.  If aitp isn't NULL, use it, otherwise,
 *    retrieve the line.
 *
 * PUBLIC: int v_txt_auto __P((SCR *, recno_t, TEXT *, size_t, TEXT *));
 */
int
v_txt_auto(sp, lno, aitp, len, tp)
    SCR *sp;
    recno_t lno;
    TEXT *aitp, *tp;
    size_t len;
{
    size_t nlen;
    char *p, *t;

    if (aitp == NULL) {
        /*
         * If the ex append command is executed with an address of 0,
         * it's possible to get here with a line number of 0.  Return
         * an indent of 0.
         */
        if (lno == 0) {
            tp->ai = 0;
            return (0);
        }
        if (db_get(sp, lno, DBG_FATAL, &t, &len))
            return (1);
    } else
        t = aitp->lb;

    /* Count whitespace characters. */
    for (p = t; len > 0; ++p, --len)
        if (!isblank(*p))
            break;

    /* Set count, check for no indentation. */
    if ((nlen = (p - t)) == 0)
        return (0);

    /* Make sure the buffer's big enough. */
    BINC_RET(sp, tp->lb, tp->lb_len, tp->len + nlen);

    /* Copy the buffer's current contents up. */
    if (tp->len != 0)
        memmove(tp->lb + nlen, tp->lb, tp->len);
    tp->len += nlen;

    /* Copy the indentation into the new buffer. */
    memmove(tp->lb, t, nlen);

    /* Set the autoindent count. */
    tp->ai = nlen;
    return (0);
}

/*
 * txt_backup --
 *    Back up to the previously edited line.
 */
static TEXT *
txt_backup(sp, tiqh, tp, flagsp)
    SCR *sp;
    TEXTH *tiqh;
    TEXT *tp;
    u_int32_t *flagsp;
{
    VI_PRIVATE *vip;
    TEXT *ntp;

    /* Get a handle on the previous TEXT structure. */
    if ((ntp = tp->q.cqe_prev) == (void *)tiqh) {
        if (!FL_ISSET(*flagsp, TXT_REPLAY))
            msgq(sp, M_BERR,
                "193|Already at the beginning of the insert");
        return (tp);
    }

    /* Bookkeeping. */
    ntp->len = ntp->sv_len;

    /* Handle appending to the line. */
    vip = VIP(sp);
    if (ntp->owrite == 0 && ntp->insert == 0) {
        ntp->lb[ntp->len] = CH_CURSOR;
        ++ntp->insert;
        ++ntp->len;
        FL_SET(*flagsp, TXT_APPENDEOL);
    } else
        FL_CLR(*flagsp, TXT_APPENDEOL);

    /* Release the current TEXT. */
    CIRCLEQ_REMOVE(tiqh, tp, q);
    text_free(tp);

    /* Update the old line on the screen. */
    if (vs_change(sp, ntp->lno + 1, LINE_DELETE))
        return (NULL);

    /* Return the new/current TEXT. */
    return (ntp);
}

/*
 * Text indentation is truly strange.  ^T and ^D do movements to the next or
 * previous shiftwidth value, i.e. for a 1-based numbering, with shiftwidth=3,
 * ^T moves a cursor on the 7th, 8th or 9th column to the 10th column, and ^D
 * moves it back.
 *
 * !!!
 * The ^T and ^D characters in historical vi had special meaning only when they
 * were the first characters entered after entering text input mode.  As normal
 * erase characters couldn't erase autoindent characters (^T in this case), it
 * meant that inserting text into previously existing text was strange -- ^T
 * only worked if it was the first keystroke(s), and then could only be erased
 * using ^D.  This implementation treats ^T specially anywhere it occurs in the
 * input, and permits the standard erase characters to erase the characters it
 * inserts.
 *
 * !!!
 * A fun test is to try:
 *    :se sw=4 ai list
 *    i<CR>^Tx<CR>^Tx<CR>^Tx<CR>^Dx<CR>^Dx<CR>^Dx<esc>
 * Historic vi loses some of the '$' marks on the line ends, but otherwise gets
 * it right.
 *
 * XXX
 * Technically, txt_dent should be part of the screen interface, as it requires
 * knowledge of character sizes, including <space>s, on the screen.  It's here
 * because it's a complicated little beast, and I didn't want to shove it down
 * into the screen.  It's probable that KEY_LEN will call into the screen once
 * there are screens with different character representations.
 *
 * txt_dent --
 *    Handle ^T indents, ^D outdents.
 *
 * If anything changes here, check the ex version to see if it needs similar
 * changes.
 */
static int
txt_dent(sp, tp, isindent)
    SCR *sp;
    TEXT *tp;
    int isindent;
{
    CHAR_T ch;
    u_long sw, ts;
    size_t cno, current, spaces, target, tabs, off;
    int ai_reset;

    ts = O_VAL(sp, O_TABSTOP);
    sw = O_VAL(sp, O_SHIFTWIDTH);

    /*
     * Since we don't know what precedes the character(s) being inserted
     * (or deleted), the preceding whitespace characters must be resolved.
     * An example is a <tab>, which doesn't need a full shiftwidth number
     * of columns because it's preceded by <space>s.  This is easy to get
     * if the user sets shiftwidth to a value less than tabstop (or worse,
     * something for which tabstop isn't a multiple) and then uses ^T to
     * indent, and ^D to outdent.
     *
     * Figure out the current and target screen columns.  In the historic
     * vi, the autoindent column was NOT determined using display widths
     * of characters as was the wrapmargin column.  For that reason, we
     * can't use the vs_column() function, but have to calculate it here.
     * This is slow, but it's normally only on the first few characters of
     * a line.
     */
    for (current = cno = 0; cno < tp->cno; ++cno)
        current += tp->lb[cno] == '\t' ?
            COL_OFF(current, ts) : KEY_LEN(sp, tp->lb[cno]);

    target = current;
    if (isindent)
        target += COL_OFF(target, sw);
    else
        target -= --target % sw;

    /*
     * The AI characters will be turned into overwrite characters if the
     * cursor immediately follows them.  We test both the cursor position
     * and the indent flag because there's no single test.  (^T can only
     * be detected by the cursor position, and while we know that the test
     * is always true for ^D, the cursor can be in more than one place, as
     * "0^D" and "^D" are different.)
     */
    ai_reset = !isindent || tp->cno == tp->ai + tp->offset;

    /*
     * Back up over any previous <blank> characters, changing them into
     * overwrite characters (including any ai characters).  Then figure
     * out the current screen column.
     */
    for (; tp->cno > tp->offset &&
        (tp->lb[tp->cno - 1] == ' ' || tp->lb[tp->cno - 1] == '\t');
        --tp->cno, ++tp->owrite);
    for (current = cno = 0; cno < tp->cno; ++cno)
        current += tp->lb[cno] == '\t' ?
            COL_OFF(current, ts) : KEY_LEN(sp, tp->lb[cno]);

    /*
     * If we didn't move up to or past the target, it's because there
     * weren't enough characters to delete, e.g. the first character
     * of the line was a tp->offset character, and the user entered
     * ^D to move to the beginning of a line.  An example of this is:
     *
     *    :set ai sw=4<cr>i<space>a<esc>i^T^D
     *
     * Otherwise, count up the total spaces/tabs needed to get from the
     * beginning of the line (or the last non-<blank> character) to the
     * target.
     */
    if (current >= target)
        spaces = tabs = 0;
    else {
        for (cno = current,
            tabs = 0; cno + COL_OFF(cno, ts) <= target; ++tabs)
            cno += COL_OFF(cno, ts);
        spaces = target - cno;
    }

    /* If we overwrote ai characters, reset the ai count. */
    if (ai_reset)
        tp->ai = tabs + spaces;

    /*
     * Call txt_insch() to insert each character, so that we get the
     * correct effect when we add a <tab> to replace N <spaces>.
     */
    for (ch = '\t'; tabs > 0; --tabs)
        (void)txt_insch(sp, tp, &ch, 0);
    for (ch = ' '; spaces > 0; --spaces)
        (void)txt_insch(sp, tp, &ch, 0);
    return (0);
}

/*
 * txt_fc --
 *    File name completion.
 */
static int
txt_fc(sp, tp, redrawp)
    SCR *sp;
    TEXT *tp;
    int *redrawp;
{
    struct stat sb;
    ARGS **argv;
    CHAR_T s_ch;
    EXCMD cmd;
    size_t indx, len, nlen, off;
    int argc, trydir;
    char *p, *t;

    trydir = 0;
    *redrawp = 0;

    /*
     * Find the beginning of this "word" -- if we're at the beginning
     * of the line, it's a special case.
     */
    if (tp->cno == 1) {
        len = 0;
        p = tp->lb;
    } else
retry:        for (len = 0,
            off = tp->cno - 1, p = tp->lb + off;; --off, --p) {
            if (isblank(*p)) {
                ++p;
                break;
            }
            ++len;
            if (off == tp->ai || off == tp->offset)
                break;
        }

    /*
     * Get enough space for a wildcard character.
     *
     * XXX
     * This won't work for "foo\", since the \ will escape the expansion
     * character.  I'm not sure if that's a bug or not...
     */
    off = p - tp->lb;
    BINC_RET(sp, tp->lb, tp->lb_len, tp->len + 1);
    p = tp->lb + off;

    s_ch = p[len];
    p[len] = '*';

    /* Build an ex command, and call the ex expansion routines. */
    ex_cinit(&cmd, 0, 0, OOBLNO, OOBLNO, 0, NULL);
    if (argv_init(sp, &cmd))
        return (1);
    if (argv_exp2(sp, &cmd, p, len + 1)) {
        p[len] = s_ch;
        return (0);
    }
    argc = cmd.argc;
    argv = cmd.argv;

    p[len] = s_ch;

    switch (argc) {
    case 0:                /* No matches. */
        if (!trydir)
            (void)sp->gp->scr_bell(sp);
        return (0);
    case 1:                /* One match. */
        /* If something changed, do the exchange. */
        nlen = strlen(cmd.argv[0]->bp);
        if (len != nlen || memcmp(cmd.argv[0]->bp, p, len))
            break;

        /* If haven't done a directory test, do it now. */
        if (!trydir &&
            !stat(cmd.argv[0]->bp, &sb) && S_ISDIR(sb.st_mode)) {
            p += len;
            goto isdir;
        }

        /* If nothing changed, period, ring the bell. */
        if (!trydir)
            (void)sp->gp->scr_bell(sp);
        return (0);
    default:            /* Multiple matches. */
        *redrawp = 1;
        if (txt_fc_col(sp, argc, argv))
            return (1);

        /* Find the length of the shortest match. */
        for (nlen = cmd.argv[0]->len; --argc > 0;) {
            if (cmd.argv[argc]->len < nlen)
                nlen = cmd.argv[argc]->len;
            for (indx = 0; indx < nlen &&
                cmd.argv[argc]->bp[indx] == cmd.argv[0]->bp[indx];
                ++indx);
            nlen = indx;
        }
        break;
    }

    /* Overwrite the expanded text first. */
    for (t = cmd.argv[0]->bp; len > 0 && nlen > 0; --len, --nlen)
        *p++ = *t++;

    /* If lost text, make the remaining old text overwrite characters. */
    if (len) {
        tp->cno -= len;
        tp->owrite += len;
    }

    /* Overwrite any overwrite characters next. */
    for (; nlen > 0 && tp->owrite > 0; --nlen, --tp->owrite, ++tp->cno)
        *p++ = *t++;

    /* Shift remaining text up, and move the cursor to the end. */
    if (nlen) {
        off = p - tp->lb;
        BINC_RET(sp, tp->lb, tp->lb_len, tp->len + nlen);
        p = tp->lb + off;

        tp->cno += nlen;
        tp->len += nlen;

        if (tp->insert != 0)
            (void)memmove(p + nlen, p, tp->insert);
        while (nlen--)
            *p++ = *t++;
    }

    /* If a single match and it's a directory, retry it. */
    if (argc == 1 && !stat(cmd.argv[0]->bp, &sb) && S_ISDIR(sb.st_mode)) {
isdir:        if (tp->owrite == 0) {
            off = p - tp->lb;
            BINC_RET(sp, tp->lb, tp->lb_len, tp->len + 1);
            p = tp->lb + off;
            if (tp->insert != 0)
                (void)memmove(p + 1, p, tp->insert);
            ++tp->len;
        } else
            --tp->owrite;

        ++tp->cno;
        *p++ = '/';

        trydir = 1;
        goto retry;
    }
    return (0);
}

/*
 * txt_fc_col --
 *    Display file names for file name completion.
 */
static int
txt_fc_col(sp, argc, argv)
    SCR *sp;
    int argc;
    ARGS **argv;
{
    ARGS **av;
    CHAR_T *p;
    GS *gp;
    size_t base, cnt, col, colwidth, numrows, numcols, prefix, row;
    int ac, nf, reset;

    gp = sp->gp;

    /* Trim any directory prefix common to all of the files. */
    if ((p = strrchr(argv[0]->bp, '/')) == NULL)
        prefix = 0;
    else {
        prefix = (p - argv[0]->bp) + 1;
        for (ac = argc - 1, av = argv + 1; ac > 0; --ac, ++av)
            if (av[0]->len < prefix ||
                memcmp(av[0]->bp, argv[0]->bp, prefix)) {
                prefix = 0;
                break;
            }
    }

    /*
     * Figure out the column width for the longest name.  Output is done on
     * 6 character "tab" boundaries for no particular reason.  (Since we
     * don't output tab characters, we ignore the terminal's tab settings.)
     * Ignore the user's tab setting because we have no idea how reasonable
     * it is.
     */
    for (ac = argc, av = argv, colwidth = 0; ac > 0; --ac, ++av) {
        for (col = 0, p = av[0]->bp + prefix; *p != '\0'; ++p)
            col += KEY_LEN(sp, *p);
        if (col > colwidth)
            colwidth = col;
    }
    colwidth += COL_OFF(colwidth, 6);

    /*
     * Writing to the bottom line of the screen is always turned off when
     * SC_TINPUT_INFO is set.  Turn it back on, we know what we're doing.
     */
    if (F_ISSET(sp, SC_TINPUT_INFO)) {
        reset = 1;
        F_CLR(sp, SC_TINPUT_INFO);
    } else
        reset = 0;

#define    CHK_INTR                            \
    if (F_ISSET(gp, G_INTERRUPTED))                    \
        goto intr;

    /* If the largest file name is too large, just print them. */
    if (colwidth > sp->cols) {
        p = msg_print(sp, av[0]->bp + prefix, &nf);
        for (ac = argc, av = argv; ac > 0; --ac, ++av) {
            (void)ex_printf(sp, "%s\n", p);
            if (F_ISSET(gp, G_INTERRUPTED))
                break;
        }
        if (nf)
            FREE_SPACE(sp, p, 0);
        CHK_INTR;
    } else {
        /* Figure out the number of columns. */
        numcols = (sp->cols - 1) / colwidth;
        if (argc > numcols) {
            numrows = argc / numcols;
            if (argc % numcols)
                ++numrows;
        } else
            numrows = 1;

        /* Display the files in sorted order. */
        for (row = 0; row < numrows; ++row) {
            for (base = row, col = 0; col < numcols; ++col) {
                p = msg_print(sp, argv[base]->bp + prefix, &nf);
                cnt = ex_printf(sp, "%s", p);
                if (nf)
                    FREE_SPACE(sp, p, 0);
                CHK_INTR;
                if ((base += numrows) >= argc)
                    break;
                (void)ex_printf(sp,
                    "%*s", (int)(colwidth - cnt), "");
                CHK_INTR;
            }
            (void)ex_puts(sp, "\n");
            CHK_INTR;
        }
        (void)ex_puts(sp, "\n");
        CHK_INTR;
    }
    (void)ex_fflush(sp);

    if (0) {
intr:        F_CLR(gp, G_INTERRUPTED);
    }
    if (reset)
        F_SET(sp, SC_TINPUT_INFO);

    return (0);
}

/*
 * txt_emark --
 *    Set the end mark on the line.
 */
static int
txt_emark(sp, tp, cno)
    SCR *sp;
    TEXT *tp;
    size_t cno;
{
    CHAR_T ch, *kp;
    size_t chlen, nlen, olen;
    char *p;

    ch = CH_ENDMARK;

    /*
     * The end mark may not be the same size as the current character.
     * Don't let the line shift.
     */
    nlen = KEY_LEN(sp, ch);
    if (tp->lb[cno] == '\t')
        (void)vs_columns(sp, tp->lb, tp->lno, &cno, &olen);
    else
        olen = KEY_LEN(sp, tp->lb[cno]);

    /*
     * If the line got longer, well, it's weird, but it's easy.  If
     * it's the same length, it's easy.  If it got shorter, we have
     * to fix it up.
     */
    if (olen > nlen) {
        BINC_RET(sp, tp->lb, tp->lb_len, tp->len + olen);
        chlen = olen - nlen;
        if (tp->insert != 0)
            memmove(tp->lb + cno + 1 + chlen,
                tp->lb + cno + 1, tp->insert);

        tp->len += chlen;
        tp->owrite += chlen;
        p = tp->lb + cno;
        if (tp->lb[cno] == '\t')
            for (cno += chlen; chlen--;)
                *p++ = ' ';
        else
            for (kp = KEY_NAME(sp, tp->lb[cno]),
                cno += chlen; chlen--;)
                *p++ = *kp++;
    }
    tp->lb[cno] = ch;
    return (vs_change(sp, tp->lno, LINE_RESET));
}

/*
 * txt_err --
 *    Handle an error during input processing.
 */
static void
txt_err(sp, tiqh)
    SCR *sp;
    TEXTH *tiqh;
{
    recno_t lno;

    /*
     * The problem with input processing is that the cursor is at an
     * indeterminate position since some input may have been lost due
     * to a malloc error.  So, try to go back to the place from which
     * the cursor started, knowing that it may no longer be available.
     *
     * We depend on at least one line number being set in the text
     * chain.
     */
    for (lno = tiqh->cqh_first->lno;
        !db_exist(sp, lno) && lno > 0; --lno);

    sp->lno = lno == 0 ? 1 : lno;
    sp->cno = 0;

    /* Redraw the screen, just in case. */
    F_SET(sp, SC_SCR_REDRAW);
}

/*
 * txt_hex --
 *    Let the user insert any character value they want.
 *
 * !!!
 * This is an extension.  The pattern "^X[0-9a-fA-F]*" is a way
 * for the user to specify a character value which their keyboard
 * may not be able to enter.
 */
static int
txt_hex(sp, tp)
    SCR *sp;
    TEXT *tp;
{
    CHAR_T savec;
    size_t len, off;
    u_long value;
    char *p, *wp;

    /*
     * Null-terminate the string.  Since nul isn't a legal hex value,
     * this should be okay, and lets us use a local routine, which
     * presumably understands the character set, to convert the value.
     */
    savec = tp->lb[tp->cno];
    tp->lb[tp->cno] = 0;

    /* Find the previous CH_HEX character. */
    for (off = tp->cno - 1, p = tp->lb + off, len = 0;; --p, --off, ++len) {
        if (*p == CH_HEX) {
            wp = p + 1;
            break;
        }
        /* Not on this line?  Shouldn't happen. */
        if (off == tp->ai || off == tp->offset)
            goto nothex;
    }

    /* If length of 0, then it wasn't a hex value. */
    if (len == 0)
        goto nothex;

    /* Get the value. */
    errno = 0;
    value = strtol(wp, NULL, 16);
    if (errno || value > MAX_CHAR_T) {
nothex:        tp->lb[tp->cno] = savec;
        return (0);
    }

    /* Restore the original character. */
    tp->lb[tp->cno] = savec;

    /* Adjust the bookkeeping. */
    tp->cno -= len;
    tp->len -= len;
    tp->lb[tp->cno - 1] = value;

    /* Copy down any overwrite characters. */
    if (tp->owrite)
        memmove(tp->lb + tp->cno, tp->lb + tp->cno + len, tp->owrite);

    /* Copy down any insert characters. */
    if (tp->insert)
        memmove(tp->lb + tp->cno + tp->owrite,
            tp->lb + tp->cno + tp->owrite + len, tp->insert);

    return (0);
}

/*
 * txt_insch --
 *
 * !!!
 * Historic vi did a special screen optimization for tab characters.  As an
 * example, for the keystrokes "iabcd<esc>0C<tab>", the tab overwrote the
 * rest of the string when it was displayed.
 *
 * Because early versions of this implementation redisplayed the entire line
 * on each keystroke, the "bcd" was pushed to the right as it ignored that
 * the user had "promised" to change the rest of the characters.  However,
 * the historic vi implementation had an even worse bug: given the keystrokes
 * "iabcd<esc>0R<tab><esc>", the "bcd" disappears, and magically reappears
 * on the second <esc> key.
 *
 * POSIX 1003.2 requires (will require) that this be fixed, specifying that
 * vi overwrite characters the user has committed to changing, on the basis
 * of the screen space they require, but that it not overwrite other characters.
 */
static int
txt_insch(sp, tp, chp, flags)
    SCR *sp;
    TEXT *tp;
    CHAR_T *chp;
    u_int flags;
{
    CHAR_T *kp, savech;
    size_t chlen, cno, copydown, olen, nlen;
    char *p;

    /*
     * The 'R' command does one-for-one replacement, because there's
     * no way to know how many characters the user intends to replace.
     */
    if (LF_ISSET(TXT_REPLACE)) {
        if (tp->owrite) {
            --tp->owrite;
            tp->lb[tp->cno++] = *chp;
            return (0);
        }
    } else if (tp->owrite) {        /* Overwrite a character. */
        cno = tp->cno;

        /*
         * If the old or new characters are tabs, then the length of the
         * display depends on the character position in the display.  We
         * don't even try to handle this here, just ask the screen.
         */
        if (*chp == '\t') {
            savech = tp->lb[cno];
            tp->lb[cno] = '\t';
            (void)vs_columns(sp, tp->lb, tp->lno, &cno, &nlen);
            tp->lb[cno] = savech;
        } else
            nlen = KEY_LEN(sp, *chp);

        /*
         * Eat overwrite characters until we run out of them or we've
         * handled the length of the new character.  If we only eat
         * part of an overwrite character, break it into its component
         * elements and display the remaining components.
         */
        for (copydown = 0; nlen != 0 && tp->owrite != 0;) {
            --tp->owrite;

            if (tp->lb[cno] == '\t')
                (void)vs_columns(sp,
                    tp->lb, tp->lno, &cno, &olen);
            else
                olen = KEY_LEN(sp, tp->lb[cno]);

            if (olen == nlen) {
                nlen = 0;
                break;
            }
            if (olen < nlen) {
                ++copydown;
                nlen -= olen;
            } else {
                BINC_RET(sp,
                    tp->lb, tp->lb_len, tp->len + olen);
                chlen = olen - nlen;
                memmove(tp->lb + cno + 1 + chlen,
                    tp->lb + cno + 1, tp->owrite + tp->insert);

                tp->len += chlen;
                tp->owrite += chlen;
                if (tp->lb[cno] == '\t')
                    for (p = tp->lb + cno + 1; chlen--;)
                        *p++ = ' ';
                else
                    for (kp =
                        KEY_NAME(sp, tp->lb[cno]) + nlen,
                        p = tp->lb + cno + 1; chlen--;)
                        *p++ = *kp++;
                nlen = 0;
                break;
            }
        }

        /*
         * If had to erase several characters, we adjust the total
         * count, and if there are any characters left, shift them
         * into position.
         */
        if (copydown != 0 && (tp->len -= copydown) != 0)
            memmove(tp->lb + cno, tp->lb + cno + copydown,
                tp->owrite + tp->insert + copydown);

        /* If we had enough overwrite characters, we're done. */
        if (nlen == 0) {
            tp->lb[tp->cno++] = *chp;
            return (0);
        }
    }

    /* Check to see if the character fits into the input buffer. */
    BINC_RET(sp, tp->lb, tp->lb_len, tp->len + 1);

    ++tp->len;
    if (tp->insert) {            /* Insert a character. */
        if (tp->insert == 1)
            tp->lb[tp->cno + 1] = tp->lb[tp->cno];
        else
            memmove(tp->lb + tp->cno + 1,
                tp->lb + tp->cno, tp->owrite + tp->insert);
    }
    tp->lb[tp->cno++] = *chp;
    return (0);
}

/*
 * txt_isrch --
 *    Do an incremental search.
 */
static int
txt_isrch(sp, vp, tp, is_flagsp)
    SCR *sp;
    VICMD *vp;
    TEXT *tp;
    u_int8_t *is_flagsp;
{
    MARK start;
    recno_t lno;
    u_int sf;

    /* If it's a one-line screen, we don't do incrementals. */
    if (IS_ONELINE(sp)) {
        FL_CLR(*is_flagsp, IS_RUNNING);
        return (0);
    }

    /*
     * If the user erases back to the beginning of the buffer, there's
     * nothing to search for.  Reset the cursor to the starting point.
     */
    if (tp->cno <= 1) {
        vp->m_final = vp->m_start;
        return (0);
    }

    /*
     * If it's an RE quote character, and not quoted, ignore it until
     * we get another character.
     */
    if (tp->lb[tp->cno - 1] == '\\' &&
        (tp->cno == 2 || tp->lb[tp->cno - 2] != '\\'))
        return (0);

    /*
     * If it's a magic shell character, and not quoted, reset the cursor
     * to the starting point.
     */
    if (strchr(O_STR(sp, O_SHELLMETA), tp->lb[tp->cno - 1]) != NULL &&
        (tp->cno == 2 || tp->lb[tp->cno - 2] != '\\'))
        vp->m_final = vp->m_start;

    /*
     * If we see the search pattern termination character, then quit doing
     * an incremental search.  There may be more, e.g., ":/foo/;/bar/",
     * and we can't handle that incrementally.  Also, reset the cursor to
     * the original location, the ex search routines don't know anything
     * about incremental searches.
     */
    if (tp->lb[0] == tp->lb[tp->cno - 1] &&
        (tp->cno == 2 || tp->lb[tp->cno - 2] != '\\')) {
        vp->m_final = vp->m_start;
        FL_CLR(*is_flagsp, IS_RUNNING);
        return (0);
    }

    /*
     * Remember the input line and discard the special input map,
     * but don't overwrite the input line on the screen.
     */
    lno = tp->lno;
    F_SET(VIP(sp), VIP_S_MODELINE);
    F_CLR(sp, SC_TINPUT | SC_TINPUT_INFO);
    if (txt_map_end(sp))
        return (1);

    /*
     * Specify a starting point and search.  If we find a match, move to
     * it and refresh the screen.  If we didn't find the match, then we
     * beep the screen.  When searching from the original cursor position,
     * we have to move the cursor, otherwise, we don't want to move the
     * cursor in case the text at the current position continues to match.
     */
    if (FL_ISSET(*is_flagsp, IS_RESTART)) {
        start = vp->m_start;
        sf = SEARCH_SET;
    } else {
        start = vp->m_final;
        sf = SEARCH_INCR | SEARCH_SET;
    }

    if (tp->lb[0] == '/' ?
        !f_search(sp,
        &start, &vp->m_final, tp->lb + 1, tp->cno - 1, NULL, sf) :
        !b_search(sp,
        &start, &vp->m_final, tp->lb + 1, tp->cno - 1, NULL, sf)) {
        sp->lno = vp->m_final.lno;
        sp->cno = vp->m_final.cno;
        FL_CLR(*is_flagsp, IS_RESTART);

        if (!KEYS_WAITING(sp) && vs_refresh(sp, 0))
            return (1);
    } else
        FL_SET(*is_flagsp, IS_RESTART);

    /* Reinstantiate the special input map. */
    if (txt_map_init(sp))
        return (1);
    F_CLR(VIP(sp), VIP_S_MODELINE);
    F_SET(sp, SC_TINPUT | SC_TINPUT_INFO);

    /* Reset the line number of the input line. */
    tp->lno = TMAP[0].lno;

    /*
     * If the colon command-line moved, i.e. the screen scrolled,
     * refresh the input line.
     *
     * XXX
     * We shouldn't be calling vs_line, here -- we need dirty bits
     * on entries in the SMAP array.
     */
    if (lno != TMAP[0].lno) {
        if (vs_line(sp, &TMAP[0], NULL, NULL))
            return (1);
        (void)sp->gp->scr_refresh(sp, 0);
    }
    return (0);
}

/*
 * txt_resolve --
 *    Resolve the input text chain into the file.
 */
static int
txt_resolve(sp, tiqh, flags)
    SCR *sp;
    TEXTH *tiqh;
    u_int32_t flags;
{
    VI_PRIVATE *vip;
    TEXT *tp;
    recno_t lno;
    int changed;

    /*
     * The first line replaces a current line, and all subsequent lines
     * are appended into the file.  Resolve autoindented characters for
     * each line before committing it.  If the latter causes the line to
     * change, we have to redisplay it, otherwise the information cached
     * about the line will be wrong.
     */
    vip = VIP(sp);
    tp = tiqh->cqh_first;

    if (LF_ISSET(TXT_AUTOINDENT))
        txt_ai_resolve(sp, tp, &changed);
    else
        changed = 0;
    if (db_set(sp, tp->lno, tp->lb, tp->len) ||
        changed && vs_change(sp, tp->lno, LINE_RESET))
        return (1);

    for (lno = tp->lno; (tp = tp->q.cqe_next) != (void *)&sp->tiq; ++lno) {
        if (LF_ISSET(TXT_AUTOINDENT))
            txt_ai_resolve(sp, tp, &changed);
        else
            changed = 0;
        if (db_append(sp, 0, lno, tp->lb, tp->len) ||
            changed && vs_change(sp, tp->lno, LINE_RESET))
            return (1);
    }

    /*
     * Clear the input flag, the look-aside buffer is no longer valid.
     * Has to be done as part of text resolution, or upon return we'll
     * be looking at incorrect data.
     */
    F_CLR(sp, SC_TINPUT);

    return (0);
}

/*
 * txt_showmatch --
 *    Show a character match.
 *
 * !!!
 * Historic vi tried to display matches even in the :colon command line.
 * I think not.
 */
static int
txt_showmatch(sp, tp)
    SCR *sp;
    TEXT *tp;
{
    GS *gp;
    VCS cs;
    MARK m;
    int cnt, endc, startc;

    gp = sp->gp;

    /*
     * Do a refresh first, in case we haven't done one in awhile,
     * so the user can see what we're complaining about.
     */
    UPDATE_POSITION(sp, tp);
    if (vs_refresh(sp, 1))
        return (1);

    /*
     * We don't display the match if it's not on the screen.  Find
     * out what the first character on the screen is.
     */
    if (vs_sm_position(sp, &m, 0, P_TOP))
        return (1);

    /* Initialize the getc() interface. */
    cs.cs_lno = tp->lno;
    cs.cs_cno = tp->cno - 1;
    if (cs_init(sp, &cs))
        return (1);
    startc = (endc = cs.cs_ch)  == ')' ? '(' : '{';

    /* Search for the match. */
    for (cnt = 1;;) {
        if (cs_prev(sp, &cs))
            return (1);
        if (cs.cs_flags != 0) {
            if (cs.cs_flags == CS_EOF || cs.cs_flags == CS_SOF) {
                msgq(sp, M_BERR,
                    "Unmatched %s", KEY_NAME(sp, endc));
                return (0);
            }
            continue;
        }
        if (cs.cs_ch == endc)
            ++cnt;
        else if (cs.cs_ch == startc && --cnt == 0)
            break;
    }

    /* If the match is on the screen, move to it. */
    if (cs.cs_lno < m.lno || cs.cs_lno == m.lno && cs.cs_cno < m.cno)
        return (0);
    sp->lno = cs.cs_lno;
    sp->cno = cs.cs_cno;
    if (vs_refresh(sp, 1))
        return (1);

    /* Wait for timeout or character arrival. */
    return (v_event_get(sp,
        NULL, O_VAL(sp, O_MATCHTIME) * 100, EC_TIMEOUT));
}

/*
 * txt_margin --
 *    Handle margin wrap.
 */
static int
txt_margin(sp, tp, wmtp, didbreak, flags)
    SCR *sp;
    TEXT *tp, *wmtp;
    int *didbreak;
    u_int32_t flags;
{
    VI_PRIVATE *vip;
    size_t len, off;
    char *p, *wp;

    /* Find the nearest previous blank. */
    for (off = tp->cno - 1, p = tp->lb + off, len = 0;; --off, --p, ++len) {
        if (isblank(*p)) {
            wp = p + 1;
            break;
        }

        /*
         * If reach the start of the line, there's nowhere to break.
         *
         * !!!
         * Historic vi belled each time a character was entered after
         * crossing the margin until a space was entered which could
         * be used to break the line.  I don't as it tends to wake the
         * cats.
         */
        if (off == tp->ai || off == tp->offset) {
            *didbreak = 0;
            return (0);
        }
    }

    /*
     * Store saved information about the rest of the line in the
     * wrapmargin TEXT structure.
     *
     * !!!
     * The offset field holds the length of the current characters
     * that the user entered, but which are getting split to the new
     * line -- it's going to be used to set the cursor value when we
     * move to the new line.
     */
    vip = VIP(sp);
    wmtp->lb = p + 1;
    wmtp->offset = len;
    wmtp->insert = LF_ISSET(TXT_APPENDEOL) ?  tp->insert - 1 : tp->insert;
    wmtp->owrite = tp->owrite;

    /* Correct current bookkeeping information. */
    tp->cno -= len;
    if (LF_ISSET(TXT_APPENDEOL)) {
        tp->len -= len + tp->owrite + (tp->insert - 1);
        tp->insert = 1;
    } else {
        tp->len -= len + tp->owrite + tp->insert;
        tp->insert = 0;
    }
    tp->owrite = 0;

    /*
     * !!!
     * Delete any trailing whitespace from the current line.
     */
    for (;; --p, --off) {
        if (!isblank(*p))
            break;
        --tp->cno;
        --tp->len;
        if (off == tp->ai || off == tp->offset)
            break;
    }
    *didbreak = 1;
    return (0);
}

/*
 * txt_Rresolve --
 *    Resolve the input line for the 'R' command.
 */
static void
txt_Rresolve(sp, tiqh, tp, orig_len)
    SCR *sp;
    TEXTH *tiqh;
    TEXT *tp;
    const size_t orig_len;
{
    TEXT *ttp;
    size_t input_len, retain;
    char *p;

    /*
     * Check to make sure that the cursor hasn't moved beyond
     * the end of the line.
     */
    if (tp->owrite == 0)
        return;

    /*
     * Calculate how many characters the user has entered,
     * plus the blanks erased by <carriage-return>/<newline>s.
     */
    for (ttp = tiqh->cqh_first, input_len = 0;;) {
        input_len += ttp == tp ? tp->cno : ttp->len + ttp->R_erase;
        if ((ttp = ttp->q.cqe_next) == (void *)&sp->tiq)
            break;
    }

    /*
     * If the user has entered less characters than the original line
     * was long, restore any overwriteable characters to the original
     * characters.  These characters are entered as "insert characters",
     * because they're after the cursor and we don't want to lose them.
     * (This is okay because the R command has no insert characters.)
     * We set owrite to 0 so that the insert characters don't get copied
     * to somewhere else, which means that the line and the length have
     * to be adjusted here as well.
     *
     * We have to retrieve the original line because the original pinned
     * page has long since been discarded.  If it doesn't exist, that's
     * okay, the user just extended the file.
     */
    if (input_len < orig_len) {
        retain = MIN(tp->owrite, orig_len - input_len);
        if (db_get(sp,
            tiqh->cqh_first->lno, DBG_FATAL | DBG_NOCACHE, &p, NULL))
            return;
        memcpy(tp->lb + tp->cno, p + input_len, retain);
        tp->len -= tp->owrite - retain;
        tp->owrite = 0;
        tp->insert += retain;
    }
}

/*
 * txt_nomorech --
 *    No more characters message.
 */
static void
txt_nomorech(sp)
    SCR *sp;
{
    msgq(sp, M_BERR, "194|No more characters to erase");
}