source: trunk/third/nvi/vi/v_replace.c @ 14302

/*-
 * Copyright (c) 1992, 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_replace.c   10.17 (Berkeley) 6/30/96";
#endif /* not lint */

#include <sys/types.h>
#include <sys/queue.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 "../common/common.h"
#include "vi.h"

/*
 * v_replace -- [count]r<char>
 *
 * !!!
 * The r command in historic vi was almost beautiful in its badness.  For
 * example, "r<erase>" and "r<word erase>" beeped the terminal and deleted
 * a single character.  "Nr<carriage return>", where N was greater than 1,
 * inserted a single carriage return.  "r<escape>" did cancel the command,
 * but "r<literal><escape>" erased a single character.  To enter a literal
 * <literal> character, it required three <literal> characters after the
 * command.  This may not be right, but at least it's not insane.
 *
 * PUBLIC: int v_replace __P((SCR *, VICMD *));
 */
int
v_replace(sp, vp)
        SCR *sp;
        VICMD *vp;
{
        EVENT ev;
        VI_PRIVATE *vip;
        TEXT *tp;
        size_t blen, len;
        u_long cnt;
        int quote, rval;
        char *bp, *p;

        vip = VIP(sp);

        /*
         * If the line doesn't exist, or it's empty, replacement isn't
         * allowed.  It's not hard to implement, but:
         *
         *      1: It's historic practice (vi beeped before the replacement
         *         character was even entered).
         *      2: For consistency, this change would require that the more
         *         general case, "Nr", when the user is < N characters from
         *         the end of the line, also work, which would be a bit odd.
         *      3: Replacing with a <newline> has somewhat odd semantics.
         */
        if (db_get(sp, vp->m_start.lno, DBG_FATAL, &p, &len))
                return (1);
        if (len == 0) {
                msgq(sp, M_BERR, "186|No characters to replace");
                return (1);
        }

        /*
         * Figure out how many characters to be replace.  For no particular
         * reason (other than that the semantics of replacing the newline
         * are confusing) only permit the replacement of the characters in
         * the current line.  I suppose we could append replacement characters
         * to the line, but I see no compelling reason to do so.  Check this
         * before we get the character to match historic practice, where Nr
         * failed immediately if there were less than N characters from the
         * cursor to the end of the line.
         */
        cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
        vp->m_stop.lno = vp->m_start.lno;
        vp->m_stop.cno = vp->m_start.cno + cnt - 1;
        if (vp->m_stop.cno > len - 1) {
                v_eol(sp, &vp->m_start);
                return (1);
        }

        /*
         * If it's not a repeat, reset the current mode and get a replacement
         * character.
         */
        quote = 0;
        if (!F_ISSET(vp, VC_ISDOT)) {
                sp->showmode = SM_REPLACE;
                if (vs_refresh(sp, 0))
                        return (1);
next:           if (v_event_get(sp, &ev, 0, 0))
                        return (1);

                switch (ev.e_event) {
                case E_CHARACTER:
                        /*
                         * <literal_next> means escape the next character.
                         * <escape> means they changed their minds.
                         */
                        if (!quote) {
                                if (ev.e_value == K_VLNEXT) {
                                        quote = 1;
                                        goto next;
                                }
                                if (ev.e_value == K_ESCAPE)
                                        return (0);
                        }
                        vip->rlast = ev.e_c;
                        vip->rvalue = ev.e_value;
                        break;
                case E_ERR:
                case E_EOF:
                        F_SET(sp, SC_EXIT_FORCE);
                        return (1);
                case E_INTERRUPT:
                        /* <interrupt> means they changed their minds. */
                        return (0);
                case E_WRESIZE:
                        /* <resize> interrupts the input mode. */
                        v_emsg(sp, NULL, VIM_WRESIZE);
                        return (0);
                case E_REPAINT:
                        if (vs_repaint(sp, &ev))
                                return (1);
                        goto next;
                default:
                        v_event_err(sp, &ev);
                        return (0);
                }
        }

        /* Copy the line. */
        GET_SPACE_RET(sp, bp, blen, len);
        memmove(bp, p, len);
        p = bp;

        /*
         * Versions of nvi before 1.57 created N new lines when they replaced
         * N characters with <carriage-return> or <newline> characters.  This
         * is different from the historic vi, which replaced N characters with
         * a single new line.  Users complained, so we match historic practice.
         */
        if (!quote && vip->rvalue == K_CR || vip->rvalue == K_NL) {
                /* Set return line. */
                vp->m_stop.lno = vp->m_start.lno + 1;
                vp->m_stop.cno = 0;

                /* The first part of the current line. */
                if (db_set(sp, vp->m_start.lno, p, vp->m_start.cno))
                        goto err_ret;

                /*
                 * The rest of the current line.  And, of course, now it gets
                 * tricky.  If there are characters left in the line and if
                 * the autoindent edit option is set, white space after the
                 * replaced character is discarded, autoindent is applied, and
                 * the cursor moves to the last indent character.
                 */
                p += vp->m_start.cno + cnt;
                len -= vp->m_start.cno + cnt;
                if (len != 0 && O_ISSET(sp, O_AUTOINDENT))
                        for (; len && isblank(*p); --len, ++p);

                if ((tp = text_init(sp, p, len, len)) == NULL)
                        goto err_ret;

                if (len != 0 && O_ISSET(sp, O_AUTOINDENT)) {
                        if (v_txt_auto(sp, vp->m_start.lno, NULL, 0, tp))
                                goto err_ret;
                        vp->m_stop.cno = tp->ai ? tp->ai - 1 : 0;
                } else
                        vp->m_stop.cno = 0;

                vp->m_stop.cno = tp->ai ? tp->ai - 1 : 0;
                if (db_append(sp, 1, vp->m_start.lno, tp->lb, tp->len))
err_ret:                rval = 1;
                else {
                        text_free(tp);
                        rval = 0;
                }
        } else {
                memset(bp + vp->m_start.cno, vip->rlast, cnt);
                rval = db_set(sp, vp->m_start.lno, bp, len);
        }
        FREE_SPACE(sp, bp, blen);

        vp->m_final = vp->m_stop;
        return (rval);
}