root/usr.bin/vi/common/put.c
/*      $OpenBSD: put.c,v 1.17 2025/08/23 21:02:10 millert Exp $        */

/*-
 * 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"

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

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

#include "common.h"

/*
 * put --
 *      Put text buffer contents into the file.
 *
 * PUBLIC: int put(SCR *, CB *, CHAR_T *, MARK *, MARK *, int, int);
 */
int
put(SCR *sp, CB *cbp, CHAR_T *namep, MARK *cp, MARK *rp, int append, int cnt)
{
        CHAR_T name;
        TEXT *ltp, *tp;
        recno_t lno;
        size_t blen, clen, len;
        int rval, i, isempty;
        char *bp, *p, *t;

        if (cbp == NULL) {
                if (namep == NULL) {
                        cbp = sp->gp->dcbp;
                        if (cbp == NULL) {
                                msgq(sp, M_ERR,
                                    "The default buffer is empty");
                                return (1);
                        }
                } else {
                        name = *namep;
                        CBNAME(sp, cbp, name);
                        if (cbp == NULL) {
                                msgq(sp, M_ERR, "Buffer %s is empty",
                                    KEY_NAME(sp, name));
                                return (1);
                        }
                }
        }
        tp = TAILQ_FIRST(&cbp->textq);

        /*
         * It's possible to do a put into an empty file, meaning that the cut
         * buffer simply becomes the file.  It's a special case so that we can
         * ignore it in general.
         *
         * !!!
         * Historically, pasting into a file with no lines in vi would preserve
         * the single blank line.  This is surely a result of the fact that the
         * historic vi couldn't deal with a file that had no lines in it.  This
         * implementation treats that as a bug, and does not retain the blank
         * line.
         *
         * Historical practice is that the cursor ends at the first character
         * in the file.
         */
        if (cp->lno == 1) {
                if (db_last(sp, &lno))
                        return (1);
                if (lno == 0 && F_ISSET(cbp, CB_LMODE)) {
                        for (i = cnt; i > 0; i--) {
                                for (; tp; ++lno, ++sp->rptlines[L_ADDED],
                                    tp = TAILQ_NEXT(tp, q))
                                        if (db_append(sp, 1, lno, tp->lb,
                                            tp->len))
                                                return (1);
                                tp = TAILQ_FIRST(&cbp->textq);
                        }
                        rp->lno = 1;
                        rp->cno = 0;
                        return (0);
                }
        }

        /* If a line mode buffer, append each new line into the file. */
        if (F_ISSET(cbp, CB_LMODE)) {
                lno = append ? cp->lno : cp->lno - 1;
                rp->lno = lno + 1;
                for (i = cnt; i > 0; i--) {
                        for (; tp;
                            ++lno, ++sp->rptlines[L_ADDED],
                            tp = TAILQ_NEXT(tp, q))
                                if (db_append(sp, 1, lno, tp->lb, tp->len))
                                        return (1);
                        tp = TAILQ_FIRST(&cbp->textq);
                }
                rp->cno = 0;
                (void)nonblank(sp, rp->lno, &rp->cno);
                return (0);
        }

        /*
         * If buffer was cut in character mode, replace the current line with
         * one built from the portion of the first line to the left of the
         * split plus the first line in the CB.  Append each intermediate line
         * in the CB.  Append a line built from the portion of the first line
         * to the right of the split plus the last line in the CB.
         *
         * Get the first line.
         */
        lno = cp->lno;
        if (db_eget(sp, lno, &p, &len, &isempty)) {
                if (!isempty)
                        return (1);
                len = 0;
        }

        GET_SPACE_RET(sp, bp, blen, tp->len + len + 1);
        t = bp;

        /* Original line, left of the split. */
        if (len > 0 && (clen = cp->cno + (append ? 1 : 0)) > 0) {
                memcpy(bp, p, clen);
                p += clen;
                t += clen;
        }

        /* First line from the CB. */
        if (tp->len != 0) {
                for (i = cnt; i > 0; i--) {
                        memcpy(t, tp->lb, tp->len);
                        t += tp->len;
                }
        }

        /* Calculate length left in the original line. */
        clen = len == 0 ? 0 : len - (cp->cno + (append ? 1 : 0));

        /*
         * !!!
         * In the historical 4BSD version of vi, character mode puts within
         * a single line have two cursor behaviors: if the put is from the
         * unnamed buffer, the cursor moves to the character inserted which
         * appears last in the file.  If the put is from a named buffer,
         * the cursor moves to the character inserted which appears first
         * in the file.  In System III/V, it was changed at some point and
         * the cursor always moves to the first character.  In both versions
         * of vi, character mode puts that cross line boundaries leave the
         * cursor on the first character.  Nvi implements the System III/V
         * behavior, and expect POSIX.2 to do so as well.
         */
        rp->lno = lno;
        rp->cno = len == 0 ? 0 : sp->cno + (append && tp->len ? 1 : 0);

        /*
         * If no more lines in the CB, append the rest of the original
         * line and quit.  Otherwise, build the last line before doing
         * the intermediate lines, because the line changes will lose
         * the cached line.
         */
        if (TAILQ_NEXT(tp, q) == NULL) {
                if (clen > 0) {
                        memcpy(t, p, clen);
                        t += clen;
                }
                if (db_set(sp, lno, bp, t - bp))
                        goto err;
                if (sp->rptlchange != lno) {
                        sp->rptlchange = lno;
                        ++sp->rptlines[L_CHANGED];
                }
        } else {
                /*
                 * Have to build both the first and last lines of the
                 * put before doing any sets or we'll lose the cached
                 * line.  Build both the first and last lines in the
                 * same buffer, so we don't have to have another buffer
                 * floating around.
                 *
                 * Last part of original line; check for space, reset
                 * the pointer into the buffer.
                 */
                ltp = TAILQ_LAST(&cbp->textq, _texth);
                len = t - bp;
                ADD_SPACE_RET(sp, bp, blen, ltp->len + clen);
                t = bp + len;

                /* Add in last part of the CB. */
                memcpy(t, ltp->lb, ltp->len);
                if (clen)
                        memcpy(t + ltp->len, p, clen);
                clen += ltp->len;

                /*
                 * Now: bp points to the first character of the first
                 * line, t points to the last character of the last
                 * line, t - bp is the length of the first line, and
                 * clen is the length of the last.  Just figured you'd
                 * want to know.
                 *
                 * Output the line replacing the original line.
                 */
                if (db_set(sp, lno, bp, t - bp))
                        goto err;
                if (sp->rptlchange != lno) {
                        sp->rptlchange = lno;
                        ++sp->rptlines[L_CHANGED];
                }

                /* Output any intermediate lines in the CB. */
                for (tp = TAILQ_NEXT(tp, q); TAILQ_NEXT(tp, q);
                    ++lno, ++sp->rptlines[L_ADDED], tp = TAILQ_NEXT(tp, q))
                        if (db_append(sp, 1, lno, tp->lb, tp->len))
                                goto err;

                if (db_append(sp, 1, lno, t, clen))
                        goto err;
                ++sp->rptlines[L_ADDED];
        }
        rval = 0;

        if (0)
err:            rval = 1;

        FREE_SPACE(sp, bp, blen);
        return (rval);
}