usr.bin/vi/delete.c

/*-
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)delete.c    8.7 (Berkeley) 12/9/93";
#endif /* not lint */

#include <sys/types.h>

#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "vi.h"

/*
 * delete --
 *      Delete a range of text.
 */
int
delete(sp, ep, fm, tm, lmode)
        SCR *sp;
        EXF *ep;
        MARK *fm, *tm;
        int lmode;
{
        recno_t lno;
        size_t blen, len, tlen;
        char *bp, *p;
        int eof;

#if defined(DEBUG) && 0
        TRACE(sp, "delete: from %lu/%d to %lu/%d%s\n",
            fm->lno, fm->cno, tm->lno, tm->cno, lmode ? " (LINE MODE)" : "");
#endif
        bp = NULL;

        /* Case 1 -- delete in line mode. */
        if (lmode) {
                for (lno = tm->lno; lno >= fm->lno; --lno)
                        if (file_dline(sp, ep, lno))
                                return (1);
                goto vdone;
        }

        /*
         * Case 2 -- delete to EOF.  This is a special case because it's
         * easier to pick it off than try and find it in the other cases.
         */
        if (file_lline(sp, ep, &lno))
                return (1);
        if (tm->lno >= lno) {
                if (tm->lno == lno) {
                        if ((p = file_gline(sp, ep, lno, &len)) == NULL) {
                                GETLINE_ERR(sp, lno);
                                return (1);
                        }
                        eof = tm->cno >= len ? 1 : 0;
                } else
                        eof = 1;
                if (eof) {
                        for (lno = tm->lno; lno > fm->lno; --lno) {
                                if (file_dline(sp, ep, lno))
                                        return (1);
                                ++sp->rptlines[L_DELETED];
                        }
                        if ((p = file_gline(sp, ep, fm->lno, &len)) == NULL) {
                                GETLINE_ERR(sp, fm->lno);
                                return (1);
                        }
                        GET_SPACE_RET(sp, bp, blen, fm->cno);
                        memmove(bp, p, fm->cno);
                        if (file_sline(sp, ep, fm->lno, bp, fm->cno))
                                return (1);
                        goto done;
                }
        }

        /* Case 3 -- delete within a single line. */
        if (tm->lno == fm->lno) {
                if ((p = file_gline(sp, ep, fm->lno, &len)) == NULL) {
                        GETLINE_ERR(sp, fm->lno);
                        return (1);
                }
                GET_SPACE_RET(sp, bp, blen, len);
                memmove(bp, p, fm->cno);
                memmove(bp + fm->cno, p + tm->cno, len - tm->cno);
                if (file_sline(sp, ep, fm->lno, bp, len - (tm->cno - fm->cno)))
                        goto err;
                goto done;
        }

        /*
         * Case 4 -- delete over multiple lines.
         *
         * Figure out how big a buffer we need.
         */
        if ((p = file_gline(sp, ep, fm->lno, &len)) == NULL) {
                GETLINE_ERR(sp, fm->lno);
                return (1);
        }
        tlen = len;
        if ((p = file_gline(sp, ep, tm->lno, &len)) == NULL) {
                GETLINE_ERR(sp, tm->lno);
                return (1);
        }

        /*
         * XXX
         * We can overflow memory here, if (len + tlen) > SIZE_T_MAX.  The
         * only portable way I've found to test is to depend on the overflow
         * being less than the value.
         */
        tlen += len;
        if (len > tlen) {
                msgq(sp, M_ERR, "Error: line length overflow");
                return (1);
        }

        GET_SPACE_RET(sp, bp, blen, tlen);

        /* Copy the start partial line into place. */
        if ((p = file_gline(sp, ep, fm->lno, &len)) == NULL) {
                GETLINE_ERR(sp, fm->lno);
                goto err;
        }
        memmove(bp, p, fm->cno);
        tlen = fm->cno;

        /* Copy the end partial line into place. */
        if ((p = file_gline(sp, ep, tm->lno, &len)) == NULL) {
                GETLINE_ERR(sp, tm->lno);
                goto err;
        }
        memmove(bp + tlen, p + tm->cno, len - tm->cno);
        tlen += len - tm->cno;

        /* Set the current line. */
        if (file_sline(sp, ep, fm->lno, bp, tlen))
                goto err;

        /* Delete the last and intermediate lines. */
        for (lno = tm->lno; lno > fm->lno; --lno)
                if (file_dline(sp, ep, lno))
                        return (1);

        /* Reporting. */
vdone:  sp->rptlines[L_DELETED] += tm->lno - fm->lno + 1;

done:   if (bp != NULL)
                FREE_SPACE(sp, bp, blen);

        return (0);

        /* Free memory. */
err:    FREE_SPACE(sp, bp, blen);

        return (1);
}