source: trunk/third/nvi/common/cut.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[] = "@(#)cut.c 10.10 (Berkeley) 9/15/96";
#endif /* not lint */

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

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

#include "common.h"

static void     cb_rotate __P((SCR *));

/*
 * cut --
 *      Put a range of lines/columns into a TEXT buffer.
 *
 * There are two buffer areas, both found in the global structure.  The first
 * is the linked list of all the buffers the user has named, the second is the
 * unnamed buffer storage.  There is a pointer, too, which is the current
 * default buffer, i.e. it may point to the unnamed buffer or a named buffer
 * depending on into what buffer the last text was cut.  Logically, in both
 * delete and yank operations, if the user names a buffer, the text is cut
 * into it.  If it's a delete of information on more than a single line, the
 * contents of the numbered buffers are rotated up one, the contents of the
 * buffer named '9' are discarded, and the text is cut into the buffer named
 * '1'.  The text is always cut into the unnamed buffer.
 *
 * In all cases, upper-case buffer names are the same as lower-case names,
 * with the exception that they cause the buffer to be appended to instead
 * of replaced.  Note, however, that if text is appended to a buffer, the
 * default buffer only contains the appended text, not the entire contents
 * of the buffer.
 *
 * !!!
 * The contents of the default buffer would disappear after most operations
 * in historic vi.  It's unclear that this is useful, so we don't bother.
 *
 * When users explicitly cut text into the numeric buffers, historic vi became
 * genuinely strange.  I've never been able to figure out what was supposed to
 * happen.  It behaved differently if you deleted text than if you yanked text,
 * and, in the latter case, the text was appended to the buffer instead of
 * replacing the contents.  Hopefully it's not worth getting right, and here
 * we just treat the numeric buffers like any other named buffer.
 *
 * PUBLIC: int cut __P((SCR *, CHAR_T *, MARK *, MARK *, int));
 */
int
cut(sp, namep, fm, tm, flags)
        SCR *sp;
        CHAR_T *namep;
        MARK *fm, *tm;
        int flags;
{
        CB *cbp;
        CHAR_T name;
        recno_t lno;
        int append, copy_one, copy_def;

        /*
         * If the user specified a buffer, put it there.  (This may require
         * a copy into the numeric buffers.  We do the copy so that we don't
         * have to reference count and so we don't have to deal with things
         * like appends to buffers that are used multiple times.)
         *
         * Otherwise, if it's supposed to be put in a numeric buffer (usually
         * a delete) put it there.  The rules for putting things in numeric
         * buffers were historically a little strange.  There were three cases.
         *
         *      1: Some motions are always line mode motions, which means
         *         that the cut always goes into the numeric buffers.
         *      2: Some motions aren't line mode motions, e.g. d10w, but
         *         can cross line boundaries.  For these commands, if the
         *         cut crosses a line boundary, it goes into the numeric
         *         buffers.  This includes most of the commands.
         *      3: Some motions aren't line mode motions, e.g. d`<char>,
         *         but always go into the numeric buffers, regardless.  This
         *         was the commands: % ` / ? ( ) N n { } -- and nvi adds ^A.
         *
         * Otherwise, put it in the unnamed buffer.
         */
        append = copy_one = copy_def = 0;
        if (namep != NULL) {
                name = *namep;
                if (LF_ISSET(CUT_NUMREQ) || LF_ISSET(CUT_NUMOPT) &&
                    (LF_ISSET(CUT_LINEMODE) || fm->lno != tm->lno)) {
                        copy_one = 1;
                        cb_rotate(sp);
                }
                if ((append = isupper(name)) == 1) {
                        if (!copy_one)
                                copy_def = 1;
                        name = tolower(name);
                }
namecb:         CBNAME(sp, cbp, name);
        } else if (LF_ISSET(CUT_NUMREQ) || LF_ISSET(CUT_NUMOPT) &&
            (LF_ISSET(CUT_LINEMODE) || fm->lno != tm->lno)) {
                name = '1';
                cb_rotate(sp);
                goto namecb;
        } else
                cbp = &sp->gp->dcb_store;

copyloop:
        /*
         * If this is a new buffer, create it and add it into the list.
         * Otherwise, if it's not an append, free its current contents.
         */
        if (cbp == NULL) {
                CALLOC_RET(sp, cbp, CB *, 1, sizeof(CB));
                cbp->name = name;
                CIRCLEQ_INIT(&cbp->textq);
                LIST_INSERT_HEAD(&sp->gp->cutq, cbp, q);
        } else if (!append) {
                text_lfree(&cbp->textq);
                cbp->len = 0;
                cbp->flags = 0;
        }


#define ENTIRE_LINE     0
        /* In line mode, it's pretty easy, just cut the lines. */
        if (LF_ISSET(CUT_LINEMODE)) {
                cbp->flags |= CB_LMODE;
                for (lno = fm->lno; lno <= tm->lno; ++lno)
                        if (cut_line(sp, lno, 0, 0, cbp))
                                goto cut_line_err;
        } else {
                /*
                 * Get the first line.  A length of 0 causes cut_line
                 * to cut from the MARK to the end of the line.
                 */
                if (cut_line(sp, fm->lno, fm->cno, fm->lno != tm->lno ?
                    ENTIRE_LINE : (tm->cno - fm->cno) + 1, cbp))
                        goto cut_line_err;

                /* Get the intermediate lines. */
                for (lno = fm->lno; ++lno < tm->lno;)
                        if (cut_line(sp, lno, 0, ENTIRE_LINE, cbp))
                                goto cut_line_err;

                /* Get the last line. */
                if (tm->lno != fm->lno &&
                    cut_line(sp, lno, 0, tm->cno + 1, cbp))
                        goto cut_line_err;
        }

        append = 0;             /* Only append to the named buffer. */
        sp->gp->dcbp = cbp;     /* Repoint the default buffer on each pass. */

        if (copy_one) {         /* Copy into numeric buffer 1. */
                name = '1';
                CBNAME(sp, cbp, name);
                copy_one = 0;
                goto copyloop;
        }
        if (copy_def) {         /* Copy into the default buffer. */
                cbp = &sp->gp->dcb_store;
                copy_def = 0;
                goto copyloop;
        }
        return (0);

cut_line_err:   
        text_lfree(&cbp->textq);
        cbp->len = 0;
        cbp->flags = 0;
        return (1);
}

/*
 * cb_rotate --
 *      Rotate the numbered buffers up one.
 */
static void
cb_rotate(sp)
        SCR *sp;
{
        CB *cbp, *del_cbp;

        del_cbp = NULL;
        for (cbp = sp->gp->cutq.lh_first; cbp != NULL; cbp = cbp->q.le_next)
                switch(cbp->name) {
                case '1':
                        cbp->name = '2';
                        break;
                case '2':
                        cbp->name = '3';
                        break;
                case '3':
                        cbp->name = '4';
                        break;
                case '4':
                        cbp->name = '5';
                        break;
                case '5':
                        cbp->name = '6';
                        break;
                case '6':
                        cbp->name = '7';
                        break;
                case '7':
                        cbp->name = '8';
                        break;
                case '8':
                        cbp->name = '9';
                        break;
                case '9':
                        del_cbp = cbp;
                        break;
                }
        if (del_cbp != NULL) {
                LIST_REMOVE(del_cbp, q);
                text_lfree(&del_cbp->textq);
                free(del_cbp);
        }
}

/*
 * cut_line --
 *      Cut a portion of a single line.
 *
 * PUBLIC: int cut_line __P((SCR *, recno_t, size_t, size_t, CB *));
 */
int
cut_line(sp, lno, fcno, clen, cbp)
        SCR *sp;
        recno_t lno;
        size_t fcno, clen;
        CB *cbp;
{
        TEXT *tp;
        size_t len;
        char *p;

        /* Get the line. */
        if (db_get(sp, lno, DBG_FATAL, &p, &len))
                return (1);

        /* Create a TEXT structure that can hold the entire line. */
        if ((tp = text_init(sp, NULL, 0, len)) == NULL)
                return (1);

        /*
         * If the line isn't empty and it's not the entire line,
         * copy the portion we want, and reset the TEXT length.
         */
        if (len != 0) {
                if (clen == 0)
                        clen = len - fcno;
                memcpy(tp->lb, p + fcno, clen);
                tp->len = clen;
        }

        /* Append to the end of the cut buffer. */
        CIRCLEQ_INSERT_TAIL(&cbp->textq, tp, q);
        cbp->len += tp->len;

        return (0);
}

/*
 * cut_close --
 *      Discard all cut buffers.
 *
 * PUBLIC: void cut_close __P((GS *));
 */
void
cut_close(gp)
        GS *gp;
{
        CB *cbp;

        /* Free cut buffer list. */
        while ((cbp = gp->cutq.lh_first) != NULL) {
                if (cbp->textq.cqh_first != (void *)&cbp->textq)
                        text_lfree(&cbp->textq);
                LIST_REMOVE(cbp, q);
                free(cbp);
        }

        /* Free default cut storage. */
        cbp = &gp->dcb_store;
        if (cbp->textq.cqh_first != (void *)&cbp->textq)
                text_lfree(&cbp->textq);
}

/*
 * text_init --
 *      Allocate a new TEXT structure.
 *
 * PUBLIC: TEXT *text_init __P((SCR *, const char *, size_t, size_t));
 */
TEXT *
text_init(sp, p, len, total_len)
        SCR *sp;
        const char *p;
        size_t len, total_len;
{
        TEXT *tp;

        CALLOC(sp, tp, TEXT *, 1, sizeof(TEXT));
        if (tp == NULL)
                return (NULL);
        /* ANSI C doesn't define a call to malloc(3) for 0 bytes. */
        if ((tp->lb_len = total_len) != 0) {
                MALLOC(sp, tp->lb, CHAR_T *, tp->lb_len);
                if (tp->lb == NULL) {
                        free(tp);
                        return (NULL);
                }
                if (p != NULL && len != 0)
                        memcpy(tp->lb, p, len);
        }
        tp->len = len;
        return (tp);
}

/*
 * text_lfree --
 *      Free a chain of text structures.
 *
 * PUBLIC: void text_lfree __P((TEXTH *));
 */
void
text_lfree(headp)
        TEXTH *headp;
{
        TEXT *tp;

        while ((tp = headp->cqh_first) != (void *)headp) {
                CIRCLEQ_REMOVE(headp, tp, q);
                text_free(tp);
        }
}

/*
 * text_free --
 *      Free a text structure.
 *
 * PUBLIC: void text_free __P((TEXT *));
 */
void
text_free(tp)
        TEXT *tp;
{
        if (tp->lb != NULL)
                free(tp->lb);
        free(tp);
}