memmove(tbp, p + oldidx, len - oldidx);
memcpy(tbp, p + oldidx, len - oldidx);
shift(sp, cmdp, rl)	SCR *sp;	EXCMD *cmdp;	enum which rl;{	recno_t from, to;	size_t blen, len, newcol, newidx, oldcol, oldidx, sw;	int curset;	char *p, *bp, *tbp;	NEEDFILE(sp, cmdp);	if (O_VAL(sp, O_SHIFTWIDTH) == 0) {		msgq(sp, M_INFO, "152|shiftwidth option set to 0");		return (0);	}	/* Copy the lines being shifted into the unnamed buffer. */	if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))		return (1);	/*	 * The historic version of vi permitted the user to string any number	 * of '>' or '<' characters together, resulting in an indent of the	 * appropriate levels.  There's a special hack in ex_cmd() so that	 * cmdp->argv[0] points to the string of '>' or '<' characters.	 *	 * Q: What's the difference between the people adding features	 *    to vi and the Girl Scouts?	 * A: The Girl Scouts have mint cookies and adult supervision.	 */	for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)		sw += O_VAL(sp, O_SHIFTWIDTH);	GET_SPACE_RET(sp, bp, blen, 256);	curset = 0;	for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {		if (db_get(sp, from, DBG_FATAL, &p, &len))			goto err;		if (!len) {			if (sp->lno == from)				curset = 1;			continue;		}		/*		 * Calculate the old indent amount and the number of		 * characters it used.		 */		for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)			if (p[oldidx] == ' ')				++oldcol;			else if (p[oldidx] == '\t')				oldcol += O_VAL(sp, O_TABSTOP) -				    oldcol % O_VAL(sp, O_TABSTOP);			else				break;		/* Calculate the new indent amount. */		if (rl == RIGHT)			newcol = oldcol + sw;		else {			newcol = oldcol < sw ? 0 : oldcol - sw;			if (newcol == oldcol) {				if (sp->lno == from)					curset = 1;				continue;			}		}		/* Get a buffer that will hold the new line. */		ADD_SPACE_RET(sp, bp, blen, newcol + len);		/*		 * Build a new indent string and count the number of		 * characters it uses.		 */		for (tbp = bp, newidx = 0;		    newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {			*tbp++ = '\t';			newcol -= O_VAL(sp, O_TABSTOP);		}		for (; newcol > 0; --newcol, ++newidx)			*tbp++ = ' ';		/* Add the original line. */		memmove(tbp, p + oldidx, len - oldidx);		/* Set the replacement line. */		if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {err:			FREE_SPACE(sp, bp, blen);			return (1);		}		/*		 * !!!		 * The shift command in historic vi had the usual bizarre		 * collection of cursor semantics.  If called from vi, the		 * cursor was repositioned to the first non-blank character		 * of the lowest numbered line shifted.  If called from ex,		 * the cursor was repositioned to the first non-blank of the		 * highest numbered line shifted.  Here, if the cursor isn't		 * part of the set of lines that are moved, move it to the		 * first non-blank of the last line shifted.  (This makes		 * ":3>>" in vi work reasonably.)  If the cursor is part of		 * the shifted lines, it doesn't get moved at all.  This		 * permits shifting of marked areas, i.e. ">'a." shifts the		 * marked area twice, something that couldn't be done with		 * historic vi.		 */		if (sp->lno == from) {			curset = 1;			if (newidx > oldidx)				sp->cno += newidx - oldidx;			else if (sp->cno >= oldidx - newidx)				sp->cno -= oldidx - newidx;		}	}	if (!curset) {		sp->lno = to;		sp->cno = 0;		(void)nonblank(sp, to, &sp->cno);	}	FREE_SPACE(sp, bp, blen);	sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;	return (0);}