ex_shift.c revision 254225 
1/*-
2 * Copyright (c) 1992, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 * Copyright (c) 1992, 1993, 1994, 1995, 1996
5 *	Keith Bostic.  All rights reserved.
6 *
7 * See the LICENSE file for redistribution information.
8 */
9
10#include "config.h"
11
12#ifndef lint
13static const char sccsid[] = "$Id: ex_shift.c,v 10.17 2001/06/25 15:19:20 skimo Exp $";
14#endif /* not lint */
15
16#include <sys/types.h>
17#include <sys/queue.h>
18#include <sys/time.h>
19
20#include <bitstring.h>
21#include <limits.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25
26#include "../common/common.h"
27
28enum which {LEFT, RIGHT};
29static int shift __P((SCR *, EXCMD *, enum which));
30
31/*
32 * ex_shiftl -- :<[<...]
33 *
34 *
35 * PUBLIC: int ex_shiftl __P((SCR *, EXCMD *));
36 */
37int
38ex_shiftl(SCR *sp, EXCMD *cmdp)
39{
40	return (shift(sp, cmdp, LEFT));
41}
42
43/*
44 * ex_shiftr -- :>[>...]
45 *
46 * PUBLIC: int ex_shiftr __P((SCR *, EXCMD *));
47 */
48int
49ex_shiftr(SCR *sp, EXCMD *cmdp)
50{
51	return (shift(sp, cmdp, RIGHT));
52}
53
54/*
55 * shift --
56 *	Ex shift support.
57 */
58static int
59shift(SCR *sp, EXCMD *cmdp, enum which rl)
60{
61	recno_t from, to;
62	size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
63	int curset;
64	CHAR_T *p;
65	CHAR_T *bp, *tbp;
66
67	NEEDFILE(sp, cmdp);
68
69	if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
70		msgq(sp, M_INFO, "152|shiftwidth option set to 0");
71		return (0);
72	}
73
74	/* Copy the lines being shifted into the unnamed buffer. */
75	if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
76		return (1);
77
78	/*
79	 * The historic version of vi permitted the user to string any number
80	 * of '>' or '<' characters together, resulting in an indent of the
81	 * appropriate levels.  There's a special hack in ex_cmd() so that
82	 * cmdp->argv[0] points to the string of '>' or '<' characters.
83	 *
84	 * Q: What's the difference between the people adding features
85	 *    to vi and the Girl Scouts?
86	 * A: The Girl Scouts have mint cookies and adult supervision.
87	 */
88	for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
89		sw += O_VAL(sp, O_SHIFTWIDTH);
90
91	GET_SPACE_RETW(sp, bp, blen, 256);
92
93	curset = 0;
94	for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
95		if (db_get(sp, from, DBG_FATAL, &p, &len))
96			goto err;
97		if (!len) {
98			if (sp->lno == from)
99				curset = 1;
100			continue;
101		}
102
103		/*
104		 * Calculate the old indent amount and the number of
105		 * characters it used.
106		 */
107		for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
108			if (p[oldidx] == ' ')
109				++oldcol;
110			else if (p[oldidx] == '\t')
111				oldcol += O_VAL(sp, O_TABSTOP) -
112				    oldcol % O_VAL(sp, O_TABSTOP);
113			else
114				break;
115
116		/* Calculate the new indent amount. */
117		if (rl == RIGHT)
118			newcol = oldcol + sw;
119		else {
120			newcol = oldcol < sw ? 0 : oldcol - sw;
121			if (newcol == oldcol) {
122				if (sp->lno == from)
123					curset = 1;
124				continue;
125			}
126		}
127
128		/* Get a buffer that will hold the new line. */
129		ADD_SPACE_RETW(sp, bp, blen, newcol + len);
130
131		/*
132		 * Build a new indent string and count the number of
133		 * characters it uses.
134		 */
135		for (tbp = bp, newidx = 0;
136		    newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
137			*tbp++ = '\t';
138			newcol -= O_VAL(sp, O_TABSTOP);
139		}
140		for (; newcol > 0; --newcol, ++newidx)
141			*tbp++ = ' ';
142
143		/* Add the original line. */
144		MEMCPY(tbp, p + oldidx, len - oldidx);
145
146		/* Set the replacement line. */
147		if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
148err:			FREE_SPACEW(sp, bp, blen);
149			return (1);
150		}
151
152		/*
153		 * !!!
154		 * The shift command in historic vi had the usual bizarre
155		 * collection of cursor semantics.  If called from vi, the
156		 * cursor was repositioned to the first non-blank character
157		 * of the lowest numbered line shifted.  If called from ex,
158		 * the cursor was repositioned to the first non-blank of the
159		 * highest numbered line shifted.  Here, if the cursor isn't
160		 * part of the set of lines that are moved, move it to the
161		 * first non-blank of the last line shifted.  (This makes
162		 * ":3>>" in vi work reasonably.)  If the cursor is part of
163		 * the shifted lines, it doesn't get moved at all.  This
164		 * permits shifting of marked areas, i.e. ">'a." shifts the
165		 * marked area twice, something that couldn't be done with
166		 * historic vi.
167		 */
168		if (sp->lno == from) {
169			curset = 1;
170			if (newidx > oldidx)
171				sp->cno += newidx - oldidx;
172			else if (sp->cno >= oldidx - newidx)
173				sp->cno -= oldidx - newidx;
174		}
175	}
176	if (!curset) {
177		sp->lno = to;
178		sp->cno = 0;
179		(void)nonblank(sp, to, &sp->cno);
180	}
181
182	FREE_SPACEW(sp, bp, blen);
183
184	sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
185	return (0);
186}
187