ex_shift.c revision 19304 
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[] = "@(#)ex_shift.c	10.11 (Berkeley) 9/15/96";
14#endif /* not lint */
15
16#include <sys/types.h>
17#include <sys/queue.h>
18
19#include <bitstring.h>
20#include <limits.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24
25#include "../common/common.h"
26
27enum which {LEFT, RIGHT};
28static int shift __P((SCR *, EXCMD *, enum which));
29
30/*
31 * ex_shiftl -- :<[<...]
32 *
33 *
34 * PUBLIC: int ex_shiftl __P((SCR *, EXCMD *));
35 */
36int
37ex_shiftl(sp, cmdp)
38	SCR *sp;
39	EXCMD *cmdp;
40{
41	return (shift(sp, cmdp, LEFT));
42}
43
44/*
45 * ex_shiftr -- :>[>...]
46 *
47 * PUBLIC: int ex_shiftr __P((SCR *, EXCMD *));
48 */
49int
50ex_shiftr(sp, cmdp)
51	SCR *sp;
52	EXCMD *cmdp;
53{
54	return (shift(sp, cmdp, RIGHT));
55}
56
57/*
58 * shift --
59 *	Ex shift support.
60 */
61static int
62shift(sp, cmdp, rl)
63	SCR *sp;
64	EXCMD *cmdp;
65	enum which rl;
66{
67	recno_t from, to;
68	size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
69	int curset;
70	char *p, *bp, *tbp;
71
72	NEEDFILE(sp, cmdp);
73
74	if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
75		msgq(sp, M_INFO, "152|shiftwidth option set to 0");
76		return (0);
77	}
78
79	/* Copy the lines being shifted into the unnamed buffer. */
80	if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
81		return (1);
82
83	/*
84	 * The historic version of vi permitted the user to string any number
85	 * of '>' or '<' characters together, resulting in an indent of the
86	 * appropriate levels.  There's a special hack in ex_cmd() so that
87	 * cmdp->argv[0] points to the string of '>' or '<' characters.
88	 *
89	 * Q: What's the difference between the people adding features
90	 *    to vi and the Girl Scouts?
91	 * A: The Girl Scouts have mint cookies and adult supervision.
92	 */
93	for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
94		sw += O_VAL(sp, O_SHIFTWIDTH);
95
96	GET_SPACE_RET(sp, bp, blen, 256);
97
98	curset = 0;
99	for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
100		if (db_get(sp, from, DBG_FATAL, &p, &len))
101			goto err;
102		if (!len) {
103			if (sp->lno == from)
104				curset = 1;
105			continue;
106		}
107
108		/*
109		 * Calculate the old indent amount and the number of
110		 * characters it used.
111		 */
112		for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
113			if (p[oldidx] == ' ')
114				++oldcol;
115			else if (p[oldidx] == '\t')
116				oldcol += O_VAL(sp, O_TABSTOP) -
117				    oldcol % O_VAL(sp, O_TABSTOP);
118			else
119				break;
120
121		/* Calculate the new indent amount. */
122		if (rl == RIGHT)
123			newcol = oldcol + sw;
124		else {
125			newcol = oldcol < sw ? 0 : oldcol - sw;
126			if (newcol == oldcol) {
127				if (sp->lno == from)
128					curset = 1;
129				continue;
130			}
131		}
132
133		/* Get a buffer that will hold the new line. */
134		ADD_SPACE_RET(sp, bp, blen, newcol + len);
135
136		/*
137		 * Build a new indent string and count the number of
138		 * characters it uses.
139		 */
140		for (tbp = bp, newidx = 0;
141		    newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
142			*tbp++ = '\t';
143			newcol -= O_VAL(sp, O_TABSTOP);
144		}
145		for (; newcol > 0; --newcol, ++newidx)
146			*tbp++ = ' ';
147
148		/* Add the original line. */
149		memcpy(tbp, p + oldidx, len - oldidx);
150
151		/* Set the replacement line. */
152		if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
153err:			FREE_SPACE(sp, bp, blen);
154			return (1);
155		}
156
157		/*
158		 * !!!
159		 * The shift command in historic vi had the usual bizarre
160		 * collection of cursor semantics.  If called from vi, the
161		 * cursor was repositioned to the first non-blank character
162		 * of the lowest numbered line shifted.  If called from ex,
163		 * the cursor was repositioned to the first non-blank of the
164		 * highest numbered line shifted.  Here, if the cursor isn't
165		 * part of the set of lines that are moved, move it to the
166		 * first non-blank of the last line shifted.  (This makes
167		 * ":3>>" in vi work reasonably.)  If the cursor is part of
168		 * the shifted lines, it doesn't get moved at all.  This
169		 * permits shifting of marked areas, i.e. ">'a." shifts the
170		 * marked area twice, something that couldn't be done with
171		 * historic vi.
172		 */
173		if (sp->lno == from) {
174			curset = 1;
175			if (newidx > oldidx)
176				sp->cno += newidx - oldidx;
177			else if (sp->cno >= oldidx - newidx)
178				sp->cno -= oldidx - newidx;
179		}
180	}
181	if (!curset) {
182		sp->lno = to;
183		sp->cno = 0;
184		(void)nonblank(sp, to, &sp->cno);
185	}
186
187	FREE_SPACE(sp, bp, blen);
188
189	sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
190	return (0);
191}
192