1 /* $OpenBSD: ex_shift.c,v 1.6 2009/10/27 23:59:47 deraadt Exp $ */
2
3 /*-
4 * Copyright (c) 1992, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 * Copyright (c) 1992, 1993, 1994, 1995, 1996
7 * Keith Bostic. All rights reserved.
8 *
9 * See the LICENSE file for redistribution information.
10 */
11
12 #include "config.h"
13
14 #include <sys/queue.h>
15
16 #include <bitstring.h>
17 #include <limits.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <string.h>
21
22 #include "../common/common.h"
23
24 enum which {LEFT, RIGHT};
25 static int shift(SCR *, EXCMD *, enum which);
26
27 /*
28 * ex_shiftl -- :<[<...]
29 *
30 *
31 * PUBLIC: int ex_shiftl(SCR *, EXCMD *);
32 */
33 int
ex_shiftl(sp,cmdp)34 ex_shiftl(sp, cmdp)
35 SCR *sp;
36 EXCMD *cmdp;
37 {
38 return (shift(sp, cmdp, LEFT));
39 }
40
41 /*
42 * ex_shiftr -- :>[>...]
43 *
44 * PUBLIC: int ex_shiftr(SCR *, EXCMD *);
45 */
46 int
ex_shiftr(sp,cmdp)47 ex_shiftr(sp, cmdp)
48 SCR *sp;
49 EXCMD *cmdp;
50 {
51 return (shift(sp, cmdp, RIGHT));
52 }
53
54 /*
55 * shift --
56 * Ex shift support.
57 */
58 static int
shift(sp,cmdp,rl)59 shift(sp, cmdp, rl)
60 SCR *sp;
61 EXCMD *cmdp;
62 enum which rl;
63 {
64 recno_t from, to;
65 size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
66 int curset;
67 char *p, *bp, *tbp;
68
69 NEEDFILE(sp, cmdp);
70
71 if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
72 msgq(sp, M_INFO, "152|shiftwidth option set to 0");
73 return (0);
74 }
75
76 /* Copy the lines being shifted into the unnamed buffer. */
77 if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
78 return (1);
79
80 /*
81 * The historic version of vi permitted the user to string any number
82 * of '>' or '<' characters together, resulting in an indent of the
83 * appropriate levels. There's a special hack in ex_cmd() so that
84 * cmdp->argv[0] points to the string of '>' or '<' characters.
85 *
86 * Q: What's the difference between the people adding features
87 * to vi and the Girl Scouts?
88 * A: The Girl Scouts have mint cookies and adult supervision.
89 */
90 for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
91 sw += O_VAL(sp, O_SHIFTWIDTH);
92
93 GET_SPACE_RET(sp, bp, blen, 256);
94
95 curset = 0;
96 for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
97 if (db_get(sp, from, DBG_FATAL, &p, &len))
98 goto err;
99 if (!len) {
100 if (sp->lno == from)
101 curset = 1;
102 continue;
103 }
104
105 /*
106 * Calculate the old indent amount and the number of
107 * characters it used.
108 */
109 for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
110 if (p[oldidx] == ' ')
111 ++oldcol;
112 else if (p[oldidx] == '\t')
113 oldcol += O_VAL(sp, O_TABSTOP) -
114 oldcol % O_VAL(sp, O_TABSTOP);
115 else
116 break;
117
118 /* Calculate the new indent amount. */
119 if (rl == RIGHT)
120 newcol = oldcol + sw;
121 else {
122 newcol = oldcol < sw ? 0 : oldcol - sw;
123 if (newcol == oldcol) {
124 if (sp->lno == from)
125 curset = 1;
126 continue;
127 }
128 }
129
130 /* Get a buffer that will hold the new line. */
131 ADD_SPACE_RET(sp, bp, blen, newcol + len);
132
133 /*
134 * Build a new indent string and count the number of
135 * characters it uses.
136 */
137 for (tbp = bp, newidx = 0;
138 newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
139 *tbp++ = '\t';
140 newcol -= O_VAL(sp, O_TABSTOP);
141 }
142 for (; newcol > 0; --newcol, ++newidx)
143 *tbp++ = ' ';
144
145 /* Add the original line. */
146 memcpy(tbp, p + oldidx, len - oldidx);
147
148 /* Set the replacement line. */
149 if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
150 err: FREE_SPACE(sp, bp, blen);
151 return (1);
152 }
153
154 /*
155 * !!!
156 * The shift command in historic vi had the usual bizarre
157 * collection of cursor semantics. If called from vi, the
158 * cursor was repositioned to the first non-blank character
159 * of the lowest numbered line shifted. If called from ex,
160 * the cursor was repositioned to the first non-blank of the
161 * highest numbered line shifted. Here, if the cursor isn't
162 * part of the set of lines that are moved, move it to the
163 * first non-blank of the last line shifted. (This makes
164 * ":3>>" in vi work reasonably.) If the cursor is part of
165 * the shifted lines, it doesn't get moved at all. This
166 * permits shifting of marked areas, i.e. ">'a." shifts the
167 * marked area twice, something that couldn't be done with
168 * historic vi.
169 */
170 if (sp->lno == from) {
171 curset = 1;
172 if (newidx > oldidx)
173 sp->cno += newidx - oldidx;
174 else if (sp->cno >= oldidx - newidx)
175 sp->cno -= oldidx - newidx;
176 }
177 }
178 if (!curset) {
179 sp->lno = to;
180 sp->cno = 0;
181 (void)nonblank(sp, to, &sp->cno);
182 }
183
184 FREE_SPACE(sp, bp, blen);
185
186 sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
187 return (0);
188 }
189