xref: /netbsd-src/external/bsd/nvi/dist/ex/ex_shift.c (revision 2f698edb5c1cb2dcd9e762b0abb50c41dde8b6b7)
1 /*	$NetBSD: ex_shift.c,v 1.3 2014/01/26 21:43:45 christos Exp $ */
2 /*-
3  * Copyright (c) 1992, 1993, 1994
4  *	The Regents of the University of California.  All rights reserved.
5  * Copyright (c) 1992, 1993, 1994, 1995, 1996
6  *	Keith Bostic.  All rights reserved.
7  *
8  * See the LICENSE file for redistribution information.
9  */
10 
11 #include "config.h"
12 
13 #include <sys/cdefs.h>
14 #if 0
15 #ifndef lint
16 static const char sccsid[] = "Id: ex_shift.c,v 10.17 2001/06/25 15:19:20 skimo Exp  (Berkeley) Date: 2001/06/25 15:19:20 ";
17 #endif /* not lint */
18 #else
19 __RCSID("$NetBSD: ex_shift.c,v 1.3 2014/01/26 21:43:45 christos Exp $");
20 #endif
21 
22 #include <sys/types.h>
23 #include <sys/queue.h>
24 
25 #include <bitstring.h>
26 #include <limits.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 
31 #include "../common/common.h"
32 
33 enum which {LEFT, RIGHT};
34 static int shift __P((SCR *, EXCMD *, enum which));
35 
36 /*
37  * ex_shiftl -- :<[<...]
38  *
39  *
40  * PUBLIC: int ex_shiftl __P((SCR *, EXCMD *));
41  */
42 int
ex_shiftl(SCR * sp,EXCMD * cmdp)43 ex_shiftl(SCR *sp, EXCMD *cmdp)
44 {
45 	return (shift(sp, cmdp, LEFT));
46 }
47 
48 /*
49  * ex_shiftr -- :>[>...]
50  *
51  * PUBLIC: int ex_shiftr __P((SCR *, EXCMD *));
52  */
53 int
ex_shiftr(SCR * sp,EXCMD * cmdp)54 ex_shiftr(SCR *sp, EXCMD *cmdp)
55 {
56 	return (shift(sp, cmdp, RIGHT));
57 }
58 
59 /*
60  * shift --
61  *	Ex shift support.
62  */
63 static int
shift(SCR * sp,EXCMD * cmdp,enum which rl)64 shift(SCR *sp, EXCMD *cmdp, enum which rl)
65 {
66 	db_recno_t from, to;
67 	size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
68 	int curset;
69 	CHAR_T *p;
70 	CHAR_T *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_RETW(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_RETW(sp, bp, blen, newcol + len);
135 
136 		/*
137 		 * Build a new indent string and count the number of
138 		 * characters it uses.
139 		 */
140 		tbp = bp;
141 		newidx = 0;
142 		if (!O_ISSET(sp, O_EXPANDTAB)) {
143 			for (; newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
144 				*tbp++ = '\t';
145 				newcol -= O_VAL(sp, O_TABSTOP);
146 			}
147 		}
148 		for (; newcol > 0; --newcol, ++newidx)
149 			*tbp++ = ' ';
150 
151 		/* Add the original line. */
152 		MEMCPYW(tbp, p + oldidx, len - oldidx);
153 
154 		/* Set the replacement line. */
155 		if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
156 err:			FREE_SPACEW(sp, bp, blen);
157 			return (1);
158 		}
159 
160 		/*
161 		 * !!!
162 		 * The shift command in historic vi had the usual bizarre
163 		 * collection of cursor semantics.  If called from vi, the
164 		 * cursor was repositioned to the first non-blank character
165 		 * of the lowest numbered line shifted.  If called from ex,
166 		 * the cursor was repositioned to the first non-blank of the
167 		 * highest numbered line shifted.  Here, if the cursor isn't
168 		 * part of the set of lines that are moved, move it to the
169 		 * first non-blank of the last line shifted.  (This makes
170 		 * ":3>>" in vi work reasonably.)  If the cursor is part of
171 		 * the shifted lines, it doesn't get moved at all.  This
172 		 * permits shifting of marked areas, i.e. ">'a." shifts the
173 		 * marked area twice, something that couldn't be done with
174 		 * historic vi.
175 		 */
176 		if (sp->lno == from) {
177 			curset = 1;
178 			if (newidx > oldidx)
179 				sp->cno += newidx - oldidx;
180 			else if (sp->cno >= oldidx - newidx)
181 				sp->cno -= oldidx - newidx;
182 		}
183 	}
184 	if (!curset) {
185 		sp->lno = to;
186 		sp->cno = 0;
187 		(void)nonblank(sp, to, &sp->cno);
188 	}
189 
190 	FREE_SPACEW(sp, bp, blen);
191 
192 	sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
193 	return (0);
194 }
195