xref: /freebsd/contrib/nvi/ex/ex_shift.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
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
13 static 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 
27 enum which {LEFT, RIGHT};
28 static int shift __P((SCR *, EXCMD *, enum which));
29 
30 /*
31  * ex_shiftl -- :<[<...]
32  *
33  *
34  * PUBLIC: int ex_shiftl __P((SCR *, EXCMD *));
35  */
36 int
37 ex_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  */
49 int
50 ex_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  */
61 static int
62 shift(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)) {
153 err:			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