xref: /freebsd/contrib/nvi/ex/ex_shift.c (revision 640235e2c2ba32947f7c59d168437ffa1280f1e6)
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[] = "$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 
28 enum which {LEFT, RIGHT};
29 static int shift(SCR *, EXCMD *, enum which);
30 
31 /*
32  * ex_shiftl -- :<[<...]
33  *
34  *
35  * PUBLIC: int ex_shiftl(SCR *, EXCMD *);
36  */
37 int
38 ex_shiftl(SCR *sp, EXCMD *cmdp)
39 {
40 	return (shift(sp, cmdp, LEFT));
41 }
42 
43 /*
44  * ex_shiftr -- :>[>...]
45  *
46  * PUBLIC: int ex_shiftr(SCR *, EXCMD *);
47  */
48 int
49 ex_shiftr(SCR *sp, EXCMD *cmdp)
50 {
51 	return (shift(sp, cmdp, RIGHT));
52 }
53 
54 /*
55  * shift --
56  *	Ex shift support.
57  */
58 static int
59 shift(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)) {
148 err:			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