xref: /freebsd/contrib/nvi/ex/ex_shift.c (revision 8eb2bee6c0f4957c6c1cea826e59cda4d18a2a64)
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 #include <sys/types.h>
13 #include <sys/queue.h>
14 #include <sys/time.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 {RETAB, 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
34 ex_shiftl(SCR *sp, EXCMD *cmdp)
35 {
36 	return (shift(sp, cmdp, LEFT));
37 }
38 
39 /*
40  * ex_shiftr -- :>[>...]
41  *
42  * PUBLIC: int ex_shiftr(SCR *, EXCMD *);
43  */
44 int
45 ex_shiftr(SCR *sp, EXCMD *cmdp)
46 {
47 	return (shift(sp, cmdp, RIGHT));
48 }
49 
50 /*
51  * ex_retab -- Expand tabs (if enabled)
52  *
53  *
54  * PUBLIC: int ex_retab(SCR *, EXCMD *);
55  */
56 int
57 ex_retab(SCR *sp, EXCMD *cmdp)
58 {
59 	return (shift(sp, cmdp, RETAB));
60 }
61 
62 /*
63  * shift --
64  *	Ex shift support.
65  */
66 static int
67 shift(SCR *sp, EXCMD *cmdp, enum which rl)
68 {
69 	recno_t from, to;
70 	size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
71 	int curset;
72 	CHAR_T *p;
73 	CHAR_T *bp, *tbp;
74 
75 	NEEDFILE(sp, cmdp);
76 
77 	if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
78 		msgq(sp, M_INFO, "152|shiftwidth option set to 0");
79 		return (0);
80 	}
81 
82 	/* Copy the lines being shifted into the unnamed buffer. */
83 	if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
84 		return (1);
85 
86 	/*
87 	 * The historic version of vi permitted the user to string any number
88 	 * of '>' or '<' characters together, resulting in an indent of the
89 	 * appropriate levels.  There's a special hack in ex_cmd() so that
90 	 * cmdp->argv[0] points to the string of '>' or '<' characters.
91 	 *
92 	 * Q: What's the difference between the people adding features
93 	 *    to vi and the Girl Scouts?
94 	 * A: The Girl Scouts have mint cookies and adult supervision.
95 	 */
96 	for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
97 		sw += O_VAL(sp, O_SHIFTWIDTH);
98 
99 	GET_SPACE_RETW(sp, bp, blen, 256);
100 
101 	curset = 0;
102 	for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
103 		if (db_get(sp, from, DBG_FATAL, &p, &len))
104 			goto err;
105 		if (!len) {
106 			if (sp->lno == from)
107 				curset = 1;
108 			continue;
109 		}
110 
111 		/*
112 		 * Calculate the old indent amount and the number of
113 		 * characters it used.
114 		 */
115 		for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
116 			if (p[oldidx] == ' ')
117 				++oldcol;
118 			else if (p[oldidx] == '\t')
119 				oldcol += O_VAL(sp, O_TABSTOP) -
120 				    oldcol % O_VAL(sp, O_TABSTOP);
121 			else
122 				break;
123 
124 		/* Calculate the new indent amount. */
125 		if (rl == RETAB)
126 			newcol = oldcol;
127 		else if (rl == RIGHT)
128 			newcol = oldcol + sw;
129 		else {
130 			newcol = oldcol < sw ? 0 : oldcol - sw;
131 			if (newcol == oldcol) {
132 				if (sp->lno == from)
133 					curset = 1;
134 				continue;
135 			}
136 		}
137 
138 		/* Get a buffer that will hold the new line. */
139 		ADD_SPACE_RETW(sp, bp, blen, newcol + len);
140 
141 		/*
142 		 * Build a new indent string and count the number of
143 		 * characters it uses.
144 		 */
145 		tbp = bp;
146 		newidx = 0;
147 		if (!O_ISSET(sp, O_EXPANDTAB)) {
148 			for (; newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
149 				*tbp++ = '\t';
150 				newcol -= O_VAL(sp, O_TABSTOP);
151 			}
152 		}
153 		for (; newcol > 0; --newcol, ++newidx)
154 			*tbp++ = ' ';
155 
156 		/* Add the original line. */
157 		MEMCPY(tbp, p + oldidx, len - oldidx);
158 
159 		/* Set the replacement line. */
160 		if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
161 err:			FREE_SPACEW(sp, bp, blen);
162 			return (1);
163 		}
164 
165 		/*
166 		 * !!!
167 		 * The shift command in historic vi had the usual bizarre
168 		 * collection of cursor semantics.  If called from vi, the
169 		 * cursor was repositioned to the first non-blank character
170 		 * of the lowest numbered line shifted.  If called from ex,
171 		 * the cursor was repositioned to the first non-blank of the
172 		 * highest numbered line shifted.  Here, if the cursor isn't
173 		 * part of the set of lines that are moved, move it to the
174 		 * first non-blank of the last line shifted.  (This makes
175 		 * ":3>>" in vi work reasonably.)  If the cursor is part of
176 		 * the shifted lines, it doesn't get moved at all.  This
177 		 * permits shifting of marked areas, i.e. ">'a." shifts the
178 		 * marked area twice, something that couldn't be done with
179 		 * historic vi.
180 		 */
181 		if (sp->lno == from) {
182 			curset = 1;
183 			if (newidx > oldidx)
184 				sp->cno += newidx - oldidx;
185 			else if (sp->cno >= oldidx - newidx)
186 				sp->cno -= oldidx - newidx;
187 		}
188 	}
189 	if (!curset) {
190 		sp->lno = to;
191 		sp->cno = 0;
192 		(void)nonblank(sp, to, &sp->cno);
193 	}
194 
195 	FREE_SPACEW(sp, bp, blen);
196 
197 	sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
198 	return (0);
199 }
200