1 /*-
2 * Copyright (c) 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 * Copyright (c) 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_z.c 10.10 (Berkeley) 3/6/96";
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 /*
28 * ex_z -- :[line] z [^-.+=] [count] [flags]
29 * Adjust window.
30 *
31 * PUBLIC: int ex_z __P((SCR *, EXCMD *));
32 */
33 int
ex_z(sp,cmdp)34 ex_z(sp, cmdp)
35 SCR *sp;
36 EXCMD *cmdp;
37 {
38 MARK abs;
39 recno_t cnt, equals, lno;
40 int eofcheck;
41
42 NEEDFILE(sp, cmdp);
43
44 /*
45 * !!!
46 * If no count specified, use either two times the size of the
47 * scrolling region, or the size of the window option. POSIX
48 * 1003.2 claims that the latter is correct, but historic ex/vi
49 * documentation and practice appear to use the scrolling region.
50 * I'm using the window size as it means that the entire screen
51 * is used instead of losing a line to roundoff. Note, we drop
52 * a line from the cnt if using the window size to leave room for
53 * the next ex prompt.
54 */
55 if (FL_ISSET(cmdp->iflags, E_C_COUNT))
56 cnt = cmdp->count;
57 else
58 #ifdef HISTORIC_PRACTICE
59 cnt = O_VAL(sp, O_SCROLL) * 2;
60 #else
61 cnt = O_VAL(sp, O_WINDOW) - 1;
62 #endif
63
64 equals = 0;
65 eofcheck = 0;
66 lno = cmdp->addr1.lno;
67
68 switch (FL_ISSET(cmdp->iflags,
69 E_C_CARAT | E_C_DASH | E_C_DOT | E_C_EQUAL | E_C_PLUS)) {
70 case E_C_CARAT: /* Display cnt * 2 before the line. */
71 eofcheck = 1;
72 if (lno > cnt * 2)
73 cmdp->addr1.lno = (lno - cnt * 2) + 1;
74 else
75 cmdp->addr1.lno = 1;
76 cmdp->addr2.lno = (cmdp->addr1.lno + cnt) - 1;
77 break;
78 case E_C_DASH: /* Line goes at the bottom of the screen. */
79 cmdp->addr1.lno = lno > cnt ? (lno - cnt) + 1 : 1;
80 cmdp->addr2.lno = lno;
81 break;
82 case E_C_DOT: /* Line goes in the middle of the screen. */
83 /*
84 * !!!
85 * Historically, the "middleness" of the line overrode the
86 * count, so that "3z.19" or "3z.20" would display the first
87 * 12 lines of the file, i.e. (N - 1) / 2 lines before and
88 * after the specified line.
89 */
90 eofcheck = 1;
91 cnt = (cnt - 1) / 2;
92 cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
93 cmdp->addr2.lno = lno + cnt;
94
95 /*
96 * !!!
97 * Historically, z. set the absolute cursor mark.
98 */
99 abs.lno = sp->lno;
100 abs.cno = sp->cno;
101 (void)mark_set(sp, ABSMARK1, &abs, 1);
102 break;
103 case E_C_EQUAL: /* Center with hyphens. */
104 /*
105 * !!!
106 * Strangeness. The '=' flag is like the '.' flag (see the
107 * above comment, it applies here as well) but with a special
108 * little hack. Print out lines of hyphens before and after
109 * the specified line. Additionally, the cursor remains set
110 * on that line.
111 */
112 eofcheck = 1;
113 cnt = (cnt - 1) / 2;
114 cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
115 cmdp->addr2.lno = lno - 1;
116 if (ex_pr(sp, cmdp))
117 return (1);
118 (void)ex_puts(sp, "----------------------------------------\n");
119 cmdp->addr2.lno = cmdp->addr1.lno = equals = lno;
120 if (ex_pr(sp, cmdp))
121 return (1);
122 (void)ex_puts(sp, "----------------------------------------\n");
123 cmdp->addr1.lno = lno + 1;
124 cmdp->addr2.lno = (lno + cnt) - 1;
125 break;
126 default:
127 /* If no line specified, move to the next one. */
128 if (F_ISSET(cmdp, E_ADDR_DEF))
129 ++lno;
130 /* FALLTHROUGH */
131 case E_C_PLUS: /* Line goes at the top of the screen. */
132 eofcheck = 1;
133 cmdp->addr1.lno = lno;
134 cmdp->addr2.lno = (lno + cnt) - 1;
135 break;
136 }
137
138 if (eofcheck) {
139 if (db_last(sp, &lno))
140 return (1);
141 if (cmdp->addr2.lno > lno)
142 cmdp->addr2.lno = lno;
143 }
144
145 if (ex_pr(sp, cmdp))
146 return (1);
147 if (equals)
148 sp->lno = equals;
149 return (0);
150 }
151