1 /* $NetBSD: getc.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: getc.c,v 10.12 2001/06/25 15:19:30 skimo Exp (Berkeley) Date: 2001/06/25 15:19:30 ";
17 #endif /* not lint */
18 #else
19 __RCSID("$NetBSD: getc.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 #include <sys/time.h>
25
26 #include <bitstring.h>
27 #include <ctype.h>
28 #include <limits.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31
32 #include "../common/common.h"
33 #include "vi.h"
34
35 /*
36 * Character stream routines --
37 * These routines return the file a character at a time. There are two
38 * special cases. First, the end of a line, end of a file, start of a
39 * file and empty lines are returned as special cases, and no character
40 * is returned. Second, empty lines include lines that have only white
41 * space in them, because the vi search functions don't care about white
42 * space, and this makes it easier for them to be consistent.
43 */
44
45 /*
46 * cs_init --
47 * Initialize character stream routines.
48 *
49 * PUBLIC: int cs_init __P((SCR *, VCS *));
50 */
51 int
cs_init(SCR * sp,VCS * csp)52 cs_init(SCR *sp, VCS *csp)
53 {
54 int isempty;
55
56 if (db_eget(sp, csp->cs_lno, &csp->cs_bp, &csp->cs_len, &isempty)) {
57 if (isempty)
58 msgq(sp, M_BERR, "177|Empty file");
59 return (1);
60 }
61 if (csp->cs_len == 0 || v_isempty(csp->cs_bp, csp->cs_len)) {
62 csp->cs_cno = 0;
63 csp->cs_flags = CS_EMP;
64 } else {
65 csp->cs_flags = 0;
66 csp->cs_ch = csp->cs_bp[csp->cs_cno];
67 }
68 return (0);
69 }
70
71 /*
72 * cs_next --
73 * Retrieve the next character.
74 *
75 * PUBLIC: int cs_next __P((SCR *, VCS *));
76 */
77 int
cs_next(SCR * sp,VCS * csp)78 cs_next(SCR *sp, VCS *csp)
79 {
80 CHAR_T *p;
81
82 switch (csp->cs_flags) {
83 case CS_EMP: /* EMP; get next line. */
84 case CS_EOL: /* EOL; get next line. */
85 if (db_get(sp, ++csp->cs_lno, 0, &p, &csp->cs_len)) {
86 --csp->cs_lno;
87 csp->cs_flags = CS_EOF;
88 } else {
89 csp->cs_bp = p;
90 if (csp->cs_len == 0 ||
91 v_isempty(csp->cs_bp, csp->cs_len)) {
92 csp->cs_cno = 0;
93 csp->cs_flags = CS_EMP;
94 } else {
95 csp->cs_flags = 0;
96 csp->cs_ch = csp->cs_bp[csp->cs_cno = 0];
97 }
98 }
99 break;
100 case 0:
101 if (csp->cs_cno == csp->cs_len - 1)
102 csp->cs_flags = CS_EOL;
103 else
104 csp->cs_ch = csp->cs_bp[++csp->cs_cno];
105 break;
106 case CS_EOF: /* EOF. */
107 break;
108 default:
109 abort();
110 /* NOTREACHED */
111 }
112 return (0);
113 }
114
115 /*
116 * cs_fspace --
117 * If on a space, eat forward until something other than a
118 * whitespace character.
119 *
120 * XXX
121 * Semantics of checking the current character were coded for the fword()
122 * function -- once the other word routines are converted, they may have
123 * to change.
124 *
125 * PUBLIC: int cs_fspace __P((SCR *, VCS *));
126 */
127 int
cs_fspace(SCR * sp,VCS * csp)128 cs_fspace(SCR *sp, VCS *csp)
129 {
130 if (csp->cs_flags != 0 || !ISBLANK2(csp->cs_ch))
131 return (0);
132 for (;;) {
133 if (cs_next(sp, csp))
134 return (1);
135 if (csp->cs_flags != 0 || !ISBLANK2(csp->cs_ch))
136 break;
137 }
138 return (0);
139 }
140
141 /*
142 * cs_fblank --
143 * Eat forward to the next non-whitespace character.
144 *
145 * PUBLIC: int cs_fblank __P((SCR *, VCS *));
146 */
147 int
cs_fblank(SCR * sp,VCS * csp)148 cs_fblank(SCR *sp, VCS *csp)
149 {
150 for (;;) {
151 if (cs_next(sp, csp))
152 return (1);
153 if (csp->cs_flags == CS_EOL || csp->cs_flags == CS_EMP ||
154 (csp->cs_flags == 0 && ISBLANK2(csp->cs_ch)))
155 continue;
156 break;
157 }
158 return (0);
159 }
160
161 /*
162 * cs_prev --
163 * Retrieve the previous character.
164 *
165 * PUBLIC: int cs_prev __P((SCR *, VCS *));
166 */
167 int
cs_prev(SCR * sp,VCS * csp)168 cs_prev(SCR *sp, VCS *csp)
169 {
170 switch (csp->cs_flags) {
171 case CS_EMP: /* EMP; get previous line. */
172 case CS_EOL: /* EOL; get previous line. */
173 if (csp->cs_lno == 1) { /* SOF. */
174 csp->cs_flags = CS_SOF;
175 break;
176 }
177 if (db_get(sp, /* The line should exist. */
178 --csp->cs_lno, DBG_FATAL, &csp->cs_bp, &csp->cs_len)) {
179 ++csp->cs_lno;
180 return (1);
181 }
182 if (csp->cs_len == 0 || v_isempty(csp->cs_bp, csp->cs_len)) {
183 csp->cs_cno = 0;
184 csp->cs_flags = CS_EMP;
185 } else {
186 csp->cs_flags = 0;
187 csp->cs_cno = csp->cs_len - 1;
188 csp->cs_ch = csp->cs_bp[csp->cs_cno];
189 }
190 break;
191 case CS_EOF: /* EOF: get previous char. */
192 case 0:
193 if (csp->cs_cno == 0)
194 if (csp->cs_lno == 1)
195 csp->cs_flags = CS_SOF;
196 else
197 csp->cs_flags = CS_EOL;
198 else
199 csp->cs_ch = csp->cs_bp[--csp->cs_cno];
200 break;
201 case CS_SOF: /* SOF. */
202 break;
203 default:
204 abort();
205 /* NOTREACHED */
206 }
207 return (0);
208 }
209
210 /*
211 * cs_bblank --
212 * Eat backward to the next non-whitespace character.
213 *
214 * PUBLIC: int cs_bblank __P((SCR *, VCS *));
215 */
216 int
cs_bblank(SCR * sp,VCS * csp)217 cs_bblank(SCR *sp, VCS *csp)
218 {
219 for (;;) {
220 if (cs_prev(sp, csp))
221 return (1);
222 if (csp->cs_flags == CS_EOL || csp->cs_flags == CS_EMP ||
223 (csp->cs_flags == 0 && ISBLANK2(csp->cs_ch)))
224 continue;
225 break;
226 }
227 return (0);
228 }
229