1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include <stdio.h>
27 #include <string.h>
28 #include <stdlib.h>
29 #include <regex.h>
30 #include <locale.h>
31 #include <langinfo.h>
32 #include <limits.h>
33 #include <errno.h>
34 #include "getresponse.h"
35
36 /* defaults - C locale values for yesstr, nostr, yesexpr (LC_MESSAGES) */
37 #define DEFAULT_YESSTR "yes"
38 #define DEFAULT_NOSTR "no"
39 #define DEFAULT_YESEXPR "^[yY]"
40 #define DEFAULT_NOEXPR "^[nN]"
41
42 #define FREE_MEM \
43 free(yesstr); \
44 free(nostr); \
45 free(yesexpr); \
46 free(noexpr)
47
48 #define SET_DEFAULT_STRS \
49 yesstr = DEFAULT_YESSTR; \
50 nostr = DEFAULT_NOSTR; \
51 yesexpr = DEFAULT_YESEXPR; \
52 noexpr = DEFAULT_NOEXPR;
53
54 /* variables used by getresponse functions */
55 char *yesstr = NULL;
56 char *nostr = NULL;
57
58 /* for regcomp()/regexec() yesexpr and noexpr */
59 static regex_t preg_yes, preg_no;
60
61 /*
62 * This function compiles a regular expression that is used to match an
63 * affirmative response from the user, and also assigns the strings used
64 * in the prompts that request affirmative or negative responses. The
65 * locale's values for YESEXPR, NOEXPR, YESSTR and NOSTR are used.
66 *
67 * If there are any problems using the locale's YESEXPR, NOEXPR, YESSTR or NOSTR
68 * values, default values of YESEXPR, YESSTR and NOSTR will be used
69 * as a fallback. The default values are the same as the C locale values.
70 */
71 int
init_yes(void)72 init_yes(void)
73 {
74 int fallback = 0;
75 char *yesexpr;
76 char *noexpr;
77
78 /* get yes expression and strings for yes/no prompts */
79 yesstr = strdup(nl_langinfo(YESSTR));
80 nostr = strdup(nl_langinfo(NOSTR));
81 yesexpr = strdup(nl_langinfo(YESEXPR));
82 noexpr = strdup(nl_langinfo(NOEXPR));
83
84 if (yesstr == NULL || nostr == NULL ||
85 yesexpr == NULL || noexpr == NULL) {
86 FREE_MEM;
87 errno = ENOMEM;
88 return (-1);
89 }
90
91 /* if problem with locale strings, use default values */
92 if (*yesstr == '\0' || *nostr == '\0' ||
93 *yesexpr == '\0' || *noexpr == '\0') {
94 FREE_MEM;
95 SET_DEFAULT_STRS;
96 fallback = 1;
97 }
98 /* Compile the yes and no expressions */
99 while (regcomp(&preg_yes, yesexpr, REG_EXTENDED | REG_NOSUB) != 0 ||
100 regcomp(&preg_no, noexpr, REG_EXTENDED | REG_NOSUB) != 0) {
101 if (fallback == 1) {
102 /* The fallback yesexpr failed, so exit */
103 errno = EINVAL;
104 return (-1);
105 }
106 /* The locale's yesexpr or noexpr failed so use fallback */
107 FREE_MEM;
108 SET_DEFAULT_STRS;
109 fallback = 1;
110 }
111 if (fallback == 0) {
112 free(yesexpr);
113 free(noexpr);
114 }
115 return (0);
116 }
117
118 void
fini_yes(void)119 fini_yes(void)
120 {
121 free(yesstr);
122 free(nostr);
123 yesstr = DEFAULT_YESSTR;
124 nostr = DEFAULT_NOSTR;
125 regfree(&preg_yes);
126 regfree(&preg_no);
127 }
128
129 static int
yes_no(int (* func)(char *))130 yes_no(int (*func)(char *))
131 {
132 int i, b;
133 char ans[LINE_MAX + 1];
134
135 /* Get user's answer */
136 i = 0;
137 for (;;) {
138 b = getchar();
139 if (b == '\n' || b == '\0' || b == EOF)
140 break;
141 if (i < LINE_MAX)
142 ans[i] = b;
143 i++;
144 }
145 if (i >= LINE_MAX)
146 ans[LINE_MAX] = '\0';
147 else
148 ans[i] = '\0';
149
150 return (func(ans));
151 }
152
153 static int
yes_no_check(char * ans,regex_t * reg1,regex_t * reg2)154 yes_no_check(char *ans, regex_t *reg1, regex_t *reg2)
155 {
156 if (regexec(reg1, ans, 0, NULL, 0) == 0) {
157 if (regexec(reg2, ans, 0, NULL, 0) == 0) {
158 /* Both Expressions Match (reg2 conservative) */
159 return (0);
160 }
161 /* Match */
162 return (1);
163 }
164 return (0);
165 }
166
167 /*
168 * yes_check() returns 1 if the input string is matched by yesexpr and is
169 * not matched by noexpr; otherwise yes_check() returns 0.
170 */
171 int
yes_check(char * ans)172 yes_check(char *ans)
173 {
174 return (yes_no_check(ans, &preg_yes, &preg_no));
175 }
176
177 /*
178 * no_check() returns 1 if the input string is matched by noexpr and is
179 * not matched by yesexpr; otherwise no_check() returns 0.
180 */
181 int
no_check(char * ans)182 no_check(char *ans)
183 {
184 return (yes_no_check(ans, &preg_no, &preg_yes));
185 }
186
187 int
yes(void)188 yes(void)
189 {
190 return (yes_no(yes_check));
191 }
192
193 int
no(void)194 no(void)
195 {
196 return (yes_no(no_check));
197 }
198