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 if (yesstr) \ 44 free(yesstr); \ 45 if (nostr) \ 46 free(nostr); \ 47 if (yesexpr) \ 48 free(yesexpr); \ 49 if (noexpr) \ 50 free(noexpr) 51 52 #define SET_DEFAULT_STRS \ 53 yesstr = DEFAULT_YESSTR; \ 54 nostr = DEFAULT_NOSTR; \ 55 yesexpr = DEFAULT_YESEXPR; \ 56 noexpr = DEFAULT_NOEXPR; 57 58 /* variables used by getresponse functions */ 59 char *yesstr = NULL; 60 char *nostr = NULL; 61 62 /* for regcomp()/regexec() yesexpr and noexpr */ 63 static regex_t preg_yes, preg_no; 64 65 /* 66 * This function compiles a regular expression that is used to match an 67 * affirmative response from the user, and also assigns the strings used 68 * in the prompts that request affirmative or negative responses. The 69 * locale's values for YESEXPR, NOEXPR, YESSTR and NOSTR are used. 70 * 71 * If there are any problems using the locale's YESEXPR, NOEXPR, YESSTR or NOSTR 72 * values, default values of YESEXPR, YESSTR and NOSTR will be used 73 * as a fallback. The default values are the same as the C locale values. 74 */ 75 int 76 init_yes(void) 77 { 78 int fallback = 0; 79 char *yesexpr; 80 char *noexpr; 81 82 /* get yes expression and strings for yes/no prompts */ 83 yesstr = strdup(nl_langinfo(YESSTR)); 84 nostr = strdup(nl_langinfo(NOSTR)); 85 yesexpr = strdup(nl_langinfo(YESEXPR)); 86 noexpr = strdup(nl_langinfo(NOEXPR)); 87 88 if (yesstr == NULL || nostr == NULL || 89 yesexpr == NULL || noexpr == NULL) { 90 FREE_MEM; 91 errno = ENOMEM; 92 return (-1); 93 } 94 95 /* if problem with locale strings, use default values */ 96 if (*yesstr == '\0' || *nostr == '\0' || 97 *yesexpr == '\0' || *noexpr == '\0') { 98 FREE_MEM; 99 SET_DEFAULT_STRS; 100 fallback = 1; 101 } 102 /* Compile the yes and no expressions */ 103 while (regcomp(&preg_yes, yesexpr, REG_EXTENDED | REG_NOSUB) != 0 || 104 regcomp(&preg_no, noexpr, REG_EXTENDED | REG_NOSUB) != 0) { 105 if (fallback == 1) { 106 /* The fallback yesexpr failed, so exit */ 107 errno = EINVAL; 108 return (-1); 109 } 110 /* The locale's yesexpr or noexpr failed so use fallback */ 111 FREE_MEM; 112 SET_DEFAULT_STRS; 113 fallback = 1; 114 } 115 return (0); 116 } 117 118 static int 119 yes_no(int (*func)(char *)) 120 { 121 int i, b; 122 char ans[LINE_MAX + 1]; 123 124 /* Get user's answer */ 125 i = 0; 126 for (;;) { 127 b = getchar(); 128 if (b == '\n' || b == '\0' || b == EOF) 129 break; 130 if (i < LINE_MAX) 131 ans[i] = b; 132 i++; 133 } 134 if (i >= LINE_MAX) 135 ans[LINE_MAX] = '\0'; 136 else 137 ans[i] = '\0'; 138 139 return (func(ans)); 140 } 141 142 static int 143 yes_no_check(char *ans, regex_t *reg1, regex_t *reg2) 144 { 145 if (regexec(reg1, ans, 0, NULL, 0) == 0) { 146 if (regexec(reg2, ans, 0, NULL, 0) == 0) { 147 /* Both Expressions Match (reg2 conservative) */ 148 return (0); 149 } 150 /* Match */ 151 return (1); 152 } 153 return (0); 154 } 155 156 /* 157 * yes_check() returns 1 if the input string is matched by yesexpr and is 158 * not matched by noexpr; otherwise yes_check() returns 0. 159 */ 160 int 161 yes_check(char *ans) 162 { 163 return (yes_no_check(ans, &preg_yes, &preg_no)); 164 } 165 166 /* 167 * no_check() returns 1 if the input string is matched by noexpr and is 168 * not matched by yesexpr; otherwise no_check() returns 0. 169 */ 170 int 171 no_check(char *ans) 172 { 173 return (yes_no_check(ans, &preg_no, &preg_yes)); 174 } 175 176 int 177 yes(void) 178 { 179 return (yes_no(yes_check)); 180 } 181 182 int 183 no(void) 184 { 185 return (yes_no(no_check)); 186 } 187