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 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 29 #include <stdio.h> 30 #include <string.h> 31 #include <stdlib.h> 32 #include <regex.h> 33 #include <locale.h> 34 #include <langinfo.h> 35 #include <limits.h> 36 #include <errno.h> 37 #include "getresponse.h" 38 39 /* defaults - C locale values for yesstr, nostr, yesexpr (LC_MESSAGES) */ 40 #define DEFAULT_YESSTR "yes" 41 #define DEFAULT_NOSTR "no" 42 #define DEFAULT_YESEXPR "^[yY]" 43 #define DEFAULT_NOEXPR "^[nN]" 44 45 #define FREE_MEM \ 46 if (yesstr) \ 47 free(yesstr); \ 48 if (nostr) \ 49 free(nostr); \ 50 if (yesexpr) \ 51 free(yesexpr); \ 52 if (noexpr) \ 53 free(noexpr) 54 55 #define SET_DEFAULT_STRS \ 56 yesstr = DEFAULT_YESSTR; \ 57 nostr = DEFAULT_NOSTR; \ 58 yesexpr = DEFAULT_YESEXPR; \ 59 noexpr = DEFAULT_NOEXPR; 60 61 /* variables used by getresponse functions */ 62 char *yesstr = NULL; 63 char *nostr = NULL; 64 65 /* for regcomp()/regexec() yesexpr and noexpr */ 66 static regex_t preg_yes, preg_no; 67 68 /* 69 * This function compiles a regular expression that is used to match an 70 * affirmative response from the user, and also assigns the strings used 71 * in the prompts that request affirmative or negative responses. The 72 * locale's values for YESEXPR, NOEXPR, YESSTR and NOSTR are used. 73 * 74 * If there are any problems using the locale's YESEXPR, NOEXPR, YESSTR or NOSTR 75 * values, default values of YESEXPR, YESSTR and NOSTR will be used 76 * as a fallback. The default values are the same as the C locale values. 77 */ 78 int 79 init_yes(void) 80 { 81 int fallback = 0; 82 char *yesexpr; 83 char *noexpr; 84 85 /* get yes expression and strings for yes/no prompts */ 86 yesstr = strdup(nl_langinfo(YESSTR)); 87 nostr = strdup(nl_langinfo(NOSTR)); 88 yesexpr = strdup(nl_langinfo(YESEXPR)); 89 noexpr = strdup(nl_langinfo(NOEXPR)); 90 91 if (yesstr == NULL || nostr == NULL || 92 yesexpr == NULL || noexpr == NULL) { 93 FREE_MEM; 94 errno = ENOMEM; 95 return (-1); 96 } 97 98 /* if problem with locale strings, use default values */ 99 if (*yesstr == '\0' || *nostr == '\0' || 100 *yesexpr == '\0' || *noexpr == '\0') { 101 FREE_MEM; 102 SET_DEFAULT_STRS; 103 fallback = 1; 104 } 105 /* Compile the yes and no expressions */ 106 while (regcomp(&preg_yes, yesexpr, REG_EXTENDED | REG_NOSUB) != 0 || 107 regcomp(&preg_no, noexpr, REG_EXTENDED | REG_NOSUB) != 0) { 108 if (fallback == 1) { 109 /* The fallback yesexpr failed, so exit */ 110 errno = EINVAL; 111 return (-1); 112 } 113 /* The locale's yesexpr or noexpr failed so use fallback */ 114 FREE_MEM; 115 SET_DEFAULT_STRS; 116 fallback = 1; 117 } 118 return (0); 119 } 120 121 static int 122 yes_no(int (*func)(char *)) 123 { 124 int i, b; 125 char ans[LINE_MAX + 1]; 126 127 /* Get user's answer */ 128 for (i = 0; b = getchar(); i++) { 129 if (b == '\n' || b == '\0' || b == EOF) 130 break; 131 if (i < LINE_MAX) 132 ans[i] = b; 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