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 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 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 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 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 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 182 no_check(char *ans) 183 { 184 return (yes_no_check(ans, &preg_no, &preg_yes)); 185 } 186 187 int 188 yes(void) 189 { 190 return (yes_no(yes_check)); 191 } 192 193 int 194 no(void) 195 { 196 return (yes_no(no_check)); 197 } 198