1 /* Determine whether string value is affirmation or negative response
2 according to current locale's data.
4 Copyright (C) 1996, 1998, 2000, 2002, 2003, 2006-2008 Free Software
7 This program is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 # include <sys/types.h>
30 # if HAVE_LANGINFO_YESEXPR
31 # include <langinfo.h>
35 # define _(msgid) gettext (msgid)
36 # define N_(msgid) gettext_noop (msgid)
38 # if HAVE_LANGINFO_YESEXPR
39 /* Return the localized regular expression pattern corresponding to
40 ENGLISH_PATTERN. NL_INDEX can be used with nl_langinfo.
41 The resulting string may only be used until the next nl_langinfo call. */
43 localized_pattern (const char *english_pattern, nl_item nl_index,
46 const char *translated_pattern;
48 /* We prefer to get the patterns from a PO file. It would be possible to
49 always use nl_langinfo (YESEXPR) instead of _("^[yY]"), and
50 nl_langinfo (NOEXPR) instead of _("^[nN]"), if we could assume that the
51 system's locale support is good. But this is not the case e.g. on Cygwin.
52 The localizations of gnulib.pot are of better quality in general.
53 Also, if we use locale info from non-free systems that don't have a
54 'localedef' command, we deprive the users of the freedom to localize
55 this pattern for their preferred language.
56 But some programs, such as 'cp', 'mv', 'rm', 'find', 'xargs', are
57 specified by POSIX to use nl_langinfo (YESEXPR). We implement this
58 behaviour if POSIXLY_CORRECT is set, for the sake of these programs. */
60 /* If the user wants strict POSIX compliance, use nl_langinfo. */
63 translated_pattern = nl_langinfo (nl_index);
64 /* Check against a broken system return value. */
65 if (translated_pattern != NULL && translated_pattern[0] != '\0')
66 return translated_pattern;
69 /* Look in the gnulib message catalog. */
70 translated_pattern = _(english_pattern);
71 if (translated_pattern == english_pattern)
73 /* The gnulib message catalog provides no translation.
74 Try the system's message catalog. */
75 translated_pattern = nl_langinfo (nl_index);
76 /* Check against a broken system return value. */
77 if (translated_pattern != NULL && translated_pattern[0] != '\0')
78 return translated_pattern;
79 /* Fall back to English. */
80 translated_pattern = english_pattern;
82 return translated_pattern;
85 # define localized_pattern(english_pattern,nl_index,posixly_correct) \
90 try (const char *response, const char *pattern, char **lastp, regex_t *re)
92 if (*lastp == NULL || strcmp (pattern, *lastp) != 0)
96 /* The pattern has changed. */
99 /* Free the old compiled pattern. */
104 /* Put the PATTERN into safe memory before calling regcomp.
105 (regcomp may call nl_langinfo, overwriting PATTERN's storage. */
106 safe_pattern = strdup (pattern);
107 if (safe_pattern == NULL)
109 /* Compile the pattern and cache it for future runs. */
110 if (regcomp (re, safe_pattern, REG_EXTENDED) != 0)
112 *lastp = safe_pattern;
115 /* See if the regular expression matches RESPONSE. */
116 return regexec (re, response, 0, NULL, 0) == 0;
121 /* Test a user response to a question.
122 Return 1 if it is affirmative, 0 if it is negative, or -1 if not clear. */
125 rpmatch (const char *response)
128 /* Match against one of the response patterns, compiling the pattern
129 first if necessary. */
131 /* We cache the response patterns and compiled regexps here. */
132 static char *last_yesexpr, *last_noexpr;
133 static regex_t cached_yesre, cached_nore;
135 # if HAVE_LANGINFO_YESEXPR
136 bool posixly_correct = (getenv ("POSIXLY_CORRECT") != NULL);
139 const char *yesexpr, *noexpr;
142 /* TRANSLATORS: A regular expression testing for an affirmative answer
143 (english: "yes"). Testing the first character may be sufficient.
144 Take care to consider upper and lower case.
145 To enquire the regular expression that your system uses for this
146 purpose, you can use the command
147 locale -k LC_MESSAGES | grep '^yesexpr=' */
148 yesexpr = localized_pattern (N_("^[yY]"), YESEXPR, posixly_correct);
149 result = try (response, yesexpr, &last_yesexpr, &cached_yesre);
155 /* TRANSLATORS: A regular expression testing for a negative answer
156 (english: "no"). Testing the first character may be sufficient.
157 Take care to consider upper and lower case.
158 To enquire the regular expression that your system uses for this
159 purpose, you can use the command
160 locale -k LC_MESSAGES | grep '^noexpr=' */
161 noexpr = localized_pattern (N_("^[nN]"), NOEXPR, posixly_correct);
162 result = try (response, noexpr, &last_noexpr, &cached_nore);
170 /* Test against "^[yY]" and "^[nN]", hardcoded to avoid requiring regex */
171 return (*response == 'y' || *response == 'Y' ? 1
172 : *response == 'n' || *response == 'N' ? 0 : -1);