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, 2006-2009 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/>. */
29 # include <sys/types.h>
32 # if HAVE_LANGINFO_YESEXPR
33 # include <langinfo.h>
37 # define _(msgid) gettext (msgid)
38 # define N_(msgid) gettext_noop (msgid)
40 # if HAVE_LANGINFO_YESEXPR
41 /* Return the localized regular expression pattern corresponding to
42 ENGLISH_PATTERN. NL_INDEX can be used with nl_langinfo.
43 The resulting string may only be used until the next nl_langinfo call. */
45 localized_pattern (const char *english_pattern, nl_item nl_index,
48 const char *translated_pattern;
50 /* We prefer to get the patterns from a PO file. It would be possible to
51 always use nl_langinfo (YESEXPR) instead of _("^[yY]"), and
52 nl_langinfo (NOEXPR) instead of _("^[nN]"), if we could assume that the
53 system's locale support is good. But this is not the case e.g. on Cygwin.
54 The localizations of gnulib.pot are of better quality in general.
55 Also, if we use locale info from non-free systems that don't have a
56 'localedef' command, we deprive the users of the freedom to localize
57 this pattern for their preferred language.
58 But some programs, such as 'cp', 'mv', 'rm', 'find', 'xargs', are
59 specified by POSIX to use nl_langinfo (YESEXPR). We implement this
60 behaviour if POSIXLY_CORRECT is set, for the sake of these programs. */
62 /* If the user wants strict POSIX compliance, use nl_langinfo. */
65 translated_pattern = nl_langinfo (nl_index);
66 /* Check against a broken system return value. */
67 if (translated_pattern != NULL && translated_pattern[0] != '\0')
68 return translated_pattern;
71 /* Look in the gnulib message catalog. */
72 translated_pattern = _(english_pattern);
73 if (translated_pattern == english_pattern)
75 /* The gnulib message catalog provides no translation.
76 Try the system's message catalog. */
77 translated_pattern = nl_langinfo (nl_index);
78 /* Check against a broken system return value. */
79 if (translated_pattern != NULL && translated_pattern[0] != '\0')
80 return translated_pattern;
81 /* Fall back to English. */
82 translated_pattern = english_pattern;
84 return translated_pattern;
87 # define localized_pattern(english_pattern,nl_index,posixly_correct) \
92 try (const char *response, const char *pattern, char **lastp, regex_t *re)
94 if (*lastp == NULL || strcmp (pattern, *lastp) != 0)
98 /* The pattern has changed. */
101 /* Free the old compiled pattern. */
106 /* Put the PATTERN into safe memory before calling regcomp.
107 (regcomp may call nl_langinfo, overwriting PATTERN's storage. */
108 safe_pattern = strdup (pattern);
109 if (safe_pattern == NULL)
111 /* Compile the pattern and cache it for future runs. */
112 if (regcomp (re, safe_pattern, REG_EXTENDED) != 0)
114 *lastp = safe_pattern;
117 /* See if the regular expression matches RESPONSE. */
118 return regexec (re, response, 0, NULL, 0) == 0;
124 rpmatch (const char *response)
127 /* Match against one of the response patterns, compiling the pattern
128 first if necessary. */
130 /* We cache the response patterns and compiled regexps here. */
131 static char *last_yesexpr, *last_noexpr;
132 static regex_t cached_yesre, cached_nore;
134 # if HAVE_LANGINFO_YESEXPR
135 bool posixly_correct = (getenv ("POSIXLY_CORRECT") != NULL);
138 const char *yesexpr, *noexpr;
141 /* TRANSLATORS: A regular expression testing for an affirmative answer
142 (english: "yes"). Testing the first character may be sufficient.
143 Take care to consider upper and lower case.
144 To enquire the regular expression that your system uses for this
145 purpose, you can use the command
146 locale -k LC_MESSAGES | grep '^yesexpr=' */
147 yesexpr = localized_pattern (N_("^[yY]"), YESEXPR, posixly_correct);
148 result = try (response, yesexpr, &last_yesexpr, &cached_yesre);
154 /* TRANSLATORS: A regular expression testing for a negative answer
155 (english: "no"). Testing the first character may be sufficient.
156 Take care to consider upper and lower case.
157 To enquire the regular expression that your system uses for this
158 purpose, you can use the command
159 locale -k LC_MESSAGES | grep '^noexpr=' */
160 noexpr = localized_pattern (N_("^[nN]"), NOEXPR, posixly_correct);
161 result = try (response, noexpr, &last_noexpr, &cached_nore);
169 /* Test against "^[yY]" and "^[nN]", hardcoded to avoid requiring regex */
170 return (*response == 'y' || *response == 'Y' ? 1
171 : *response == 'n' || *response == 'N' ? 0 : -1);