2 Copyright (C) 2012 Paul Davis
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include "pbd/compose.h"
26 #include "pbd/debug.h"
27 #include "pbd/error.h"
28 #include "pbd/locale_guard.h"
32 /* Neither C nor C++ pick up a user's preferred locale choice without the
33 * application actively taking steps to make this happen.
35 * For C: setlocale (LC_ALL, "");
36 * For C++ (assuming that the C version was called):
37 * std::locale::global (std::locale (setlocale (LC_ALL, 0)));
39 * The application needs to make these calls, probably in main().
41 * Setting the C++ locale will change the C locale, but not the other way 'round.
42 * and some plugin may change either behind our back.
45 LocaleGuard::LocaleGuard ()
48 /* A LocaleGuard object ensures that the
49 * LC_NUMERIC/std::locale::numeric aspect of the C and C++ locales are
50 * set to "C" during its lifetime, so that printf/iostreams use a
51 * portable format for numeric output (i.e. 1234.5 is always 1234.5 and
52 * not sometimes 1234,5, as it would be in fr or de locales)
55 char const * const current_c_locale = setlocale (LC_NUMERIC, 0);
57 if (strcmp ("C", current_c_locale) != 0) {
58 old_c_locale = strdup (current_c_locale);
59 setlocale (LC_NUMERIC, "C");
60 pre_cpp_locale = std::locale();
61 DEBUG_TRACE (DEBUG::Locale, string_compose ("LG: change C locale from '%1' => 'C' (C++ locale is %2)\n", old_c_locale, pre_cpp_locale.name()));
65 LocaleGuard::~LocaleGuard ()
67 char const * current_c_locale = setlocale (LC_NUMERIC, 0);
68 std::locale current_cpp_locale;
70 if (current_cpp_locale != pre_cpp_locale) {
72 PBD::warning << string_compose ("LocaleGuard: someone (a plugin) changed the C++ locale from\n\t%1\nto\n\t%2\n, expect non-portable session files. Decimal OK ? %3",
73 old_cpp_locale.name(), current_cpp_locale.name(),
74 (std::use_facet<std::numpunct<char> >(std::locale()).decimal_point() == '.'))
78 /* this resets C & C++ locales */
79 std::locale::global (old_cpp_locale);
80 DEBUG_TRACE (DEBUG::Locale, string_compose ("LG: restore C & C++ locale: '%1'\n", std::locale().name()));
82 /* see comments in the constructor regarding the
85 * This should restore restore numeric handling back to
86 * the default (which may reflect user
87 * preferences). This probably can't fail, because
88 * old_c_locale was already in use during the
89 * constructor for this object.
91 * Still ... Apple ... locale support ... just sayin' ....
93 setlocale (LC_NUMERIC, old_c_locale);
94 DEBUG_TRACE (DEBUG::Locale, string_compose ("LG: C++ locale API failed, restore C locale from %1 to\n'%2'\n(C++ is '%3')\n", current_c_locale, old_c_locale, std::locale().name()));
98 if (old_c_locale && (strcmp (current_c_locale, old_c_locale) != 0)) {
99 /* reset only the C locale */
100 setlocale (LC_NUMERIC, old_c_locale);
101 DEBUG_TRACE (DEBUG::Locale, string_compose ("LG: restore C locale from %1 to\n'%2'\n(C++ is '%3')\n", current_c_locale, old_c_locale, std::locale().name()));
104 free (const_cast<char*> (old_c_locale));