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glibc  2.9
duplocale.c
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00001 /* Duplicate handle for selection of locales.
00002    Copyright (C) 1997,2000,2001,2002,2005,2008 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
00005 
00006    The GNU C Library is free software; you can redistribute it and/or
00007    modify it under the terms of the GNU Lesser General Public
00008    License as published by the Free Software Foundation; either
00009    version 2.1 of the License, or (at your option) any later version.
00010 
00011    The GNU C Library is distributed in the hope that it will be useful,
00012    but WITHOUT ANY WARRANTY; without even the implied warranty of
00013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014    Lesser General Public License for more details.
00015 
00016    You should have received a copy of the GNU Lesser General Public
00017    License along with the GNU C Library; if not, write to the Free
00018    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00019    02111-1307 USA.  */
00020 
00021 #include <locale.h>
00022 #include <bits/libc-lock.h>
00023 #include <stdlib.h>
00024 #include <string.h>
00025 
00026 #include <localeinfo.h>
00027 
00028 
00029 /* Lock for protecting global data.  */
00030 __libc_rwlock_define (extern , __libc_setlocale_lock attribute_hidden)
00031 
00032 
00033 __locale_t
00034 __duplocale (__locale_t dataset)
00035 {
00036   /* This static object is returned for newlocale (LC_ALL_MASK, "C").  */
00037   if (dataset == _nl_C_locobj_ptr)
00038     return dataset;
00039 
00040   __locale_t result;
00041   int cnt;
00042   size_t names_len = 0;
00043 
00044   /* Calculate the total space we need to store all the names.  */
00045   for (cnt = 0; cnt < __LC_LAST; ++cnt)
00046     if (cnt != LC_ALL && dataset->__names[cnt] != _nl_C_name)
00047       names_len += strlen (dataset->__names[cnt]) + 1;
00048 
00049   /* Get memory.  */
00050   result = malloc (sizeof (struct __locale_struct) + names_len);
00051 
00052   if (result != NULL)
00053     {
00054       char *namep = (char *) (result + 1);
00055 
00056       /* We modify global data (the usage counts).  */
00057       __libc_rwlock_wrlock (__libc_setlocale_lock);
00058 
00059       for (cnt = 0; cnt < __LC_LAST; ++cnt)
00060        if (cnt != LC_ALL)
00061          {
00062            result->__locales[cnt] = dataset->__locales[cnt];
00063            if (result->__locales[cnt]->usage_count < MAX_USAGE_COUNT)
00064              ++result->__locales[cnt]->usage_count;
00065 
00066            if (dataset->__names[cnt] == _nl_C_name)
00067              result->__names[cnt] = _nl_C_name;
00068            else
00069              {
00070               result->__names[cnt] = namep;
00071               namep = __stpcpy (namep, dataset->__names[cnt]) + 1;
00072              }
00073          }
00074 
00075       /* Update the special members.  */
00076       result->__ctype_b = dataset->__ctype_b;
00077       result->__ctype_tolower = dataset->__ctype_tolower;
00078       result->__ctype_toupper = dataset->__ctype_toupper;
00079 
00080       /* It's done.  */
00081       __libc_rwlock_unlock (__libc_setlocale_lock);
00082     }
00083 
00084   return result;
00085 }
00086 weak_alias (__duplocale, duplocale)