jnlib/w32-reg.c

   1 /* w32-reg.c -  MS-Windows Registry access
   2  * Copyright (C) 1999, 2002, 2007 Free Software Foundation, Inc.
   3  *
   4  * This file is part of JNLIB.
   5  *
   6  * JNLIB is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as
   8  * published by the Free Software Foundation; either version 3 of
   9  * the License, or (at your option) any later version.
  10  *
  11  * JNLIB is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <config.h>
  21 #ifdef HAVE_W32_SYSTEM
  22  /* This module is only used in this environment */
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <stdarg.h>
  28 #include <windows.h>
  29
  30 #include "libjnlib-config.h"
  31 #include "w32help.h"
  32
  33 static HKEY
  34 get_root_key(const char *root)
  35 {
  36   HKEY root_key;
  37
  38   if (!root)
  39     root_key = HKEY_CURRENT_USER;
  40   else if (!strcmp( root, "HKEY_CLASSES_ROOT" ) )
  41     root_key = HKEY_CLASSES_ROOT;
  42   else if (!strcmp( root, "HKEY_CURRENT_USER" ) )
  43     root_key = HKEY_CURRENT_USER;
  44   else if (!strcmp( root, "HKEY_LOCAL_MACHINE" ) )
  45     root_key = HKEY_LOCAL_MACHINE;
  46   else if (!strcmp( root, "HKEY_USERS" ) )
  47     root_key = HKEY_USERS;
  48   else if (!strcmp( root, "HKEY_PERFORMANCE_DATA" ) )
  49     root_key = HKEY_PERFORMANCE_DATA;
  50   else if (!strcmp( root, "HKEY_CURRENT_CONFIG" ) )
  51     root_key = HKEY_CURRENT_CONFIG;
  52   else
  53     return NULL;
  54
  55   return root_key;
  56 }
  57
  58
  59 /* Return a string from the Win32 Registry or NULL in case of error.
  60    Caller must release the return value.  A NULL for root is an alias
  61    for HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE in turn.  */
  62 char *
  63 read_w32_registry_string (const char *root, const char *dir, const char *name)
  64 {
  65   HKEY root_key, key_handle;
  66   DWORD n1, nbytes, type;
  67   char *result = NULL;
  68
  69   if ( !(root_key = get_root_key(root) ) )
  70     return NULL;
  71
  72   if ( RegOpenKeyEx( root_key, dir, 0, KEY_READ, &key_handle ) )
  73     {
  74       if (root)
  75         return NULL; /* No need for a RegClose, so return immediately. */
  76       /* It seems to be common practise to fall back to HKLM. */
  77       if (RegOpenKeyEx (HKEY_LOCAL_MACHINE, dir, 0, KEY_READ, &key_handle) )
  78         return NULL; /* Still no need for a RegClose. */
  79     }
  80
  81   nbytes = 1;
  82   if (RegQueryValueEx( key_handle, name, 0, NULL, NULL, &nbytes ) )
  83     goto leave;
  84   result = jnlib_malloc ((n1=nbytes+1));
  85   if (!result)
  86     goto leave;
  87   if (RegQueryValueEx( key_handle, name, 0, &type, result, &n1 ))
  88     {
  89       jnlib_free (result);
  90       result = NULL;
  91       goto leave;
  92     }
  93   result[nbytes] = 0; /* Make sure it is a string.  */
  94   if (type == REG_EXPAND_SZ && strchr (result, '%'))
  95     {
  96       char *tmp;
  97
  98       n1 += 1000;
  99       tmp = jnlib_malloc (n1+1);
 100       if (!tmp)
 101         goto leave;
 102       nbytes = ExpandEnvironmentStrings (result, tmp, n1);
 103       if (nbytes && nbytes > n1)
 104         {
 105           jnlib_free (tmp);
 106           n1 = nbytes;
 107           tmp = jnlib_malloc (n1 + 1);
 108           if (!tmp)
 109             goto leave;
 110           nbytes = ExpandEnvironmentStrings (result, tmp, n1);
 111           if (nbytes && nbytes > n1)
 112             {
 113               /* Oops - truncated, better don't expand at all.  */
 114               jnlib_free (tmp);
 115               goto leave;
 116             }
 117           tmp[nbytes] = 0;
 118           jnlib_free (result);
 119           result = tmp;
 120         }
 121       else if (nbytes)
 122         {
 123           /* Okay, reduce the length.  */
 124           tmp[nbytes] = 0;
 125           jnlib_free (result);
 126           result = jnlib_malloc (strlen (tmp)+1);
 127           if (!result)
 128             result = tmp;
 129             else
 130               {
 131                 strcpy (result, tmp);
 132                 jnlib_free (tmp);
 133               }
 134         }
 135       else
 136         {
 137           /* Error - don't expand.  */
 138           jnlib_free (tmp);
 139         }
 140     }
 141
 142  leave:
 143   RegCloseKey (key_handle);
 144   return result;
 145 }
 146
 147
 148 int
 149 write_w32_registry_string (const char *root, const char *dir,
 150                            const char *name, const char *value)
 151 {
 152   HKEY root_key, reg_key;
 153
 154   if ( !(root_key = get_root_key(root) ) )
 155     return -1;
 156
 157   if ( RegOpenKeyEx( root_key, dir, 0, KEY_WRITE, &reg_key )
 158        != ERROR_SUCCESS )
 159     return -1;
 160
 161   if ( RegSetValueEx (reg_key, name, 0, REG_SZ, (BYTE *)value,
 162                       strlen( value ) ) != ERROR_SUCCESS )
 163     {
 164       if ( RegCreateKey( root_key, name, &reg_key ) != ERROR_SUCCESS )
 165         {
 166           RegCloseKey(reg_key);
 167           return -1;
 168         }
 169       if ( RegSetValueEx (reg_key, name, 0, REG_SZ, (BYTE *)value,
 170                           strlen( value ) ) != ERROR_SUCCESS )
 171         {
 172           RegCloseKey(reg_key);
 173           return -1;
 174         }
 175     }
 176
 177   RegCloseKey (reg_key);
 178
 179   return 0;
 180 }
 181
 182 #endif /*HAVE_W32_SYSTEM*/