source/texk/kpathsea/file-p.c

   1 /* file-p.c: file predicates.
   2
   3    Copyright 1992, 1993, 1994, 2008 Karl Berry.
   4
   5    This library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    This library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this library; if not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include <kpathsea/config.h>
  19
  20 #include <kpathsea/xstat.h>
  21
  22
  23 /* Test whether FILENAME1 and FILENAME2 are actually the same file.  If
  24    stat fails on either of the names, we return false, without error.  */
  25
  26 boolean
  27 same_file_p (const_string filename1,  const_string filename2)
  28 {
  29 #ifdef _WIN32
  30     intptr_t handle1, handle2;
  31     FILE *f1, *f2;
  32     BY_HANDLE_FILE_INFORMATION fileinfo1, fileinfo2;
  33
  34     f1 = fopen(filename1, "r");
  35     if(!f1) return false;
  36     f2 = fopen(filename2, "r");
  37     if(!f2) {
  38       fclose(f1);
  39       return false;
  40     }
  41
  42     handle1 = _get_osfhandle(fileno(f1));
  43     handle2 = _get_osfhandle(fileno(f2));
  44
  45     if (!GetFileInformationByHandle((HANDLE)handle1, &fileinfo1)) {
  46       fclose(f1);
  47       fclose(f2);
  48       return false;
  49     }
  50
  51     if (!GetFileInformationByHandle((HANDLE)handle2, &fileinfo2)) {
  52       fclose(f1);
  53       fclose(f2);
  54       return false;
  55     }
  56
  57     fclose(f1);
  58     fclose(f2);
  59
  60     if (fileinfo1.dwVolumeSerialNumber == fileinfo2.dwVolumeSerialNumber &&
  61       fileinfo1.nFileIndexHigh == fileinfo2.nFileIndexHigh &&
  62       fileinfo1.nFileIndexLow == fileinfo2.nFileIndexLow)
  63       return true;
  64     else
  65       return false;
  66 #else
  67     struct stat sb1, sb2;
  68     /* These are put in variables only so the results can be inspected
  69        under gdb.  */
  70     int r1 = stat (filename1, &sb1);
  71     int r2 = stat (filename2, &sb2);
  72
  73     return r1 == 0 && r2 == 0 ? SAME_FILE_P (sb1, sb2) : false;
  74 #endif
  75 }