lib/chown.c

   1 /* provide consistent interface to chown for systems that don't interpret
   2    an ID of -1 as meaning `don't change the corresponding ID'.
   3    Copyright (C) 1997 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program 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
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19 /* written by Jim Meyering */
  20
  21 #include <config.h>
  22
  23 /* Disable the definition of chown to rpl_chown (from config.h) in this
  24    file.  Otherwise, we'd get conflicting prototypes for rpl_chown on
  25    most systems.  */
  26 #undef chown
  27
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #if HAVE_UNISTD_H
  31 # include <unistd.h>
  32 #endif
  33
  34 /* FIXME: describe.  */
  35
  36 int
  37 rpl_chown (const char *file, uid_t uid, gid_t gid)
  38 {
  39   if (gid == (gid_t) -1 || uid == (uid_t) -1)
  40     {
  41       struct stat file_stats;
  42
  43       /* Stat file to get id(s) that should remain unchanged.  */
  44       if (stat (file, &file_stats))
  45         return 1;
  46
  47       if (gid == (gid_t) -1)
  48         gid = file_stats.st_gid;
  49
  50       if (uid == (uid_t) -1)
  51         uid = file_stats.st_uid;
  52     }
  53
  54   return chown (file, uid, gid);
  55 }