lib/lchown.c

   1 /* Provide a stub lchown function for systems that lack it.
   2    Copyright (C) 1998, 1999, 2002 Free Software Foundation, Inc.
   3
   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, or (at your option)
   7    any later version.
   8
   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.
  13
  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 Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* written by Jim Meyering */
  19
  20 #include <config.h>
  21
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <errno.h>
  25 #ifndef errno
  26 extern int errno;
  27 #endif
  28 #include "lchown.h"
  29
  30 #ifdef STAT_MACROS_BROKEN
  31 # undef S_ISLNK
  32 #endif
  33
  34 #ifndef S_ISLNK
  35 # ifdef S_IFLNK
  36 #  define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
  37 # else
  38 #  define S_ISLNK(m) 0
  39 # endif
  40 #endif
  41
  42 /* Declare chown to avoid a warning.  Don't include unistd.h,
  43    because it may have a conflicting prototype for lchown.  */
  44 int chown ();
  45
  46 /* Work just like chown, except when FILE is a symbolic link.
  47    In that case, set errno to ENOSYS and return -1.  */
  48
  49 int
  50 lchown (const char *file, uid_t uid, gid_t gid)
  51 {
  52   struct stat stats;
  53
  54   if (lstat (file, &stats) == 0 && S_ISLNK (stats.st_mode))
  55     {
  56       errno = ENOSYS;
  57       return -1;
  58     }
  59
  60   return chown (file, uid, gid);
  61 }