libiberty/unlink-if-ordinary.c

   1 /* unlink-if-ordinary.c - remove link to a file unless it is special
   2    Copyright (C) 2004-2017 Free Software Foundation, Inc.
   3
   4 This file is part of the libiberty library.  This library is free
   5 software; you can redistribute it and/or modify it under the
   6 terms of the GNU General Public License as published by the
   7 Free Software Foundation; either version 2, or (at your option)
   8 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
  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 GNU CC; see the file COPYING.  If not, write to
  17 the Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
  18
  19 As a special exception, if you link this library with files
  20 compiled with a GNU compiler to produce an executable, this does not cause
  21 the resulting executable to be covered by the GNU General Public License.
  22 This exception does not however invalidate any other reasons why
  23 the executable file might be covered by the GNU General Public License. */
  24
  25 /*
  26
  27 @deftypefn Supplemental int unlink_if_ordinary (const char*)
  28
  29 Unlinks the named file, unless it is special (e.g. a device file).
  30 Returns 0 when the file was unlinked, a negative value (and errno set) when
  31 there was an error deleting the file, and a positive value if no attempt
  32 was made to unlink the file because it is special.
  33
  34 @end deftypefn
  35
  36 */
  37
  38 #ifdef HAVE_CONFIG_H
  39 #include "config.h"
  40 #endif
  41
  42 #include <sys/types.h>
  43
  44 #ifdef HAVE_UNISTD_H
  45 #include <unistd.h>
  46 #endif
  47 #if HAVE_SYS_STAT_H
  48 #include <sys/stat.h>
  49 #endif
  50
  51 #include "libiberty.h"
  52
  53 #ifndef S_ISLNK
  54 #ifdef S_IFLNK
  55 #define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
  56 #else
  57 #define S_ISLNK(m) 0
  58 #define lstat stat
  59 #endif
  60 #endif
  61
  62 int
  63 unlink_if_ordinary (const char *name)
  64 {
  65   struct stat st;
  66
  67   if (lstat (name, &st) == 0
  68       && (S_ISREG (st.st_mode) || S_ISLNK (st.st_mode)))
  69     return unlink (name);
  70
  71   return 1;
  72 }