external/gpl2/xcvs/dist/lib/lstat.c

   1 /* Work around a bug of lstat on some systems
   2
   3    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free
   4    Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  19
  20 /* written by Jim Meyering */
  21
  22 #ifdef HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 /* The specification of these functions is in sys_stat.h.  But we cannot
  27    include this include file here, because on some systems, a
  28    "#define lstat lstat64" is being used, and sys_stat.h deletes this
  29    definition.  */
  30
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35
  36 #include "stat-macros.h"
  37 #include "xalloc.h"
  38
  39 /* lstat works differently on Linux and Solaris systems.  POSIX (see
  40    `pathname resolution' in the glossary) requires that programs like `ls'
  41    take into consideration the fact that FILE has a trailing slash when
  42    FILE is a symbolic link.  On Linux systems, the lstat function already
  43    has the desired semantics (in treating `lstat("symlink/",sbuf)' just like
  44    `lstat("symlink/.",sbuf)', but on Solaris it does not.
  45
  46    If FILE has a trailing slash and specifies a symbolic link,
  47    then append a `.' to FILE and call lstat a second time.  */
  48
  49 int
  50 rpl_lstat (const char *file, struct stat *sbuf)
  51 {
  52   size_t len;
  53   char *new_file;
  54
  55   int lstat_result = lstat (file, sbuf);
  56
  57   if (lstat_result != 0 || !S_ISLNK (sbuf->st_mode))
  58     return lstat_result;
  59
  60   len = strlen (file);
  61   if (len == 0 || file[len - 1] != '/')
  62     return lstat_result;
  63
  64   /* FILE refers to a symbolic link and the name ends with a slash.
  65      Append a `.' to FILE and repeat the lstat call.  */
  66
  67   /* Add one for the `.' we'll append, and one more for the trailing NUL.  */
  68   new_file = xmalloc (len + 1 + 1);
  69   memcpy (new_file, file, len);
  70   new_file[len] = '.';
  71   new_file[len + 1] = 0;
  72
  73   lstat_result = lstat (new_file, sbuf);
  74   free (new_file);
  75
  76   return lstat_result;
  77 }