kc3-lang/gnulib/lib/same.c

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• Hash : e94d9807
  Author :
  Date : 2004-08-06T06:19:08
  

  (same_name): Return bool, not int.
  (errno): Don't declare; we assume C89 or better now.
  

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• lib/same.c

• /* Determine whether two file names refer to the same file.
  
     Copyright (C) 1997, 1998, 1999, 2000, 2002, 2003, 2004 Free
     Software Foundation, Inc.
  
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2, or (at your option)
     any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software Foundation,
     Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  
  /* written by Jim Meyering */
  
  #if HAVE_CONFIG_H
  # include <config.h>
  #endif
  
  #include <stdbool.h>
  #include <stdio.h>
  #ifdef HAVE_UNISTD_H
  # include <unistd.h>
  #endif
  #include <stdlib.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <ctype.h>
  #include <errno.h>
  
  #include <string.h>
  
  #include <limits.h>
  #ifndef _POSIX_NAME_MAX
  # define _POSIX_NAME_MAX 14
  #endif
  
  #include "same.h"
  #include "dirname.h"
  #include "error.h"
  #include "xalloc.h"
  
  #define MIN(a, b) ((a) < (b) ? (a) : (b))
  
  #define SAME_INODE(Stat_buf_1, Stat_buf_2) \
    ((Stat_buf_1).st_ino == (Stat_buf_2).st_ino \
     && (Stat_buf_1).st_dev == (Stat_buf_2).st_dev)
  
  /* Return nonzero if SOURCE and DEST point to the same name in the same
     directory.  */
  
  bool
  same_name (const char *source, const char *dest)
  {
    /* Compare the basenames.  */
    char const *source_basename = base_name (source);
    char const *dest_basename = base_name (dest);
    size_t source_baselen = base_len (source_basename);
    size_t dest_baselen = base_len (dest_basename);
    bool identical_basenames =
      (source_baselen == dest_baselen
       && memcmp (source_basename, dest_basename, dest_baselen) == 0);
    bool compare_dirs = identical_basenames;
    bool same = false;
  
  #if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
    /* This implementation silently truncates pathname components.  If
       the base names might be truncated, check whether the truncated
       base names are the same, while checking the directories.  */
    size_t slen_max = HAVE_LONG_FILE_NAMES ? 255 : _POSIX_NAME_MAX;
    size_t min_baselen = MIN (source_baselen, dest_baselen);
    if (slen_max <= min_baselen
        && memcmp (source_basename, dest_basename, slen_max) == 0)
      compare_dirs = true;
  #endif
  
    if (compare_dirs)
      {
        struct stat source_dir_stats;
        struct stat dest_dir_stats;
        char *source_dirname, *dest_dirname;
  
        /* Compare the parent directories (via the device and inode numbers).  */
        source_dirname = dir_name (source);
        dest_dirname = dir_name (dest);
  
        if (stat (source_dirname, &source_dir_stats))
  	{
  	  /* Shouldn't happen.  */
  	  error (1, errno, "%s", source_dirname);
  	}
  
        if (stat (dest_dirname, &dest_dir_stats))
  	{
  	  /* Shouldn't happen.  */
  	  error (1, errno, "%s", dest_dirname);
  	}
  
        same = SAME_INODE (source_dir_stats, dest_dir_stats);
  
  #if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
        if (same && ! identical_basenames)
  	{
  	  long name_max = (errno = 0, pathconf (dest_dirname, _PC_NAME_MAX));
  	  if (name_max < 0)
  	    {
  	      if (errno)
  		{
  		  /* Shouldn't happen.  */
  		  error (1, errno, "%s", dest_dirname);
  		}
  	      same = false;
  	    }
  	  else
  	    same = (name_max <= min_baselen
  		    && memcmp (source_basename, dest_basename, name_max) == 0);
  	}
  #endif
  
        free (source_dirname);
        free (dest_dirname);
      }
  
    return same;
  }
  

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