1  /* Convert file size to number of blocks on System V-like machines.
       2  
       3     Copyright (C) 1990, 1997-1999, 2004-2006, 2009-2023 Free Software
       4     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 3 of the License, or
       9     (at your option) 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, see <https://www.gnu.org/licenses/>.  */
      18  
      19  /* Written by Brian L. Matthews, blm@6sceng.UUCP. */
      20  
      21  #include <config.h>
      22  
      23  #include <sys/types.h>
      24  
      25  #if HAVE_SYS_PARAM_H
      26  # include <sys/param.h>
      27  #endif
      28  
      29  #if !HAVE_STRUCT_STAT_ST_BLOCKS && !defined _POSIX_SOURCE && defined BSIZE
      30  
      31  # include <unistd.h>
      32  
      33  # ifndef NINDIR
      34  
      35  #  if defined __DJGPP__
      36  typedef long daddr_t; /* for disk address */
      37  #  endif
      38  
      39  /* Some SysV's, like Irix, seem to lack this.  Hope it's correct. */
      40  /* Number of inode pointers per indirect block. */
      41  #  define NINDIR (BSIZE / sizeof (daddr_t))
      42  # endif /* !NINDIR */
      43  
      44  /* Number of direct block addresses in an inode. */
      45  # define NDIR   10
      46  
      47  /* Return the number of 512-byte blocks in a file of SIZE bytes. */
      48  
      49  off_t
      50  st_blocks (off_t size)
      51  {
      52    off_t datablks = size / 512 + (size % 512 != 0);
      53    off_t indrblks = 0;
      54  
      55    if (datablks > NDIR)
      56      {
      57        indrblks = (datablks - NDIR - 1) / NINDIR + 1;
      58  
      59        if (datablks > NDIR + NINDIR)
      60          {
      61            indrblks += (datablks - NDIR - NINDIR - 1) / (NINDIR * NINDIR) + 1;
      62  
      63            if (datablks > NDIR + NINDIR + NINDIR * NINDIR)
      64              indrblks++;
      65          }
      66      }
      67  
      68    return datablks + indrblks;
      69  }
      70  #else
      71  /* This declaration is solely to ensure that after preprocessing
      72     this file is never empty.  */
      73  typedef int textutils_fileblocks_unused;
      74  #endif