fs/iso9660/iso9660_lseek.c

   1 /*
   2  *
   3  * (c) 2005-2009 Laurent Vivier <Laurent@vivier.eu>
   4  *
   5  * This file has been copied from EMILE, http://emile.sf.net
   6  *
   7  */
   8
   9 #include "libiso9660.h"
  10
  11 int iso9660_lseek(iso9660_FILE *_file, long offset, int whence)
  12 {
  13         iso9660_FILE *file = (iso9660_FILE*)_file;
  14         long new_offset;
  15
  16         switch(whence)
  17         {
  18         case SEEK_SET:
  19                 new_offset = offset;
  20                 break;
  21         case SEEK_CUR:
  22                 new_offset = file->offset + offset;
  23                 break;
  24         case SEEK_END:
  25                 new_offset = file->size + offset;
  26                 break;
  27         default:
  28                 return -1;
  29         }
  30
  31         if ( (new_offset < 0) || (new_offset > file->size) )
  32                 return -1;
  33
  34         file->offset = new_offset;
  35
  36         return new_offset;
  37 }