tools/vbindiff/curses/FileIO.hpp

   1 //--------------------------------------------------------------------
   2 //
   3 //   Visual Binary Diff
   4 //   Copyright 1997-2005 by Christopher J. Madsen
   5 //
   6 //   Support functions for Posix file I/O
   7 //
   8 //   This program is free software; you can redistribute it and/or
   9 //   modify it under the terms of the GNU General Public License as
  10 //   published by the Free Software Foundation; either version 2 of
  11 //   the License, or (at your option) any later version.
  12 //
  13 //   This program is distributed in the hope that it will be useful,
  14 //   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 //   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 //   GNU General Public License for more details.
  17 //
  18 //   You should have received a copy of the GNU General Public License
  19 //   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 //--------------------------------------------------------------------
  21
  22 #ifndef INCLUDED_FILEIO_HPP
  23
  24 #define INCLUDED_FILEIO_HPP
  25
  26 #include <errno.h>
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29
  30 typedef int      File;
  31 typedef off_t    FPos;
  32 typedef ssize_t  Size;
  33
  34 const int
  35   SeekEnd = SEEK_END,
  36   SeekPos = SEEK_SET;
  37
  38 const File InvalidFile = -1;
  39
  40 //--------------------------------------------------------------------
  41 inline const char* ErrorMsg()
  42 {
  43   return strerror(errno);
  44 } // end ErrorMsg
  45
  46 //--------------------------------------------------------------------
  47 inline File OpenFile(const char* path, bool writable=false)
  48 {
  49   return open(path, (writable ? O_RDWR : O_RDONLY));
  50 } // end OpenFile
  51
  52 //--------------------------------------------------------------------
  53 inline void CloseFile(File file)
  54 {
  55   close(file);
  56 } // end CloseFile
  57
  58 //--------------------------------------------------------------------
  59 bool WriteFile(File file, const void* buffer, Size count)
  60 {
  61   const char* ptr = reinterpret_cast<const char*>(buffer);
  62
  63   while (count > 0) {
  64     Size bytesWritten = write(file, ptr, count);
  65     if (bytesWritten < 1) {
  66       if (errno == EINTR)
  67         bytesWritten = 0;
  68       else
  69         return false;
  70     }
  71
  72     ptr   += bytesWritten;
  73     count -= bytesWritten;
  74   } // end while more to write
  75
  76   return true;
  77 } // end WriteFile
  78
  79 //--------------------------------------------------------------------
  80 inline Size ReadFile(File file, void* buffer, Size count)
  81 {
  82   return read(file, buffer, count);
  83 } // end ReadFile
  84
  85 //--------------------------------------------------------------------
  86 inline FPos SeekFile(File file, FPos position, int whence=SeekPos)
  87 {
  88   return lseek(file, position, whence);
  89 } // end SeekFile
  90
  91 #endif // INCLUDED_FILEIO_HPP
  92
  93 // Local Variables:
  94 //     c-file-style: "cjm"
  95 // End: