function hexview(file)
%HEXVIEW View a file in hexadecimal mode.
%
%   HEXVIEW FILE displays the file FILE in hexadecimal mode with byte offsets
%   and ascii strings.

%   Author:      Peter John Acklam
%   Time-stamp:  2003-11-04 00:43:00 +0100
%   E-mail:      pjacklam@online.no
%   URL:         http://home.online.no/~pjacklam

   % check number of arguments
   error(nargchk(1, 1, nargin));

   % see if the file exists
   if ~exist(file, 'file')
      error([file ': No such file.']);
   end

   % try to open the file for reading
   fid = fopen(file, 'rb');
   if fid < 0
      error([file ': Can''t open file for reading.']);
   end

   blocksize = 16;      % number of bytes for each line
   dot       = '.';     % used for non-printable characters
   offset    = 0;       % file offset of data for current line

   while ~feof(fid)

      % read a block of data from the file
      [data, count] = fread(fid, blocksize, 'uchar');

      % print the offset and the hex values for the data
      fprintf(1, '%08X: ', offset);
      fprintf(1, ' %02X', data);

      % replace non-printable characters
      data(data < 32 | data > 126) = dot;

      % fill line if necessary (only used on last line if at all)
      if count < blocksize
         fprintf(repmat( '   ', 1, blocksize - count));
      end

      % print a space, the actual data and a newline
      fprintf(1, '  ');
      fprintf(1, '%c', data);
      fprintf(1, '\n');

      % update offset value
      offset = offset + blocksize;

   end

   % close file
   fclose(fid);