Documentation of savebindatasp

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Function Synopsis

SaveStatus = savebindatasp(FileLS, varargin)

Help text

 SAVing BINary DATA to a file with a Secure Protokoll

 Interface to the function savebindata2 employing a secure protokoll
 for the access to the data file by the saving process and an 
 external process.
 Before accessing the data file the existence of a send lock file is
 tested (background: another process accesses the data file for 
 sending it to another computer). When the lock file exists, the 
 reading/saving is delayed.
 Before saving a write lock file is created in the directory of
 the data file. This signals the other process, that the file can 
 not be accessed.
 The name of send and write flag file is created from the name of 
 the data file and the prefix 'send_' and 'write_' respectively.
 The actual saving is done by the standard function savebindata2. 

 Syntax:  savebindatasp(FileLS, varargin)

 Input parameters:
    FileLS    - String containing the name of the mat-file
                   if the file doesn't exist, it will be created
    P1-Pxx    - (optional) input variables (all in varargin)
                   even numbers: string containing name of next variable
                   odd  numbers: variable
                   example: P1 contains the name of the variable in P2
                            P3 the name of the variable in P4 and so on

 Output parameter:
    SaveStatus - Scalar defining the result of the save operation

 Example:
  % mat-file 'filename.mat' doesn't exist
  >>savebindata2('FileName', 'var2', var2, 'var3', var3)
  % now mat-file 'filename.mat' contains 1 struct variable 
  % called 'GEATbxData' with 2 fields called: 'var2' and 'var3'

 See also: geamain2

Cross-Reference Information

Listing of function savebindatasp

%  Author:  Hartmut Pohlheim
%  History: 22.06.2002  file created


function SaveStatus = savebindatasp(FileLS, varargin)

   % Preset the status of the saving process (not used currently)
   SaveStatus = 0;

   % Get the file name parts
   [FP, FN, FE] = fileparts(FileLS);
      
   % Create Write-Flag file 
   FFE = '.lck';
   WFName = fullfile(FP, ['write_', FN, FFE]);
   [FlagId, ErrMessage] = fopen(WFName, 'w');
   
   if FlagId == -1,
      warning(sprintf('Error during fopen of the Write-Flag file (%s): %s', WFName, ErrMessage)); return;
   else fprintf(FlagId, 'Write-Flag'); fclose (FlagId); end

   % Create file name for send file
   SFName = fullfile(FP, ['send_', FN, FFE]);
   SFFileExist = 1;
   % Wait while send-flag exist, pause reduces processor burden
   while all([SFFileExist >= 1, SFFileExist < 120]),
      [fidgen, error_message] = fopen(SFName, 'r');
      % Flag file does not exist, go out of while loop and proceed
      if fidgen == -1, SFFileExist = 0;
      % Flag file exists, wait till it is deleted by other process
      else
         fclose(fidgen);
         SFFileExist = SFFileExist + 1;
         % Include here the pause (1) command when compiling with R12/Compiler 2.1
         % pause(1)
         for ipause = 1:1e4, a = sqrt(ipause); end
         if SFFileExist == 2,
            warning(sprintf('Waiting with save bin data (max 2min), other process is activ (or flag file %s was not deleted)\n', SFName));
         end
      end
   end

   if SFFileExist == 0,
      savebindata2(FileLS, varargin{:});
   else
      warning(sprintf('Save of binary data failed, other process is still activ (or flag file %s was not deleted)\n', SFName));
   end
      
   % Remove the Write-flag file (the delete command can only be compiled with Matlab6)
   dos(['del ', WFName, ' &;']);
   % delete(WFName);


% End of function