Iterating a directory

• TDirectoryIterator
• TDirectoryTreeIterator

TDirectoryTreeIterator performs recursive iterations; it moves down through subdirectories as it encounters them. TDirectoryTreeIterator moves up only after iterating through all files and directories within a subdirectory.

Because directories can contain other directories as well as files, the results of iteration are often heterogenous.

TParentlessDirectoriesIterator iterates over all parentless (topmost or "root") directories on all mounted volumes and returns a TDirectory for the top of each separate directory hierarchy on the system.

Using TDirectoryIterator

  void Example::DisplayDirectory (const TDirectory& theDirectory) const
  {
      TPropertyIDSet                      idSet;
      TPropertySet                        propertySet;
      TPropertyIDFor<TFileSystemEntityName>nameProp(TFileSystemEntity::kName);
      TPropertyIDFor<TTime>  createTimeProp(TFileSystemEntity::kCreationTime);
      TPropertyIDFor<TTime>modifyTimeProp(TFileSystemEntity::kModificationTime);
      TStandardText name;
      TTime date;
  
      // Set up the idSet to retrieve to the file system entity name, 
      // creation time, and modification time
  
      idSet.Add(nameProp);
      idSet.Add(createTimeProp);
      idSet.Add(modifyTimeProp);
  
      PrintText("Displaying contents of directory");
      PrintText(theDirectory.GetName());
      PrintText("...\n\n\n");
  
      // Create an iterator, passing in the directory to iterate, 
      // the idSet, and the no query identifier
  
      TDirectoryIterator iterator(theDirectory, idSet, TDirectoryIterator::kNoQuery);
  
      // Get the first entity in this directory (could be a file or another directory)
  
      TFileSystemEntity anEntity = iterator.First(propertySet);
  
      // keep iterating as long as there are entities left to iterate through
  
      while (anEntity != TDirectoryIterator::kEndOfIteration)
      {
          propertySet.Get(nameProp);
          name = nameProp.GetValue();
          PrintName(name, " ", "\n");
  
          propertySet.Get(createTimeProp);
          date = createTimeProp.GetValue();
          PrintName(date, " ", "\n");
  
          propertySet.Get(modifyTimeProp);
          date = modifyTimeProp.GetValue();
          PrintName(date, " ", "\n");
              
          anEntity = iterator.Next(propertySet);
      }
  }

Using TDirectoryTreeIterator

  void Example::DisplayDirectory (const TDirectory& theDirectory) const
  {
      TPropertyIDSet                      idSet;
      TPropertySet                        propertySet;
      TPropertyIDFor<TFileSystemEntityName>nameProp(TFileSystemEntity::kName);
      TPropertyIDFor<TTime>  createTimeProp(TFileSystemEntity::kCreationTime);
      TPropertyIDFor<TTime>modifyTimeProp(TFileSystemEntity::kModificationTime);
      TStandardText                       name;
      TTime                               date;
  
      // Set up the idSet to retrieve to the file system entity name, 
      // creation time, and modification time
  
      idSet.Add(nameProp);
      idSet.Add(createTimeProp);
      idSet.Add(modifyTimeProp);
  
      // Create an iterator, passing in the directory to iterate, 
      // the idSet, and indicate that no query should be applied
  
      TDirectoryTreeIterator iterator(theDirectory, idSet, TDirectoryIterator::kNoQuery);
  
      // Get the first entity in this directory (could be a file or another directory)
  
      TFileSystemEntity anEntity = iterator.First(propertySet);
  
      // keep iterating as long as there are entities left to iterate through
  
      while (anEntity != TDirectoryTreeIterator::kEndOfIteration)
      {
          // Retrieve each property and print it...
  
          propertySet.Get(nameProp);
          name = nameProperty.GetValue();
          PrintName(name, "", "   ");
  
          propertySet.Get(createTimeProp);
          date = createTimeProp.GetValue();
          PrintDate(date, "", "   ");
  
          propertySet.Get(modifyTimeProp);
          date = modifyTimeProp.GetValue();
          PrintDate(date,  "", "\n");
      
     // Get the next entity
  
          anEntity = iterator.Next(propertySet);
      }   
  }