The Blue File Redirector is a key component of Blue Share that enables generic file system API abstraction. This means that applications can be written to a single API, have the operations translated to a desired API, and then pass those operations on to the target file system. The Blue File redirector is architecturally significant for both the Blue Share Client and the Blue Share Server. The Blue File Redirector consists of three layers: APIs, redirector, and handlers. The APIs provide an interface to applications. The redirector performs the path mapping and directing of operations to target handlers while the handlers translate the desired operation to a form suitable for the target file system API.

The native client API is similar to the Win32 API. POSIX or platform specific APIs are also available. The Win32 like APIs supported are:
  • BlueCloseHandle - Close an open file handle
  • BlueCreateFile - Create or open a File
  • BlueCreateDirectory - Create a directory
  • BlueDeleteFile - Delete a file
  • BlueRemoveDirectory - Delete a directory
  • BlueFindFirstFile - Begin a directory scan
  • BlueFindNextFile - Continue a directory scan
  • BlueFindClose - End a directory scan
  • BlueFlushFileBuffers - Flush writes to a file
  • BlueFileGetAttributesEx - Get File attributes
  • BlueGetFileInformationByHandle - Get File Information
  • BlueMoveFile - Rename a file
  • BlueReadFile - Read from a file
  • BlueWriteFile - Write to a file
  • BlueCreateOverlapped - Create an overlapped I/O context
  • BlueDestroyOverlapped - Destroy an overlapped I/O context
  • BlueSetOverlappedOffset - Set an overlapped context’s file offset
  • BlueGetOverlappedResult - Get the result of an overlapped I/O
  • BlueSetEndOfFile - Set End of File
  • BlueSetFileAttributes - Set File Attributes
  • BlueSetFileInformationByHandle - Set File Information
  • BlueSetFilePointer - Set File Pointer
  • BlueTransactNamedPipe - Issue a Transaction to a Named Pipe
  • BlueGetLastError - Get Last Error from Blue File
  • BlueGetDiskFreeSpace - Get Free Space on Disk
  • BlueGetVolumeInformation - Get Information on Volume
  • BlueLockFileEx - Lock a file region
  • BlueUnlockFileEx - Unlock a file region
The Blue File redirector maps these file operations through the specified file URL to a destination file handler. The destination file handler is extensible. Handlers provided by Blue Share are:
  • Posix File Handler
  • NTFS/Win32 File Handler
  • CIFS Client File Handler
  • Mailslot File Handler
  • Named Pipe File Handler
  • Printer File Handler
Applications can be written to the Blue File API transparent to whether the target file is native to the OS or is abstracted through Blue Share to a remote share. This also allows a Blue Share server to map exported shares to local file systems, to loopback shares to the local system, or to proxy shares to a remote system. Application developers have maximum flexibility to configure the Blue Share Client and Server through the redirector in whatever manner to achieve optimal function.