速腾中控:Duplicate File Hard Linker (DFHL) 硬连接

Small command line tool to reduce the size of duplicate files on one partition. Despite all other known tools the files in this implementation are not being listed, archived or removed but going to be hard linked using NTFS hard links. The tool runs in Windows NT 4.0 / 2000 / XP and 2003 Server and requires a NTFS file system to run on.

Features

• Command line Tool for Windows NT4.0/2000/XP/2003
• Links duplicate files in file system using NTFS "Hard Link" facility. For further information please take a look to Website at Microsoft.
• Runs recursive through a tree of folders on one partition
• Compares all files byte-per-byte to ensure really only equal files to be hard linked
• Check-Mode (default) allows listing of all optimization possibilities. In this mode no changes will be done.
• Additional options allow control of which parameters of files will be compared, to check attributes and time stamps of files
• All read/compare operations were optimized for maximum performance and will reach almost the maximum throughput of the physical disk. The system will be loaded only in background.
• File system short named (8.3 Names) can be lost during hard linking. This can lead to problems with programs requiring 8.3 names.
• Further optimizations by using file hashes. A hash is now compared before running a byte-by-byte compare.

Limitations

• Hard Links can only be created on same partition. A permission overriding link creation is not possible due to physical limitations.
• Only NTFS is supported as file system for hard links.
• All hard linked files share the same set of file attributes, security descriptors and timestamps. Changes on one file Meta attribute will reflect to the other linked file immediately. This is limited by the underlying file system.
• When removing files which are hard linked, the space will only be freed on hard drive when the last reference of the file is going to be removed.
• Already linked files can not be linked again to gain space - of course...

Command Line Parameters

Usage:

dfhl [options] [path] [...]

Use Cases

• If you have a collection of duplicate files in a disk archive
• Archive with a lot of similar files which take away a huge amount of space

System Requirements

• Windows NT 4.0, 2000, XP, 2003 Server
• Full control (as file permission) over the analyzed files
• NTFS-File System

Change Log

• Changes from Version 1.2 to Version 2.0
  • Changing to long path support - paths can now contain up to 32000 characters.
  • Further optimizations, file hashes are now used for compare operations besides a byte-by-byte compare to gain speed. Nevertheless, a byte-by-byte compare is always done to ensure that file content matches.
  • Refactored lot of code and made more object oriented stuff...
  • Further statistics for looking inside.
• Changes from Version 1.1 to Version 1.2
  • Bugfix if supplied path contained a tailing backslash
  • Program continues to run even if a folder is not accessible
  • Set GPL as software license for program
• Changes from Version 1.0 to Version 1.1
  • Added Support for Windows NT 4.0, missing Hardlink API was created
  • Removed typos
  • A system check prior execution verifies system environment

Installation

Installation is not required. The program just consists of one .EXE-file, which can be called. Just copy the files to a folder inside the PATH of your system.