# Dictionary

Some materials about the file system properties have been taken from http://www.windowsfaq.ru/. All links to MSDN which are mentioned in the Dictionary will be opened in a separate window as search results within msdn.microsoft.com.

### Plugin

Software component-addon to the FAR Manager, which permits the implementation of additional functions. In fact, plugin is an ordinary library that runs in the console process environment, so it functions like an ordinary console Win32 application. The plugin concept itself allows you to tune the shell as you want by adding necessary and discarding unnecessary stuff.

### Reparse Points

Most innovations in the Windows 2000 file system become possible due to the introduction of the Reparse Points concept, which allows attaching of the additional data storage subsystems without using the additional programs.

Reparse points are actually file system objects with special attributes that allow using the extended functionality of data storage subsystem. Any file or directory can contain a reparse point. It means that several kinds of extended functionality are available at once when accessing the resource at the same path.
See also: MSDN: Reparse Points

### Directory Junctions

Directory Junctions allow you to map any local folder to any other local folder. For example, if you have three folders, C:\folder1, C:\folder2 and C:\documents, you can create directory junctions in such a way that C:\documents will look like a subfolder of two other folders, i.e. folders C:\folder1\documents and C:\folder2\documents will exist.

It was supposed initially that a special utility called linkd.exe will be supplied for creation of directory junctions, but it isn't included in Win2000 and supplied as a part of the Resource Kit. Also, directory junctions can be created using API, but this requires writing own software.

At first sight, Directory Junctions and Distributed File System implement the same functions, since they both can make multiple distributed folders look like a single folder tree. But there are some essential differences between them:

- DFS uses the Active Directory service for storing its data
- Due to the Active Directory using, DFS can provide fault protection and system load balancing, while directory junctions can't, although it isn't necessary when using a local computer
- DFS is intended mainly to the integration of the network resources into the common namespace, while directory junctions join the local resources only
- DFS can operate on several file systems, while directory junctions are based on NTFS 5.0 only
- DFS requires a client application, while directory junctions don't

See also: MSDN: Directory Junctions, MSDN: Inside Win2K NTFS, Part 1.

### Mount Points

Mount Points are essentially the same as the Directory Junctions, but they only allow mapping of the root folder of one volume to a local folder of another volume. Mount points are created with the help of reparse points and therefore need NTFS 5.0.

Mount Points are useful for increasing the volume size without changing the actual structure of the volumes on the disk. For example, with a volume mount point set the user might see drive D as "C:\Documents" as well as "D:", and the size of drive C will seem to increase.
See also: MSDN: Volume Mount Points

### Hard Links

Hard Link is the term used when a file has more than one name. For example, a file has names 1.txt and 2.txt. If the user deletes 1.txt, 2.txt remains, and vice versa. In other words, once the file has a new name, the names are equivalent. A file actually is deleted when its last hard link is deleted. Hard links cannot be cross volume boundaries, this means you cannot hardlink, for example, D:\somefile.txt to C:\somefilelink.txt. Keep in mind, that having the same drive letter in the path, files may reside on different volumes (see Mount Points). You can create a hard link only if the underlying filesystem supports it.
See also: MSDN: Hard Links, Q106166 - Windows NT Backup and Hard Links.

### Symbolic Links

Much more efficient feature that allows virtual folders creating - just as virtual disks created using SUBST command in DOS. It has a wide range of uses - folder structure simplification, for example. If you don't like the name "`Documents and settings\Administrator\Documents`", you can link it to the root folder, so the system will still handle the real name of this folder while you are working with much more convenient, shorter name, fully equivalent to the real one.

Keep in mind, that symbolic links created under Windows Vista will not be accessible under previous versions of Windows.

See also: MSDN: Symbolic Links, Windows 2000 Magazine: Inside Win2K NTFS, Part 1.

### Sparse File

NTFS 5 supports sparse files, in which much of the data is zeros. Such file can be marked as sparse file. The system does not allocate hard drive space to a sparse file except in regions where it contains nonzero data. It keeps the information about location of nonzero values only. This method allows optimal data allocation on NTFS volumes when storing sparse files and handling them by applications.
See also: MSDN: Sparse Files, NTFS possibilities.

### Numeric sort

The sorting algorithm which is used by the operating system to sort file lists was changed in Windows XP. A numeric sort is used instead of string sort. FAR also allows using numeric sort as in Windows XP - in other words, leading zeros in a file name are ignored. The following example shows how the files are sorted:

Numeric sort is on (Windows XP) | Numeric sort is off (Windows 2000)
--- | ---
Ie4_01 | Ie4_01
Ie4_128 | Ie4_128
Ie5 | Ie401sp2
Ie6 | Ie5
Ie401sp2 | Ie501sp2
Ie501sp2 | Ie6
5.txt | 11.txt
11.txt | 5.txt
88.txt | 88.txt

See also: Q319827 - The Sort Order for Files and Folders Whose Names....