Attributes of the file
Below is the terminology for non-nix-compatible systems (DOS, OS / 2, Windows). The family of "nix" operating systems and their ways of storing files differ and require separate consideration.
Attributes of the file are special labels,allowing the file system to identify the actions that can be performed on them. The appearance of such attributes was caused by the need to increase the fault tolerance of the file system. Since the information in the file system is stored sequentially, then there must be some signs by which it will be possible to distinguish the file from the directory, the system folder from the backup.
At a low level, this is implemented by specialmethods (marking) of the initial and final clusters of the storage device. But only low-level programs have access to such addressing, as, for example, the operating system. For application software, special labels have been added to this marking, allowing you to change the attributes of the file.
There are a small number of them, since they originally appeared in the old operating and file systems, and their support for modern OS - the need for compatibility.
Attributes of the file are as follows:
- Read only. This means that a record is not allowed in the file, and it is intended for reading. If you have it, the OS does not allow you to make changes to the file. The attribute is relevant for storing constant information or data with restricted access.
- System. System file or directory. Serves for increased protection of system information about data and equipment. An object with such an attribute is much more difficult to modify or delete. In some cases, the OS completely blocks access to such files - they can be used only by the kernel of the operating system.
- Archive. Indicates that the file has been modified. This attribute is critical for backup. With a large amount of redundant information, there is a significant acceleration of updating the archives, if you only copy the changed data - objects that have file attributes - archive.
- Hidden - hidden file. It is most often used in conjunction with the system attribute. This attribute makes the file invisible when viewing the contents of the directory.
An ordinary user does not use file properties when working with files. An exception can be considered only a few points:
If on removable media or hard disksuddenly "disappeared" files and folders. This happens very often when a computer is infected with a certain type of virus, which changes the attributes of the file to "system" and "hidden." Do not panic, the problem is solved trivially. You can change the attributes of a file through the "Properties" dialog box of the file or by using any Explorer program (with the exception of Microsoft Explorer). Also, if you can access the command line, you can view and change the file attributes with the ATTRIB system command. Run it with the key "/?" you can see a list of possible actions with the files.
Opposite situation - there are a number of files,access to which must be restricted, prevented from changing them, or the possibility of removal. Then changing the attributes of the files will allow you to cope with this task.
Setting the attribute "archive" allowseffectively make up-to-date backups when multiple users work on one project. Project consolidation systems can be configured to provide the latest versions of data for all users with remote access.
At present, with the advent of modernfile systems, increasing the requirements for protection and speed of processing information, the attributes of the file are no longer so in demand. They were replaced by complex add-ins with indexes, caching and parallel access.</ p>>