What is the DATA file extension? File Management, File Types, File System, File Attributes What is a Data File

Executable files

1.1. Batch (BAT)

1.2. Software (COM, EXE)

2.1. Simple texts (TXT)

2.2. Complex (DOC)

2.3. Spreadsheets (XLS)

2.4. Databases (MDB)

2.5. Archive (RAR, ZIP)

2.6. Graphic (BMP, JPG, GIF)

2.7. Application components (LIB, OVL)

2.8. Temporary (TMP), etc.

3. Shortcuts– minifiles containing links to other objects for the purpose of opening them (PIF, LNK)

File attributes:

“Hidden” – not visible unless you specifically set to view hidden files;

“Ready for archiving” – will be archived by the archiving (duplication) wizard;

“Compressed” – will be compressed to save disk space;

“Encrypted” – cannot be opened and copied in another user session, but can be deleted and renamed;

“Indexed” – will be marked for quick search in the future.

Note. The attributes “Compressed”, “Encrypted”, “Indexed” can only be set in the NTFS file system.

Managing File System Objects

Types of operations with FS objects:

1. Navigation and search

2. Creation and deletion

3. Editing and viewing

4. Renaming and setting attributes

5. Copy and move

6. Archiving and unarchiving

Ways to create objects:

1. Program - editor or program wizard

2. File shell or file manager

3. Copying (via clipboard or dragging)

Options for opening objects:

1. Folder: List contents

2. Executable file: launch

3. Data file: launch the editor or viewer registered (associated) for this document type

Options for the consequences of dragging an object (“Drag and Drop”):

1. Left cell “Mice” - moving within a disk, copying between disks

2. Right cell "Mice" - select from context menu at the end of dragging

3. Ctrl+left key. "Mice" - copying

4. Shift+left key. "Mice" - moving

Features of copy-move:

1. When copying: a duplicate byte content is created

2. When moving within one disk, the full file name in FAT changes

3. When moving between different disks, first the file is copied, then the FAT indicates the deletion of this file

Conclusion: within one disk, a move operation is faster than a copy operation, and vice versa between different disks.

Examples of MS-DOS commands:

1. External:

1.3. Format the disk: FORMAT disk_name

2. Internal (executed by the command processor):

2.1. Create directory: MD directory_name

2.2. Removing a directory: RD directory_name

2.3. Deleting the DEL file filename

2.4. View the contents of the current directory: DIR

2.5. Exiting the shell: EXIT

Table Ways to copy and move files

Files saved in the data format are used by Analysis Studio, and this application stores part data used for offline analysis in these files. This data can be entered into a corresponding data file created by the Analysis Studio user. Typically classified as data files, these DATA files are attached with a .data extension and are more specifically called Analysis Studio offline data files. Appricon has developed the Analysis Studio data format and software to provide users with offline data storage and analytical functionality with useful instatistical data research, storage, management and analysis. The content of these data files may include data encoded in text or tab delimited formats. Analysis Studio file headers can also be included in this file data by the Analysis Studio user. A user disconnected from the Analysis Studio server typically accesses these file data offline, although the Analysis Studio software also allows the user to access the contents of these data files even in real time. The content of these data files can also be imported from other databases such as Microsoft SQL Server and Microsoft Access databases. Analysis Studio software links the data file into a corresponding STP file, and the content of these STP files consists of object metadata and schematic design details. A Microsoft Windows user can delete the Analysis Studio header file of a data file in order to open and view its contents using Microsoft Excel 2010 spreadsheets.

Good day, dear user, in this article we will talk about such a topic as files. Namely, we will look at: File management, file types, file structure, file attributes.

File system

One of the main tasks of the OS is to provide convenience to the user when working with data stored on disks. To do this, the OS replaces the physical structure of the stored data with some user-friendly logical model, which is implemented in the form of a directory tree displayed on the screen by utilities such as Norton Commander, Far Manager or Windows Explorer. The basic element of this model is file, which is the same as file system in general, can be characterized by both logical and physical structure.

File management

File– a named area of ​​external memory intended for reading and writing data.

Files are stored in power-independent memory. An exception is an electronic disk, when a structure that imitates a file system is created in the OP.

File system(FS) is an OS component that provides organization for the creation, storage and access to named data sets - files.

The file system includes: The file system includes:

• The collection of all files on the disk.
• Sets of data structures used to manage files (file directories, file descriptors, free and used disk space allocation tables).
• A set of system software tools that implement various operations on files: creation, destruction, reading, writing, naming, searching.

The problems solved by the FS depend on the way the computing process is organized as a whole. The simplest type is a file system in single-user and single-program operating systems. The main functions in such a FS are aimed at solving the following tasks:

• Naming files.
• Software interface for applications.
• Mapping the logical file system model onto the physical organization of the data warehouse.
• FS resistance to power failures, hardware and software errors.

FS tasks become more complicated in single-user multitasking operating systems, which are designed for the work of one user, but make it possible to run several processes simultaneously. To the tasks listed above, a new task is added - shared access to a file from several processes.

The file in this case is a shared resource, which means the FS must solve the whole range of problems associated with such resources. In particular: there must be means for blocking a file and its parts, reconciling copies, preventing races, and eliminating deadlocks. In multi-user systems, another task appears: Protecting the files of one user from unauthorized access by another user.

The functions of the FS, which operates as part of a network OS, become even more complex; it needs to organize protection files one user from unauthorized access of another user.

Main purpose file system and corresponding to it file management systems– organization of convenient management of files organized as files: instead of low-level access to data indicating the specific physical addresses of the record we need, logical access is used indicating the file name and record in it.

The terms “file system” and “file management system” must be distinguished: the file system determines, first of all, the principles of access to data organized as files. And the term “file management system” should be used in relation to a specific implementation of the file system, i.e. This is a set of software modules that provide work with files in a specific OS.

Example

The FAT (file allocation table) file system has many implementations as a file management system

• The system developed for the first PCs was simply called FAT (now called simply FAT-12). It was designed to work with floppy disks, and for some time it was used to work with hard drives.
• Then it was improved to work with larger hard drives, and this new implementation was called FAT-16. this name is also used in relation to the SUF of MS-DOS itself.
• The implementation of SUF for OS/2 is called super-FAT (the main difference is the ability to support extended attributes for each file).
• There is a version of SUF for Windows 9x/NT, etc. (FAT-32).

File types

Regular files: contain information of an arbitrary nature that is entered into them by the user or that is generated as a result of the operation of system and user programs. The contents of a regular file are determined by the application that works with it.

Regular files can be of two types:

1. Software(executable) – are programs written in the OS command language and perform some system functions (have extensions .exe, .com, .bat).
2. Data files– all other types of files: text and graphic documents, spreadsheets, databases, etc.

Catalogs- this is, on the one hand, a group of files combined by the user based on certain considerations (for example, files containing game programs, or files that make up one software package), and on the other hand, this is a special type of files that contain system help information about a set of files grouped by users according to some informal criteria (file type, location on disk, access rights, date of creation and modification).

Special files– these are dummy files associated with input/output devices, which are used to unify the mechanism for accessing files and external devices. Special files allow the user to perform I/O operations using normal file write or file read commands. These commands are processed first by FS programs, and then at some stage of the request execution they are converted by the OS into control commands for the corresponding device (PRN, LPT1 - for the printer port (symbolic names, for the OS - these are files), CON - for the keyboard).

Example. Copy con text1 (working with the keyboard).

File structure

File structure– the entire set of files on the disk and the relationships between them (the order in which files are stored on the disk).

Types of file structures:

• simple, or single-level: A directory is a linear sequence of files.
• hierarchical or multi-level: A directory itself can be part of another directory and contain many files and subdirectories within it. The hierarchical structure can be of two types: “Tree” and “Network”. Directories form a “Tree” if the file is allowed to be included in only one directory (OS MS-DOS, Windows) and “Network” - if the file can be included in several directories at once (UNIX).
• The file structure can be represented as a graph describing the hierarchy of directories and files:

File name types

Files are identified by names. Users give files symbolic names, this takes into account OS restrictions on both the characters used and the length of the name. In early file systems these boundaries were quite narrow. So in popular FAT file system The length of names is limited by the well-known 8.3 scheme (8 characters - the name itself, 3 characters - the name extension), and in UNIX System V the name cannot contain more than 14 characters.

However, it is much more convenient for the user to work with long names, since they allow you to give the file a truly mnemonic name, by which, even after a fairly long period of time, you can remember what this file contains. Therefore, modern file systems tend to support long symbolic file names.

For example, Windows NT specifies in its NTFS file system that a file name can be up to 255 characters long, not counting the terminating null character.

Moving to long names creates a compatibility issue with previously created applications that use short names. In order for applications to access files according to previously accepted conventions, the file system must be able to provide equivalent short names (aliases) to files that have long names. Thus, one of the important tasks becomes the problem of generating appropriate short names.

Symbolic names can be of three types: simple, compound and relative:

1. Simple name identifies a file within one directory, assigned to files taking into account the symbol nomenclature and name length.
2. Full name is a chain of simple symbolic names of all directories through which the path from the root to a given file, disk name, file name passes. So the full name is composite, in which simple names are separated from each other by a separator accepted in the OS.
3. The file can also be identified relative name. The relative file name is determined through the concept of "current directory". At any given time, one of the directories is current, and this directory is selected by the user himself at the command of the OS. The file system captures the name of the current directory so that it can then use it as a complement to relative names to form the fully qualified file name.

In a tree-like file structure, there is a one-to-one correspondence between a file and its full name - “one file - one full name”. In a network file structure, a file can be included in several directories, which means it can have several full names; The correspondence here is “one file - many full names.”

For file 2.doc, define all three types of name, provided that the current directory is the 2008_year directory.

• Simple name: 2.doc
• Full name: C:\2008_year\Documents\2.doc
• Relative name: Documents\2.doc

File attributes

An important characteristic of a file is its attributes. Attributes– this is information describing the properties of files. Examples of possible file attributes:

• Read-Only attribute;
• Sign “hidden file” (Hidden);
• Sign “system file” (System);
• Sign “archive file” (Archive);
• File type (regular file, directory, special file);
• Owner of the file;
• File Creator;
• Password to access the file;
• Information about permitted file access operations;
• Time of creation, last access and last modification;
• Current file size;
• Maximum file size;
• Sign “temporary (remove after process completion)”;
• Blocking sign.

In different types of file systems, different sets of attributes may be used to characterize files (for example, in a single-user OS, the set of attributes will not contain characteristics related to the user and security (the creator of the file, the password for accessing the file, etc.).

The user can access attributes using the facilities provided for this purpose by the file system. Typically, you can read the values ​​of any attributes, but only change some, for example, you can change the access rights of a file, but you cannot change the creation date or the current size of the file.

File permissions

Defining access rights to a file means defining for each user a set of operations that he can apply to a given file. Different file systems can have their own list of differentiated access operations. This list may include the following operations:

• file creation.
• file destruction.
• writing to a file.
• opening a file.
• closing the file.
• reading from file.
• file addition.
• search in the file.
• getting file attributes.
• setting new attribute values.
• renaming.
• file execution.
• reading a catalog, etc.

In the most general case access rights can be described by a matrix of access rights, in which the columns correspond to all files in the system, the rows correspond to all users, and at the intersection of rows and columns the permitted operations are indicated:

In some systems, users may be divided into separate categories. For all users of the same category, uniform access rights are defined, for example, in the UNIX system, all users are divided into three categories: the owner of the file, members of its group, and everyone else.

(data file) A file located on a computer system that contains data, as opposed to files containing a program. See: computer programming. A data file is usually divided into records and fields.

• - The stone of Destiny...

  Encyclopedia of Mythology

• - a named collection of bytes, recorded on a hard or floppy disk, in which a separate element of a computer system is stored, for example. Word document or drawing...

  Encyclopedia of technology

• - a set of pieces of information of the same type in structure and method of use, placed on data carriers of the external memory of a computer and considered in the process of transmission and processing as a single whole...

  Big Encyclopedic Polytechnic Dictionary

• - A collection/complex of interrelated information in a computer, stored in its storage as a single whole. The file may contain a program that can be copied into RAM and executed...

  Dictionary of business terms

• - a collection of related records considered as a single whole...

  Great Accounting Dictionary

• - a set of ordered and interconnected pieces of information that has a description for identifying departments. portions...

  Natural science. encyclopedic Dictionary

• - A file containing system information about the server’s operation and information about user actions: - date and time of the user’s visit; - IP address of the user’s computer; - name of the user's browser...

  Dictionary of business terms

• - a file containing system information about the operation of the server and information about user actions: - date and time of the user’s visit; - IP address of the user’s computer; - name of the user's browser...

  Financial Dictionary

• - a set of related records stored in the external memory of a computer and considered as a whole. Typically, a file is uniquely identified by specifying the file name, its extension, and the path to the file...

  Financial Dictionary

• - a set of records located in a different order in relation to the source file. See. also: Files  ...

  Financial Dictionary

• - a set of records arranged in the order they were received at the recording point. See. also: Files  ...

  Financial Dictionary

• - a set of records, the elements of which are obtained by processing the original or inverted files. See. also: Files  ...

  Financial Dictionary

• - a collection of related records considered as a single whole. For example, one line of a personnel questionnaire is considered as an element, the entire questionnaire is considered as a record, a complete set of such records is considered as a file...

  Large economic dictionary

• - "..."" means any data set subject to automated processing.....

  Official terminology

• - a set of ordered and interconnected pieces of information from homogeneous elements, having a description for identifying individual pieces...

  Modern encyclopedia

• - ; pl. fa/yly, R....

  Spelling dictionary of the Russian language

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