Determining the file type by content. How can I find out the file extension if it has been lost? How to open a file if there is no extension, but the contents of the file are known

30.07.2014 23349

As you know, any information, be it text, image or video, in fact, is nothing more than a set of binary code - a sequence of zeros and ones. It is in this form that data is stored on the hard disk. Concept binary code almost abstract, this is not a record in the usual sense of the word, binary or machine code is rather a state of microscopic cells on a magnetic surface hard disk... The positive charge of such a cell has a plus or 1, negative - a minus or 0.

Logically combined sequences of zeros and ones make up what we call files. But we also know that there are a lot of file types. There are text files, multimedia, archive, system, executable, and so on. How does the operating system determine how to read or process a particular file? Application programs recognize a file type by its extension - a set of characters following the file name and separated from it by a period.

But what if the extension is removed? That's right, the operating system will not be able to open such a file, since it will not know which program to use for this. However, this will not change the logical structure or the contents of the renamed file. You yourself can be convinced of this by removing the extension of a file, and then trying to open it with the appropriate program. We are sure that you will not have any problems with this.

Therefore, at all no extension determines the type of file. What then? The file type determines its format, or otherwise the specification of the data structure. Extension and format are very often confused, although in reality they are completely different concepts. This raises a completely natural question, but how to determine the file format if its extension for some reason was lost? It turns out to be very simple.

Roughly speaking, all files consist of two parts. The first part is a header containing various meta-information including data that allows applications to identify this file. The second part is the "body" of the file. The part of the file header that is responsible for determining the type of file is called a descriptor or description. The most common descriptor types are HEX and ASCII. The first type of headers can only be viewed with special utilities - hex editors.

To view descriptors of the second type, you can do with the usual text editor, the same Notepad or. However, it should be borne in mind that not all byte sequences can be translated into ASCII code, so it is still better to use HEX editors to determine the format. The file opened in the HEX editor is displayed as a matrix of a sequence of bytes. Each cell corresponds to one byte. The descriptor data is contained just in the first three cells (rarely two or four), located horizontally. They are six characters in hexadecimal, for example 49 44 33 or ff d8 e0.

Naturally, they need decryption. And you can decipher them on special sites with format descriptions. One of the best sites where you can determine the format by the HEX descriptor is open-file.ru... There are other similar resources, but they are not that convenient. On open-file.ru there is a special search form where you can insert a HEX or ASCII descriptor and punch it through the database. The system will quickly find the appropriate format and provide you with its full description.

With HEX editors, everything is more or less clear, but as we said, you can also use text editors to define ASCII headers. The principle is the same, we open the file with Notepad or Notepad ++, copy the first characters and paste them into the search field of the same open-file or another site that supports search by headings.

It would seem that everything is very simple, but there are difficulties in identifying formats. Sometimes ASCII headers coincide with the file extension (RAR and PDF), but it may also be that the header appears to belong to several formats at once. This can be seen in the example of the DOCX office format (PK and 50 4b 03 04). In such cases, it is problematic to accurately determine the format.

Very often users have to face the problem when a file has a certain type, we try to open it with the program offered by default, but it does not open. For example, send by mail text file(extension .txt), open it, and there are only a huge number of incomprehensible characters. This file may well turn out to be, for example, a .rar - archive. An inexperienced user may not understand at all how to determine the type of this file, and what program can open it. It is also possible that the file has no extension at all. In this case, it is displayed by the system as "unrecognized".

In order to determine the type of file even if there is no extension, i.e. a set of characters (usually three) after the period at the end of the file name, for example, "doc", "gif", we suggest using a free program File Type Verificator (FTV) by Shedko software.

Download the program

You can download the File Type Verificator (FTV) program from the official website of the developers at the link.

If you have any difficulties with downloading the program from the above link, we suggest downloading the program from free service"Yandex.Disk" at this link. The program file corresponds to the current version (April 2011). The administration asks the reader of the article to leave a message in the comments if the file is not available. Thanks.

Program installation

Run the downloaded program file, the installation wizard window will open:

Check the box " I accept the terms of the agreement", click" Further". A window for selecting the installation directory will open:

After the installation is complete, the following window will open:

If you want the program to start immediately, leave a check mark next to the " Launch File Type Verificator". Press the button" Ready".

If after restarting the program you see that it has an English-language interface, go to Main menu to point " Tools"and select the item" Select Language"(fig. 6):

In the window that opens (Fig. 7), select from the drop-down list under the inscription " Select preferable language" paragraph " Russian.ini", click" OK"and restart the program.

If the Russian language was not there, we suggest referring to the item " Russification of the program". If the Russian interface is not required for you or it is already available in the program, you can skip the next subsection of the article.

Russification File Type Verificator

For Russification File programs Type Verificator (FTV), you need to download a special file (" Russian.zip") on this page .

Now you need to extract the files from the archive. To do this, you can use an archiver such as WinRar. Also on our site is an article on the free program Zipeg for Windows. It allows you to extract files from the archive. The article is available at.

Unzip the files from the archive to some temporary folder. After that, copy them (there will be 2 files: " Russian.ini" and " russian.chm") to the folder" langs". To do this, open" My computer"(or press the" Win + E"; key" Win"has a system icon" Windows"and is usually located next to the" Ctrl"), select the drive that you selected when installing the program (if you installed the program to the default folder, then most likely this is the" C: "drive). Then go to the" Program Files", find the program installation folder" FileType Verificator", and in it you will find the folder" langs".

There are tens of thousands of different file formats in the information world. How to open a file of an unknown format that cannot be opened by standard programs?

What to do first

Before you open or run a file that came by e-mail or located on a flash drive, without fail antivirus program and make sure that he is neither a carrier of the virus.

File extension

A file name extension is an alphabetic or numeric character that appears after the file name and separated from it by a period. A file extension can tell a lot about a file format.

But how can you find out the extension of a file name if only the file names are displayed in Explorer and the extensions are hidden?

In the main menu of Explorer, select Tools, and in the drop-down menu, select Folder Options. Go to the View tab, in the Advanced Options window uncheck the Hide extensions for registered file types option and click OK. Now in Explorer, file extensions are shown after a period in file names.

Another way to find out the file extension, if it is not displayed in Explorer, is to right-click on the file and select Properties from the pop-up menu. In the properties window, the file name will always be displayed with the extension separated from the file name by a period.

Common file types and formats

File type	Extension
Audio	.aac .ac3 .acm .cdr .kar .kfn .m3u .mid .midi .mp3 .wav
Video	.3gp .3mm .avi .dat .mkv .mov .mp4 .mpeg .mpg .vob .wmv
Graphic	.bmp .cdr .djvu .gif .ico .jpg .jpeg .psd .tif .thumb
Text	.doc .docx .dot .faq .log .mg .rtf .txt
Archival	.7z .arc .arj .rar .rev .tar .tgz .zip
Performing	.app .bat .cmd .com .exe
Internet	.asp .cer .chm .htm .html .js .jsp .rss .vbd .xul .zfo
Systemic	.ani .cab .cur .dll .hlp .ico .nfo .reg .sys
Backups	.asd .bak .bup .da0 .gho .nba .old .tib
Database	.cdb .db .dbf .dsk .fpt .mdb .odb .pdb .sql .xld
Scripts	.aps .asm .dcu .def .dsp .jav .json .pas .res .src

Default program assignment

For most file formats in operating system programs are assigned that are used by default to open files of a certain type.

What if there is no program assigned to the file format that can be used to open the file?

Right-click on the file in the explorer and select Open with from the pop-up menu. From the secondary pop-up menu, select Select Program.

In the Select an application window that opens, select one of the proposed programs and click OK. For example, you have selected the WinDjView program.

In order to associate this program with files of this type on a permanent basis, before clicking OK, check the box next to Use the selected program for all files of this type.

If the list of offered programs is not the desired program, you can specify the program to open files manually.

To do this, in the Program Selection window, click the Browse button and specify the location of the required program, or rather, its executable file.

For example, you have chosen the AllReader2 program, or rather - executable file AllReader2.exe.

Now all files of this format will always be opened by this program, until you reassign some other program to open them.

Usually the operating system itself opens or offers to open the file with some program. If you still cannot open the file, you can find out what program is needed for this by contacting the all-knowing community of the World Wide Web.

Let there always be a program for all your files that can open them!

Let's imagine a situation that an important document was sent to you, after which the sender went offline. After downloading the file, you find that it does not have an extension. Of course, in this case, it is better to clarify the information with the sender of the file, but it is not always possible to contact him. Then you need to define the extension yourself in order to open this file. This article will look at ways to accomplish this task.

How do I find out the file extension?

If the file extension has been lost, we must open this very file with notepad to see the contents, but it is better to use free program Notepad ++ because when opening large files, notepad stops responding and takes a very long time to load text.

Let's take 7 files:

img_jpg;
img_gif;
music;
document;
zip archive;
rar archive;
program.exe.

Images

We open the first one, for example img, and we see a set of incomprehensible letters and symbols. Let's turn our attention to the first line with the inscription ‰ PNG. This means that png.

In the second image, we will see the following:

It means that this file v jpg format(jpeg).

If you have a GIF file, then the program will display GIF89a.

Music

How to find out what is the extension of an audio recording file? This is not so difficult to do.

Going into Notepad, we will see the following symbols (image below), which tell us that this file belongs to the MP3 format.

If you saw the inscription OggS, then you should know that you are faced with

The documents

It should be noted that all programs (tables, orders, materials, etc.) will have a single inscription "RP" if you have Microsoft OFFICE 2003 and below or "RK" if you have Microsoft OFFICE versions 2007 and up. Further we see the inscription .xml, which tells us that this is a product of MS. After that, we simply iterate over all programs, from Doc to Pptx. This significantly increases the search time for the desired format, but then you will definitely be able to find the type you need.

If you are too lazy to go through all the types, then you can use the Online TrID File Identifier online resource, which will be discussed below.

Video recording

To find out the extension of the video file, we have to open it in Notepad ++, where we will see the following entries, saying that we have a video in MP4 format.

If you are faced with AVI, then the corresponding entry will appear.

Program

How to find a file without an extension?

When opening the contents of the program file at the very beginning, we can observe a short MZ record, which tells us that we are undoubtedly exe file.

Online TrID File Identifier

If you do not want to download Notepad ++, or you are just too lazy to press the right mouse button and then the left one, then to your attention is a service that will help you find out the file extension. This is not at all difficult to do; for this, follow these simple steps.

You need to select a file and press the "Start" button. The resource, with an accuracy of percentages, will show the type of file that was uploaded, the name of the program, and a link to information about the product.

Done, now you can safely install the lost extension.

How do I install the extension?

In order to set the file type, you need to click right click by file and rename it by adding a period and file type to the end of the name. Attention! You cannot use spaces in the extension.

Are there other ways to find the file format?

Yes, there are a large number of resources, programs and manuals. They will tell you how to find out the file extension.

Renamed the file, but nothing changed. What to do?

In this case, check the spelling of the extension. For example, to rename in MS Word, you need to write not doc, but docx.

You can also double-click on the file with the left mouse button and open it using the desired program from the list of installed ones, select it in the MS store or find the program on your computer if it is not in the list.

You may not have installed a program that supports this extension. Download and install this program.

Can there be errors in online resources? Where can you find the file extension?

Yes, they definitely can. No service is immune from the appearance of algorithm errors. But if you are afraid that the resource will make a mistake, then just do everything manually.

Conclusion

Congratulations! You have seen ways to help you find out what extension a file has. You should now be able to install it on your computer. This information can be very useful for any computer user, because everyone can face such a problem.

There are many types of files. They can be text, graphics, music, software, etc. To make it easier for both the user and the operating system to navigate in such a variety, each file has its own extension, which is a kind of identifier. The guide below will help you understand why you need to know the file extension, how to enable the display of such information in the operating room. Windows system and how you can determine the format of a file that does not have a visible extension.

Sometimes, in one way or another, the user's computer gets files that his operating system did not have to work with before. Most likely, the program required to interact with this kind of files will not be installed either. The system notifies about this with a message of the following type:

It contains information about the file name, as well as a standard message notifying that the operating system does not know which programs support this extension. The user has 2 options for further actions:

Find suitable program in the Internet.
Select required application independently from the list of installed ones.

Practice shows that the first option is useless - usually nothing sensible can be found. But the second solution is very effective. Knowing the file extension, you can easily find a suitable program using the capabilities of your favorite search engine.

How to enable display of extensions

By default, the display of extensions in the Windows operating system is disabled. Experienced Users if necessary, they can activate this function on their own, but inexperienced people do not need it - you can accidentally change the extension of an important system file which will lead to various disruptions to Windows.

If you need to enable the display of extensions, you probably know why you are doing this. In such a situation, follow the instructions below.

How to find out the file format without extension

Even after enabling the display of the extension, some files will be displayed without it. An example can be seen in the following screenshot.

The landing page looks like this.