What is a DEF file?

Lists the exports and attributes of the program to be linked using the Application Linker. Used in development software when creating a DLL.

DEF files are used by Microsoft Visual C++, a Microsoft component Visual Studio, as well as other C++ development software.

How to open a DEF file?

The most common problem that arises when you cannot open a paradoxical DEF file is the absence of the appropriate program installed on your device. The solution is very simple, just select and install one program (or several) to service DEF from the list that you will find on this page. After correct installation The computer itself must associate the installed software with the DEF file that you cannot open.

Programs that will open a DEF file

Other problems with the DEF file

Have you downloaded and installed one of the programs correctly and the problem with the DEF file still occurs? There could be several reasons for this situation - we present a few reasons that create the most problems with DEF files:

• The DEF file affected by the problem is corrupted
• the file is not downloaded completely (download the file again from the same source, or from the email message application)
• there is no corresponding DEF file association in the "Windows Registry" with installed program for its maintenance
• the file is infected with a virus or malware
• the program serving the DEF file does not have the appropriate computer resources, or the appropriate controllers are not installed to allow the program to start

We hope that we helped you solve the problem with the DEF file. If you don't know where you can download an application from our list, click on the link (this is the name of the program) - you will find more detailed information regarding where to download a secure installation version of the required application.

A visit to this page should help you answer these or similar questions specifically:

• How to open a file with a DEF extension?
• How to convert a DEF file to another format?
• What is the DEF file format extension?
• What programs support the DEF file?

If, after viewing the materials on this page, you still have not received a satisfactory answer to any of the questions presented above, this means that the information presented here about the DEF file is incomplete. Contact us using the contact form and write what information you did not find.

What else could cause problems?

There may be more reasons why you cannot open a DEF file (not just the lack of a corresponding application).
Firstly- the DEF file may be incorrectly linked (incompatible) with installed application for its maintenance. In this case, you need to change this connection yourself. To do this, right-click on the DEF file that you want to edit, click the option "Open with" and then select the program you installed from the list. After this action, problems with opening the DEF file should completely disappear.
Secondly- the file you want to open may simply be damaged. In this case, it would be best to find a new version of it, or download it again from the same source (perhaps for some reason in the previous session the download of the DEF file did not finish and it could not be opened correctly).

Do you want to help?

If you have additional information about the DEF file extension, we will be grateful if you share it with users of our site. Use the form below and send us your information about the DEF file.

If you have installed on your computer antivirus program Can scan all files on your computer, as well as each file individually. You can scan any file by clicking right click mouse on the file and selecting the appropriate option to scan the file for viruses.

For example, in this figure it is highlighted file my-file.def, then you need to right-click on this file and select the option in the file menu "scan with AVG". When choosing this parameter will open AVG Antivirus, which will scan this file for viruses.

Sometimes an error may occur as a result incorrect software installation, which may be due to a problem encountered during the installation process. This may interfere with your operating system link your DEF file to the correct application software , influencing the so-called "file extension associations".

Sometimes simple reinstalling Microsoft Visual Studio may solve your problem by linking DEF correctly with Microsoft Visual Studio. In other cases, problems with file associations may result from bad software programming developer and you may need to contact the developer for further assistance.

Advice: Try updating Microsoft Visual Studio to latest version to make sure you have the latest patches and updates installed.

This may seem too obvious, but often The DEF file itself may be causing the problem. If you received the file via an attachment email or downloaded it from a website and the download process was interrupted (for example, a power outage or other reason), the file may become damaged. If possible, try to get new copy DEF file and try to open it again.

Carefully: A damaged file may cause collateral damage to a previous or existing malware on your PC, so it is very important to keep an updated antivirus running on your computer at all times.

If your file is DEF related to the hardware on your computer to open the file you may need update device drivers associated with this equipment.

This problem usually associated with media file types, which depend on successfully opening the hardware inside the computer, e.g. sound card or video cards. For example, if you are trying to open an audio file but cannot open it, you may need to update sound card drivers.

Advice: If when you try to open a DEF file you receive .SYS file error message, the problem could probably be associated with corrupted or outdated device drivers that need to be updated. This process can be made easier by using driver update software such as DriverDoc.

If the steps do not solve the problem and you are still having problems opening DEF files, this could be due to lack of available system resources. Some versions of DEF files may require a significant amount of resources (for example, memory/RAM, computing power) to open properly on your computer. This problem is quite common if you are using fairly old computer hardware and at the same time a much newer operating system.

This problem can occur when the computer has difficulty completing a task because operating system(and other services running in the background) can consume too many resources to open a DEF file. Try closing all applications on your PC before opening Module Definition File. Freeing up all available resources on your computer will provide the best conditions for attempting to open the DEF file.

If you completed all the steps described above and your DEF file still won't open, you may need to run equipment update. In most cases, even when using older versions of hardware, the processing power can still be more than sufficient for most user applications (unless you're doing a lot of CPU-intensive work, such as 3D rendering, financial/scientific modeling, or intensive multimedia work) . Thus, it is likely that your computer does not have enough memory(more commonly called "RAM", or RAM) to perform the file open task.

A module definition file (DEF file) is text file, containing one or more module statements describing various attributes DLLs. If you do not use a DLL to export functions keyword __declspec(dllexport), then the DLL will require a DEF file.

The DEF file must contain at least the following module definition statements.

The first statement in the file must be LIBRARY. This statement identifies the DEF file as belonging to a DLL. The LIBRARY statement is followed by the name of the DLL file. The linker places this name in the DLL import library.

The EXPORTS statement lists the names and, optionally, sequence numbers of the functions exported by the DLL. To assign a serial number to a function, you must place the symbol (@) after the function name and indicate the number. Sequence numbers must range from 1 to N, where N is the number of functions exported by the DLL. If you need to export functions by sequence number, see section and also this section.

For example, a DLL containing code to implement a binary search tree might look like this:

LIBRARY BTREE EXPORTS Insert @1 Delete @2 Member @3 Min @4

If you use MFC to create the DLL, the wizard creates a skeleton DEF file and automatically adds it to the project. All that remains is to specify the names of the functions to be exported to this file. For non-MFC DLLs, you must create the DEF file yourself and add it to the project.

When exporting a function to a C++ file, you must either put the decorated names in the DEF file or define the exported functions using standard means linking C using the external alias "C". If you need to put decorated names in the DEF file, you can get them by using a linker tool or option. Note that the decorated names produced by the compiler vary by compiler. If you put the decorated names generated by the Visual C++ compiler into a DEF file, then applications that link to the DLL must also be built using the same version of Visual C++ so that the decorated names in the calling application match the exported names in the DLL DEF file .

What kind of file is this - DEF?

DEF files are native to the MUGEN game engine. A DEF file is a text file containing key information about the game character. The DEF document also stores links to other files, such as , or . Eingine games are distributed by free license and is no longer deposited by Elecbyte, the creator of the engine.

User-created DEF files can be found on Mugen-related gaming forums. The engine is still in use and developed by a community of fans.

Program(s) that can open a file .DEF

Windows

Linux

How to open DEF files

If a situation arises in which you cannot open the DEF file on your computer, there may be several reasons. The first and at the same time the most important (it occurs most often) is the absence of a corresponding application serving DEF among those installed on your computer.

The most in a simple way The solution to this problem is to find and download the appropriate application. The first part of the task has already been completed - programs for maintaining the DEF file can be found below. Now you just need to download and install the appropriate application.

In the further part of this page you will find other possible reasons causing problems with DEF files.

Possible problems with files in the DEF format

The inability to open and work with the DEF file should not mean at all that we do not have the appropriate software installed on our computer. There may be other problems that also block our ability to work with the Definition Format file. Below is a list of possible problems.

• Corruption of a DEF file which is being opened.
• Incorrect DEF file associations in registry entries.
• Accidental removal of DEF extension description from Windows registry
• Incomplete installation of an application that supports the DEF format
• The DEF file which is being opened is infected with an undesirable malware.
• There is too little space on your computer to open the DEF file.
• Drivers for the equipment used by the computer to open a DEF file are out of date.

If you are sure that all of the above reasons are not present in your case (or have already been excluded), the DEF file should work with your programs without any problems. If the problem with the DEF file is still not resolved, this may mean that in this case there is another, rare problem with the DEF file. In this case, the only thing left is the help of a specialist.