A file extension is an optional alphanumeric identifier which comes after the last found period in a file name. A file extension itself does not define what type of data is in a file, but it does give a hint as to what is *supposed* to be in the file.

learn more… | top users | synonyms

2
votes
1answer
5k views

How to automatically recover lost file extensions?

We're recoverying bunches of data from a crashed partition of which we had no backup, using a data recovery software. Files are getting recovered, but file names are lost. Is there any software or ...
1
vote
3answers
3k views

Firefox saves the file without extension

When I download a file, Firefox removes the file extension. I mean, if I download "something.pdf", it saves the file as "something". I didn't have this problem before yesterday. Any help would be ...
3
votes
5answers
5k views

How do I unassociate a program from a file type?

If I have a file.class and I opened it with Notepad, how do I destroy that association so that Notepad is not associated with .class? I do not want to change the .class association to another program -...
0
votes
1answer
3k views

How to open/convert a .xmdx file?

I have a file that was sent to me with a .xmdx extension. Is there any way to convert it to something readable or open it with a third party application? I have never seen a file like this before so I ...
2
votes
1answer
2k views

how can i create security catalog(.cat file)

A catalog file contains a list of files and a digest of those files. A digest is a number generated by an algorithm to uniquely identify a given file, like a fingerprint. The digest is used for ...
2
votes
2answers
396 views

Details about “Hide Extensions of Known file types” from Windows Explorer

What does "known file types" actually mean? What makes a file type "known"? Can I explicitly add or remove extensions/types from the list of "known" file types?
0
votes
2answers
1k views

How to open .BNDL files

I want to edit a .BNDL file in windows 7 but when I open it with notepad or Microsoft Office 2010, I get a file with weird characters. Is there a way to edit this file in windows? Regards
1
vote
3answers
852 views

Sending *.exe by changing extension failed

I know you can send .exe through email by changing their extension. I've been using this often. But strange thing happen when I tried to send this specific ".exe" file. It failed!! It's this ...
0
votes
2answers
200 views

show file extensions in windows 8 [duplicate]

Possible Duplicate: How to display the extension of the file on windows 8 I am not able to show file extensions in windows 8.I can not find the folder options,that used to be there in windows ...
1
vote
2answers
241 views

Is there some way Linux editors can tell the programming language without the file extension?

I am editing some scripts on Linux without the languages file extensions, and it seems that the editors, namely vi, nano and gedit are not applying syntax highlighting because the filenames don't use ...
5
votes
3answers
793 views

Applications are being opened by IE instead of running normally

I rewrote the Question to add everything that i tried so far. Many of my applications are being opened by Internet Explorer. (not all) For example when I run Firefox.exe (from shortcut) I get IE run ...
2
votes
2answers
154 views

How to add extensions to a lot of files using content of each file?

I've got over 10,000 files that don't have extensions from older versions of the Mac OS. They're extremely nested in file structure, and they also have all sorts of strange formatting and characters. ...
-2
votes
3answers
1k views

How to open a file without any extension in windows 7? [closed]

I recently downloaded a file but it just looks plain, i mean no icon like winzip or anything and in the 'Type' column it just shows 'file'. i have no clue how to open such kind of file.
3
votes
1answer
3k views

Midnight Commander on OSX - bindings for file extensions and arrows

I am using Midnight Commander on Mac OS X (version 4.8.4) I have two problems and I would be very glad if you can help me: First: The binding for file extensions are set for Linux distribution. ...
2
votes
1answer
730 views

Notepad++ find in files filter for files with no extension

I'm using Notepad++'s "Find in Files" functionality to find specific text in a large number of text files across a large number of directories and subdirectories. I understand how to specify file ...
5
votes
2answers
722 views

Windows file association for README, INSTALL, LICENSE and the like [duplicate]

Possible Duplicate: How to set the default program for opening files without an extension in Windows? Many files originating in the UNIX world come without file extension. Popular examples ...
1
vote
2answers
307 views

Default file extensions in .bash_profile

I use Mac OS Lion and I would like to declare in my .bash_profile the file extensions and the default application to open them. For example, I want to associate all .txt files to TextMate so that ...
1
vote
1answer
94 views

What is a good file extention for CLI PHP programs?

I use PHP for some OS scripting, is there any proper file extension other than .php for PHP cli programs? So I can assign php.exe to run these kind of files directly. Is .phps a good candidate? I ...
0
votes
1answer
1k views

How do I open a BDC file?

I have a file with a .bdc extension. I've read that it's some kind of dictionary file, but I have no clue what software I can use to open it. Can someone help me out?
2
votes
1answer
251 views

Default program not choosing on Windows 7

I have a file with a .kv6 extension. I used Slab6 (the correct and only program) to edit this file. Slab6 was set as the default program to open it upon double click, but today it stopped using that ...
2
votes
0answers
115 views

Identify recovered filetype

I'm searching some info about this file. It was recovered from a failed HD, with Ontrack EasyRecovery. The file extension may not be accurate. I tried with TrID (I'm the developer), and based on the ...
4
votes
1answer
137 views

Windows explorer displays application path instead of file type

Windows explorer in Type columns sometime displays Type name like: "XXX File", sometime displays associated application name like "Adobe Acrobat Document", and for some application it displays full ...
1
vote
3answers
111 views

What file types could possibly be a worm or contain a viral infection

On Windows what file extensions do you have to look out for concerning viruses/worms? I ask because I'm wondering if there's a point in scanning .cfm files.
34
votes
4answers
66k views

How do I find out the file type without an extension? [duplicate]

After recovering my HDD, I ended up with a lot of files with no extension. Many of them are .bin files. Is there any way to find out what file format they actually are? Many of them have no ...
19
votes
2answers
20k views

Programatically associate file extensions with application on Windows

I've just recently reinstalled Windows and in setting up my environment I've noticed that all my associations for the various programming languages I edit in Notepad++ have gone (naturally). I am ...
2
votes
3answers
13k views

how do I determine the file type of a video file [duplicate]

Possible Duplicate: Tool to view video/audio file information Sometimes I get the url of a video embedded in a webpage and download it, just to find the file has no extension name. I can play ...
0
votes
1answer
648 views

How to remove trailing whitespace from file extensions and folders snow?

How can I remove trailing whitespace from file extensions and folders in snow leopard ? Ideally I would be able to run a single command within a directory that would search and remove for all files ...
12
votes
2answers
5k views

Show/hide extension of a file through OS X command line

I'm looking for a way, via terminal, to change whether or not a specific file's extension is shown in the Finder, something along the lines of: $ hideextension ~/music/somesong.mp3 Without having ...
16
votes
3answers
8k views

How to extract a complete list of extension types within a directory?

Within a directory, and recursively within it's sub-directories, meaning every directory within a directory is processed, how do I compile a complete list of unique extensions within the directory? ...
6
votes
1answer
4k views

Is there a difference between .JPG and .jpg?

Files that have uppercase extensions (specifically .JPG) are not opening or being recognized in Windows Live Photo Gallery. .jpg files work as expected. What could be causing this issue?
1
vote
2answers
3k views

Change Icon of *.dll Back To Original

My idiotic little brother opened a *.dll file with notepad, now it's got that NotePad icon on it. It's a real mess because now I can never distinguish between *.dlls and text files. How do I change ...
-1
votes
1answer
473 views

How do I save an HDR file for the web?

I made an HDR picture by combining three images in Photomatrix, but I don't know how to use the resulting .hdr file. Moreover, when I open it in phtoshop, it only displays the first image of the three,...
1
vote
5answers
24k views

Excel 2010 File Format/Extension Not Valid. Unable to Manually Change File Extension

I am at work and having problems opening an excel file. I continue to get the error: Excel cannot open the file XXX.xlsx" because the file format or file extension is not valid. Verify that the ...
6
votes
3answers
4k views

Searching for Extensionless Files in Windows 7

I cannot for the life of me figure out a way to have Windows 7 Explorer search for files with no extension. In XP it was nice and simple: just search for files named *. but in 7, that does not work ...
1
vote
1answer
760 views

Opening a .osx file in default program

I'm trying to run Fluenz on my computer and it's a .osx file. When I try to open it, it opens in Textmate. Kind of odd. Does anyone know how to restore its original default program? I think that I ...
7
votes
3answers
2k views

“file.myext” is not a valid Win32 application

I have written a registry that creates .myext. Double-clicking on my file.myext refers to my executable file (converted from a batch file that opens a .jar) which then opens my notepad application. ...
1
vote
1answer
130 views

Why do I sometimes get double extension names in OS X?

Sometimes when downloading files, I end up with a file like "foo.txt.txt". Sometimes I end up with just "foo" (and then manually change the extension later). Is this a common problem with OS X? What ...
1
vote
1answer
698 views

Make the extension .fw.png open in a different program to .png?

I want files ending in .fw.png to open in Adobe Fireworks but I want regular .png files to open in my standard image viewer program. Is this possible?
2
votes
1answer
2k views

How to play .qtch files?

So I have qtch files that apparently were created with QT 7+ because they can't be played (with QT 7+ or VLC) just by renaming their extension (as fileinfo.com says). Any solution out there ?
1
vote
1answer
704 views

How do you open or view the contents of .ch3 files?

We have some Harvard Graphics containing documentation from a legacy system. How can I open or view the contents of these .ch3 files? Or has the file format gone past deprecation?
3
votes
1answer
8k views

What's the difference between an *.ova file and a *.ovf file when exporting from VirtualBox?

I'm trying to export a Virtual Machine I have on VirtualBox so I can back it up, and when I went to export it, I was prompted with a "Save As..." dialog that asks me if I want to save it as a .ovf or ...
1
vote
1answer
704 views

Missing File extension in list for Select Default Program

Can't open xls files. Go to Set Default Program but the file extension isn't in the list and can't find a means of adding it. This seemed to happen after an auto Win 7 update. Any ideas?
6
votes
3answers
7k views

Automatically hide files with certain extension in Windows

Is it possible for Windows to automatically hide files with a certain extension? Let's say some program generates a set of files (I cant alter the sources of the program), and I would like some of ...
3
votes
1answer
538 views

How do I rename a file or folder to .something in Windows 7?

When I try to rename a folder to .svn or a file to .myemacs, for example, a popup says: You must specify a file name. Do you have a workaround ?
2
votes
1answer
2k views

Is there a way to show only specific file extensions?

Call me crazy, but I'm sure I remember this capability existing in previous versions of Windows. In Windows 7, we can have file extensions Off... or On. Pick one. Is there some obscure switch ...
3
votes
1answer
95 views

Handling files without an extension

I'd like to know how Windows XP, Vista and 7 handle files without a file extension. I'd test it myself, but I don't have access to a Windows machine currently. To my knowledge, Windows XP throws up ...
1
vote
4answers
2k views

What are the most popular file extensions for COMPRESSed files? [closed]

I was just wondering, what's the difference between these file formats? Shouldn't there be just one or two that generally tend to perform superior to most others?
6
votes
4answers
460 views

Are you allowed to come up with any desired file extension (for Unix, Linux, Windows)?

I want to create a file called "message" that contains text only. How does the system know what program to use to read it if I decide to call it: message.txt? message.dat? message.enc? message.cpz? ...
5
votes
2answers
962 views

How does a file have no extension?

Take for instance: cat /etc/passwd Why doesn't this file have an extension such as *.txt*, *.dat*, etc? Or does an extension exist, but it's just being hidden? Does this apply strictly to Unix-...
0
votes
2answers
717 views

What are the alternatives of .txt?

For some reason, I can't save .txt files on my web server. I have a text file hosted on my web server, but the ending is not .txt I was wondering what ending should I choose, so that whoever sees ...