Extensions for multi-part RAR files include the ".partXXX"

(Directory Opus 12):

My question pertains to the way CERTAIN FILE EXTENSIONS (NOT ‘FILE TYPES’) are displayed in the ‘Detailed’ (and possibly other) File Lister Views in Directory Opus 12. Here’s a specific example:

Suppose I have an Archive file by the name of SarahLee.rar.

This file’s (File) EXTENSION (the EXT column) will display as .RAR AND its File Type (column) will display as ‘WinRAR archive’.

HOWEVER: suppose I have a series of multiple, ‘split’ WinRAR archive files named ‘X.part001.rar’, ‘X.part002.rar’, ‘X.part003.rar’, ‘X.part004.rar’, ‘X.part005.rar’… ETC., while the File Type column will display as ‘WinRAR archive’, THE FILE EXTENSION of each and every file is not displayed as ‘rar’ as one might expect but rather the FILE EXTENSIONS are displayed as ‘part001.rar’, ‘part002.rar’, ‘part003.rar’, ‘part004.rar’, ‘part005.rar’, etc.

I do not understand why this is happening and would like to change it.

I 'always thought' that the File Extension field should be equal to the rightmost text in the file name IMMEDIATELY TO THE RIGHT OF THE LAST ‘.’ (period) so why is Directory Opus displaying it this way???

(By the way, Windows Explorer “operates as you would expect” in terms of displaying the ‘correct’ File Extension…(.

Bottom line: I would appreciate it if anyone can offer an explanation for this behavior AND HOW I MIGHT GO ABOUT CHANGING IT TO DISPLAY THE FILE EXTENSION 'PROPERLY' IN DIRECTORY OPUS 12 so that the file extensions in situations like this are all ‘.rar’ and the file type (column) still displays them as ‘WinRAR archive’.


The file extension of a multi-part rar includes the part number. That way the filename stem (everything except the extension) is the same for all parts. This is completely intentional.

If you extract an archive into a folder, the folder is named after the archive, minus the file extension.

If you extract multi-part RAR archive from X.part001.rar into a folder, you want it to go into a folder called X, not into a folder called X.part001. So X is the name and .part001.rar is the extension.

If you batch rename a set of multi-part RAR files and turn on the "ignore extensions" checkbox, you'd want to rename just the archive name and keep the .partXXX.rar extensions as-is.

It makes even more sense if you consider the case of split 7z archives:


And a split text file:


If you only saw the 001, 002, 003 extensions, the split 7z archive isn't even a 7z file and would not be handled properly. For split 7z to work properly we need to support multi-part extensions. The same support carries over to split RAR files, although it's less necessary with those and more for consistency and so you can get the name of the archive properly when extracting into a folder, or when doing batch renames.

(Some parts of Opus, such as commands and scripting, let you choose whether to see "multi-part extensions" like this, or just see the last part of the extension, as needed. You could add a column to do the same if you wanted it.)

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Thanks for your VERY prompt reply/explanation. I can ‘see’ your points and they are indeed valid. The ‘problem’ that I was running into (and irritation) is that if I was viewing a list of files and folders in a particular directory and they all were .RAR files but some did not have a ‘partnnn’ ‘Extension Prefix’ (if I can call it that), a “Find As You Type” search for ‘RAR’ would return all the non-partnnn files that might be associated with the ‘root’/first file of the archives set but if there were ‘partnnn’ RAR files they would ALL be included in the search results. Quite often all I want to see is ‘the first’ archive file of a given archive ‘set’ because I’m looking for that first filed only to do an extraction and if you have literally hundreds of ‘partnnn’ files, you have to do a heck of a lot of scrolling down to find something. (Of course I could always use a different search method but ‘Find As You Type’ is so nice…

I think I will look into your suggestion about creating a custom column to do is I want.

Thanks again. (Especially for the unbelievably fast response).

You could hide all the .partxxx.rar files, except for when xxx != 001, either by default (in all folders or just some) or via a button or hotkey you can click to toggle them on and off.

That's what I'd do if I needed to find the first parts and hide the others a lot.

If you want to set that up and need help, please link your account and I'll work out the exact details. (Let me know if you want it to be applied to some/all folders by default, or if you want a button, hotkey, etc.)

Me too. That's why I have this show filter on a button:

Set SHOWFILTERFILENAME=regex:.*part0*1.rar
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