Pretty nice that DOPUS is using iFilters. I didn't realize this at first. Had a small issue with that though when using the 'Search inside archives' option.
Steps to reproduce:
1.) Create an encrypted file that requires iFilters to parse properly. (I used a binary excel file: .xlsb)
2.) Write a non common word/text entry to the file and save it. (I used 'Appletomato')
3.) Create a .rar and a .zip archive.
4.) Add the file from step 1 to both archives.
5.) Place all three files in a directory.
6.) Search this directory with 'Containing text' set to 'Appletomato' (or whatever you used) and the 'Search inside archives' option enabled.
On my computer I only get 2 matches instead of 3. The text is recognized in the original file and in the .zip archive, but not in the .rar archive.
I thought the .rar archive might not be decoded properly (for whatever reason), but if I add a textfile containing the word 'Appletomato' to the .rar archive, the search does list this archive too. So it must be something with iFilters/.rar files.
Is this a wrong setting on my machine or can anybody reproduce the issue too?
From a quick test here with a Wordpad .docx document, IFilters do not work inside Zip or RAR on my machine. (I would necessarily expect them to either, at least by default, especially with RAR which Windows itself does not understand.)
Basic plain-text searching does work, but that's something Opus does itself without passing it through the Windows IFilter API or any external components.
There are 3rd party Zip and RAR IFilters you can install which apparently enable recursive searching inside archives via IFilters, according to their websites. (I have not used them so cannot vouch for how well they work.) Maybe you have a Zip one installed and that is why they are working? It's also possible it is a deficiency in the Wordpad IFilter but not in the Excel one you're using (I don't have Excel to hand to test).
As an aside: Searching solid RAR or 7z contents can be extremely slow, so watch out for that. RAR is not solid by defualt but 7z is (depending on the tools used to create the archives).
Okay, not a big deal, I was just wondering because it worked in the zip file so I thought it could be a wrong setting or another issue. Didn't even know there are ifilters to install, that gives you the ability to search withing archives too. Maybe I have indeed such a tool installed for .zip, but can't remember.
I also can confirm that plain text search works within .rar files.