Searching indexed folders with extensionless files

I often index developer project files (programming stuff; c/cpp/swift you name it) in devonthink. This gives me access to DT’s great search facility, navigation and reading all in one. Great to get a handle on a big project that is new to me.

I have dealt with “normal” code files only, however, today I received a project that contains a fairly large amount of makefiles spread throughout the project. It is these makefiles I need to search. They have no extension (eventhough they are regular text files). Outside DT I would normally open them with Bbedit so I set macos to always open with BBedit. However, DT continuous to show them as having no ‘kind’ property. More importantly, searching for text in DT never includes those makefiles. If I pick a string from a makefile and search for it with the containing folder selected, DT never finds it.

Is there a preference setting I missed? Anything else I can do to have DT search through these files?

Not all text file extensions are seen as text, regardless if they functionally are or not.
Select DEVONthink’s Help > Documentation > Appendix > Hidden preferences and you’ll find an option for adding extensions for other file types.

Hey thats nice, and it seems to be working … somewhat. I added two extensions:

defaults write com.devon-technologies.thinkpro2 AdditionalPlainTextExtensions -string .mk.ld

And restarted DT. I know I have a .ld file that contains the string “backup_ram_memory”. Using the search string facility in the top right, search for set to ‘all’, option set to ‘in selection’ it now finds the file of interest. yay! However, when I use the Tools/Search… facility, setting the database to the appropriate location, the same string is never found!

With a different string ‘APP_FLASH’, the right top search string finds 4 files (two .md and two .ld), the Tools/Search… finds only 1 (an .md file). When I run “grep -r APP_FLASH .” on the top folder I get over 100 files btw.

Besides the mismatch mentioned above, how would i add a file that has no extension? E.g., the ‘makefile’ is just that, no extension.

grep wouldn’t be comparable unless you were using Contents as the search scope.

Also, you need to examine the options under the magnifying glass in the search field.

Lastly, you can’t add extensionless files.

Both search method’s options were set identical i.e. ‘all’. So excluding extensionless files, grep’s output and both search methods should have been identical. no?

Two screenshots to illustrate my issue:
https://ibb.co/cZC4Ep
https://ibb.co/jzEvLU

Ah so, what did I miss?