People seem to have already asked about indexing file system:
but I want to actually just index a certain working directory and be able to do that manually (so that I make sure my search is correct). Basically, I am on working a project and I need be able to search in contents quickly. I already use 'locate' and 'updatedb' commands, but those search for file names only. I am looking for similar commands but file contents.
Just in case you are wondering why I don't use tracker also like answered in the two posts, tracker have a set of prespecified folders to search in them, and whenever you make a search, you search in all of them. What I want is to be able to search in every project separately.