Unix utilities (cat, grep, ls etc.) for Android?

I'm transitioning to *one* folder with many (txt-)files, adapting (letters instead of symbols, lowercase only, no spaces) Merlin Manns txt-setup . With cat, grep, head and other Unix-utilities , it's better than a folder structure. I use this on Ubuntu, storing the files in my Dropbox-folder. I'd like to have the same functionality on Android, but have come up empty handed. They don't have to be the same tools, and if I can only cover *part* of the functionality, that's a great start. How can I get this (or similar) functionality?