i also have a Spetznaz survival tool strapped to my ruck, chop, dig, saw, not much it won't do... 
Probably the best idea is to have several different knives including a machete, a few Swiss Army knives, several fixed blade such as a Kabar, a Cold Steel SRK, a file, a sharpening stone, maybe a stockman pocket knife or anything else you want.
I usually have at hand a 38 year old Cold Steel Recon Tanto, a Chris Reeve Large Sabenza, and a Schrade something-or-other pocket clip folder.
i also have a Spetznaz survival tool strapped to my ruck, chop, dig, saw, not much it won't do... That’s pretty much what I have on me most of the time. I haven’t been without a knife (except on an airplane) since I was about 6 years old. I’m a white collar worker in NY and get some looks whenever I pull out the appropriate tool when someone needs it. The one thing a don’t own is a specialty survival knife. Maybe I should get one of those???