Any suggestions on this?

I haven't run across a reference which addresses all of the subtlties between the different *NIX flavors in a purely command-by-command, dictionary-type layout, but I have two which I use quite often:

UNIX Power Tools from O'Reilly Press is a very good overall *NIX reference. It's much more than just a command reference though, and isn't Linux-specific. The downside is that the actual commands and their usage aren't categorized in an alphabetical sort of way, but are more grouped according to their functionality. However, I'd still highly suggest it for any *NIX user.

Another is Linux System Commands published by M&T. Although Linux-specific, it is a command reference and nothing more. I've haven't found their books easy to navigate though, as they all seem to lack an intuitive structure (i.e.: evreything might be there, just not quite where you would expect to find it).

Sorry if this sounds like a not-so-glowing review of either, but I'd go for UNIX Power Tools in terms of a general (read: non-Linux-specific) UNIX reference book.

I just picked up Unix Shells by Example Third Edition. It covers all the basic Unix shells with good examples of each, including the korn shell and even bash for Linux. I find it very good so far in covering the shells and their commands along with some shell scripting.. might be a good source for you to check out. I give it two thumbs up.

I might not have asked the question properly? Im using Mandy8.1 who's kernel is a unix clone which I would think would mean something very similar to unix. However when searching for a book on linux commands I find books delinating between both of them when in fact one is supposed to be a clone of the other. My question is, I bought "Linux in a Nutshell" by O'Reilly which gives all commands, arguements, shell explanations and a bunch of other goodies, however will this apply to an os based on unix such as BSD even though the book is about linux...? Or should I have bought UNIX in a nutshell which would be a cross reference to both. They seem like they would say the same thing....

Most of the Unix-clones are very similar to each other commandwise, considering that they are all clones of the same system. The real differences come in the way the system is laid out, how it boots, and so on. Doing an 'ls' on just about any *nix will give you a list of the files and directories - somethings just don't change much.

well if your using Linux, a Linux in a Nutshell would be best. Even though a Unix book will do the job just as well in covering commands, the default kernel shell for Linux is bash, most likely that is what your using, you could pick up a book about bash. I think O'reily has a book covering it. But the book you have will cover bash.
The book I mentioned earlier covers all the major shells with commands that *nix uses.

Thanks guys I think Ill stick with the book I bought!

Clone probably isn't the best word to to use when talking about UNIX derivatives. The word variant is often used, and IMHO is a better decriptive.

There are a scores of UNIX variants in the family tree; many of them long obsolete, many still in use. Linux came from the desire to improve on Minix, itself a "lightweight" UNIX offshoot spawned in the early 80's. Given that these *NIXes were developed as improvements to the original or as solution-specific implementations of it, it's no surprise that that there are some (often quirky, subtle, or just plain frustrating) differences between them. Remeber that even the different DOSes that used to floate around (IBM-DOS, DR-DOS, MS-DOS, etc.) suffered from the same problems in terms of subtle differences in commands, syntax, etc.

If you're interested, there's a mind-blowing timeline of the "UNIX Family Tree" available here.