How to Know what Command are available?

UNIX Solaris
1

Hi Gurus of Unix, I have a question
I have a Server "SUNW, Ultra-80", I have the Paasword of user and the root. but when i put the following comand, appear the following:

# top
top: not found
# ntpq -p
ntpq: read: Connection refused

But, If I put the command in other machine (SUNW,A70 for example), these command function normally
The question: How Can I Know what commands are available in this machine, and if is posibble to install or enable more.

Regard
Andres

2

Fun question.

One way is to look at every directory in your $PATH.

If you are using bash, another way is to just type a letter and hit TAB twice.

Or, find your MAN or Info directory and peek around there.

3 
apropos

is a useful command