list of commands & utilities [WAS: change file names]

[Zhao Peng]

Hello All,

With the recent "change file names" experience, I'm wondering if there 
is a simply way to get a comprehensive list of A*L*L available commands 
& utilities on a given linux OS.(Mine is Red Hat Enterprise). If so, how?

If I have the list, I definitely will go through it to see if I could 
find any command/utility which might be helpful for solving my problem, 
before I post any question here.

Thanks a lot!
Zhao