Changing History to only store unique commands

[Peter Hindrichs]

I hope this is appropriate for this forum, if not just advise and I  
will not continue.

I have wanted to set up my history to only show a one time occurrence  
of each command that I use.

I found this on the web:  "http://reviews.cnet.com/8301-13727_7-10361343-263.html?tag=mncol;title 
"

I followed the procedure and couldn't get the file to save. After some  
research I found that I had to create the ".bash_profile" file, which  
I did and it

worked. However at this point I couldn't access the ports, so I  
removed the .bash_profile, closed the terminal and reopened and now my  
ports are back

with no issues.

My question is can I under ports set up the same kind of profile, so  
that history will not show any duplications. If this is possible how  
would I go about doing this ?

Many Thanks in advance.

Peter