Accessing Oracle's Web Interface (Oracle Enterprise Manager)

I wanted to access the Oracle Web Interface for administering the database on a Cent OS system. However, I hadn't performed this oracle installation myself so I started by doing:

netstat -a | more

And looking carefully through the list to see if I could spot it but I couldn't!

Eventually I found the answer here. There is a file which contains the Oracle Enterprise Manager URL for each database installed and that file's location is:

$ORACLE_HOME/install/readme.txt

For example:
/home/oracle/app/oracle/product/11.1.0/db_1/install

Here's what mine looked like:

Enterprise Manager Database Control URL - (orcl) :
https://localhost:1158/em

Enterprise Manager Database Control URL - (bbb) :
https://localhost:5501/em

Enterprise Manager Database Control URL - (aaa) :
https://localhost:5500/em

And there you have it! Enjoy!