echo $CATALINA_HOME I get a blank line, but when I
ls $CATALINA_HOME I correctly get a listing of the directory. Why can't I echo it? I am running Ubuntu 11.04.
There is no environment variable $CATALINA_HOME unless you defined it beforehand. You can see that the output of ls will always display the current directory (that is not necessarily your home directory!) if invoked with an empty or undefinded variable:
The current user's home directory is stored in $HOME:
The current user name is stored in $USER: