There are "tons" of monitoring scripts available freely on the net. The gui tools only act as a front end to execute those queries. I was forced to work with Oracle because I had unix experience and couldn't even do a "select " statement. However by going out to the net and downloading some scripts(and testing on a test machine) I was able to monitor the DB and learn about SQL.
Once you've gotten about 8-15 scripts that show most of the stuff you need to see(tablespaces, tables, users, privs, syns, blah blah blah) than you can write a simple shell script that uses that "case" statement to prompt the user to choose one of your scripts.