The SQLPLUS utility is the Oracle equivalent of iSQL.
It includes a few shortcuts to make life easier:
@FILENAME
This will excecute FILENAME (or FILENAME.SQL)
SHOW ERRORS
This will show the detailed errors for the last command.
L
This lists the last command entered.
Beware that stored procedures or functions cannot include blank lines (as far as i can tell – I got so many errors that I removed them).
Without some of these commands it is as user-friendly as a cornered rat.
Developer Rants 