hi allian,
I invoke the pl/sql from a shell by sqlplus. So the only way to pass a parameter to the shell is the exit status which can be from 0 to 255. If you want to get more than one output parameters is better to display them on screen with DBMS_OUTPUT.PUT_LINE(par1||' '||par2) and pipe this output to awk for manipulation. Another way it could be writing to a file and treating the file after.
I hope it helps,
ducasio