Here is an alternative to Tom's script, since you seem to have a specific procedure.

If you seem to have a stored procedure like:

----------------------------------------------------
create or replace procedure calc (a number, b number,
c out number, d out number)
is
begin
c:=a+b;
d:=a*b;
end calc;
----------------------------------------------------

You should do this:

----------------- Start of ksh script --------------
#!/bin/ksh

cat << EOF >/tmp/$$.sql

set termout off
set feedback off
set echo off
set serveroutput on
spool /tmp/$$.ksh
declare
a number:=10;
b number:=20;
c number;
d number;
begin
calc (a,b,c,d) -- This is where your proc comes in
dbms_output.put_line('VAR1='||c); -- These are your ksh
dbms_output.put_line('VAR2='||d); -- variable assignments
end;
/
spool off
exit
EOF

# you can choose your authentication scheme
sqlplus username/password@hoststring @/tmp/$$.sql

. /tmp/$$.ksh

echo $VAR1
echo $VAR2

rm /tmp/$$.sql /tmp/$$.tmp

------------------ End of ksh script ---------------

Just a couple of comments:

- Do not forget to "set serveroutput on"
- "spool off" should be inside the sql code, not in the ksh script body

There was a small error in my script above. A semicolon (;) is missing:

...
begin
calc (a,b,c,d); <-- There should be a semicolon here
dbms_output.put_line('VAR1='||c);
...

Just that...

Thanks !