[SQL] running scripts like oracle sqlplus

[Steven Dahlin]

I have been trying to figure out how I can run a pgsql script like I can run
a plsql script with oracle's sqlplus.  Here is a sample script file for what
I want to run:

declare
  sysuserid integer := 0;
  hwcustid  integer := 0;
begin

select nextval( 'user_seq' ) into  sysuserid;
select nextval( 'customer_seq' ) into  hwcustid;

insert into user
(
  user_id,
  customer_id,
  create_user,
  update_user
)
values
(
  sysuserid,
  hwcustid,
  sysuserid,
  sysuserid
);

insert into customer
(
  customer_id,
  create_user,
  update_user
)
values
(
  hwcustid,
  sysuserid,
  sysuserid
);

commit;

end;

I try to run the script in psql and thru pgadmin and cannot seem to make
them work.  I do not want to turn it into a function.  I just want it to
execute the block in a fashion similar to Oracle'sqlplus running
@scriptfile.sql.

Thanks