How to Execute Hotbackup Script in shell

hi
i have written a hotbackup script  as ....

set serveroutput on
set line 500
set head off
set feed off

declare
  copy_cmnd constant varchar2(30) := 'cp';
  copy_dest constant varchar2(30) := '/backup/';
  dbname  varchar2(30);
  logmode varchar2(30);

begin
  select name, log_mode
  into   dbname, logmode
  from  v$database;

  if logmode <> 'ARCHIVELOG' then
     raise_application_error(-20000,
                     'ERROR: Database must be in ARCHIVELOG mode!!!');
     return;
  end if;

  -- Loop through tablespaces
  for c1 in (select tablespace_name ts
             from   sys.dba_tablespaces)
  loop
    dbms_output.put_line('alter tablespace '||c1.ts||' begin backup;');
    -- Loop through tablespaces' data files
    for c2 in (select file_name fil
               from   sys.dba_data_files
               where  tablespace_name = c1.ts)
    loop
      dbms_output.put_line('!'||copy_cmnd||' '||c2.fil||' '||copy_dest);
    end loop;

    dbms_output.put_line('alter tablespace '||c1.ts||' end backup;');
  end loop;

  -- Backup controlfile and switch logfiles
  dbms_output.put_line('alter database backup controlfile to trace;');
  dbms_output.put_line('alter database backup controlfile to '||''''||
                       copy_dest||'control.'||dbname||'.'||
                       to_char(sysdate,'DDMonYYHH24MI')||''''||';');
  dbms_output.put_line('alter system switch logfile;');
end;
/

set head on
set feed on
set serveroutput off
------------------------------------------------------------------------------------------------


This file is saved as hotbackup.sql
now my question is how should i execute this sql file on a shell command
i am using oracle 9i [Release 2] on redhat linux 9.0
also
if i want to set a cron job for it
how should i go for it  ?....


thanks

tushar