CREATE OR REPLACE PROCEDURE print_clob_to_output (p_clob IN CLOB)  
 IS  
   l_offset     INT := 1;  
 BEGIN  
   dbms_output.put_line('Print CLOB');    
    loop  
        exit when l_offset > dbms_lob.getlength(p_clob);  
        dbms_output.put_line( dbms_lob.substr( p_clob, 255, l_offset ) );  
        l_offset := l_offset + 255;  
    end loop;  
 END print_clob_to_output;

declare 
l_clob  CLOB; 
BEGIN 
 
 l_clob :='CLOB text'; 
 
 print_clob_to_output (l_clob); 
end;