CREATE OR REPLACE PACKAGE pk_test AS
    PROCEDURE proc_test(
        cvarIN      IN     varchar2
        --,cvarOUT     OUT    varchar2
        );
END pk_test;
/
CREATE OR REPLACE PACKAGE BODY pk_test AS
    PROCEDURE proc_test(
       cvarIN      IN     varchar2 
       --,       cvarOUT     OUT    varchar2
       )
    IS
      cvarWork              varchar2(30);
    BEGIN
      DBMS_OUTPUT.ENABLE(1000000);
      select dummy into cvarWork from dual;
      dbms_output.put_line('VarIN: '||cvarIN||'   cvarWork: '||cvarWork);
    EXCEPTION 
    WHEN OTHERS THEN
      NULL;
    END proc_test;
END pk_test;
/

SET SERVEROUTPUT ON
EXEC pk_test.PROC_TEST('XXX');