11:32:25 SQL> @x
11:32:27 SQL> declare
11:32:27   2  x varchar2(4000);
11:32:27   3  begin
11:32:27   4  x := 'String1 ';
11:32:27   5  x := x || 'String2 ';
11:32:27   6  x := x || 'String3 ';
11:32:27   7  x := x || 'String4 ';
11:32:27   8  x := x || 'String5 ';
11:32:27   9  x := x || 'String6 ';
11:32:27  10  dbms_output.put_line(x);
11:32:27  11  end;
11:32:27  12  /
String1 String2 String3 String4 String5 String6

PL/SQL procedure successfully completed.

11:32:27 SQL> 

DECLARE
 v_file  UTL_FILE.FILE_TYPE ; 
 vstragg  varchar2(4000);
BEGIN
 v_file := UTL_FILE.FOPEN( 'DATA_PUMP_DIR' , 'T_DTIA_TS_ADDR.txt','w',32767);
select replace(stragg(DATA_TYPE), ',',' || '' , ''') INTO vstragg from (
SELECT COLUMN_NAME,
  (CASE DATA_TYPE
    WHEN 'VARCHAR2' THEN '"||'||COLUMN_NAME||'||"'
    WHEN 'NUMBER' THEN COLUMN_NAME
    WHEN 'CHAR' THEN  '"||'||COLUMN_NAME||'||"'
    WHEN substr('TIME', 1, 4) THEN  (to_CHAR(COLUMN_NAME, 'YYYY-MM-DD')|| '-'||
to_CHAR(COLUMN_NAME,'HH24'||'.'||'MI'||'.'||'SS'||'.'||'FF')) 
    END) DATA_TYPE   FROM USER_TAB_COLS WHERE TABLE_NAME = 'T_DTIA_TS_ADDR');

UTL_file.put_line( v_file,    vstragg);
UTL_FILE.FCLOSE(v_file); 
  EXCEPTION 
  when others 
  then 
 dbms_output.put_line(sqlerrm); 
  end;
/

CREATE OR REPLACE PROCEDURE run_query1(p_sql IN VARCHAR2
                                     ,p_dir IN VARCHAR2
                                     ,p_header_file IN VARCHAR2
                                     ,p_data_file IN VARCHAR2 := NULL) IS
  v_finaltxt  VARCHAR2(4000);
  v_v_val     VARCHAR2(4000);
  v_n_val     NUMBER;
  v_d_val     DATE;
  v_ret       NUMBER;
  c           NUMBER;
  d           NUMBER;
  col_cnt     INTEGER;
  f           BOOLEAN;
  rec_tab     DBMS_SQL.DESC_TAB;
  col_num     NUMBER;
  v_fh        UTL_FILE.FILE_TYPE;
  v_samefile  BOOLEAN := (NVL(p_data_file,p_header_file) = p_header_file);
BEGIN
  c := DBMS_SQL.OPEN_CURSOR;
  DBMS_SQL.PARSE(c, p_sql, DBMS_SQL.NATIVE);
  d := DBMS_SQL.EXECUTE(c);
  DBMS_SQL.DESCRIBE_COLUMNS(c, col_cnt, rec_tab);
  dbms_output.put_line (' col_cnt : ' || col_cnt);
  FOR j in 1..col_cnt
  LOOP
    CASE rec_tab(j).col_type
      WHEN 1 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
      WHEN 2 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_n_val);
      WHEN 12 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_d_val);
    ELSE
      DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
    END CASE;
  END LOOP;
  -- This part outputs the HEADER
 v_fh := UTL_FILE.FOPEN(upper(p_dir),p_header_file,'w',32767);

    DBMS_OUTPUT.PUT_LINE(v_finaltxt);
   UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
   IF NOT v_samefile THEN
     UTL_FILE.FCLOSE(v_fh);
  END IF;
  
  -- This part outputs the DATA
  IF NOT v_samefile THEN
    v_fh := UTL_FILE.FOPEN(upper(p_dir),p_data_file,'w',32767);
  END IF;
  LOOP
    v_ret := DBMS_SQL.FETCH_ROWS(c);
    EXIT WHEN v_ret = 0;
    v_finaltxt := NULL;
    FOR j in 1..col_cnt
    LOOP
      CASE rec_tab(j).col_type
        WHEN 1 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_v_val);
                    v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
        WHEN 2 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_n_val);
                    v_finaltxt := ltrim(v_finaltxt||','||v_n_val,',');
        WHEN 12 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_d_val);
                 v_finaltxt := ltrim(v_finaltxt||','||to_char(v_d_val,'YYYY-MM-DD'||'-'||'HH24.MI.SS'));
              --   l,'DD/MM/YYYY HH24:MI:SS'),',');
      ELSE
        v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
      END CASE;
    END LOOP;
  --  DBMS_OUTPUT.PUT_LINE(v_finaltxt);
    UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
  END LOOP;
  UTL_FILE.FCLOSE(v_fh);
  DBMS_SQL.CLOSE_CURSOR(c);
END;
/