How to execute a procedure and function at command line?

Question

I tried to execute the following function at command line.
CREATE OR REPLACE FUNCTION FN_IS_SYSDATE_TICKING
RETURN BOOLEAN
IS
ls_value     VARCHAR2(100) DEFAULT 'NONE';
BEGIN
SELECT value
INTO ls_value
FROM V$PARAMETER
WHERE name = 'fixed_date';
IF ls_value = 'NONE' THEN
RETURN TRUE;
ELSE
RETURN FALSE;
END IF;
EXCEPTION
WHEN OTHERS THEN
RETURN TRUE;
END FN_IS_SYSDATE_TICKING();
At Command Line, I entered
var v1 BOOLEAN;
exec :v1 := RSSC.FN_IS_SYSDATE_TICKING();
print v1;
It is giving boolean is not declared.

Answer 1

Works for me:
SQL> CREATE OR REPLACE FUNCTION FN_IS_SYSDATE_TICKING RETURN VARCHAR2
  2  IS
  3    ls_value VARCHAR2(100) DEFAULT 'NONE';
  4  BEGIN
  5    SELECT value
  6      INTO ls_value
  7      FROM V$PARAMETER
  8     WHERE name = 'fixed_date'
  9    ;
10    IF ls_value = 'NONE'
11    THEN
12      RETURN 'TRUE';
13    ELSE
14      RETURN 'FALSE';
15    END IF;
16  EXCEPTION
17  WHEN OTHERS THEN
18    RETURN 'TRUE';
19  END FN_IS_SYSDATE_TICKING;
20  /
Functie is aangemaakt.
SQL> var v1 varchar2(5);
SQL> exec :v1 := FN_IS_SYSDATE_TICKING;
PL/SQL-procedure is geslaagd.
SQL> print v1;
V1
FALSE{code}Note that I had to specify a length for the varchar2.
Regards,
Rob.