Doubts on the trimed Spaces

I am using Pro*C for Oracle8.1.7

I have a doubt on Varchar2 column :
Describing emp....
NAME Null? Type
------------------------------- --------- -----
EMPNO NOT NULL NUMBER(4,0)
ENAME VARCHAR2(10)

But the ENAME stores only 5 chars

In .PC file

typedef char asciiz[11];

EXEC SQL TYPE asciiz IS CHARZ(11) REFERENCE;

struct emp_info
{
asciie emp_name;
float salary;
float commission;
};
...
EXEC SQL DECLARE salespeople CURSOR FOR
SELECT RTRIM(ENAME), SAL, COMM
FROM EMP
WHERE JOB LIKE 'SALES%';
.......

for (;;)
{
EXEC SQL FETCH salespeople INTO :emp_rec_ptr;
printf("%s %9.2f %12.2f\n", emp_rec_ptr->emp_name,
emp_rec_ptr->salary, emp_rec_ptr->commission);
printf("length (name) = %d \n",strlen(emp_rec_ptr->emp_name));
}

It shows the length of emp_name is 10 ( right padded space )

Why it happens like that ?