How do I determine the length of a column?

Question

Does anyone know how to determine the length of an Oracle column through sql statements? I know in SQL Server you can use the COL_LENGTH function to find the maximum length for a particular column, but I haven't been able to find an equivalent for Oracle.
We have a column in a database that is a VARCHAR2 and can be any szie from 64 to 255 characters. I need to determine on the fly from a running client application what size the column is in the current database.
Thank you very much for any help you can give me.

Answer 1

select data_length from user_tab_columns
where table_name='YOUR_TABLE' and column_name='YOUR_COLUMN';
if you want function to return this value, create function like below..
create or replace function col_len(t varchar2,c varchar2)
return number is
n number;
begin
select data_length into n from user_tab_columns
where table_name=upper(t) and column_name=upper(c);
return n;
exception
when others then
return 0;
end;
/