To see all of the functions across all databases, use the SHOW FUNCTION STATUS command : Function Data Dictionary « Procedure Function « MySQL Tutorial

1. MySQL Tutorial
2. Procedure Function
3. Function Data Dictionary

\G switch from the mysql client utility to display the results in rows, rather than in columns.

mysql>
mysql> DELIMITER //
mysql>
mysql> CREATE FUNCTION myFunction (item_sum DECIMAL(10,2))
    -> RETURNS DECIMAL(10,1)
    -> BEGIN
    ->
    ->
    -> RETURN ROUND(item_sum,1);
    ->
    -> END
    -> //
Query OK, 0 rows affected (0.02 sec)

mysql> DELIMITER ;
mysql>
mysql> select myFunction(123.12);
+--------------------+
| myFunction(123.12) |
+--------------------+
|              123.1 |
+--------------------+
1 row in set (0.00 sec)

mysql>
mysql>
mysql> SHOW FUNCTION STATUS\G
*************************** 1. row ***************************
           Db: test
         Name: delivery_day_shipping
         Type: FUNCTION
      Definer: root@localhost
     Modified: 2007-07-23 17:17:21
      Created: 2007-07-23 17:17:21
Security_type: DEFINER
      Comment:
*************************** 2. row ***************************
           Db: test
         Name: myFunction
         Type: FUNCTION
      Definer: root@localhost
     Modified: 2007-07-23 18:58:39
      Created: 2007-07-23 18:58:39
Security_type: DEFINER
      Comment:
2 rows in set (0.01 sec)

mysql>
mysql>
mysql> drop function myFunction;
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql>