Visualizar uma trigger

Utilize a tabela TRIGGERS do INFORMATION_SCHEMA.

Exemplo:

mysql> delimiter |
mysql>
mysql> CREATE TRIGGER teste_trigger BEFORE INSERT ON teste
-> FOR EACH ROW BEGIN

 -> INSERT INTO test2 SET nome = NEW.nome;
 -> END;
 -> |

Query OK, 0 rows affected (0.00 sec)

mysql> \u information_schema

mysql> desc TRIGGERS;
+----------------------------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------------------------+--------------+------+-----+---------+-------+
| TRIGGER_CATALOG | varchar(512) | YES | | NULL | |
| TRIGGER_SCHEMA | varchar(64) | NO | | | |
| TRIGGER_NAME | varchar(64) | NO | | | |
| EVENT_MANIPULATION | varchar(6) | NO | | | |
| EVENT_OBJECT_CATALOG | varchar(512) | YES | | NULL | |
| EVENT_OBJECT_SCHEMA | varchar(64) | NO | | | |
| EVENT_OBJECT_TABLE | varchar(64) | NO | | | |
| ACTION_ORDER | bigint(4) | NO | | 0 | |
| ACTION_CONDITION | longtext | YES | | NULL | |
| ACTION_STATEMENT | longtext | NO | | NULL | |
| ACTION_ORIENTATION | varchar(9) | NO | | | |
| ACTION_TIMING | varchar(6) | NO | | | |
| ACTION_REFERENCE_OLD_TABLE | varchar(64) | YES | | NULL | |
| ACTION_REFERENCE_NEW_TABLE | varchar(64) | YES | | NULL | |
| ACTION_REFERENCE_OLD_ROW | varchar(3) | NO | | | |
| ACTION_REFERENCE_NEW_ROW | varchar(3) | NO | | | |
| CREATED | datetime | YES | | NULL | |
| SQL_MODE | longtext | NO | | NULL | |
| DEFINER | longtext | NO | | NULL | |
+----------------------------+--------------+------+-----+---------+-------+
19 rows in set (0.00 sec)

mysql> SELECT ACTION_STATEMENT FROM TRIGGERS;
+--------------------------------------------------------+
| ACTION_STATEMENT |
+--------------------------------------------------------+
| BEGIN

 INSERT INTO test2 SET nome = NEW.nome;
 END |

+--------------------------------------------------------+
1 row in set (0.00 sec)