How to set MySQL session wait_timeout from the command line?

As you can see from the output below, I'm using the MySQL shell to change the session's wait_timeout variable to 30 seconds. It works.

However, Is there anyway to set this variable from the command line?

$ mysql -u root -h 127.0.0.1 -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 48543
Server version: 5.6.39 MySQL Community Server (GPL)

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mysql> SHOW SESSION VARIABLES LIKE 'wait_timeout';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wait_timeout  | 28800 |
+---------------+-------+
1 row in set (0.00 sec)

mysql> SET session wait_timeout=30;
Query OK, 0 rows affected (0.00 sec)

mysql> SHOW SESSION VARIABLES LIKE 'wait_timeout';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wait_timeout  | 30    |
+---------------+-------+
1 row in set (0.00 sec)

mysql> select now() from dual;
+---------------------+
| now()               |
+---------------------+
| 2018-01-23 17:16:52 |
+---------------------+
1 row in set (0.00 sec)

mysql> select now() from dual;
ERROR 2013 (HY000): Lost connection to MySQL server during query