Why isn't my !include directive working in MySQL?

Question

I am experimenting with option files in MySQL. I have a ~/.my.cnf file which includes only the following:

!include /Users/myself/Workspace/project_time/mysql/foo.cnf

[client]
i_am_a_dummy

And I have a file /Users/myself/Workspace/project_time/mysql/foo.cnf which includes only the following:

[mysqld]
skip_column_names

I have newlines at the end of each file.

I also have a database, new_database, which includes a table t1.

I run MySQL with the command mysql -uroot -p new_database; and type in my password at the prompt, after which I see the MySQL prompt. When I type select * from t1; at the prompt, I would expect to see the output without headers, like so:

mysql> select * from t1;
+------+------+------+
| 2001 | 1    | 1    |
| 2001 | 1    | 20   |
| 2001 | 1    | 30   |
| 2001 | 2    | 2    |
| 2001 | 2    | 23   |
| 2001 | 2    | 23   |
+------+------+------+
6 rows in set (0.00 sec)

Unfortunately, instead I see the following:

mysql> select * from t1;
+------+-------+------+
| year | month | day  |
+------+-------+------+
| 2001 |     1 |    1 |
| 2001 |     1 |   20 |
| 2001 |     1 |   30 |
| 2001 |     2 |    2 |
| 2001 |     2 |   23 |
| 2001 |     2 |   23 |
+------+-------+------+
6 rows in set (0.00 sec)

I have already tried to use [client] as the option group in foo.cnf instead of [mysqld], but that did not work.

When I add skip_column_names directly to ~/.my.cnf (just below i_am_a_dummy), it works as expected.

What am I missing?

Answer 1

When I created foo.cnf, I set the permissions to 777. Apparently world-writable config files are ignored:

~/Workspace/project_time/mysql ()  $ mysql --print-defaults -uroot -p<secret> new_database;
mysql: [Warning] World-writable config file '/Users/myself/Workspace/project_time/mysql/foo.cnf' is ignored.
mysql would have been started with the following arguments:
--i_am_a_dummy -uroot -p<secret> new_database 

When I reset the permissions for foo.cnf to 755 and re-run the command, I get the following:

~/Workspace/project_time/mysql ()  $ chmod 755 foo.cnf 
~/Workspace/project_time/mysql ()  $ mysql --print-defaults -uroot -p<secret> new_database;
mysql would have been started with the following arguments:
--skip_column_names --i_am_a_dummy -uroot -p<secret> new_database 

And when I invoke the aforementioned SELECT statement in the CLI, it appears as expected:

mysql> select * from t1;
+------+------+------+
| 2001 | 1    | 1    |
| 2001 | 1    | 20   |
| 2001 | 1    | 30   |
| 2001 | 2    | 2    |
| 2001 | 2    | 23   |
| 2001 | 2    | 23   |
+------+------+------+
6 rows in set (0.00 sec)

EDIT: The warning is actually printed out even when not passing the --print-defaults flag, I just didn't notice it among the other output in the CLI. Since --print-defaults results in much less output on start-up, the warning was easier to notice.