What does the e flag and special characters do in mysql?

Question

I am studying mysql from http://dev.mysql.com/doc/refman/5.7/en/batch-mode.html . On second paragraph it says:

If you are running mysql under Windows and have some special characters in the file that cause problems, you can do this:

C:\> mysql -e "source batch-file"

• What are special characters? If I save a file in notepad, would there be automatic special characters saved in the file? How to know whether they are there or not? Are they hidden?

• What would the -e flag do? Where can I find its explanation in mysql documentation?

Answer 1

-e is actually short for --execute, that's probably why you had trouble finding it. http://dev.mysql.com/doc/refman/5.7/en/mysql-command-options.html#option_mysql_execute

Execute the statement and quit. The default output format is like that produced with --batch. See Section 5.2.4, “Using Options on the Command Line”, for some examples. With this option, mysql does not use the history file.

A special charater is something that needs to be escaped in an SQL query. You will know when you run into them because mysql will produce errors.