Ways to prevent direct access to or view or download config.php files in php _php tips

Or, does the design of PHP itself avoid directly viewing the contents of a file? From a security standpoint, what protection does this system-level file have to do?
The answer of Perfect netizen
After investigation, the following common methods are obtained:

1 Define an identity variable in the program

Copy Code code as follows:

Define (' In_sys ', TRUE);

2 Get this variable in the config.php

Copy Code code as follows:

if (!defined (' In_sys ')) {
Exit (' no access ');
}