PHP System Constants

(1) __file__:p hp program file name. It can help us get the current file in the physical location of the server.

(2) __line__:P HP program file line number. It can tell us the current code in the first few lines.

(3) Php_version: The version number of the current parser. It can tell us the current PHP parser version number, we can know in advance whether our PHP code can be parsed by the PHP parser.

(4) Php_os: Executes the current PHP version of the operating system name. It can tell us the name of the operating system used by the server, and we can optimize our code based on the operating system.

PHP System Constants