Opens or reuses a connection to a MySQL server. The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling mysql_close().
The MySQL server. It can also include a port number. e.g. "hostname:port" or a path to a local socket e.g. ":/path/to/socket" for the localhost.
If the PHP directive mysql.default_host is undefined (default), then the default value is 'localhost:3306'
The username. Default value is the name of the user that owns the server process.
The password. Default value is an empty password.
If a second call is made to mysql_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned. The new_link parameter modifies this behavior and makes mysql_connect() always open a new link, even if mysql_connect() was called before with the same parameters.
The client_flags parameter can be a combination of the following constants: MYSQL_CLIENT_COMPRESS, MYSQL_CLIENT_IGNORE_SPACE or MYSQL_CLIENT_INTERACTIVE.
Note: Whenever you specify "localhost" or "localhost:port" as server, the MySQL client library will override this and try to connect to a local socket (named pipe on Windows). If you want to use TCP/IP, use "127.0.0.1" instead of "localhost". If the MySQL client library tries to connect to the wrong local socket, you should set the correct path as mysql.default_host in your PHP configuration and leave the server field blank.
Note: The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling mysql_close().
Note: You can suppress the error message on failure by prepending a @ to the function name.