php 信息

PHP_VERSION  常量 显示出当前Php版本  同 phpversion（）函数功能相同

phpinfo()函数 可以带个int类型的参数

以下来源PHP手册： 

bool phpinfo ( [int what] )
Name (constant) Value Description

INFO_GENERAL	1	The configuration line, php.ini location, build date, Web Server, System and more.
INFO_CREDITS	2	PHP Credits. See also phpcredits().
INFO_CONFIGURATION	4	Current Local and Master values for PHP directives. See also ini_get().
INFO_MODULES	8	Loaded modules and their respective settings. See also get_loaded_extensions().
INFO_ENVIRONMENT	16	Environment Variable information that's also available in $_ENV.
INFO_VARIABLES	32	Shows all predefined variables from EGPCS (Environment, GET, POST, Cookie, Server).
INFO_LICENSE	64	PHP License information. See also the license FAQ.
INFO_ALL	-1	Shows all of the above. This is the default value.