apache_getenv(key) does not work on an php cgi installation, in this case rather use $_SERVER["REDIRECT_key"]
(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
apache_getenv — 获取 Apache subprocess_env 变量
$variable, bool $walk_to_top = false): string|false
获取 variable 指定的环境变量。
variableApache 环境变量
walk_to_top是否获取对Apache各层可用的顶层变量
成功时返回 Apache 环境变量值，失败时返回 false
示例 #1 apache_getenv() 示例
该示例显示如何取得 Apache 环境变量 SERVER_ADDR的值。
<?php
$ret = apache_getenv("SERVER_ADDR");
echo $ret;
?>以上示例的输出类似于：
42.24.42.240
apache_getenv(key) does not work on an php cgi installation, in this case rather use $_SERVER["REDIRECT_key"]This manual page is unclear as to whether it will fetch Apache configuration environment variables set by "SetEnv" (including "SetEnvIf[NoCase]" or "BrowserMatch" e.g.) as the only example given is with a pre-defined CGI interface variable (which is also available via the $_SERVER[] array). If custom Apache runtime configuration variables are indeed fetchable via this interface, let's say so or give an example of such.