PHP - Manual: $_ENV

2024-11-22

$_ENV

$_ENV — 环境变量

说明

通过环境方式传递给当前脚本的变量的数组。

这些变量被从 PHP 解析器的运行环境导入到 PHP 的全局命名空间。很多是由支持 PHP 运行的 Shell 提供的，并且不同的系统很可能运行着不同种类的 Shell，所以不可能有一份确定的列表。请查看你的 Shell 文档来获取定义的环境变量列表。

其他环境变量包含了 CGI 变量，而不管 PHP 是以服务器模块还是 CGI 处理器的方式运行。

范例

示例 #1 $_ENV 范例


<?php
echo 'My username is ' .$_ENV["USER"] . '!';
?>

假设 "bjori" 运行此段脚本

以上例程的输出类似于：

My username is bjori!

注释

注意:
“Superglobal”也称为自动化的全局变量。这就表示其在脚本的所有作用域中都是可用的。不需要在函数或方法中用 global $variable; 来访问它。

参见

getenv() - 获取一个环境变量的值
过滤器扩展

add a note

User Contributed Notes 10 notes

down

133

gabe-php at mudbugmedia dot com ¶

12 years ago


If your $_ENV array is mysteriously empty, but you still see the variables when calling getenv() or in your phpinfo(), check your http://us.php.net/manual/en/ini.core.php#ini.variables-order ini setting to ensure it includes "E" in the string.

down

david at davidfavor dot com ¶

10 years ago


Comments for this page seem to indicate getenv() returns environment variables in all cases.

For getenv() to work, php.ini variables_order must contain 'E'.

down

aasasdasdf at yandex dot ru ¶

8 years ago


Please note that writing to $_ENV does not actually set an environment variable, i.e. the variable will not propagate to any child processes you launch (except forked script processes, in which case it's just a variable in the script's memory). To set real environment variables, you must use putenv().

Basically, setting a variable in $_ENV does not have any meaning besides setting or overriding a script-wide global variable. Thus, one should never modify $_ENV except for testing purposes (and then be careful to use putenv() too, if appropriate).

PHP  will not trigger any kind of error or notice when writing to $_ENV.

down

anonymous ¶

11 years ago


If $_ENV is empty because variables_order does not include it, it will be filled with values fetched by getenv().

For example, when calling getenv("REMOTE_ADDR"), $_ENV['REMOTE_ADDR'] will be defined as well (if such an environment variable exists).

down

php at isnoop dot net ¶

12 years ago


If you wish to define an environment variable in your Apache vhost file, use the directive SetEnv.

SetEnv varname "variable value"

It is important to note that this new variable will appear in $_SERVER, not $_ENV.

down

Andrew @ Island Architectural Woodwork ¶

6 months ago


When placing the environment variables in the httpd.conf file of my Apache server, I can access those variables by using getenv(). When I use $_ENV[] or $_SERVER[], they are not accessible. Inside my php.ini file, the variables-order property is configured with 'E' included; noted by other users.

When placing the environment variables in the httpd-vhosts.conf file of my Apache server, I can access those variables by using getenv(), as well as $_SERVER[]. Using $_ENV[] still does not work for me. Calling getenv() before $_ENV[] didn't seem to work either.

$_SERVER[] will remain as my solution.

down

-3

Tit Petric ¶

5 years ago


If you're using php-fpm you might want to set `clean_env = no`. This setting cleans the environment variables by default, meaning that PHP would be started with a clean environment.

down

-7

kobenews at cox dot net ¶

4 years ago


If running php-fpm with the default production variables_order = GPCS, $_ENV will always be an empty array. Instead of reading the superglobal $_ENV use the built-in function getenv() or read from $_SERVER['ENV-KEY-HERE'].

down

-16

Guy ¶

4 years ago


@Tit Petric - I believe you meant: clear_env=no

not clean_env

Set the above in your PHP-FPM config to prevent clearing ENV vars

down

-64

ewilde aht bsmdevelopment dawt com ¶

13 years ago


When running a PHP program under the command line, the $_SERVER["SERVER_NAME"] variable does not contain the hostname. However, the following works for me under Unix/Linux and Windows:


<?php

if (isset($_ENV["HOSTNAME"]))

    $MachineName = $_ENV["HOSTNAME"];

else if  (isset($_ENV["COMPUTERNAME"]))

    $MachineName = $_ENV["COMPUTERNAME"];

else $MachineName = "";

?>

add a note

官方地址：https://www.php.net/manual/en/reserved.variables.environment.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络 JAVA NoSQL 数据库面试 C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet ADORecordSet对象 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 adodb手册 opcache预加载 Composer的Packagist资源 mysql面试题 php中几种注释规范 php 修改图片大小 PHP获取指定函数定义在哪个文件中及行号 PHP7 mcrypt替代方案 Packagist / Composer 中国全量镜像 laravel框架查看sql语句方式利用php soap实现web service

略微加速

PHP官方手册 - 互联网笔记

$_ENV

说明

范例

注释

参见

User Contributed Notes 10 notes