Boolean-like values are evaluated as follows: "true", "on", "yes" evaluate to "1" (string 1), while "false", "off", "no" evaluate to "" (empty string).
(PHP 4, PHP 5, PHP 7)
get_cfg_var — 获取 PHP 配置选项的值
$option
) : string
获取 PHP 配置选项 option 的值。
此函数不会返回 PHP 编译的配置信息，或从 Apache 配置文件读取。
检查系统是否使用了一个配置文件，并尝试获取 cfg_file_path 的配置设置的值。 如果有效，将会使用一个配置文件。
option配置选项的名称。
返回 option 指定的当前 PHP 配置变量的值，错误发生时返回 FALSE。
| 版本 | 说明 |
|---|---|
| 5.3.0 | get_cfg_var() 被修复，能够返回 "array" 的 ini 选项。 |
Boolean-like values are evaluated as follows: "true", "on", "yes" evaluate to "1" (string 1), while "false", "off", "no" evaluate to "" (empty string).
keep in mind get_cfg_var() returns a string(1) '1' for the value: On
<?php
//in php.ini
//A = On
$A1 = get_cfg_var("A") === "On";
$A2 = get_cfg_var("A") === 1;
$A3 = get_cfg_var("A") === "1";
//$A1 is false
//$A2 is false
//$A3 is true
?>
The difference between ini_get() and get_cfg_var() is as follows:
@) ini_get(): returns the current value in .htaccess or as defined in PHP_INI_USER or PHP_INI_PERDIR
@) get_cfg_var: returns the values defined in the php.ini
settings with the value of 'yes' will be returned as '1'.
<?php
//#my ini file
//A = 1
//B = any-thing
//C = yes
//D = /some/path/file
get_cfg_var('A') // returns '1'
get_cfg_var('B') // returns 'any-thing'
get_cfg_var('C') // returns '1', wait, why?
get_cfg_var('D') // returns '/some/path/file'
?>
I had my setting = yes and then checked it as ==="yes" for epic fail.
Regarding the statement by the earlier poster that:
"Unfortunately, you almost never want to know the original value in the config file. Instead, you want to know the value currently in effect."
I have found this useful for changing the error reporting levels for a few specific pages while testing. I turn on all error_reporting while testing, but for a few pages I want to turn off notices. So, I put this at the top of the page:
<?php
error_reporting(8183);
?>
and this at the bottom:
<?php
error_reporting(get_cfg_var('error_reporting'));
?>
to put it back to whatever default I had at the time.
get_cfg_var returns the value from php.ini directly,while the ini_get returns the runtime config value. I have tried it on PHP 5.1.6
[EDIT by danbrown AT php DOT net: The author of this note means that ini_get() will return values set by ini_set(), .htaccess, a local php.ini file, and other functions at runtime. Conversely, get_cfg_var() will return strictly the server php.ini.]