(PHP 4, PHP 5)
ini_get — 获取一个配置选项的值
$varname
)成功时返回配置选项的值。
varname
配置选项名称。
成功是返回配置选项值的字符串,null 的值则返回空字符串。如果配置选项不存在,将会返回 FALSE
。
Example #1 一些 ini_get() 例子
<?php
/*
我们的 php.ini 包含了以下的设置:
display_errors = On
register_globals = Off
post_max_size = 8M
*/
echo 'display_errors = ' . ini_get('display_errors') . "\n";
echo 'register_globals = ' . ini_get('register_globals') . "\n";
echo 'post_max_size = ' . ini_get('post_max_size') . "\n";
echo 'post_max_size+1 = ' . (ini_get('post_max_size')+1) . "\n";
echo 'post_max_size in bytes = ' . return_bytes(ini_get('post_max_size'));
function return_bytes($val) {
$val = trim($val);
$last = strtolower($val[strlen($val)-1]);
switch($last) {
// 自 PHP 5.1.0 起可以使用修饰符 'G'
case 'g':
$val *= 1024;
case 'm':
$val *= 1024;
case 'k':
$val *= 1024;
}
return $val;
}
?>
以上例程的输出类似于:
display_errors = 1 register_globals = 0 post_max_size = 8M post_max_size+1 = 9 post_max_size in bytes = 8388608
Note: 当查询一个 boolean 值
一个 off 的 boolean ini 值将会以空字符串或者 "0" 返回;on 的 ini 值会以 "1" 返回。 此函数也会返回 INI 值的文字字符串。
Note: 当查询一个内存尺寸的值
许多内存尺寸的 ini 值,类似 upload_max_filesize 是以简写表示法储存在 php.ini 文件里。 ini_get() 会返回 php.ini 文件中储存的确切字符串,而不是它的等量 integer。 尝试对这些值使用常规算术运算函数将不会得到预期的结果。 以上例子显示了转换简写表示法为字节的一种方式,和 PHP 源码所做的比较像。
Dmitry Vinogradov (2012-08-02 21:06:04)
Here's more comprehensive function returning number of bytes from strings like max_post_size or upload_max_filesize. It handles both 'k'/'kb', 'm'/'mb', and 'g'/'gb' at the end of the string, and is case insensitive.
<?php
function return_bytes($val)
{
$val = trim($val);
switch (strtolower(substr($val, -1)))
{
case 'm': $val = (int)substr($val, 0, -1) * 1048576; break;
case 'k': $val = (int)substr($val, 0, -1) * 1024; break;
case 'g': $val = (int)substr($val, 0, -1) * 1073741824; break;
case 'b':
switch (strtolower(substr($val, -2, 1)))
{
case 'm': $val = (int)substr($val, 0, -2) * 1048576; break;
case 'k': $val = (int)substr($val, 0, -2) * 1024; break;
case 'g': $val = (int)substr($val, 0, -2) * 1073741824; break;
default : break;
} break;
default: break;
}
return $val;
}
?>
Ivo Mandalski (2011-11-15 08:27:52)
This version of return_bytes takes care of the MB, GB, KB cases along with the M,G,K ones.
Hope this is helpful!
<?php
public static function return_bytes ($val)
{
if(empty($val))return 0;
$val = trim($val);
preg_match('#([0-9]+)[\s]*([a-z]+)#i', $val, $matches);
$last = '';
if(isset($matches[2])){
$last = $matches[2];
}
if(isset($matches[1])){
$val = (int) $matches[1];
}
switch (strtolower($last))
{
case 'g':
case 'gb':
$val *= 1024;
case 'm':
case 'mb':
$val *= 1024;
case 'k':
case 'kb':
$val *= 1024;
}
return (int) $val;
}
?>
Stas Trefilov, OpteamIS (2010-03-26 10:08:06)
another version of return_bytes which returns faster and does not use multiple multiplications (sorry:). even if it is resolved at compile time it is not a good practice;
no local variables are allocated;
the trim() is omitted (php already trimmed values when reading php.ini file);
strtolower() is replaced by second case which wins us one more function call for the price of doubling the number of cases to process (may slower the worst-case scenario when ariving to default: takes six comparisons instead of three comparisons and a function call);
cases are ordered by most frequent goes first (uppercase M-values being the default sizes);
specs say we must handle integer sizes so float values are converted to integers and 0.8G becomes 0;
'Gb', 'Mb', 'Kb' shorthand byte options are not implemented since are not in specs, see
http://www.php.net/manual/en/faq.using.php#faq.using.shorthandbytes
<?php
function return_bytes ($size_str)
{
switch (substr ($size_str, -1))
{
case 'M': case 'm': return (int)$size_str * 1048576;
case 'K': case 'k': return (int)$size_str * 1024;
case 'G': case 'g': return (int)$size_str * 1073741824;
default: return $size_str;
}
}
?>
nicolas dot grekas+php at gmail dot com (2009-08-19 10:51:14)
Here is how to accurately test for boolean php.ini values:
<?php
function ini_get_bool($a)
{
$b = ini_get($a);
switch (strtolower($b))
{
case 'on':
case 'yes':
case 'true':
return 'assert.active' !== $a;
case 'stdout':
case 'stderr':
return 'display_errors' === $a;
default:
return (bool) (int) $b;
}
}
?>
Nathaniel Sabanski (2009-03-15 02:20:34)
Here's a simplified version of return_bytes() that does not rely on non-breaking cases and variable variables.
<?php
function return_bytes($val)
{
$val = trim($val);
$last = strtolower(substr($val, -1));
if($last == 'g')
$val = $val*1024*1024*1024;
if($last == 'm')
$val = $val*1024*1024;
if($last == 'k')
$val = $val*1024;
return $val;
}
?>
peter (2008-07-29 14:25:11)
The above example function called return_bytes() assumes that ini_get('upload_max_filesize') delivers only one letter at the end. As I've seen 'Mb' and things like that, I'd suggest to change the $last = ... part into $last = strtolower(substr($val,strlen($val/1),1)).
I'd call it $unit then.
filh at filh dot org (2005-11-21 06:24:55)
Concerning the value retourned, it depends on how you set it.
I had the problem with horde-3 which test the safe_mode value.
THan :
- if you set the value with php_admin_value safe_mode Off (or On) ini_get returns the string
- if you set the value with php_admin_flag safe_mode Off (or On) ini_get returns the boolean.
(2005-10-31 23:16:05)
Important: The manual says that ini_get will return 0 or an empty string for boolean config values that are set to off in php.ini.
This is technically correct, however when you use
php_value register_globals off
in an .htaccess file, ini_get will return the string, which will "evaluate" to 1. So if you are using mod_php you have to check boolean config values against the strings (upper/lowercase etc.) anyhow or you will get wrong results.
david dot tulloh at infaze dot com dot au (2005-06-21 19:01:37)
You can set custom entries in the ini file to provide globals such as database details.
However these must be retrieved with get_cfg_var, ini_get won't work.
Der Graph (2004-08-16 11:59:05)
It might be useful for included scripts that include other files to extend the 'include_path' variable:
<?php ini_set('include_path',ini_get('include_path').':../includes:'); ?>
Sometimes, it may also be useful to store the current 'include_path' in a variable, overwrite it, include, and then restore the old 'include_path'.
fbeyer at <nospam>clickhand dot de (2002-08-13 07:29:50)
If you want to test ini flags (eg. On/Off), I recommend to explicitly cast the value returned by ini_get() to boolean - it is cleaner as you only get true or false, not 0 or 1 or "" as described above.
<?php
$register_globals = (bool) ini_get('register_gobals');
?>
C fans may of course also cast it to (int) to play with 0 and 1 - that's also cleaner to print().