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 $size_str;
}
}
?>
ini_get
(PHP 4, PHP 5, PHP 7, PHP 8)
ini_get — Restituisce il valore delle opzioni di configurazione
Descrizione
Restituisce il valore delle opzioni di configurazione. In caso di errore, tipo la richiesta per un valore inesistente, sarà restituita una stringa vuota.
Nota: Richieste per valori booleani
Nel file ini, il valore booleano
offsarà restituito come stringa vuota o "0", mentre il valoreonsarà restituito come "1".
Nota: Richieste per le dimensioni della memoria
Diversi parametri attinenti alle dimensioni di memoria, tipo upload_max_filesize sono registrati nel php.ini in notazione abbreviata. La funzione ini_get() restituirà l'esatto valore presente nel php.ini, e NON l'intero equivalente. L'esecuzione delle normali funzioni aritmetiche su questi valori potrà dare risultati inattesi. L'esempio seguente illustra come si possa convertire la notazione breve in byte in modo molto simile a come fa il PHP.
Example #1 Qualche esempio di ini_get()
<?php
/*
Il nostro php.ini contiene i seguenti parametri:
display_errors = On
register_globals = Off
post_max_size = 8M
*/
echo 'display_errors = ' . ini_get('display_errors') . "\n";
echo 'register_globals = ' . ini_get('register_globals') . "\n";
echo 'post_max_size = ' . ini_get('post_max_size') . "\n";
echo 'post_max_size+1 = ' . (ini_get('post_max_size')+1) . "\n";
echo 'post_max_size in bytes = ' . return_bytes(ini_get('post_max_size'));
function return_bytes($val) {
$val = trim($val);
$last = $val{strlen($val)-1};
switch($last) {
case 'k':
case 'K':
return (int) $val * 1024;
break;
case 'm':
case 'M':
return (int) $val * 1048576;
break;
default:
return $val;
}
}
?>Lo script produrrà:
display_errors = 1 register_globals = 0 post_max_size = 8M post_max_size+1 = 9 post_max_size in bytes = 8388608
Vedere anche: get_cfg_var(), ini_get_all(), ini_restore() e ini_set().
add a note
User Contributed Notes 12 notes
Stas Trefilov, OpteamIS ¶
14 years ago
IceNV ¶
7 years ago
Be aware that max_execution_time can be altered by XDebug.
While debugging a script locally that made use of <?php ini_get('max_execution_time'); ?> it returned 0 when XDebug remote debugging was enabled and the IDE was listening to it.
It makes sense, since debugging manually takes time so we don't want the script to time out ; but in that particular case, it made it look to the script like max_execution_time was 0, so calculations were wrong.
You can see in phpinfo() that local value is 0 in that case, but master value is the correct one you set in your php.ini.
devsrealmGuy ¶
3 years ago
Here is another way to get the result in bytes using PHP8
<?php
/**
* @param string $size
* @return int
* @author DevsrealmGuy
*/
public function getBytes(string $size): int
{
$size = trim($size);
#
# Separate the value from the metric(i.e MB, GB, KB)
#
preg_match('/([0-9]+)[\s]*([a-zA-Z]+)/', $size, $matches);
$value = (isset($matches[1])) ? $matches[1] : 0;
$metric = (isset($matches[2])) ? strtolower($matches[2]) : 'b';
#
# Result of $value multiplied by the matched case
# Note: (1024 ** 2) is same as (1024 * 1024) or pow(1024, 2)
#
$value *= match ($metric) {
'k', 'kb' => 1024,
'm', 'mb' => (1024 ** 2),
'g', 'gb' => (1024 ** 3),
't', 'tb' => (1024 ** 4),
default => 0
};
return (int)$value;
}
#
# TEST: This default to 0 if it doesn't conform with the match standard
#
echo getBytes('2GB') . "</br>";
# OUTPUT: 2147483648
echo getBytes('4tb') . "</br>";
# OUTPUT: 4398046511104
echo getBytes('5345etrgrfd') . "</br>";
# OUTPUT: 0
echo getBytes('357568336586') . "</br>";
# OUTPUT: 0
?>
filh at filh dot org ¶
18 years ago
Concerning the value retourned, it depends on how you set it.
I had the problem with horde-3 which test the safe_mode value.
THan :
- if you set the value with php_admin_value safe_mode Off (or On) ini_get returns the string
- if you set the value with php_admin_flag safe_mode Off (or On) ini_get returns the boolean.
Ivo Mandalski ¶
12 years ago
This version of return_bytes takes care of the MB, GB, KB cases along with the M,G,K ones.
Hope this is helpful!
<?php
public static function return_bytes ($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) $val;
}
?>
bishop@php ¶
9 years ago
Yet another implementation of return_bytes:
<?php
function return_bytes($val)
{
assert('1 === preg_match("/^\d+([kmg])?$/i", $val)');
static $map = array ('k' => 1024, 'm' => 1048576, 'g' => 1073741824);
return (int)$val * @($map[strtolower(substr($val, -1))] ?: 1);
}
?>
If you're using PHP >= 7, you might replace ?: with ?? to avoid the use of the @ silencer.
peter ¶
16 years ago
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 $unit then.
david dot tulloh at infaze dot com dot au ¶
19 years ago
You can set custom entries in the ini file to provide globals such as database details.
However these must be retrieved with get_cfg_var, ini_get won't work.
nicolas dot grekas+php at gmail dot com ¶
15 years ago
Here is how to accurately test for boolean php.ini values:
<?php
function ini_get_bool($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;
}
}
?>
Joe Huss detain at interserver dot net ¶
2 years ago
Here is a version combining a few of the examples here that does *not* require php8 nor does it generate a warning
/**
* gets the value in bytes converted from a human readable string like 10G'
*
* @param mixed $val the human readable/shorthand version of the value
* @return int the value converted to bytes
*/
function return_bytes($val) {
$val = trim($val);
preg_match('/([0-9]+)[\s]*([a-zA-Z]+)/', $val, $matches);
$value = (isset($matches[1])) ? intval($matches[1]) : 0;
$metric = (isset($matches[2])) ? strtolower($matches[2]) : 'b';
switch ($metric) {
case 'tb':
case 't':
$value *= 1024;
case 'gb':
case 'g':
$value *= 1024;
case 'mb':
case 'm':
$value *= 1024;
case 'kb':
case 'k':
$value *= 1024;
}
return $value;
}
Der Graph ¶
20 years ago
It might be useful for included scripts that include other files to extend the 'include_path' variable:
<?php ini_set('include_path',ini_get('include_path').':../includes:'); ?>
Sometimes, it may also be useful to store the current 'include_path' in a variable, overwrite it, include, and then restore the old 'include_path'.
bishop at php dot net ¶
9 years ago
In a similar vein, converting flags to booleans proper:
<?php
function return_boolean($val)
{
static $map = array ('on' => true, 'true' => true, 'off' => false, 'false' => false);
return @($map[strtolower($val)] ?: (bool)$val);
}
?>
If you're using PHP >= 7, consider replacing ?: with ?? and removing the @ silencer.
