php用ini_get获取php.ini里变量值的方法

string ini_get ( string varname )

<?php
/
Our php.ini contains the following settings:
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) {
    // The 'G' modifier is available since PHP 5.1.0
    case 'g':
      $val = 1024;
    case 'm':
      $val = 1024;
    case 'k':
      $val = 1024;
  }
  return $val;
}
?>

display_errors = 1
register_globals = 0
post_max_size = 8M
post_max_size+1 = 9
post_max_size in bytes = 8388608

<?php
print_r(ini_get_all("pcre"));
print_r(ini_get_all());
?>

Array
(
  [pcre.backtrack_limit] => Array
    (
      [global_value] => 100000
      [local_value] => 100000
      [aess] => 7
    )
  [pcre.recursion_limit] => Array
    (
      [global_value] => 100000
      [local_value] => 100000
      [aess] => 7
    )
)
Array
(
  [allow_call_time_pass_reference] => Array
    (
      [global_value] => 0
      [local_value] => 0
      [aess] => 6
    )
  [allow_url_fopen] => Array
    (
      [global_value] => 1
      [local_value] => 1
      [aess] => 4
    )
  ...
)

<?php
print_r(ini_get_all("pcre", false)); // Added in PHP 5.3.0
print_r(ini_get_all(null, false)); // Added in PHP 5.3.0
?>

Array
(
  [pcre.backtrack_limit] => 100000
  [pcre.recursion_limit] => 100000
)
Array
(
  [allow_call_time_pass_reference] => 0
  [allow_url_fopen] => 1
  ...
)