Drupal 已经相当优雅地实现了这一点:
// Returns a file size limit in bytes based on the PHP upload_max_filesize
// and post_max_size
function file_upload_max_size() {
static $max_size = -1;
if ($max_size < 0) {
// Start with post_max_size.
$post_max_size = parse_size(ini_get('post_max_size'));
if ($post_max_size > 0) {
$max_size = $post_max_size;
}
// If upload_max_size is less, then reduce. Except if upload_max_size is
// zero, which indicates no limit.
$upload_max = parse_size(ini_get('upload_max_filesize'));
if ($upload_max > 0 && $upload_max < $max_size) {
$max_size = $upload_max;
}
}
return $max_size;
}
function parse_size($size) {
$unit = preg_replace('/[^bkmgtpezy]/i', '', $size); // Remove the non-unit characters from the size.
$size = preg_replace('/[^0-9\.]/', '', $size); // Remove the non-numeric characters from the size.
if ($unit) {
// Find the position of the unit in the ordered string which is the power of magnitude to multiply a kilobyte by.
return round($size * pow(1024, stripos('bkmgtpezy', $unit[0])));
}
else {
return round($size);
}
}
以上功能可在 Drupal 的任何地方使用,或者您可以将其复制并在自己的项目中使用,但须遵守 GPL 许可协议第2版或更高版本的条款。
至于您提问的第二部分和第三部分,您需要直接解析 php.ini
文件。这些基本上是配置错误,而 PHP 正在采用后备行为。看起来您实际上可以在 PHP 中获取已加载的 php.ini
文件位置,尽管尝试从中读取可能无法与 basedir 或 safe-mode 启用一起工作:
$max_size = -1;
$post_overhead = 1024; // POST data contains more than just the file upload; see comment from @jlh
$files = array_merge(array(php_ini_loaded_file()), explode(",\n", php_ini_scanned_files()));
foreach (array_filter($files) as $file) {
$ini = parse_ini_file($file);
$regex = '/^([0-9]+)([bkmgtpezy])$/i';
if (!empty($ini['post_max_size']) && preg_match($regex, $ini['post_max_size'], $match)) {
$post_max_size = round($match[1] * pow(1024, stripos('bkmgtpezy', strtolower($match[2])));
if ($post_max_size > 0) {
$max_size = $post_max_size - $post_overhead;
}
}
if (!empty($ini['upload_max_filesize']) && preg_match($regex, $ini['upload_max_filesize'], $match)) {
$upload_max_filesize = round($match[1] * pow(1024, stripos('bkmgtpezy', strtolower($match[2])));
if ($upload_max_filesize > 0 && ($max_size <= 0 || $max_size > $upload_max_filesize) {
$max_size = $upload_max_filesize;
}
}
}
echo $max_size;
(int)ini_get("upload_max_filesize")*1024
将其转换为KB。例如,2M -> 2048。 - Afraz Ahmad