(PECL xattr >= 0.9.0)
xattr_get — Get an extended attribute
$filename, string $name, int $flags = 0): stringThis function gets the value of an extended attribute of a file.
擴展的屬性有兩種 不同的命名空間：user
和 root。user 命名空間對所有用戶(hù)均有效，而 root
命名空間僅對擁有 root 權限的用戶(hù)有效。
xattr 默認在 user 命名空間上操作，但可使用
flags 參數進(jìn)行更改。
filenameThe file from which we get the attribute.
nameThe name of the attribute.
flags
XATTR_DONTFOLLOW |
Do not follow the symbolic link but operate on symbolic link itself. |
XATTR_ROOT |
Set attribute in root (trusted) namespace. Requires root privileges. |
Returns a string containing the value or false if the attribute doesn't
exist.
示例 #1 Checks if system administrator has signed the file
<?php
$file = '/usr/local/sbin/some_binary';
$signature = xattr_get($file, 'Root signature', XATTR_ROOT);
/* ... check if $signature is valid ... */
?>