xattr_get
(PECL xattr >= 0.9.0)
xattr_get — Get an extended attribute
说明
xattr_get
( string
$filename
, string $name
[, int $flags = 0
] ) : stringThis function gets the value of an extended attribute of a file.
扩展的属性有两种 不同的命名空间：user
和 root。user 命名空间对所有用户均有效，而 root
命名空间仅对拥有 root 权限的用户有效。
xattr 默认在 user 命名空间上操作，但可使用
flags 参数进行更改。
参数
-
filename -
The file from which we get the attribute.
-
name -
The name of the attribute.
-
flags -
Supported xattr flags XATTR_DONTFOLLOWDo not follow the symbolic link but operate on symbolic link itself. XATTR_ROOTSet attribute in root (trusted) namespace. Requires root privileges.
返回值
Returns a string containing the value or FALSE if the attribute doesn't
exist.
范例
Example #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 ... */
?>
参见
- xattr_list() - Get a list of extended attributes
- xattr_set() - Set an extended attribute
- xattr_remove() - Remove an extended attribute