xattr_get

(PECL)

xattr_get --  Get an extended attribute

说明

string xattr_get ( string filename, string name [, int flags] )

This function gets the value of an extended attribute of a file.

扩展的属性有两个不同的名字空间:user 和 root 名字空间。user 名字空间对所有用户均有效,而 root 名字空间仅对拥有 root 权限的用户有效。xattr 默认在 user 名字空间上进行操作,但是可以使用 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

表 1. 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

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 ... */

?>

参见

xattr_list()
xattr_set()
xattr_remove()