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

表格 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

例子 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()