CLIV. xattr Functions

简介

The xattr extension allows for the manipulation of extended attributes on a filesystem.

需求

To use xattr, you will need libattr installed. It is available at http://oss.sgi.com/projects/xfs/.

注: These functions only work on filesystems that support extended attributes, and have them enabled at mount time. Some common filesystems that support extended attributes are ext2, ext3, reiserfs, jfs, and xfs.

安装

xattr is currently available through PECL http://pecl.php.net/package/xattr.

If PEAR is available on your *nix-like system you can use the pear installer to install the xattr extension, by the following command: pear -v install xattr.

You can always download the tar.gz package and install xattr by hand:
例子 1. xattr install by hand
gunzip xattr-xxx.tgz tar -xvf xattr-xxx.tar cd xattr-xxx phpize ./configure && make && make install

预定义常量

以下常量由本扩展模块定义，因此只有在本扩展模块被编译到 PHP 中，或者在运行时被动态加载后才有效。

XATTR_ROOT (integer): Set attribute in root (trusted) namespace. Requires root privileges.
XATTR_DONTFOLLOW (integer): Do not follow the symbolic link but operate on symbolic link itself.
XATTR_CREATE (integer): Function will fail if extended attribute already exists.
XATTR_REPLACE (integer): Function will fail if extended attribute doesn't exist.

目录
xattr_get -- Get an extended attribute
xattr_list -- Get a list of extended attributes
xattr_remove -- Remove an extended attribute
xattr_set -- Set an extended attribute
xattr_supported -- Check if filesystem supports extended attributes