xattr extension allows to manipulate extended attributes on filesystems that support them.
To use xattr, you will need libattr installed, available
on the Linux XFS homepage ftp://oss.sgi.com/projects/xfs/download.
xattr is currently available through PECL
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:
Example 1. xattr install by hand
tar -xvf xattr-xxx.tar
./configure && make && make install
The constants below are defined by this extension, and
will only be available when the extension has either
been compiled into PHP or dynamically loaded at runtime.