预定义常量

下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。

XATTR_ROOT (int)

Set attribute in root (trusted) namespace. Requires root privileges.

XATTR_DONTFOLLOW (int)

Do not follow the symbolic link but operate on symbolic link itself.

XATTR_CREATE (int)

Function will fail if extended attribute already exists.

XATTR_REPLACE (int)

Function will fail if extended attribute doesn't exist.