This function sets the value of an extended attribute of a file.
扩展的属性有两个不同的命名空间: user 和 root 命名空间。User 命名空间对所有用户均有效,而 root 命名空间仅对拥有 root 权限的用户有效。xattr 默认在 user 命名空间上进行操作,但是您可以使用 flags 参数进行更改。
The file in which we set the attribute.
The name of the extended attribute. This attribute will be created if it doesn't exist or replaced otherwise. You can change this behaviour by using the flags parameter.
The value of the attribute.
表格 1. Supported xattr flags
XATTR_CREATE | Function will fail if extended attribute already exists. |
XATTR_REPLACE | Function will fail if extended attribute doesn't exist. |
XATTR_DONTFOLLOW | Do not follow the symbolic link but operate on symbolic link itself. |
XATTR_ROOT | Set attribute in root (trusted) namespace. Requires root privileges. |