Files extended attributes (xattr)

Files’ metadata in UNIX-like systems.

• Some are not interpreted by kernels.

Linux: key-value pairs.

• Keys can be defined or undefined.

• If defined, their value can be empty or not.

• Key’s namespaces.

  • namespace.attr_name[.attr_name]

Namespaces.

• security

  • For files’ capabilities.

  • setcap / getcap.

• system

  • ACL

• trusted

  • Protected metadata

• user

  • setfattr / lsattr / getfattr