Extended file attributes linux

https://en.wikipedia.org/wiki/Extended_file_attributes

Are not commonly used by user-space Linux programs
( used by Beagle, OpenStack Swift, Dropbox, KDE’s semantic metadata framework (Baloo), Chromium, Wget , cURL )

The Linux kernel allows extended attribute to have names of up to 255 bytes and values of up to 64 KiB
XFS and ReiserFS do this.
ext2/3/4 and btrfs impose much smaller limits, requiring all the attributes (names and values) of one file to fit in one “filesystem block” (usually 4 KiB).

As per POSIX.1e, the attribute names are required to start with 1 of these 4 :
- security
- system
- trusted
- user
followed by a period
These 4 defines the four namespaces of extended attributes.

so , if you want to add a extended attr “genre” , the attr name become s: “user.genre”

tools

zie linux tools for extended attributes
file mgr’s that support ext. attributes : caja & (dolphin)[[review-file-managers#4.Dolphin]] (KDE)