=========================== 	Setup
ext2, ext3, reiser add user_xattr flag
/dev/hda1   /	ext3	defaults,noatime,user_xattr 0 1

setfattr, getfattr, and attr

setfattr -n user.testing -v "this is a test" test-1.txt
-n  specifies the name of the attribute
-v  value of the attribute

Period-delimited attribute namespaces are used to reduce naming conflicts. All
attributes explicitly added by users must be in the 'user' namespace, which is
why the attribute in the example is named 'user.testing'.

getfattr -n user.testing test-1.txt

# file: test-1.txt
user.testing="this is a test"
  
getfattr --only-values -n user.testing test-1.txt

To preserve the attributes for use in another system:
getfattr --dump * > data_file
setfattr --restore=data_file

=========================== 	Examples:
setfattr -n user.article.title -v "Innovations in Window Management"

article-commentary-wm_innovations.txt

---------   add an attribute to multiple files at once
setfattr -n user.article.author -v "Rafael" *.txt