## SYNOPSIS

           attr [ -LRq ] -s attrname [ -V attrvalue ] pathname

           attr [ -LRq ] -g attrname pathname

           attr [ -LRq ] -r attrname pathname

## OVERVIEW

           Extended  attributes  implement  the ability for a user to
           attach name:value pairs to objects within the XFS filesys
           tem.

           They  could  be  used  to store meta-information about the
           file.  For example "character-set=kanji" could tell a doc
           ument browser to use the Kanji character set when display
           ing that document  and  "thumbnail=..."  could  provide  a
           reduced  resolution  overview of a high resolution graphic
           image.

           This document describes the attr command, which is  mostly
           compatible  with the IRIX command of the same name.  It is
           thus aimed specifically at users of the XFS  filesystem  -
           for  filesystem  independent  extended attribute manipula
           tion, consult the getfattr(1) and  setfattr(1)  documenta
           tion.

           In the XFS filesystem, the names can be up to 256 bytes in
           length, terminated by the first 0  byte.   The  intent  is
           that  they  be  printable  ASCII  (or other character set)
           names for the attribute.  The values can be up to 64KB  of
           arbitrary binary data.

           Attributes  can  be  attached  to all types of XFS inodes:
           regular files, directories, symbolic links, device  nodes,
           etc.

           XFS  uses 2 disjoint attribute name spaces associated with
           every filesystem object.   They  are  the  root  and  user
           address spaces.  The root address space is accessable only
           to the superuser, and then only by specifying a flag argu
           ment to the function call.  Other users will not see or be
           able to modify attributes in the root address space.   The
           user address space is protected by the normal file permis
           sions mechanism, so the owner of the file can  decide  who
           is  able  to  see and/or modify the value of attributes on
           any particular file.

## DESCRIPTION

           The attr  utility  allows  the  manipulation  of  extended
           attributes  associated with filesystem objects from within
           shell scripts.

           SET/CREATE
                  The -s attrname option tells attr to set the  named
                  attribute  of  the  object  to  the value read from
                  s</I<B>st</I<B>td</I<B>di</I<B>in</I<B>n.  If an  attribute  with  that  name  already
                  exists,  its  value will be replaced with this one.
                  If an attribute with that  name  does  not  already
                  exist,  one  will be created with this value.  With
                  the -V attrvalue flag, the attribute will be set to
                  have  a  value  of  attrvalue and s</I<B>st</I<B>td</I<B>di</I<B>in</I<B>n will not be
                  read.  With the -q flag, s</I<B>st</I<B>td</I<B>do</I<B>ou</I<B>ut</I<B>t will not  be  used.
                  Without   the   -q  flag,  a  message  showing  the
                  attribute  name  and  the  entire  value  will   be
                  printed.

           When the -L option is given and the named object is a sym
           bolic link, operate on the attributes of the object refer
           enced  by the symbolic link.  Without this option, operate
           on the attributes of the symbolic link itself.

           When the -R option is given and the process has  appropri
           ate  privileges,  operate  in the root attribute namespace
           rather that the USER attribute namespace.

           When the -q option is given attr will try to  keep  quiet.
           It  will  output  error  messages (to s</I<B>st</I<B>td</I<B>de</I<B>er</I<B>rr</I<B>r) but will not
           print status messages (to s</I<B>st</I<B>td</I<B>do</I<B>ou</I<B>ut</I<B>t).

## NOTES

           The standard file interchange/archive programs tar(1), and
           cpio(1)  will  not archive or restore extended attributes,
           while the xfsdump(8) program will.

## CAVEATS

           The list option present in the IRIX version of  this  com
           mand  is  not supported.  getfattr provides a mechanism to
           retrieve all of the attribute names.

## SEE ALSO

           getfattr(1),   setfattr(1),   attr_get(3),    attr_set(3),
           attr_multi(3), attr_remove(3), attr(5), and xfsdump(8).

    Dec 2001               Extended Attributes                ATTR(1)