Provided by: attr_2.4.46-5ubuntu1_amd64 bug

NAME

       attr - extended attributes on XFS filesystem objects

SYNOPSIS

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

       attr [ -LRSq ] -g attrname pathname

       attr [ -LRSq ] -r attrname pathname

       attr [ -LRSq ] -l pathname

OVERVIEW

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

       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  manipulation,  consult  the  getfattr(1)  and
       setfattr(1) documentation.

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

       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 argument 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 permissions 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.

       There are four main operations that attr can perform:

       GET    The  -g attrname option tells attr to search the named object and print (to stdout)
              the value associated with that attribute name.  With the -q flag,  stdout  will  be
              exactly  and  only the value of the attribute, suitable for storage directly into a
              file or processing via a piped command.

       LIST   The -l option tells attr  to  list  the  names  of  all  the  attributes  that  are
              associated  with  the object, and the number of bytes in the value of each of those
              attributes.  With the -q flag, stdout will be a simple list of only  the  attribute
              names, one per line, suitable for input into a script.

       REMOVE The  -r  attrname option tells attr to remove an attribute with the given name from
              the object if the attribute exists.  There is no output on sucessful completion.

       SET/CREATE
              The -s attrname option tells attr to set the named attribute of the object  to  the
              value  read  from  stdin.  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  stdin  will  not  be  read.
              With  the -q flag, stdout 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  symbolic  link,  operate  on  the
       attributes of the object referenced 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 appropriate  privileges,  operate  in  the
       root attribute namespace rather that the USER attribute namespace.

       The -S option is similar, except it specifies use of the security attribute namespace.

       When  the  -q  option is given attr will try to keep quiet.  It will output error messages
       (to stderr) but will not print status messages (to stdout).

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 command 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).