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ATTR(1) 			      XFS Compatibility API				  ATTR(1)

       attr - extended attributes on XFS filesystem objects

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

       attr [ -LRSq ] -g attrname pathname

       attr [ -LRSq ] -r attrname pathname

       attr [ -LRSq ] -l pathname

       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  set-
       fattr(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,  sym-
       bolic 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 accessible  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.

       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  associ-
	      ated  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 successful completion.

	      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).

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

       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.

       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)
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