{ "mode": "man", "parameter": "ATTR", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/ATTR/1/json", "generated": "2026-06-03T14:21:16Z", "synopsis": "attr [ -LRSq ] -s attrname [ -V attrvalue ] pathname\nattr [ -LRSq ] -g attrname pathname\nattr [ -LRSq ] -r attrname pathname\nattr [ -LRSq ] -l pathname", "sections": { "NAME": { "content": "attr - extended attributes on filesystem objects\n", "subsections": [] }, "SYNOPSIS": { "content": "attr [ -LRSq ] -s attrname [ -V attrvalue ] pathname\n\nattr [ -LRSq ] -g attrname pathname\n\nattr [ -LRSq ] -r attrname pathname\n\nattr [ -LRSq ] -l pathname\n\n", "subsections": [] }, "OVERVIEW": { "content": "Extended attributes implement the ability for a user to attach name:value pairs to objects\nwithin the filesystem.\n\nThis document describes the attr command, which is mostly compatible with the IRIX command of\nthe same name. It was originally aimed specifically at users of the XFS filesystem, even\nthough it can be used now on any filesystem that supports extended attributes, but for the\ngeneric and more portable interface for filesystem independent extended attribute manipula‐\ntion, consult the getfattr(1) and setfattr(1) documentation.\n\nExtended attributes can be used to store meta-information about the file. For example \"char‐\nacter-set=kanji\" could tell a document browser to use the Kanji character set when displaying\nthat document and \"thumbnail=...\" could provide a reduced resolution overview of a high reso‐\nlution graphic image.\n\nIn supported filesystems, the names can be up to 256 bytes in length, terminated by the first\n0 byte. The intent is that they be printable ASCII (or other character set) names for the\nattribute. The values can be up to 64KB of arbitrary binary data.\n\nAttributes can be attached to all types of inodes: regular files, directories, symbolic\nlinks, device nodes, etc.\n\nExtended attributes use 2 disjoint attribute name spaces associated with every filesystem ob‐\nject. They are the root and user address spaces. The root address space is accessible only\nto the superuser, and then only by specifying a flag argument to the function call. Other\nusers will not see or be able to modify attributes in the root address space. The user ad‐\ndress space is protected by the normal file permissions mechanism, so the owner of the file\ncan decide who is able to see and/or modify the value of attributes on any particular file.\n", "subsections": [] }, "DESCRIPTION": { "content": "The attr utility allows the manipulation of extended attributes associated with filesystem\nobjects from within shell scripts.\n\nThere are four main operations that attr can perform:\n\nGET The -g attrname option tells attr to search the named object and print (to ssttddoouutt) the\nvalue associated with that attribute name. With the -q flag, ssttddoouutt will be exactly\nand only the value of the attribute, suitable for storage directly into a file or pro‐\ncessing via a piped command.\n\nLIST The -l option tells attr to list the names of all the attributes that are associated\nwith the object, and the number of bytes in the value of each of those attributes.\nWith the -q flag, ssttddoouutt will be a simple list of only the attribute names, one per\nline, suitable for input into a script.\n\nREMOVE The -r attrname option tells attr to remove an attribute with the given name from the\nobject if the attribute exists. There is no output on successful completion.\n\nSET/CREATE\nThe -s attrname option tells attr to set the named attribute of the object to the\nvalue read from ssttddiinn. If an attribute with that name already exists, its value will\nbe replaced with this one. If an attribute with that name does not already exist, one\nwill be created with this value. With the -V attrvalue flag, the attribute will be\nset to have a value of attrvalue and ssttddiinn will not be read. With the -q flag, ssttddoouutt\nwill not be used. Without the -q flag, a message showing the attribute name and the\nentire value will be printed.\n\nWhen the -L option is given and the named object is a symbolic link, operate on the at‐\ntributes of the object referenced by the symbolic link. Without this option, operate on the\nattributes of the symbolic link itself.\n\nWhen the -R option is given and the process has appropriate privileges, operate in the root\nattribute namespace rather that the USER attribute namespace.\n\nThe -S option is similar, except it specifies use of the security attribute namespace.\n\nWhen the -q option is given attr will try to keep quiet. It will output error messages (to\nssttddeerrrr) but will not print status messages (to ssttddoouutt).\n", "subsections": [] }, "NOTES": { "content": "The standard file interchange/archive programs tar(1), and cpio(1) will not archive or re‐\nstore extended attributes, while the xfsdump(8) program will.\n", "subsections": [] }, "CAVEATS": { "content": "The list option present in the IRIX version of this command is not supported. getfattr pro‐\nvides a mechanism to retrieve all of the attribute names.\n", "subsections": [] }, "AUTHOR": { "content": "Andreas Gruenbacher, and the SGI XFS development team,\n.\n\nPlease send your bug reports or comments to or\n.\n", "subsections": [] }, "SEE ALSO": { "content": "getfattr(1), setfattr(1), attrget(3), attrset(3), attrmulti(3), attrremove(3), attr(5),\nxfsdump(8)\n\n\n\nDec 2001 Extended Attributes ATTR(1)", "subsections": [] } }, "summary": "attr - extended attributes on filesystem objects", "flags": [], "examples": [], "see_also": [ { "name": "getfattr", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/getfattr/1/json" }, { "name": "setfattr", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/setfattr/1/json" }, { "name": "attrget", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/attrget/3/json" }, { "name": "attrset", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/attrset/3/json" }, { "name": "attrmulti", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/attrmulti/3/json" }, { "name": "attrremove", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/attrremove/3/json" }, { "name": "attr", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/attr/5/json" }, { "name": "xfsdump", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/xfsdump/8/json" } ] }