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IRIX Base Documentation 1998 November
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IRIX 6.5.2 Base Documentation November 1998.img
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catman
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attr.z
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attr
Wrap
Text File
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1998-10-20
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7KB
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133 lines
aaaattttttttrrrr((((1111)))) aaaattttttttrrrr((((1111))))
NNNNAAAAMMMMEEEE
attr - manipulate Extended Attributes on filesystem objects
SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
aaaattttttttrrrr [ ----LLLLRRRRqqqq ] ----ssss aaaattttttttrrrrnnnnaaaammmmeeee [ ----VVVV aaaattttttttrrrrvvvvaaaalllluuuueeee ] ppppaaaatttthhhhnnnnaaaammmmeeee
aaaattttttttrrrr [ ----LLLLRRRRqqqq ] ----gggg aaaattttttttrrrrnnnnaaaammmmeeee ppppaaaatttthhhhnnnnaaaammmmeeee
aaaattttttttrrrr [ ----LLLLRRRRqqqq ] ----rrrr aaaattttttttrrrrnnnnaaaammmmeeee ppppaaaatttthhhhnnnnaaaammmmeeee
aaaattttttttrrrr [ ----LLLLRRRRqqqq ] ----llll ppppaaaatttthhhhnnnnaaaammmmeeee
OOOOVVVVEEEERRRRVVVVIIIIEEEEWWWW
Extended Attributes implement the ability for a user to attach name/value
pairs to objects within the filesystem. They are currently only
supported in XFS filesystems.
They could 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.
The _n_a_m_e_s 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 _v_a_l_u_e_s can be up to 256KB of arbitrary binary data.
Attributes can be attached to all types of inodes: regular files,
directories, symbolic links, device nodes, etc.
There are 2 disjoint attribute name spaces associated with every
filesystem object. They are the rrrrooooooootttt and uuuusssseeeerrrr address spaces. The rrrrooooooootttt
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 rrrrooooooootttt address space. The uuuusssseeeerrrr
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.
Attributes are currently supported only in the XFS filesystem type.
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
The _a_t_t_r utility allows the manipulation of Extended Attributes
associated with filesystem objects from within shell scripts.
There are four main operations that _a_t_t_r can perform:
GGGGEEEETTTT The ----gggg aaaattttttttrrrrnnnnaaaammmmeeee option tells _a_t_t_r to search the named object and
print (to _ssss_tttt_dddd_oooo_uuuu_tttt) the value associated with that attribute name.
With the ----qqqq flag, _ssss_tttt_dddd_oooo_uuuu_tttt will be exactly and only the value of the
PPPPaaaaggggeeee 1111
aaaattttttttrrrr((((1111)))) aaaattttttttrrrr((((1111))))
attribute, suitable for storage directly into a file or processing
via a piped command.
LLLLIIIISSSSTTTT The ----llll option tells _a_t_t_r 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 ----qqqq flag, _ssss_tttt_dddd_oooo_uuuu_tttt will be
a simple list of only the attribute names, one per line, suitable
for input into a script.
RRRREEEEMMMMOOOOVVVVEEEE
The ----rrrr aaaattttttttrrrrnnnnaaaammmmeeee option tells _a_t_t_r to remove an attribute with the
given name from the object if the attribute exists. There is no
output on sucessful completion.
SSSSEEEETTTT////CCCCRRRREEEEAAAATTTTEEEE
The ----ssss aaaattttttttrrrrnnnnaaaammmmeeee option tells _a_t_t_r to set the named attribute of the
object to the value read from _ssss_tttt_dddd_iiii_nnnn. 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 ----VVVV aaaattttttttrrrrvvvvaaaalllluuuueeee flag, the attribute will be
set to have a value of aaaattttttttrrrrvvvvaaaalllluuuueeee and _ssss_tttt_dddd_iiii_nnnn will not be read. With
the ----qqqq flag, _ssss_tttt_dddd_oooo_uuuu_tttt will not be used. Without the ----qqqq flag, a
message showing the attribute name and the entire value will be
printed.
When the ----LLLL 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 ----RRRR option is given and the process has appropriate privileges,
operate in the _r_o_o_t attribute namespace rather that the _U_S_E_R attribute
namespace.
When the ----qqqq option is given _a_t_t_r will try to keep quiet. It will output
error messages (to _ssss_tttt_dddd_eeee_rrrr_rrrr) but will not print status messages (to
_ssss_tttt_dddd_oooo_uuuu_tttt).
NNNNOOOOTTTTEEEESSSS
The standard file interchange/archive programs _t_a_r(1), _c_p_i_o(1), and
_b_r_u(1) will not archive or restore Extended Attributes, while the
_x_f_s_d_u_m_p(1m) program will.
SSSSEEEEEEEE AAAALLLLSSSSOOOO
attr_get(2), attr_getf(2), attr_list(2), attr_listf(2), attr_multi(2),
attr_multif(2), attr_remove(2), attr_removef(2), attr_set(2),
attr_setf(2), xfsdump(1m).
PPPPaaaaggggeeee 2222