1ATTR_SET(3)                  XFS Compatibility API                 ATTR_SET(3)
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NAME

6       attr_set, attr_setf - set the value of a user attribute of a filesystem
7       object
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C SYNOPSIS

10       #include <attr/attributes.h>
11
12       int attr_set (const char *path, const char *attrname,
13                     const char *attrvalue, const int valuelength,
14                     int flags);
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16       int attr_setf (int fd, const char *attrname,
17                      const char *attrvalue, const int valuelength,
18                      int flags);
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DESCRIPTION

21       The attr_set and attr_setf functions provide a way to create attributes
22       and set/change their values.
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24       Path  points  to  a path name for a filesystem object, and fd refers to
25       the file descriptor associated with a file.  If the attribute  attrname
26       does not exist, an attribute with the given name and value will be cre‐
27       ated and associated with that indicated filesystem object.  If  an  at‐
28       tribute  with  that  name already exists on that filesystem object, the
29       existing value is replaced with the new value given in this call.   The
30       new  attribute value is copied from the attrvalue buffer for a total of
31       valuelength bytes.  The flags argument can contain the  following  sym‐
32       bols bitwise OR'ed together:
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34       ATTR_ROOT
35              Look for attrname in the root address space, not in the user ad‐
36              dress space.  (limited to use by super-user only)
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38       ATTR_DONTFOLLOW
39              Do not follow  symbolic  links  when  resolving  a  path  on  an
40              attr_set  function  call.   The  default  is  to follow symbolic
41              links.
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43       ATTR_CREATE
44              Return an error (EEXIST) if an attribute of the given  name  al‐
45              ready  exists on the indicated filesystem object, otherwise cre‐
46              ate an attribute with the given name and value.   This  flag  is
47              used  to  implement  a  pure create operation, without this flag
48              attr_set will create the attribute if it does not already exist.
49              An  error  (EINVAL)  will  be  returned  if both ATTR_CREATE and
50              ATTR_REPLACE are set in the same call.
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52       ATTR_REPLACE
53              Return an error (ENOATTR) if an attribute of the given name does
54              not  already exist on the indicated filesystem object, otherwise
55              replace the existing attribute´s value  with  the  given  value.
56              This  flag  is  used  to implement a pure replacement operation,
57              without this flag attr_set will create the attribute if it  does
58              not  already  exist.  An error (EINVAL) will be returned if both
59              ATTR_CREATE and ATTR_REPLACE are set in the same call.
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61       attr_set will fail if one or more of the following are true:
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63       [ENOATTR]        The attribute name given is not  associated  with  the
64                        indicated  filesystem object and the ATTR_REPLACE flag
65                        bit was set.
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67       [E2BIG]          The value of the given attribute is too large, it  ex‐
68                        ceeds  the  maximum  allowable  size  of  an attribute
69                        value.
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71       [EEXIST]         The attribute name given is  already  associated  with
72                        the  indicated  filesystem  object and the ATTR_CREATE
73                        flag bit was set.
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75       [ENOENT]         The named file does not exist.
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77       [EPERM]          The effective user ID does not match the owner of  the
78                        file and the effective user ID is not super-user.
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80       [ENOTDIR]        A component of the path prefix is not a directory.
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82       [EACCES]         Search permission is denied on a component of the path
83                        prefix.
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85       [EINVAL]         A bit was set in the flag argument that is not defined
86                        for  this  system  call,  or  both the ATTR_CREATE and
87                        ATTR_REPLACE flags bits were set.
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89       [EFAULT]         Path, attrname, or attrvalue points outside the  allo‐
90                        cated address space of the process.
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92       [ELOOP]          A path name lookup involved too many symbolic links.
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94       [ENAMETOOLONG]   The length of path exceeds {MAXPATHLEN}, or a pathname
95                        component is longer than {MAXNAMELEN}.
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97       attr_setf will fail if:
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99       [ENOATTR]      The attribute name given is not associated with the  in‐
100                      dicated  filesystem object and the ATTR_REPLACE flag bit
101                      was set.
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103       [E2BIG]        The value of the given attribute is too  large,  it  ex‐
104                      ceeds the maximum allowable size of an attribute value.
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106       [EEXIST]       The  attribute name given is already associated with the
107                      indicated filesystem object and the ATTR_CREATE flag bit
108                      was set.
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110       [EINVAL]       A  bit  was set in the flag argument that is not defined
111                      for this  system  call,  or  both  the  ATTR_CREATE  and
112                      ATTR_REPLACE  flags  bits  were  set,  or fd refers to a
113                      socket, not a file.
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115       [EFAULT]       Attrname, or attrvalue points outside the allocated  ad‐
116                      dress space of the process.
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118       [EBADF]        Fd does not refer to a valid descriptor.
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DIAGNOSTICS

121       On  success,  zero is returned.  On error, -1 is returned, and errno is
122       set appropriately.
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SEE ALSO

125       attr(1), attr_get(3), attr_list(3), attr_multi(3), attr_remove(3)
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129Dec 2001                      Extended Attributes                  ATTR_SET(3)
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