1ATTR_SET(3) XFS Compatibility API ATTR_SET(3)
2
6 attr_set, attr_setf - set the value of a user attribute of a filesystem
7 object
8
10 #include <attr/attributes.h>
11 int attr_set (const char *path, const char *attrname,
13 const char *attrvalue, const int valuelength,
14 int flags);
15 int attr_setf (int fd, const char *attrname,
17 const char *attrvalue, const int valuelength,
18 int flags);
19
21 The attr_set and attr_setf functions provide a way to create attributes
22 and set/change their values.
23 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:
33 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)
37 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.
42 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.
51 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.
60 attr_set will fail if one or more of the following are true:
62 [ENOATTR] The attribute name given is not associated with the
64 indicated filesystem object and the ATTR_REPLACE flag
65 bit was set.
66 [E2BIG] The value of the given attribute is too large, it ex‐
68 ceeds the maximum allowable size of an attribute
69 value.
70 [EEXIST] The attribute name given is already associated with
72 the indicated filesystem object and the ATTR_CREATE
73 flag bit was set.
74 [ENOENT] The named file does not exist.
76 [EPERM] The effective user ID does not match the owner of the
78 file and the effective user ID is not super-user.
79 [ENOTDIR] A component of the path prefix is not a directory.
81 [EACCES] Search permission is denied on a component of the path
83 prefix.
84 [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.
88 [EFAULT] Path, attrname, or attrvalue points outside the allo‐
90 cated address space of the process.
91 [ELOOP] A path name lookup involved too many symbolic links.
93 [ENAMETOOLONG] The length of path exceeds {MAXPATHLEN}, or a pathname
95 component is longer than {MAXNAMELEN}.
96 attr_setf will fail if:
98 [ENOATTR] The attribute name given is not associated with the in‐
100 dicated filesystem object and the ATTR_REPLACE flag bit
101 was set.
102 [E2BIG] The value of the given attribute is too large, it ex‐
104 ceeds the maximum allowable size of an attribute value.
105 [EEXIST] The attribute name given is already associated with the
107 indicated filesystem object and the ATTR_CREATE flag bit
108 was set.
109 [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.
114 [EFAULT] Attrname, or attrvalue points outside the allocated ad‐
116 dress space of the process.
117 [EBADF] Fd does not refer to a valid descriptor.
119
121 On success, zero is returned. On error, -1 is returned, and errno is
122 set appropriately.
123
125 attr(1), attr_get(3), attr_list(3), attr_multi(3), attr_remove(3)
126Dec 2001 Extended Attributes ATTR_SET(3)