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NAME | C SYNOPSIS | DESCRIPTION | DIAGNOSTICS | SEE ALSO | COLOPHON |
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ATTR_GET(3) XFS Compatibility API ATTR_GET(3)
attr_get, attr_getf - get the value of a user attribute of a
filesystem object
#include <attr/attributes.h>
int attr_get (const char *path, const char *attrname,
char *attrvalue, int *valuelength, int flags);
int attr_getf (int fd, const char *attrname,
char *attrvalue, int *valuelength, int flags);
The attr_get and attr_getf functions provide a way to retrieve the
value of an attribute.
Path points to a path name for a filesystem object, and fd refers
to the file descriptor associated with a file. If the attribute
attrname exists, the value associated with it will be copied into
the attrvalue buffer. The valuelength argument is an input/output
argument that on the call to attr_get should contain the maximum
size of attribute value the process is willing to accept. On
return, the valuelength will have been modified to show the actual
size of the attribute value returned. The flags argument can
contain the following symbols bitwise OR'ed together:
ATTR_ROOT
Look for attrname in the root address space, not in the
user address space. (limited to use by super-user only)
ATTR_DONTFOLLOW
Do not follow symbolic links when resolving a path on an
attr_get function call. The default is to follow symbolic
links.
attr_get will fail if one or more of the following are true:
[ENOATTR]
The attribute name given is not associated with the
indicated filesystem object.
[E2BIG]
The value of the given attribute is too large to fit into
the buffer. The integer that the valuelength argument
points to has been modified to show the actual number of
bytes that would be required to store the value of that
attribute.
[ENOENT]
The named file does not exist.
[EPERM]
The effective user ID does not match the owner of the file
and the effective user ID is not super-user.
[ENOTDIR]
A component of the path prefix is not a directory.
[EACCES]
Search permission is denied on a component of the path
prefix.
[EINVAL]
A bit was set in the flag argument that is not defined for
this system call.
[EFAULT]
Path, attrname, attrvalue, or valuelength points outside
the allocated address space of the process.
[ELOOP]
A path name lookup involved too many symbolic links.
[ENAMETOOLONG]
The length of path exceeds {MAXPATHLEN}, or a pathname
component is longer than {MAXNAMELEN}.
attr_getf will fail if:
[ENOATTR]
The attribute name given is not associated with the
indicated filesystem object.
[E2BIG]
The value of the given attribute is too large to fit into
the buffer. The integer that the valuelength argument
points to has been modified to show the actual number of
bytes that would be required to store the value of that
attribute.
[EINVAL]
A bit was set in the flag argument that is not defined for
this system call, or fd refers to a socket, not a file.
[EFAULT]
Attrname, attrvalue, or valuelength points outside the
allocated address space of the process.
[EBADF]
Fd does not refer to a valid descriptor.
On success, zero is returned. On error, -1 is returned, and errno
is set appropriately.
attr(1), attr_list(3), attr_multi(3), attr_remove(3), attr_set(3)
This page is part of the attr (manipulating filesystem extended
attributes) project. Information about the project can be found
at ⟨http://savannah.nongnu.org/projects/attr⟩. If you have a bug
report for this manual page, see
⟨http://savannah.nongnu.org/bugs/?group=attr⟩. This page was
obtained from the project's upstream Git repository
⟨git://git.savannah.nongnu.org/attr.git⟩ on 2025-08-11. (At that
time, the date of the most recent commit that was found in the
repository was 2025-06-07.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Dec 2001 Extended Attributes ATTR_GET(3)
Pages that refer to this page: attr(1), attr_multi(3), attr_remove(3), attr_set(3)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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