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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 filesys‐
tem 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 numnber 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 2018-02-02. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2018-01-21.) 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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