attr_set(3) — Linux manual page

NAME | C SYNOPSIS | DESCRIPTION | DIAGNOSTICS | SEE ALSO | COLOPHON

ATTR_SET(3)               XFS Compatibility API              ATTR_SET(3)

NAME         top

       attr_set, attr_setf - set the value of a user attribute of a
       filesystem object

C SYNOPSIS         top

       #include <attr/attributes.h>

       int attr_set (const char *path, const char *attrname,
                     const char *attrvalue, const int valuelength,
                     int flags);

       int attr_setf (int fd, const char *attrname,
                      const char *attrvalue, const int valuelength,
                      int flags);

DESCRIPTION         top

       The attr_set and attr_setf functions provide a way to create
       attributes and set/change their values.

       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 does not exist, an attribute with the given name and
       value will be created and associated with that indicated
       filesystem object.  If an attribute with that name already exists
       on that filesystem object, the existing value is replaced with
       the new value given in this call.  The new attribute value is
       copied from the attrvalue buffer for a total of valuelength
       bytes.  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_set function call.  The default is to follow symbolic
              links.

       ATTR_CREATE
              Return an error (EEXIST) if an attribute of the given name
              already exists on the indicated filesystem object,
              otherwise create an attribute with the given name and
              value.  This flag is used to implement a pure create
              operation, without this flag attr_set will create the
              attribute if it does not already exist.  An error (EINVAL)
              will be returned if both ATTR_CREATE and ATTR_REPLACE are
              set in the same call.

       ATTR_REPLACE
              Return an error (ENOATTR) if an attribute of the given
              name does not already exist on the indicated filesystem
              object, otherwise replace the existing attribute´s value
              with the given value.  This flag is used to implement a
              pure replacement operation, without this flag attr_set
              will create the attribute if it does not already exist.
              An error (EINVAL) will be returned if both ATTR_CREATE and
              ATTR_REPLACE are set in the same call.

       attr_set will fail if one or more of the following are true:

       [ENOATTR]
              The attribute name given is not associated with the
              indicated filesystem object and the ATTR_REPLACE flag bit
              was set.

       [E2BIG]
              The value of the given attribute is too large, it exceeds
              the maximum allowable size of an attribute value.

       [EEXIST]
              The attribute name given is already associated with the
              indicated filesystem object and the ATTR_CREATE flag bit
              was set.

       [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, or both the ATTR_CREATE and ATTR_REPLACE
              flags bits were set.

       [EFAULT]
              Path, attrname, or attrvalue 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_setf will fail if:

       [ENOATTR]
              The attribute name given is not associated with the
              indicated filesystem object and the ATTR_REPLACE flag bit
              was set.

       [E2BIG]
              The value of the given attribute is too large, it exceeds
              the maximum allowable size of an attribute value.

       [EEXIST]
              The attribute name given is already associated with the
              indicated filesystem object and the ATTR_CREATE flag bit
              was set.

       [EINVAL]
              A bit was set in the flag argument that is not defined for
              this system call, or both the ATTR_CREATE and ATTR_REPLACE
              flags bits were set, or fd refers to a socket, not a file.

       [EFAULT]
              Attrname, or attrvalue points outside the allocated
              address space of the process.

       [EBADF]
              Fd does not refer to a valid descriptor.

DIAGNOSTICS         top

       On success, zero is returned.  On error, -1 is returned, and
       errno is set appropriately.

SEE ALSO         top

       attr(1), attr_get(3), attr_list(3), attr_multi(3), attr_remove(3)

COLOPHON         top

       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 2021-04-01.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-03-16.)  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_SET(3)

Pages that refer to this page: attr(1)attr_get(3)attr_list(3)attr_multi(3)attr_remove(3)