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 filesys‐
       tem 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), and
       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 2017-05-03.  If you dis‐
       cover 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_get(3)attr_list(3)attr_multi(3)attr_remove(3)