attr_remove(2)

NAME
     attr_remove, attr_removef - remove a user attribute of a filesystem
     object

C SYNOPSIS
     #include <sys/attributes.h>

     int attr_remove (const char *path, const char *attrname, int flags);

     int attr_removef (int fd, const char *attrname, int flags);

OVERVIEW
     The attr group of system calls implement the ability for a user to attach
     name/value pairs to objects within the filesystem.

     They could be used to store meta-information about the file.  For example
     "character-set=kanji" could tell a document browser to use the Kanji
     character set when displaying that document and "thumbnail=..." could
     provide a reduced resolution overview of a high resolution graphic image.

     The names can be up to MAXNAMELEN bytes in length, terminated by the
     first 0 byte.  The intent is that they be printable ASCII (or other
     character set) names for the attribute.

     The values can be up to ATTR_MAX_VALUELEN (currently 64KB) of arbitrary
     binary data.

     Attributes can be attached to all types of inodes:  regular files,
     directories, symbolic links, device nodes, etc.

     There are 2 disjoint attribute name spaces associated with every
     filesystem object.  They are the root and user address spaces.  The root
     address space is accessible only to privileged users, and only then by
     specifying a flag argument to the function call.  A privileged user can
     be either the superuser in an IRIX environment, or a user with
     CAP_DEVICE_MGT capability.  Other users will not see or be able to modify
     attributes in the root address space.  The user address space is
     protected by the normal file permissions mechanism, so the owner of the
     file can decide who is able to see and/or modify the value of attributes
     on any particular file.

     Attributes are currently fully supported only in the XFS, CXFS and UDF
     filesystem types.  Other filesystem types may provide a partial
     implementation.

DESCRIPTION
     The attr_remove and attr_removef functions provide a way to remove
     previously created attributes from filesystem objects.

     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 attribute name and value will be removed from the fileystem
     object.  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_remove
          function call.  The default is to follow symbolic links.

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

     [ENOATTR]        The attribute name given is not associated with the
                      indicated filesystem object.

     [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 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_removef will fail if:

     [ENOATTR]      The attribute name given is not associated with the
                    indicated filesystem object.

     [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 points outside the allocated address space of the
                    process.

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

SEE ALSO
     attr(1),
     attr_get(2), attr_getf(2),
     attr_list(2), attr_listf(2)
     attr_multi(2), attr_multif(2)
     attr_set(2), attr_setf(2),

DIAGNOSTICS
     Upon successful completion, a value of 0 is returned.  Otherwise, a value
     of -1 is returned and errno is set to indicate the error.