umount(3)                                               umount(3)



     NAME
          umount - unmount a file system

     SYNOPSIS
          int umount(spec)
          char *spec;

     DESCRIPTION
          umount requests that a previously mounted file system con-
          tained on the block special device identified by spec be un-
          mounted.  spec is a pointer to a path name.  After unmount-
          ing the file system, the directory upon which the file sys-
          tem was mounted reverts to its ordinary interpretation.

          umount may be invoked only by the superuser.

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

          [EPERM]        The process's effective user ID is not su-
                         peruser.

          [ENXIO]        spec does not exist.

          [ENOTBLK]      spec is not a block special device.

          [EINVAL]       spec is not mounted.

          [EBUSY]        A file on spec is busy.

          [EFAULT]       spec points to an illegal address.

     RETURN VALUE
          Upon successful completion a value of 0 is returned.  Other-
          wise, a value of -1 is returned and errno is set to indicate
          the error.

     SEE ALSO
          fsmount(2), unmount(2), mount(3).
















     April, 1990                                                     1