umount(3)                           CLIX                           umount(3)



  NAME

    umount - Unmounts a file system

  LIBRARY

    Standard C Library (libc.a)

  SYNOPSIS

    int umount(
      char *file );

  PARAMETERS

    file   Specifies a block special file or mount point directory of the file
           system to be unmounted.

  DESCRIPTION

    The umount() function requests that a previously mounted file system
    contained on the block special device or directory identified by file be
    unmounted.  After unmounting the file system, the directory upon which the
    file system was mounted reverts to its ordinary interpretation.
    Subordinate cache directories are removed by the system when they are
    unmounted; the cache root directory is not removed automatically by the
    system.

    The umount() function may be invoked only by the superuser.

  EXAMPLES

    The following unmounts a mounted file system, key in the following:

    if (umount("/usr")
         perror("umount failed");


  NOTE

    If the umount request is a jukebox request, the file /tmp/.mntque will be
    parsed for mounts in progress.  If the umount request is currently being
    mounted and found in this file, umount will sleep until the mount request
    is serviced.

  RETURN VALUES

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

  ERRORS



  2/94 - Intergraph Corporation                                              1

  umount(3)                           CLIX                           umount(3)



    The umount() function fails if one or more of the following are true:

    [EPERM]
           The process' effective user ID is not superuser.

    [EINVAL]
           The pathname to which file points does not exist.

    [ENOTBLK]
           The value of file is not a block special device.

    [EINVAL]
           The pathname to which file points is not mounted.

    [EBUSY]
           A file on file is busy.

    [EFAULT]
           The value of file points to an illegal address.

    [EREMOTE]
           The pathname specified by file is remote.

    [ENOLINK]
           The pathname specified by file is on a remote machine, and the link
           to that machine is no longer active.

    [EMULTIHOP]
           Components of the path pointed to by file require hopping to
           multiple remote machines.

  RELATED INFORMATION

    Functions:  mount(3)




















  2                                              Intergraph Corporation - 2/94