UMOUNT(2)                                               UMOUNT(2)



     NAME
          umount - unmount a file system

     SYNOPSIS
          int umount (file)
          char *file;

     DESCRIPTION
          umount requests that a previously mounted file system
          contained on the block special device or directory
          identified by file be unmounted.  File is a pointer to a
          path name.  After unmounting the file system, the directory
          upon which the file system was mounted reverts to its
          ordinary interpretation.

          umount may be invoked only by the super-user.

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

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

          [EINVAL]       File does not exist.

          [ENOTBLK]      File is not a block special device.

          [EINVAL]       File is not mounted.

          [EBUSY]        A file on file is busy.

          [EFAULT]       File points to an illegal address.

          [EREMOTE]      File is remote.

          [ENOLINK]      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                         that machine is no longer active.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.

     SEE ALSO
          mount(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.

     ORIGIN
          AT&T V.3





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