umount(2)                  DG/UX 4.30                   umount(2)



     NAME
          umount - Remove a file system device.

     SYNOPSIS
          #include <sys/mount.h>

          int   umount  (special)
          char *          special;

     PARAMETERS
          special        Address of a pathname.

     DESCRIPTION
          Umount removes the file system device identified by
          <special> or mounted on the directory <special> from the set
          of active file system devices with the following
          consequences:

          *    The filename store contained on <special> is removed
               from the system filename store.  Thus, all files
               contained on <special> can no longer be named.

          *    The filesystem contained on <special> is removed from
               the system flat file store.  Thus, all files contained
               on <special> can no longer be accessed.

          *    None of the files on <special> may be open.  No process
               may have its current working directory on <special>.

          *    The filename store contained on <special> cannot
               contain a mount point of any other file system device
               at the time of the call to umount.

          *    <Special> must have previously been the subject of a
               successful mount operation.  If umount is successful,
               the sub-tree over which <special> was mounted reappears
               in the system file name store.  These files can now be
               named.

          If an error occurs, no changes are made.

     ACCESS CONTROL
          The calling process's effective user id must be the
          superuser.

     RETURN VALUE
          0              <Special> was successfully unmounted.


          -1             An error occurred.  Errno is set to indicate
                         the error.




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     umount(2)                  DG/UX 4.30                   umount(2)



     EXCEPTIONS
          Errno may be set to one of the following error codes:


          EBUSY          There are still processes accessing file
                         system objects on <special>.


          EBUSY          A file contained on <special> is the mount
                         point of another file system device.


          EINVAL         <Special> is not mounted.


          ENOENT         The named file does not exist.


          ENOTBLK        <Special> is not a block special file.


          ENXIO          The device associated with <special> does not
                         exist.


          EIO            I/O error when flushing file system
                         information.


          EPERM          Permission to unmount the file system device
                         is denied to the calling process.


          ENOENT         A non-terminal component of the pathname does
                         not exist.


          ENOTDIR        A non-terminal component of the pathname was
                         not a directory or symbolic link.


          ENAMETOOLONG   The pathname exceeds the length limit for
                         pathnames.


          ENAMETOOLONG   A component of the pathname exceeds the
                         length limit for filenames.


          ENOMEM         There are not enough system resources to
                         resolve the pathname or to expand a symbolic
                         link.



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     umount(2)                  DG/UX 4.30                   umount(2)



          ELOOP          The number of symbolic links encountered
                         during pathname resolution exceeded
                         MAXSYMLINKS.  A symbolic link cycle is
                         suspected.


          EPERM          The pathname contains a character not in the
                         allowed character set.


          EFAULT         The pathname does not completely reside in
                         the process's address space or the pathname
                         does not terminate in the process's address
                         space.

     SEE ALSO
          The related manual sections:  mount(2), nfsmount(2)
          fs(4).





































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