UMOUNT(2)            INTERACTIVE UNIX System            UMOUNT(2)



          NAME
               umount - unmount a file system

          SYNOPSIS
               int umount (file)
               char *file;

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

               The umount system call may be invoked only by the super-
               user.

               The umount system call will fail if one or more of the fol-
               lowing is 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                              that machine is no longer active.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.

               [ENOTDIR]      A component of the path-prefix is not a
                              directory.

               [ENOENT]       The named file does not exist.

          SEE ALSO
               mount(2).

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


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          UMOUNT(2)            INTERACTIVE UNIX System            UMOUNT(2)



               the error.






















































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