umount(2)                                                            umount(2)



NAME
     umount - unmount a file system

C SYNOPSIS
     #include <sys/mount.h>

     int umount(const 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 a process with the super-user privilege.

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

     EPERM               The calling process does not have the super-user
                         privilege.

     EINVAL              file does not exist.

     ELOOP               Too many symbolic links were encountered in
                         translating the path pointed to by file.

     ENAMETOOLONG        The length of the file argument exceeds {PATHMAX},
                         or the length of a file component exceeds {NAMEMAX}
                         while POSIXNOTRUNC is in effect.

     ENOTDIR             file does not point to a directory.

     ENOENT              A component ofthe path prefix does not exist or is a
                         null pathname.

     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                         machine is no longer active.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.




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umount(2)                                                            umount(2)



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.

















































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