umount(S)                      6 January 1993                      umount(S)


 Name

    umount - unmount a file system

 Syntax


    cc ... -lc


    #include <prototypes.h>

    int umount (file)
    char *file;


 Description

    The umount system call 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.

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

    The umount system call fails if one or more of the following is true:

    [EBUSY]        A file on file is busy.

    [EFAULT]       file points to an illegal address.

    [EINVAL]       file does not exist, or is not mounted.

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

    [ENOENT]       The named file does not exist.

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                   is no longer active.

    [ENOTBLK]      file is not a block special device.

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

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

    [EREMOTE]      file is remote.


 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.

 See also

    mount(S)

 Standards conformance

    umount is conformant with:
    AT&T SVID Issue 2; however this routine has been withdrawn from XPG3.