NAME

umount − unmount a file system

SYNOPSIS

int umount (spec)
char ∗spec;

DESCRIPTION

Umount requests that a previously mounted file system contained on the block special device identified by spec be unmounted.  Spec 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. 

ERRORS

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

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

­[ENOENT] Spec does not exist. 

­[ENOTBLK] Spec is not a block special device. 

­[EINVAL] Spec is not mounted. 

­[EBUSY] A file on spec is busy. 

­[EFAULT] Spec points outside the process’s allocated address space.  The reliable detection of this error will be implementation dependent. 

­[ENXIO] The device associated with spec does not exist. 

­[ENOTDIR] A component of spec is not a directory. 

[ENOENT] Spec is null. 

­[ENAMETOOLONG] Spec exceeds MAXPATHLEN characters. 

RETURN VALUE

Upon successful completion a value of 0 is returned.  Otherwise, a value of −1 is returned and errno is set to indicate the error. 

HARDWARE DEPENDENCIES

Integral Personal Computer:
For superuser capabilities described above, it is not necessary to be superuser.

SEE ALSO

mount(1M), mount(2). 

BUGS

If umount is called from the program level (i.e. not from the mount(1M) level), the table of mounted devices contained in /etc/mnttab is not updated. 

Hewlett-Packard Company  —  Version B.1,  April 12, 1993