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. 

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

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

­[ENXIO] 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 to an illegal address. 

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.

SEE ALSO

mount(2), unmount(2). 

NOTE

umount(2) cannot be used to unmount NFS file systems. Use unmount(2) to unmount any file system type. 

CX/UX Programmer’s Reference Manual