umount - unmount file system (extension)

Syntax	#include <sys/mount.h> int umount(const char *path);
Description	umount() can be used to unmount a file system that was mounted earlier with mount() under the directory pointed to by path (mount point). The path argument may point to a block-special file or a directory. After unmounting the file system, the directory in which the file system was mounted reverts to its ordinary interpretation.
Return val.	0 -1	upon successful completion. if an error occurs. errno is set to indicate the error.
Errors	umount() will fail if:
	EBUSY	A file in path is being used.
	EFAULT	path points to an invalid address.
	EINVAL	path does not exist or path has not been mounted.
	ELOOP	Too many symbolic links were encountered when resolving the path pointed to by path.
	ENAMETOOLONG
		path is longer than {PATH_MAX}, or the length of a path component exceeds {NAME_MAX}.
	ENOTBLK	path is not a block-special file.
	EPERM	The effective user ID is not that of a process with appropriate privileges.
	EREMOTE	path points to a remote pathname.
Notes	umount() may only be called under the effective user ID of a process with appropriate privileges. umount() is executed only for POSIX files.
See also	mount(), sys/mount.h.